orthopedi

Question 1

35. Following preoperative chemotherapy, the percent of tumor necrosis has been shown to be of prognostic value for which of the following tumors ?

a. Rhabdomyosarcoma
b. Chondrosarcoma
c. Metastatic adenocarcinoma
d. Osteosarcoma
e. Giant cell tumor of bone

Answer 1

Answer: d. Osteosarcoma

Huvos grade 1,2,3,4: grading for histological response to preoperative chemotherapy

• grade-I : little or no necrosis (involving 50 per cent of the tumor or less);
• grade-II : necrosis of more than 50 per cent but less than 90 per cent of the tumor;
• grade-Ill : only scattered foci of viable tumor cells (necrosis of 90 to 99 per cent of the tumor); grade-IV response, by no viable tumor (100 per cent necrosis).

The histological response to preoperative chemotherapy was determined retrospectively by the same pathologist in a blinded fashion.

Huvos grade 3,4 : kemo efektif.

Question 2

What factor is most likely to be associated with non union of the type II odontoid fracture?

1. Fracture displacement greater than 4 mm
2. Advanced age of patient
3. Posterior versus anterior displacement
4. Blood supply to dens fragment
5. Presence of neurologic injury

Answer 2

Answer: 4. Blood supply to dens fragment

Classification of Odontoid fracture: (Anderson and Alonzo)

• Type I: Oblique avulsion fracture of the apex (5%)
• Type II: Fracture at the junction of the body and the neck; high nonunion rate, which can lead to myelopathy (60%)
• Type IIA: Highly unstable comminuted injury extending from the waist of the odontoid into the body of the axis
• Type III: Fracture extending into the cancellous body of C2 and possibly involving the lateral facets (30%)

Treatment

• Type I: If it is an isolated injury, stability of the fracture pattern allows for immobilization in a cervical orthosis.
• Type II: This is controversial, because the lack of periosteum and cancellous bone and the presence in watershed area result in a high incidence of nonunion (36%). Risk factors include age >50 years, >5 mm displacement, and posterior displacement. It may require screw fixation of the odontoid or C1-C2 posterior fusion for adequate treatment. Nonoperative treatment is halo immobilization.
• Type III: There is a high likelihood of union with halo immobilization owing to the cancellous bed of the fracture site.

Question 3

A patient has a burst fracture at L 1 with 70% canal compromise from a single retropulsed bone fragment and complete surgical decompression and stabilization is performed. One month later the bulbocavernosus reflex is still absent, but function of the lower extremity is normal. What is the most likely diagnosis ?

1. Residual cord or conus compression
2. Conus medullaris injury
3. Persistent spinal shock
4. Spinal cord infarction
5. Cauda equina syndrome

Answer 3

Answer: 1. Residual cord or conus compression

Bulbocavernosus Reflex:

• The bulbocavernosus reflex refers to contraction of the anal sphincter in response to stimulation of the trigone of the bladder with either a squeeze on the glans penis, a tap on the mons pubis, or a pull on a urethral catheter.
• The absence of this reflex indicates spinal shock.
• The return of the bulbocavernosus reflex, generally within 24 hours of the initial injury, hallmarks the end of spinal shock.
• The presence of a complete lesion after spinal shock has resolved portends a virtually nonexistent chance of neurologic recovery.
• The bulbocavernosus reflex is not prognostic for lesions involving the conus medullaris or the cauda equina.

Conus Medullaris Syndrome:

• This is seen in T12-L1 injuries and involves a loss of voluntary bowel and bladder control (S2-4 parasympathetic control) with preserved lumbar root function.
• It may be complete or incomplete; the bulbocavernosus reflex may be permanently lost.
• It is uncommon as a pure lesion and more common with an associated lumbar root lesion (mixed conus-cauda lesion).

Question 4

1. Titanium, an extremely reactive metal, is one of the most biocompatible implant material because :

a. Nothing in the biologic environment reacts with titanium
b. Physiologic condition inhibit titanium reaction
c. Protein coat the titanium and “insulate” it from the body
d. Titanium spontaneously forms a stable oxide coating
e. Titanium alloy are less reactive than metal

Answer 4

Answer : d. Titanium spontaneously forms a stable oxide coating
Reference : Miller 5th edition . Chapter 1 Basic science: biomaterial.

Titanium is extremely biocompatible material; it rapidly forms an adherent oxide coating (self-passivation), TiO2, that covers its surface (a nonreactive ceramic coating), thus makes these material extremely biocompatible. Another advantage of titanium is its relatively low E (most closely emulates the axial and torsional stiffness of bone) and high yield strength.

Orthopaedic implants are typically made of 316L (L = low carbon) stainless steel (iron, chromium, and nickel), “supermetal” alloys (e.g., Co-Cr-molybdenum (Mo) [65% Co, 35% Cr, 5% Mo] made with a special forging process), and titanium alloy (Ti-6Al-4V). Each possesses a different stiffness (E) (Fig. 1–97). Problems associated with certain metals include wear, stress shielding (increased in metals with a higher E), and ion release (Co-Cr causes macrophage proliferation and synovial degeneration)

Question 5

2. Which of the following cell membrane proteins convey chemotherapeutic resistance to tumor cells:

a. CD 44 glycoprotein
b. P-glycoproteins
c. Paracrine peptides
d. Matrix metalloproteinases (MMPs)
e. Stromelysins

Answer 5

Answer: b. p-glycoprotein.
Reference : Ling V (1997). “Multidrug resistance: molecular mechanisms and clinical relevance”. Cancer Chemother. Pharmacol. 40 Suppl (7): S3–8. doi:10.1007/s002800051053. PMID 9272126.

P-glycoprotein also known as multidrug resistance protein

One of the mechanism resistance of cancer cells is through expression of the multidrug resistance gene 1 (MDR1). MDR 1 codes for a membrane phosphoglicoprotein (p-glycoprotein).

At least four basic mechanisms of drug resistance are now recognized under the category of the MDR phenotype.

• changes in glutathione metabolism
• alterations in topoisomerase II
• non-P-glycoprotein (P-gp)-mediated mechanisms
• P-gp-mediated mechanisms (1,2).
• Recent evidence has suggested that P-gp may be of particular relevance to osteosarcoma.

P-gp is a glycoprotein encoded by the MDR-1 gene on the long arm of chromosome 7 in humans .

Lovell & Winter’s Pediatric Orthopedic. 6th ed. Ch 14. 2006. Lippincott Williams & Wilkins.

Question 6

3. Which of the following antibiotic is bacteriostatic at therapeutic serum concentration ?
   a. Penicillin
   b. Cefoxitin
   c. Clindamycin
   d. Vancomysin
   e. Bacitracin

Answer 6

Answer : c. Clindamycin

Mechanism of action ß lactam antibiotic including penicillin and cephalosporin and so does vancomycin: inhibit peptidoglycan synthesis in bacterial wall result in autolysis bacteries. Thus they are bactericid.
Cefoxitin is 2nd generation of cephalosporin.
Bacitracin also has mechanism of action inhibitin synthesis of bacterial wall. Bacitracin interferes with the dephosphorylation of the C55-isoprenyl pyrophosphate, a molecule that carries the building-blocks of the peptidoglycan bacterial cell wall outside of the inner membrane
Reference Goodman and Gilman’s. The Pharmacological Basic of Therapeutic. 12th ed.

Clindamycin has a bacteriostatic effect. It is a bacterial protein synthesis inhibitor by inhibiting ribosomal translocation, in a similar way to macrolides. It does so by binding to the 50S rRNA of the large bacterial ribosome subunit.
Reference : Lincosamides, Oxazolidinones, and Streptogramins”. Merck Manual of Diagnosis and Therapy. Merck & Co.. November 2005. Retrieved 2007-12-01

Question 7

4. What antibiotic works by inhibiting peptidoglycan synthesis ?

a. Penicillin
b. Gentamycin
c. Rifampicin
d. Tetracycline
e. Clindamycin

Answer 7

Answer : a. penicillin

Penicillin and cephalosporins such as cefoxitin, vancomycin, and bacitracin are all bactericidal by causing loss of bacterial cell viability, either by activating enzymes that disrupt cell membrane or by inhibiting synthesis of cell wall. Clindamycin is bacteriostatic and acts by inhibiting sintesis protein.

Question 8

5. Which of the following organism is (are) most likely to cause hematogenous osteomyelitis in hemodialysis patients ?

a. Escherichia coli and Klebsiella pneumonia
b. Staphylococci
c. Candida species
d. Anaerobic oral organism
e. Anaerobic enteral organism

Answer 8

Answer : b. Staphylococci

Hemodialysis patients and intravenous drug abusers—S. aureus, S. epidermidis, and Pseudomonas aeruginosa are common organisms. The treatment of choice is one of the penicillinase-resistant synthetic penicillins (PRSPs) plus ciprofloxacin; an alternative treatment is vancomycin with ciprofloxacin.
Reference : Miller’s Review of Orthopedics. 5th ed. Chapter 5 :Orthopedic infection and Microbiology. 2008. Elsevier inc.

Question 9

6. The pharmacologic effect of warfarin is caused by what mechanism ?

a. Inhibition of platelet aggregation
b. Inhibition of hepatic enzymes that activates vitamin K
c. Bonding to vitamin K dependent cloting factors II, VII, IX,X
d. Bonding to antithrombin III which increase its affinity for activated factor X and thrombin
e. Direct binding to vitamin K

Answer 9

Answer: b. inhibition of hepatic enzymes that activates vitamin K
Warfarin inhibits the vitamin K-dependent synthesis of biologically active forms of the calcium-dependent clotting factors II, VII, IX and X, as well as the regulatory factors protein C, protein S, and protein Z.
Jawaban buku AAOS comprehensive review ; b. warfarin inhibit hepatic enzymes that activates vitamin K, vitamin K epoxide. This inhibition leads to reduced carboxylation of vitamin K dependent protein (protrombin, and factor VII, IX, X). Warfarin does not act by binding directly to vitamin K or clotting factor.

References :
• Ansell J, Hirsh J, Poller L, Bussey H, Jacobson A, Hylek E (2004). “The pharmacology and management of the vitamin K antagonists: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy”. Chest 126 (3 Suppl): 204S–233S. Doi :10.1378/chest.126.3_suppl.204S. PMID 15383473.
• Freedman MD (March 1992). “Oral anticoagulants: pharmacodynamics, clinical indications and adverse effects”. J Clin Pharmacol 32 (3): 196–209. PMID 1564123

Question 10

7. The risk of human immunodeficiency virus (HIV) transmission via a processed musculoskeletal allograft obtained from an American Association of Tissue Bank (AATB) certified bone bank is estimated to be :
   a. 1 in 50,000
   b. 1 in 100,000
   c. 1 in 500,000
   d. 1 in 1,5 million
   e. 1 in 5 million

Answer 10

Answer: d. 1 in 1,5 million.
Reference : AAOS Comprehensive Orthopedic Review: Study Questions. 2009.

Question 11

8. Warfarin limit the risk of deep venous thrombosis (DVT) by which of the following action ?

a. Competitive inhibition of vitamin K dependent clotting factors
b. Inhibition of the post translational modification of vitamin K dependent clotting factors
c. Reversible inhibition of platelet function
d. Potentiation of antithrombin III

Answer 11

Answer : b. Inhibition of the post translational modification of vitamin K dependent clotting factors

Question 12

9. Most natural biologic material are anisotropic, meaning that their stress strain curve exhibits:

a. Different moduli for compressive and tensile stress
b. A high degree of nonlinearity
c. A high sensitivity to the size of the test specimen
d. Dependence on the rate loading
e. Dependence of the direction of load application

Answer 12

Answer ; e. Dependence of the direction of load application
Reference Miller’s Review of Orthopedic. 5th ed. Chapter 1 Basic Science. Section 8, subsection 2. 2008. Elsevier inc.

Isotropic materials—Possess the same mechanical properties in all directions (e.g., a golf ball)

Anisotropic materials—Have mechanical properties that vary with the direction of the applied load (e.g., bone is stronger axially than radially)

Question 13

10. Which of the following factors is most commonly associated with late aseptic loosening of cemented acetabular components ?

a. Increased frictional torque
b. Recurrent neck socket impingement
c. Fatique failure of cement
d. Poor initial component fixation
e. Polyethylene wear

Answer 13

Answer : e. Polyethylene wear

Polyethylene wear are foreign body material which elicit hystiocytic (osteoclast) response to begin an osteolytic process.

Osteolytic process—As a result of particle ingestion by the macrophages, the activated macrophage (osteoclast) liberates osteolytic factors, including tumor necrosis factor (TNF)-α, interleukin-1β, interleukin-6, prostaglandins, oxide radicals, hydrogen peroxide, and acid phosphatase. Interleukin-1β, interleukin-6, prostaglandins works paracrine stimulating end nerve fiber, causing PAIN. These factors activate the osteoclast system and together assist in the dissolution of bone. Osteoclastic resorption of bone around the prosthesis allows prosthetic micromotion to occur. This leads to further generation of wear debris. Additional lysis of bone allows for prosthetic macromotion, loosening, and pain. Symptoms pain after hemiarthroplasty even without periprosthetic radioluscent area, is a symptoms that osteolytic process has begin. Give your patient BIPHOSPHONATE to repress osteoclast activity.

Cara kerja biphosphonate :
Bisphosphonates inhibit osteoclast resorption of bone (by preventing the osteoclast from forming the ruffled border necessary for expression of acid hydrolases)

Question 14

11. Methicillin resistant Staphylococcus aureus can be effectively with an oral quinolone and which of the following antibiotics to achieve synergy?
    a. Penicillin
    b. Probenecid
    c. Rifampin
    d. Cefoxitin
    e. Amoxillin

Answer 14

Answer : c. Rifampicin
Rifampin has been shown to have synergy with quinolones in the treatment of MRSA. Together they lessen development of resistant mutant.

Question 15

12. A fully differentiated osteoclast has receptors for which of the following proteins ?

a. Parathyroid hormone (PTH)
b. Calcitonin
c. Cholecalciferol
d. Bone morphogenetic protein (BMP)
e. Interleukin -2 (IL-2)

Answer 15

Answer : b. Calcitonin

Calcitonin—A 32–amino acid peptide hormone produced by the clear cells in the parafollicles of the thyroid gland; has a limited role in calcium regulation (see Table 1–13). Increased extracellular calcium levels cause secretion of calcitonin, which is controlled by a β2 receptor. Calcitonin inhibits osteoclastic bone resorption (osteoclasts have calcitonin receptors; decreases osteoclast number and activity) and decreases serum calcium

Question 16

13. Cephalosporin are effective antibiotic agents because of their action on what aspect of bacterial metabolism ?
    a. DNA gene
    b. Cell wall
    c. mRNA
    d. cell membrane
    e. protein

Answer 16

Answer : b. Cell wall

Question 17

14. The structure of cartilage proteoglycan can be described as

a. Multiple hyaluronate molecules bound to core protein, which is subsequently bound to a glycosaminoglycan chain
b. Multiple glycosaminoglycan chains bound to hyaluronate, which is subsequently bound to core protein
c. Multiple glycosaminoglycan bound to core protein, which is subsequently bound to hyaluronate via a link protein
d. Multiple link protein bound to core protein, which is subsequently bound to glycosaminoglycan
e. Multiple hyaluronate chains bound to link protein, which is subsequently bound to glycosaminoglycan

Answer 17

Answer: c. Glycosaminoglycan molecules bound to core protein forming proteoglycan aggrecan, subsequently proteoglycan aggrecan bound to hyaluronate via a link protein, forming proteoglycan aggregate.

Reference Miller’s Review of Orthopedic. 5th ed. Chapter 1 Basic Science. 2008. Elsevier inc.

Question 18

15. Virtually all biological material are viscoelastic, which means their mechanical behavior is dependent on what factor ?

a. Load applied
b. Cross sectional area
c. Rate of loading
d. Mode of loading
e. Direction of loading

Answer 18

Answer : c. rate of loading

Material—Related to a substance or element. Defined by mechanical properties (force, stress, strain) and rheologic properties (elasticity [ability to regain original shape], plasticity [permanent deformation], viscosity [resistance to flow or shear stress], and strength).

a. Brittle materials (e.g., PMMA)—Exhibit a linear stress–strain curve up to the point of failure. Brittle materials undergo only fully recoverable (elastic) deformation prior to failure and have little or no capacity to undergo permanent (plastic) deformation prior to failure.
b. Ductile materials (e.g., metal)—Undergo a large amount of plastic deformation prior to failure. Ductility is a measure of postyield deformation.
c. Viscoelastic materials (e.g., bone and ligaments)—Exhibit stress–strain behavior that is time-rate dependent (varies with the material); the material’s deformation and properties depend on the load and the rate at which the load is applied. Viscoelastic materials exhibit properties of both a fluid (viscosity; resistance to flow) and a solid (elasticity). The modulus of viscoelastic material increases as the strain rate increases. Viscoelastic behavior is a function of the internal friction of the material. Viscoelastic materials also exhibit hysteresis: Loading and unloading curves differ because energy is dissipated during loading. Most biologic tissues (bone, ligament, muscle, etc.) exhibit viscoelasticity.
d. Isotropic materials—Possess the same mechanical properties in all directions (e.g., a golf ball)
e. Anisotropic materials—Have mechanical properties that vary with the direction of the applied load (e.g., bone is stronger axially than radially)
f. Homogeneous materials—Have a uniform structure or composition throughout.

Question 19

16. What is the dominant component of articular cartilage extracellular matrix by weight ?
    a. Wear
    b. Collagen
    c. Keratan sulfate
    d. Chondroitin sulfate
    e. Nerve and lymphatic tissue

Answer 19

Answer ; a. wear ??. Pasti maksudnya WATER !!
Reference Miller’s Review of Orthopedics. 5th ed. Chapter 1 section 2.
Articular cartilage composition
a. Water (65-80% of wet weight)—Shifts in and out of cartilage to allow deformation of cartilage surface in response to stress. Water is not distributed homogeneously (65% in deep zone, 80% at surface). Water content increases (90%) in osteoarthritis (Table 1–18). Water is also responsible for nutrition and lubrication. Increased water content leads to increased permeability, decreased strength, and decreased Young’s modulus (E).
b. Collagen (10-20% of wet weight; >50% of dry weight) (Fig 1–36)—Type II collagen accounts for approximately 95% of the total collagen content of articular cartilage and provides a cartilaginous framework and tensile strength. Type II collagen is very stable, with a half-life of approximately 25 years. Increased amounts of glycine, proline, hydroxyproline, and hydrogen bonding are responsible for its unique characteristics. Hydroxyproline is unique to collagen and can be measured in the urine to assess bone turnover. Small amounts of types V, VI, IX, X, and XI collagen are present in the matrix of articular cartilage. An overview of all collagen types is shown in Table 1–19. Collagen type VI is a minor component of normal articular cartilage, but its content increases significantly in early osteoarthritis. Collagen type X is produced only by hypertrophic chondrocytes during enchondral ossification (growth plate, fracture callus, HO formation, calcifying cartilaginous tumors) and is associated with calcification of cartilage; a genetic defect in type X collagen is responsible for Schmid’s metaphyseal chondrodysplasia (affects the hypertrophic physeal zone). Collagen type XI is an adhesive holding the collagen lattice together.
c. Proteoglycans (10-15% of wet weight)—Protein polysaccharides provide compressive strength. Proteoglycans are produced by chondrocytes, are secreted into the extracellular matrix, and are composed of subunits known as glycosaminoglycans (GAGs, disaccharide polymers). These GAGs include two subtypes of chondroitin sulfate (the most prevalent GAG in cartilage) and keratin sulfate. The concentration of chondroitin-4-sulfate decreases with age, that of chondroitin-6-sulfate remains essentially constant, and that of keratin sulfate increases with age. GAGs are bound to a protein core by sugar bonds to form a proteoglycan aggrecan molecule. Link proteins stabilize these aggrecan molecules to hyaluronic acid to form a proteoglycan aggregate. Proteoglycans have a half-life of 3 months, provide structural properties for the articular cartilage, provide elastic strength, produce cartilage’s porous structure, and trap and hold water (regulate and retain fluid in the matrix). Figure 1–37 illustrates a proteoglycan aggregate and an aggrecan molecule.
d. Chondrocytes (5% of wet weight)—Active in protein synthesis, possess a double effusion barrier; produce collagen, proteoglycans, and some enzymes for cartilage metabolism, including the metalloproteinases (breakdown cartilage matrix) and tissue inhibitor of metalloproteinases (TIMPs; inhibit the metalloproteinases); least active in the calcified zone. Deeper cartilage zones have chondrocytes with a decreased rough endoplasmic reticulum (RER) and increased intraplasmic filaments (degenerative products). Chondroblasts, derived from undifferentiated mesenchymal cells (stimulated by motion), are later trapped in lacunae to become chondrocytes.
e. Other matrix components
(1) Adhesives (noncollagenous proteins, such as fibronectin, chondronectin, and anchorin CII)—Involved in interactions between chondrocytes and fibrils. Fibronectin may be associated with osteoarthritis.
(2) Lipids—Unknown function

Question 20

17. A 2 week old infant has been referred for evaluation of nonmovement of the hip. History reveals that the patient was delivered 6 weeks premature by cesarean section. Examination reveals no fever, and there is mild swelling of the thigh. Passive movement of the hip appears to elicit tenderness and very limited hip motion. A radiograph of the pelvis shows mild subluxation of the left hip. The next step in evaluation should consist of :

a. Aspiration of the left hip
b. Application of Pavlik harness
c. A gallium scan
d. An MRI scan of the spine
e. Modified Bryan traction

Answer 20

Answer : a. Aspiration of the left hip

Early diagnosis is important : Rule out these differential diagnosis:
Septic arthritis
Transient synovitis
Early coxitis TB
Hip subluxation.

If clinical findings suggest bone or joint sepsis, aspiration is mandatory (for Gram staining and culture). Radiograph may reveal subluxation (due to joint effusion, due to infection). DDH is not painful and not accompany by localized swelling. If no purulent material obtained from aspiration, an arthrogram should be obtained to rule out femoral epiphysiolysis.

Question 21

18. A 12 year old girl has had lower back pain for the past 6 months that interferes with her ability to participate in sports. She denies any history of radicular symptoms, sensory changes, or bowel and bladder dysfunction. Examination reveals a shuffling gait, restriction of forward bending, and tight hamstrings. Radiographs show a grade III spondylolisthesis of L5 on S1, with a slip angle 20°. Management should consist of :

a. Brace treatment
b. Laminectomy, nerve root decompression, and in situ fusion of L4 to the sacrum
c. In situ fusion of L4 to the sacrum
d. Excision of the L5 lamina
e. Physical therapy

Answer 21

Answer : c. In situ fusion of L4 to the sacrum

Indication for surgical treatment of spondilolisthesis:
• pain and/or progressive deformity
• persisten pain or neurologic deficit that not respond to nonsurgical therapy
Choice of surgical treatment :
• insitu posterolateral L5-S1 fusion is adequate for mild spondilolisthesis
• extension of fusion to L4 offers better mechanical advantage for more severe slips (Meyerding gr II)

DO NOT perform laminectomy alone in children It is contraindicated. Nerve root decompression is indicated if radiculopathy present clinically.
Ref. AAOS Comprehensive Orthopedic Review.

Question 22

Marfan Syndrome is associated with defects in which of the following structural proteins ?

a. Elastin
b. Fibrillin
c. Fibronectin
d. Type II collagen
e. Type III collagen

Answer 22

Answer : b. Fibrillin
Reference Miller’s Review of Orthopedics. 5th ed. Chapter 1 section 4 subsection 3.
COMPREHENSIVE COMPILATION OF INHERITANCE PATTERN, DEFECT, AND ASSOCIATED GENE OF MUSCULOSKELETAL-RELATED DISORDERS
Disorder Inheritance Pattern Defect Associated Gene
Dysplasias
Achondroplasia Autosomal dominant Defect in the fibroblast growth factor (FGF) receptor 3 FGF receptor 3 gene
Diastrophic dysplasia Autosomal recessive Mutation of a gene coding for a sulfate transport protein Sulfate-transporter gene (chromosome 5)
Kniest’s dysplasia Autosomal dominant Defect in type II collagen COL 2A1
Laron’s dysplasia (pituitary dwarfism) Autosomal recessive Defect in the growth hormone receptor
McCune-Albright syndrome (polyostotic fibrous dysplasia, café-au-lait spots, precocious puberty) Sporadic mutation Germ line defect in the Gsα protein Mutation of Gsα subunit of the receptor/adenylyl cyclase–coupling G proteins
Metaphyseal chondrodysplasia (Jansen form) Autosomal dominant
Metaphyseal chondrodysplasia (McKusick form) Autosomal recessive
Metaphyseal chondrodysplasia (Schmid-tarda form) Autosomal dominant Defect in type X collagen COL 10A1
Multiple epiphyseal dysplasia Autosomal dominant (most commonly) Cartilage oligomeric matrix protein
Spondyloepiphyseal dysplasia Autosomal dominant (congenita form)
X-linked recessive (tarda form)
Defect in type II collagen Linked to X p22.12-p22.31 and COL 2A1
Achondrogenesis Autosomal recessive Fetal cartilage fails to mature
Apert syndrome Sporadic mutation/autosomal dominant
Chondrodysplasia punctata (Conradi–Hünerman) Autosomal dominant
Chondrodysplasia punctata (rhizomelic form) Autosomal recessive Defect in subcellular organelles (peroxisomes)
Cleidocranial dysplasia (dysostosis) Autosomal dominant Mutation of a gene coding for a protein related to osteoblast function cbfal
Dysplasia epiphysealis hemimelica (Trevor’s disease) ??
Ellis-van Creveld syndrome (chondroectodermal dysplasia) Autosomal recessive
Fibrodysplasia ossifican progressiva Sporadic mutation/autosomal dominant
Geroderma osteodysplastica (Walt Disney dwarfism) Autosomal recessive
Grebe chondrodysplasia Autosomal recessive
Hypochondroplasia Sporadic mutation/autosomal dominant
Kabuki make-up syndrome Sporadic mutation
Mesomelic dysplasia (Langer type) Autosomal recessive
Mesomelic dysplasia (Nievergelt type) Autosomal dominant
Mesomelic dysplasia (Reinhardt-Pfeiffer type) Autosomal dominant
Mesomelic dysplasia (Werner type) Autosomal dominant
Metatrophic dysplasia Autosomal recessive
Progressive diaphyseal dysplasia (Camurati-Engelmann disease) Autosomal dominant
Pseudoachondroplastic dysplasia Autosomal dominant
Pyknodysostosis Autosomal recessive
Spondylometaphyseal chondrodysplasia Autosomal dominant
Spondylothoracic dysplasia (Jarcho-Levin syndrome) Autosomal recessive
Thanatophoric dwarfism Autosomal dominant
Tooth-and-nail syndrome Autosomal dominant
Treacher Collins syndrome (mandibulofacial dysostosis) Autosomal dominant
Metabolic Bone Diseases
Hereditary vitamin D–dependent rickets Autosomal recessive See Table 1–15
Hypophosphatasia Autosomal recessive See Table 1–15
Hypophosphatemic rickets (vitamin D–resistant rickets) X-linked dominant See Table 1–15
Osteogenesis imperfecta Autosomal dominant (types I and IV) Defect in type I collagen (abnormal cross-linking) COL 1A1, COL 1A2
Autosomal recessive (types II and III)
Albright hereditary osteodystrophy (pseudohypoparathyroidism) Uncertain Parathyroid hormone has no effect at the target cells (in the kidney, bone, and intestine)
Infantile cortical hyperostosis (Caffey’s disease) ???
Ochronosis (alkaptonuria) Autosomal recessive Defect in the homogentisic acid oxidase system
Osteopetrosis Autosomal dominant (mild, tarda form)
Autosomal recessive (infantile, malignant form)
Connective Tissue Disorders
Marfan’s syndrome Autosomal dominant Fibrillin abnormalities (some patients also have type I collagen abnormalities) Fibrillin gene (chromosome 15)
Ehlers-Danlos syndrome (there are at least 13 varieties) Autosomal dominant (most common) Defects in types I and III collagen have been described for some varieties; lysyl oxidase abnormalities COL 1A2 (for Ehlers-Danlos type VII)
Homocystinuria Autosomal recessive Deficiency of the enzyme cystathionine β-synthase
Mucopolysaccharidosis
Hunter’s syndrome (“gargoylism”) X-linked recessive
Hurler’s syndrome Autosomal recessive Deficiency of the enzyme α-L-iduronidase
Maroteaux-Lamy syndrome Autosomal recessive
Morquio’s syndrome Autosomal recessive
Sanfilippo’s syndrome Autosomal recessive
Scheie’s syndrome Autosomal recessive Deficiency of the enzyme α-L-iduronidase
Muscular Dystrophies
Duchenne’s muscular dystrophy X-linked recessive Defect on the short arm of the X chromosome Dystrophin gene
Becker’s dystrophy X-linked recessive
Fascioscapulohumeral dystrophy Autosomal dominant
Limb-girdle dystrophy Autosomal recessive
Steinert’s disease (myotonic dystrophy) Autosomal dominant
Hematologic Disorders
Hemophilia (A and B) X-linked recessive Hemophilia A–factor VIII deficiency
Hemophilia B–factor IX deficiency
Sickle cell anemia Autosomal recessive Hemoglobin abnormality (hemoglobin S)
Gaucher’s disease Autosomal recessive Deficient activity of the enzyme β-glucosidase (glucocerebrosidase)
Hemochromatosis Autosomal recessive
Niemann-Pick disease Autosomal recessive Accumulation of sphingomyelin in cellular lysosomes
Smith-Lemli-Opitz syndrome Uncertain
Thalassemia Autosomal recessive Abnormal production of hemoglobin A
von Willebrand’s disease Autosomal dominant
Chromosomal Disorders with Musculoskeletal Abnormalities
Down syndrome Trisomy of chromosome 21
Angelman’s syndrome Chromosome 15 abnormality
Clinodactyly Associated with many genetic anomalies, including trisomy of chromosomes 8 and 21
Edward’s syndrome Trisomy of chromosome 18
Fragile X syndrome X-linked trait (does not follow the typical pattern of an X-linked trait) Xq27-Xq28
Klinefelter’s syndrome (XXY) Male has an extra X chromosome
Langer-Giedion syndrome Sporadic mutation Chromosome 8 abnormality
Nail-patella syndrome Autosomal dominant Chromosome 9 abnormality
Patau’s syndrome Trisomy of chromosome 13
Turner’s syndrome (XO) Female missing one of the two X chromosomes
Neurologic Disorders
Charcot-Marie-Tooth disease Autosomal dominant (most common)
Congenital insensitivity to pain Autosomal recessive
Dejerine-Sottas disease Autosomal recessive
Friedreich’s ataxia Autosomal recessive
Huntington’s disease Autosomal dominant
Menkes’ syndrome X-linked recessive Inability to absorb and use copper
Pelizaeus-Merzbacher disease X-linked recessive Defect in the gene for proteolipid (a component of myelin)
Riley-Day syndrome Autosomal recessive
Spinal muscular atrophy (Werdnig-Hoffman disease and Kugelberg-Welander disease) Autosomal recessive
Sturge-Weber syndrome Sporadic mutation
Tay-Sachs disease Autosomal recessive Deficiency in the enzyme hexosaminidase A
Diseases Associated with Neoplasias
Ewing’s sarcoma 11;22 chromosomal translocation (EWS/FL11 fusion gene)
Multiple endocrine neoplasia I (MEN I) Autosomal dominant RET
MEN II Autosomal dominant
MEN III Autosomal dominant Chromosome 10 abnormality
Neurofibromatosis (von Recklinghausen’s disease) Autosomal dominant NF1, NF2
Synovial sarcoma X;18 chromosomal translocation (STT/SSX fusion gene)
Miscellaneous Disorders
Malignant hyperthermia Autosomal dominant
Osteochondromatosis Autosomal dominant
Polydactyly Autosomal dominant (a small number of cases of sporadic gene mutations have been reported)
Captodactyly Autosomal dominant
Cerebro-oculofacioskeletal syndrome Autosomal recessive
Congenital contractural arachnodactyly Fibrillin gene (chromosome 5)
Distal arthrogryposis syndrome Autosomal dominant
Dupuytren’s contracture Autosomal dominant (with partial sex limitation)
Fabry’s disease X-linked recessive Deficiency of α-galactosidase A
Fanconi’s pancytopenia Autosomal recessive
Freeman-Sheldon syndrome Autosomal dominant
(craniocarpotarsal dysplasia; whistling face syndrome) Autosomal recessive
GM1 gangliosidosis Autosomal recessive
Hereditary anonychia Autosomal dominant
Autosomal recessive
Holt-Oram syndrome Autosomal dominant
Humeroradial synostosis Autosomal dominant
Autosomal recessive
Klippel-Feil syndrome Faulty development of spinal segments along the embryonic neural tube
Klippel-Trénaunay-Weber syndrome Sporadic mutation
Krabbe’s disease Autosomal recessive Deficiency of galactocerebroside β-galactosidase
Larsen’s syndrome Autosomal dominant
Autosomal recessive
Lesch-Nyhan disease X-linked trait Absence of the enzyme hypoxanthine guanine phosphoribosyl transferase
Madelung’s deformity Autosomal dominant
Mannosidosis Autosomal recessive Deficiency of the enzyme α-monosidase
Maple syrup urine disease Autosomal recessive Defective metabolism of the amino acids leucine, isoleucine, and valine
Meckel’s syndrome (Gruber’s syndrome) Autosomal recessive
Mobius’ syndrome Autosomal dominant
Mucolipidosis (oligosaccharidosis) Autosomal recessive A family of enzyme deficiency diseases
Multiple exostoses Autosomal dominant
Multiple pterygium syndrome Autosomal recessive
Noonan’s syndrome Sporadic mutation
Oral-facial-digital (OFD) syndrome OFD I—X-linked dominant
OFD II (Mohr’s syndrome)— autosomal recessive
Osler-Weber-Rendu syndrome (hereditary hemorrhagic telangiectasia) Autosomal dominant
Pfeiffer’s syndrome (acrocephalosyndactyly) Sporadic mutation/autosomal dominant
Phenylketonuria Autosomal recessive Enzyme deficiency characterized by the inability to convert phenylalanine to tyrosine due to a chromosome 12 abnormality
Phytanic acid storage disease Autosomal recessive
Progeria (Hutchinson-Gilford progeria syndrome) Autosomal dominant
Proteus syndrome Autosomal dominant
Prune-belly syndrome Uncertain Localized mesodermal defect
Radioulnar synostosis Autosomal dominant
Rett’s syndrome Sporadic mutation/X-linked dominant
Roberts’ syndrome (pseudothalidomide syndrome) Sporadic mutation/autosomal recessive
Russell-Silver syndrome Sporadic mutation (possibly X-linked)
Saethre-Chotzen syndrome Autosomal dominant
Sandhoff’s disease Autosomal recessive Enzyme deficiency of hexosaminidase A and B
Schwartz-Jampel syndrome Autosomal recessive
Seckel’s syndrome (bird-headed dwarfism) Autosomal recessive
Stickler’s syndrome (hereditary progressive arthro-ophthalmopathy) Autosomal dominant Collagen abnormality
TAR syndrome (thrombocytopenia–aplasia of radius syndrome) Autosomal recessive
Tarsal coalition Autosomal dominant
Trichorhinophalangeal syndrome Autosomal dominant
Urea cycle defects Argininemia—autosomal recessive
Argininosuccinic aciduria—autosomal recessive
Carbamyl phosphate synthetase deficiency—autosomal recessive
Citrullinemia—autosomal recessive
Ornathine transcarbamylase deficiency—X-linked
A group of enzyme disorders characterized by high levels of ammonia in the blood and tissues
VATER association Sporadic mutation
Werner’s syndrome Autosomal recessive
Zygodactyly Autosomal dominant

Question 23

20. A 7-year old boy with a closed supracondylar fracture of distal humerus is unable to flex the distal interphalangeal (DIP) joint of his index finger and the interphalangeal (IP) joint of his thumb. These findings are most likely due to a deficit involving fibers of which following nerves ?
    a. Ulnar
    b. Radial
    c. Musculocutaneous
    d. Anterior interosseous
    e. Posterior interosseous

Answer 23

Answer : d. Anterior interosseous

Median(C(5)6-T1): runs between 2 heads of PT[*], through ligament of Struthers[*] and lacertus fibrosus[*], under FDS[*] into carpal tunnel[*] (Martin Gruber formation: ulnar motor branches run with median nerve then branch to ulnar nerve distally). In wrist, median divides to Motor branch and palmar cutaneous (runs between FCR/PL): at risk in CTS release

Sensory: NONE (in forearm)
Motor: ANTERIOR COMPARTMENT OF FOREARM

Superficial Flexors Pronator Teres [PT]

Flexor Carpi Radialis [FCR]

Palmaris longus [PL]

Flexor digitorum superficialis[FDS][sometimes considered a “middle” flexor]

Deep Flexors Anterior Interosseous N. (AIN) AIN compressed by PT in forearm, injured in supracondylar fractures

Flexor digitorum profundus [digits 2, 3]
Flexor pollicis longus [FPL]
Pronator Quadratus [PQ]
* Potential nerve compression site

Question 24

27. Examination of 7 year old boy reveals 20° of valgus following a lawn mover to lateral femoral epiphysis. Treatment consists of total distal femoral epiphysiodesis and varus osteotomy. Following surgery he has a limb length discrepancy of 3 cm and 5° genu valgum. Assumsing that he undergoes no further treatment, the patient’s predicted limb-length discrepancy at maturity would be how many centimeter ?
    a. Less than 7
    b. 7 to 10
    c. 11 to 13
    d. 14 to 17
    e. Greater than 17

Answer 24

Answer : c. 11 to 13

The distal femoral epiphysis growa approximately 1 cm per year, in boys growth ceases at approximately age 16 years old. Therefore the patient’s limb length discrepancy at maturity would be 12 cm ( 9 cm plus 3 cm discrepancy he suffered from the previous surgery)
Ref: AAOS Orthopedic Comprehensive Review. Page 82. 2009.

Question 25

28. A 4 year old child sustains a spiral fracture to the tibia in an unwitnessed fall. History reveals three other fractures to long bones, and the parents are vague about the etiology of each. There is no family history of bone disease. The parents ask if the child has osteogenesis imperfect (OI); however, there are no clinical or radiographic indication of this diagnosis. In addition to fracture care, management should include: a. Notification of child protective services and hospital admission b. A punch biopsy of skin for collagen analysis c. DNA testing for OI d. Calcium, phosphate, and alkaline phosphatase studies e. Placement of intramedullary rods to prevent further fracture

Answer 25

Answer : c. Notification of child protective services and hospital admission ## Footnote OI : Mutation on genes encoding type I collagen : COL1A1 and COL1A2. DD multiple fractures in children : OI and child abuse. DNA testing not commercially available for OI. In this patient, physician suspect nonaccidental trauma and is legally obliged to notify child protective service. Work up for both OI and abuse can be done during hospitalization

Question 26

29. A 6 year old boy with spastic diplegic cerebral palsy has a crouched gait. Examination reveals hip flexion contracture of 15º and popliteal angle of 70º. Equinus contractures measure 10º with the knee extended. Which of the following surgical procedure performed alone, will worsen the crouching ? a. Iliopsoas release from the lesser trochanter b. Iliopsoas release at the pelvic brim c. Hamstring lengthening d. Heel cord lengthening e. Splint posterior tibial tendon transfer

Answer 26

Answer : d. Heel cord lengthening ## Footnote Children with bspastic diplegic cerebral palsy often have multiple joints contractures. Because the gait abnormalities can be complex, isolated surgery is rarely indicated. To avoid compensatory at other joints, it is preferable to correct all deformities in a single operation. Isolated heel cord lengthening in the presence of thight hamstring and tight hip flexor, will lead to progressive flexion at the knees and hips, thus worsening the crouched gait Split posterior tibial tendon is indicated for heel varus.

Question 27

30. Which of the following pathogens are most commonly associated with neonatal septic arthritis and osteomyelitis ? a. Staphylococcus aureus and Escherichia coli b. Staphylococcus aureus and group A streptococci c. Staphylococcus aureus and group B streptococci d. Haemophilus influenza and Escherichia coli e. Haemophilus influenza and group A streptococci

Answer 27

Answer c. Staphylococcus aureus and group B streptococci Reference : Miller’s Review of Orthopedics. 5th ed. Chapter 1. Section 5. Reference : AAOS Orthopedic Comprehensive Review. 2009. Newborn (up to 4 months of age)—The most common organisms include Staphylococcus aureus, gram-negative bacilli, and group B streptococcus. Primary empirical therapy includes nafcillin or oxacillin plus a third-generation cephalosporin. Alternative antibiotic therapy includes vancomycin plus a third-generation cephalosporin. Newborns with hematogenous osteomyelitis may be afebrile, and the best predictors of the osteomyelitis are local signs in the extremity, including warmth. Almost 70% of newborn patients with hematogenous osteomyelitis have positive blood cultures. Children 4 years of age or older—The most common organisms are S. aureus, group A streptococcus, and coliforms (uncommon). The empirical treatment of choice is nafcillin or oxacillin; alternative regimens include vancomycin or clindamycin. When the Gram stain shows gram-negative organisms, a third-generation cephalosporin should be added. With recent immunization programs, Haemophilus influenzae bone infections causing hematogenous osteomyelitis have been almost completely eliminated. Adults 21 years of age or older—The most common organism is S. aureus, but a wide variety of other organisms have been isolated. Initial empirical therapy includes nafcillin, oxacillin, or cefazolin; vancomycin can be used as an alternative initial therapy. Sickle cell anemia—Salmonella is a characteristic organism. The primary treatment is with one of the fluoroquinolones (only in adults); alternative treatment is with a third-generation cephalosporin. Hemodialysis patients and intravenous drug abusers—S. aureus, S. epidermidis, and Pseudomonas aeruginosa are common organisms. The treatment of choice is one of the penicillinase-resistant synthetic penicillins (PRSPs) plus ciprofloxacin; an alternative treatment is vancomycin with ciprofloxacin.

Question 28

31. During soft tissue release for an idiopathic clubfoot, it is noted than the peroneus longus tendon has been transected in the midfoot. Failure into repair this structure may be lead to a. Cavus b. Claw toes c. A dorsal bunion d. Hindfoot valgus e. Forefoot pronation

Answer 28

Answer: c. A dorsal bunion A statistically significant varus displacement of the first metatarsal was observed only after transection of the peroneus longus tendon. It was concluded that the peroneus longus tendon is a strong retaining mechanism of the first metatarsal to opposes the tibialis anterior dorsal pull on 1st ray . When tendon peroneus longus injured, flexor hallucis longus try to compensate by flex the MTP. Thus forming deformity dorsal bunion. Dorsal bunion can be result from sequel of poliomyelitis or direct injury to tendon peroneus longus. Ref : Bohne WH, Lee KT, Peterson MG. Action of the peroneus longus tendon on the first metatarsal against metatarsus primus varus force. Foot Ankle Int. 1997 Aug;18(8):510-2.

Question 29

32. The use of multiagent adjuvant chemotherapy is associated with a clear survival benefit in which of the following diseases? a. Renal carcinoma b. Osteosarcoma c. Differentiated chondrosarcoma d. Adult soft tissue sarcoma e. Melanoma

Answer 29

Answer: b. Osteosarcoma ## Footnote Osteosarcoma is the most common bone tumor in children and adolescents. The most common sites are the distal femur and proximal tibia, and some 15–20% of patients have clinically detectable metastases at the time of diagnosis. Most studies in osteosarcoma include only patients with “classical osteosarcoma”, a good prognostic group of patients without metastases at presentation, extremity localized tumors and age \< 40 years. However, nonclassical osteosarcoma represents more than 40% of the entire high-grade osteosarcoma population, emphasizing the need for focus also on this group of patients in clinical research (Huvos 1991, Saeter and Bruland 1998). The modern multidisciplinary approach to the osteosarcoma patients has significantly improved outcome, especially for the patients with classical disease. Before the introduction of intensive polyagent chemotherapy, 2-year overall survival around 15–20% was reported (Harvei and Solheim 1981, Friedman and Carter 1972). With todayʼs combination of chemotherapy and surgery long-term survival rates of more than 70% have been reported in several studies (Saeter et al. 1991, Bacci et al. 1993, Fuchs et al. 1998, Smeland et al. 2003). Neoadjuvant chemotherapy with high-dose ifosfamide added to methotrexate, cisplatin, and doxorubicin for patients with localized osteosarcoma of the extremity.

Question 30

21. A 12 year old girl has progressive development of cavus feet. Examination reveals slightly diminished vibratory sensation on the bottom of the foot. Reflexes are 1+ at the knees and ankles. Motor examination shows that all muscles are 5/5 in the foot, except the peroneal and anterior tibial muscles are rated as 4+/5. Which of the following studies is considered most diagnostic ? a. Nerve conduction velocity studies b. Biopsy of the quadriceps femoris muscle c. Biopsy of the sural nerve d. DNA testing e. Chromosomal analysis

Answer 30

Answer ; d. DNA testing This patient most likely has a form of Charcot –Marie-Tooth disease, or hereditary motor-sensory-neuropathy. The most common varieties can now diagnosed with DNA testing. Mutation could be in peripheral myelin protein-22 (PMP 22)gene in HMSN type IA and in the connexin gene in the x linked HMSN. Reference: AAOS Comprehensive Orthopedic Review. 2009.

Question 31

22. A newborn has a flail upper extremity after a difficult right occiput anterior vaginal delivery. Examination shows an obvious fracture of the right clavicle. Following stimulation, there is no movement of the arm or hand and there appears to be no sensation in the hand. Management should include : a. A CT scan arteriogram b. An MRI scan of the brachial plexus c. Nerve conduction velocity studies and an electromyogram d. Surgical exploration and repair of the brachial plexus e. Observation for 60 days before obtaining further test

Answer 31

Answer: e. Observation for 60 days before obtaining further test BIRTH BRACHIAL PLEXUS PALSY Type Roots Deficit Prognosis Erb-Duchenne palsy C5, 6 Deltoid, cuff, elbow flexors, wrist and hand dorsiflexors; “waiter's tip” deformity. Best prognosis. Total plexus C5, T1 Sensory and motor; flaccid arm. Worst prognosis. Klumpke C8, T1 Wrist flexors, intrinsics; Horner's Poor prognosis. Brachial plexus palsy—Decreasing in severity as a result of better obstetric management, yet 2 per 1000 births still have an injury associated with stretching or contusion of the brachial plexus. Occurs most often with large babies, shoulder dystocia, forceps delivery, breech position, and prolonged labor. Three types are commonly recognized, as mentioned in table above.

Question 32

23. The most severe and rapidly progressive form of congenital scoliosis is : a. Block vertebra b. Semisegmented hemivertebra c. Fully segemented hemivertebra d. Unilateral unsegmented bar e. Unilateral unsegmented bar with contralateral hemivertebra

Answer 32

Answer: e. Unilateral unsegmented bar with contralateral hemivertebra PROGRESSION OF CONGENITAL SCOLIOSIS PATTERNS AND TREATMENT OPTIONS Risk of Progression (Highest to Lowest) Character of Curve Progression Treatment Options Unilateral unsegmented bar with contralateral hemivertebra Rapid and relentless Posterior spinal fusion (add anterior fusion for girls age \< 10 yr, boys \< 12 yr) Unilateral unsegmented bar Rapid Same Fully segmented hemivertebra Steady Anterior spinal fusion Hemivertebra excision Partially segmented hemivertebra Less rapid; curve usually \< 40 degrees at maturity Observation, hemivertebra excision Incarcerated hemivertebra May slowly progress Observation Nonsegmented hemivertebra Little progression Observation

Question 33

24. Posterior spinal fusion for scoliosis should be performed on a patient with Duchenne muscular dystrophy when a. The patient is still ambulatory b. Lordotic posture is present c. The forced vital capacity (FVC) is less than 30% of the predicted value d. Curve magnitude measures 25% or greater e. Orthotic management fails

Answer 33

Answer : d. Curve magnitude measures 25% or greater ## Footnote Surgery is indicated in patients with Duchenne's muscular dystrophy for curves greater than 30 degrees and usually involves fusion from T2 to the pelvis. Preoperative assessment of pulmonary function (should be over 40% predicted) and cardiac function is necessary Reference: AAOS Comprehensive Orthopedic Review. 2009.

Question 34

25. Which of the following deformities is most likely associated with slight valgus of femur, dimpling over the tibia, mild leg length discrepancy, increased heel valgus, and tarsal coalition? a. Type 1 fibular hemimelia b. Type 2 tibial hemimelia c. Type 4 proximal focal femoral deficiency (PFFD) d. Posterior medial bowing of the tibia e. Congenital pseudoarthrosis of the tibia

Answer 34

Answer: a. Type 1 fibular hemimelia. (Ref: AAOS). Seharusnya type II menurut klasifikasi Conventry Johnson (b) ? Tibial bowing—Three types based on the apex of the curve. 1. Posteromedial-physiologic bowing—Usually of the middle and distal thirds of the tibia and may be the result of abnormal intrauterine positioning (Fig. 3–36). It is commonly associated with calcaneovalgus feet and tight anterior structures. Spontaneous correction is the rule, but follow the patient to evaluate LLD. The most common sequela of posteromedial bowing is an average LLD of 3-4 cm, which may require an age-appropriate epiphysiodesis of the long limb. Tibial osteotomies are not indicated. 2. Anteromedial tibial bowing—Typically caused by fibular hemimelia; a congenital longitudinal deficiency of the fibula is the most common long-bone deficiency. It is usually associated with anteromedial bowing, ankle instability, equinovarus foot (with or without lateral rays), tarsal coalition, and femoral shortening. Classically, skin dimpling is seen over the tibia. Significant LLD often results from this disorder. The fibular deficiency can be intercalary, which involves the whole bone (absent fibula) or terminal. Fibular hemimelia is frequently associated with femoral abnormalities such as coxa vara and PFFD. Radiographic findings include complete or partial absence of the fibula, a ball-and-socket ankle (secondary to tarsal coalitions), and deficient lateral rays in the foot. Treatment varies from a simple shoe lift or bracing to Syme's amputation. Treatment decisions are based on the degree of foot deformity, the number of rays, and the degree of shortening of the limb. Amputation is usually done to treat limbs with severe shortening and/or a stiff, nonfunctional foot at about 10 months of age. For less severe cases, reconstructive procedures, including lengthening, may be an alternative. This procedure should include resection of the fibular anlage to avoid future foot problems. 3. Anterolateral tibial bowing—Congenital pseudarthrosis of the tibia is the most common cause of anterolateral bowing. It is often accompanied by neurofibromatosis (50%, but only 10% of patients with neurofibromatosis have this disorder). Classification (Boyd's) is based on bowing and the presence of cystic changes, sclerosis, or dysplasia; dysplasia and cystic changes are the most common. Initial treatment includes a total-contact brace to protect the patient from fractures. Intramedullary fixation with excision of hamartomatous tissue and autogenous bone grafting are options for nonhealing fractures. A vascularized fibular graft or Ilizarov's method should also be considered if bracing fails. Osteotomies to correct the anterolateral bowing are contraindicated. Amputation (Syme's) and prosthetic fitting are indicated after two or three failed surgical attempts. Syme's amputation is preferred to below-knee amputation in these patients because the soft tissue available at the heel pad is superior to that in the calf as a weight-bearing stump. The soft tissue in the calf in these patients is often scarred and atrophic. 4. Other lower limb deficiencies—Include tibial hemimelia, an AD disorder that is a congenital longitudinal deficiency of the tibia. Tibial hemimelia is the only long-bone deficiency with a known inheritance pattern (AD). It is much less common than fibular hemimelia and is often associated with other bony abnormalities (especially a lobster-claw hand). Clinically, the extremity is shortened and bowed anterolaterally with a prominent fibular head and an equinovarus foot, with the sole of the foot facing the perineum. The treatment for severe deformities with an entirely absent tibia is a knee disarticulation. Fibular transposition (Brown's) has been unsuccessful, especially with absent quadriceps function and an absent proximal tibia. When the proximal tibia and quadriceps functions are present, the fibula can be transposed to the residual tibia and create a functional below-knee amputation. ## Footnote Classification of congenital absence of fibula (Conventry Johnson 1952) Type I Partial unilateral absence of fibula Shortening of the extremity Minimal or no bowing of the tibia Little or no deformity of the foot No other congenital anomalies Type II Fibula completely or almost completely absent Unilateral deformity Anterior bowing of the tibia with skin dimple Equinovalgus of the foot Foot deformity may include absence of tarsal bone, rays, or tarsal coalition Type III Bilateral type I atau II with deformities elsewhere in the body

Question 35

26. Which of the following types of iliac osteotomy provides the greatest potential for increased coverage ? a. Ganz periacetabular b. Pamberton innominate c. Salter innominate d. Sutherland double innominate e. Steels tripe innominate

Answer 35

Answer : a. Ganz periacetabular Surgical choice based on the degree of acetabular dysplasia and the age of the children. Procedures (a) The Salter osteotomy—May lengthen the affected leg up to 1 cm. (b) The Pemberton acetabuloplasty—A good choice for residual dysplasia because it reduces acetabular volume (bends on triradiate cartilage). (c) Acetabular reorientation procedures in older patients—Include the triple innominate osteotomy (Steel or Tönnis). (d) Dega-type osteotomies—Often favored for paralytic dislocations and in patients with posterior acetabular deficiency. (e) The Ganz periacetabular osteotomy—Provides improved three-dimensional correction because the cuts are close to the acetabulum, allow immediate weight bearing, spare stripping of the abductor muscles, allow for a capsulotomy to inspect the joint, and are performed through a single incision. However, the triradiate cartilage must be closed. (f) The Chiari osteotomy—A salvage procedure when a concentric reduction of the femoral head within the acetabulum cannot be achieved. This osteotomy shortens the affected leg and requires periarticular soft tissue metaplasia for success. It depends on metaplastic tissue (fibrocartilage) for a successful result. (g) The lateral shelf acetabular augmentation procedure—Done in patients over 8 years old with inadequate lateral coverage or trochanteric advancement and increased trochanteric overgrowth (improves hip abductor biomechanics). It depends on metaplastic tissue (fibrocartilage) for a successful result. ## Footnote COMMON PELVIC OSTEOTOMIES Osteotomy Procedure Requirement Femoral Intertrochanteric osteotomy (VDRO) Concentric reduction \< 8 years of age Salter's Open wedge osteotomy through ileum Concentric reduction \< 8 years of age Pemberton's Through acetabular roof to triradiate cartilage Concentric reduction \< 8 years of age Sutherland's (double) Salter's + pubic osteotomy Concentric reduction Open triradiate cartilage Steel's (triple) Salter's + osteotomy of both rami Concentric reduction Open triradiate cartilage Ganz Periacetabular osteotomy Surgeon's experience Closed triradiate cartilage Chiari's Through ilium above acetabulum (makes new roof) Salvage procedure for asymmetrical incongruity Shelf 's Slotted lateral acetabular augmentation Salvage procedure for asymmetrical incongruity VDRO, varus derotation osteotomy. Reference : Miller’s Review of Orthopaedic. 5th ed. 2008. Elsevier inc.

Question 36

28. A 4 year old child sustains a spiral fracture to the tibia in an unwitnessed fall. History reveals three other fractures to long bones, and the parents are vague about the etiology of each. There is no family history of bone disease. The parents ask if the child has osteogenesis imperfect (OI); however, there are no clinical or radiographic indication of this diagnosis. In addition to fracture care, management should include: a. Notification of child protective services and hospital admission b. A punch biopsy of skin for collagen analysis c. DNA testing for OI d. Calcium, phosphate, and alkaline phosphatase studies e. Placement of intramedullary rods to prevent further fracture

Answer 36

Answer : c. Notification of child protective services and hospital admission ## Footnote OI : Mutation on genes encoding type I collagen : COL1A1 and COL1A2. DD multiple fractures in children : OI and child abuse. DNA testing not commercially available for OI. In this patient, physician suspect nonaccidental trauma and is legally obliged to notify child protective service. Work up for both OI and abuse can be done during hospitalization. TABLE SPECIFICITY OF RADIOLOGIC FINDINGS High Specificity Classic metaphyseal lesions Rib fractures, especially posterior Scapular fractures Spinous process fractures Sternal fractures Moderate Specificity Multiple fractures, especially bilateral Fractures of different ages Epiphyseal separations Vertebral body fractures and subluxations Digital fractures Complex skull fractures Common, but low specificity Subperiosteal new bone formation Clavicular fractures Long bone shaft fractures Linear skull fractures Highest specificity applies to infants. From Kleinman PK. Diagnostic imaging of child abuse, 2nd ed. St. Louis, MO: Mosby, 1998:9. Osteogenesis Imperfecta Differentiating child abuse from OI is one of the most classic differential diagnostic challenges that the orthopaedist and radiologist can face. Claiming that their child has OI can be a common defense used by an abusive family in legal defenses. The classification of Sillence is well known. OI is a rare disorder of type I collagen (incidence of approximately 1 in 25,000 live births). OI type I is mild and is typically distinguished by distinctly blue sclerae (however, some children with OI type I do not have blue sclerae). OI type II is lethal in the perinatal period. OI type III is severe and causes progressive deformity. OI type IV is typically a milder form, with normal sclerae. Of the two subtypes, type IVA has no dentinogenesis imperfecta. OI is either dominantly inherited or occurs sporadically as a consequence of a new mutation. However, mosaicism has been reported and could explain the occurrence of more than one affected child to apparently “unaffected” parents. The only types that represent a practical differential challenge of abuse are the unusual type I OI without blue sclerae and type IVA OI. Certainly biochemical analysis of type I collagen can be instrumental in confirming cases of OI when abuse is otherwise considered to be the cause (60). If testing is indicated, a skin biopsy for cultured dermal fibroblasts can detect approximately 85% of OI cases. If there is a reliable reporter and a history of multiple fractures with minimal trauma, OI is likely. Smith offered these guidelines (62): • In suspicious circumstances, suspect child abuse. • Consider collagen testing if o bruises or burns are not seen o the reported injury seems too minor to have caused a fracture o fractures occur in different environments When the diagnosis is uncertain, children are typically placed in protective custody. In such an environment, a child with OI type IVA will still fracture. The fractures will likely cease to occur in the abused child. Children with OI can also be victims of abuse (63). Collagen synthesis testing is rarely required to rule out OI, as the diagnosis would have already been strongly suspected in most cases (64). The reliability of bone mineral density (BMD) measurements to differentiate between abuse and OI is unknown, as values for BMD are not available for either typically developing children younger than 2 years or for children with OI Reference: Lovell & Winter’s Pediatric Orthopedic. 6th ed. Ch 34.

Question 37

30. Which of the following pathogens are most commonly associated with neonatal septic arthritis and osteomyelitis ? a. Staphylococcus aureus and Escherichia coli b. Staphylococcus aureus and group A streptococci c. Staphylococcus aureus and group B streptococci d. Haemophilus influenza and Escherichia coli e. Haemophilus influenza and group A streptococci

Answer 37

Answer c. Staphylococcus aureus and group B streptococci Reference : Miller’s Review of Orthopedics. 5th ed. Chapter 1. Section 5. Reference : AAOS Orthopedic Comprehensive Review. 2009. ## Footnote Newborn (up to 4 months of age)—The most common organisms include Staphylococcus aureus, gram-negative bacilli, and group B streptococcus. Primary empirical therapy includes nafcillin or oxacillin plus a third-generation cephalosporin. Alternative antibiotic therapy includes vancomycin plus a third-generation cephalosporin. Newborns with hematogenous osteomyelitis may be afebrile, and the best predictors of the osteomyelitis are local signs in the extremity, including warmth. Almost 70% of newborn patients with hematogenous osteomyelitis have positive blood cultures. Children 4 years of age or older—The most common organisms are S. aureus, group A streptococcus, and coliforms (uncommon). The empirical treatment of choice is nafcillin or oxacillin; alternative regimens include vancomycin or clindamycin. When the Gram stain shows gram-negative organisms, a third-generation cephalosporin should be added. With recent immunization programs, Haemophilus influenzae bone infections causing hematogenous osteomyelitis have been almost completely eliminated. Adults 21 years of age or older—The most common organism is S. aureus, but a wide variety of other organisms have been isolated. Initial empirical therapy includes nafcillin, oxacillin, or cefazolin; vancomycin can be used as an alternative initial therapy. Sickle cell anemia—Salmonella is a characteristic organism. The primary treatment is with one of the fluoroquinolones (only in adults); alternative treatment is with a third-generation cephalosporin. Hemodialysis patients and intravenous drug abusers—S. aureus, S. epidermidis, and Pseudomonas aeruginosa are common organisms. The treatment of choice is one of the penicillinase-resistant synthetic penicillins (PRSPs) plus ciprofloxacin; an alternative treatment is vancomycin with ciprofloxacin.

Question 38

31. During soft tissue release for an idiopathic clubfoot, it is noted than the peroneus longus tendon has been transected in the midfoot. Failure into repair this structure may be lead to a. Cavus b. Claw toes c. A dorsal bunion d. Hindfoot valgus e. Forefoot pronation

Answer 38

Answer: c. A dorsal bunion A statistically significant varus displacement of the first metatarsal was observed only after transection of the peroneus longus tendon. It was concluded that the peroneus longus tendon is a strong retaining mechanism of the first metatarsal to opposes the tibialis anterior dorsal pull on 1st ray . When tendon peroneus longus injured, flexor hallucis longus try to compensate by flex the MTP. Thus forming deformity dorsal bunion. Dorsal bunion can be result from sequel of poliomyelitis or direct injury to tendon peroneus longus. ## Footnote Ref : Bohne WH, Lee KT, Peterson MG. Action of the peroneus longus tendon on the first metatarsal against metatarsus primus varus force. Foot Ankle Int. 1997 Aug;18(8):510-2.

Answer 39

Answer : e. Presence of metastases Eventhough size greater than 15 cm, extra-compartment involvement, number of mitotic figures per high power filed (grade), large size in a proximal location are given bad prognosis but presence of metastases is the worst

Question 40

34. What is the most common presentation of a benign bone tumor in childhood ? a. Pain b. Deformity c. Pathologic fracture d. Presence af a mass e. Incidental finding

Answer 40

Answer : e. Incidental finding Benign bone tumor can be classified as : laten, active, aggressive. Only aggressive benign bone tumors are associated with soft tissue mass, and they are far less common than indolent bone tumors, especially in children. Ref : AAOS comprehensive review.

Question 41

35. Soft tissue sarcomas most commonly metastasize to the a. Liver b. Lung c. Bone d. Regional nodes e. Distant nodes

Answer 41

Answer: b. Lung

Question 42

36. Following preoperative chemotherapy, the percent of tumor necrosis has been shown to be of prognostic value for which of the following tumors ? a. Rhabdomyosarcoma b. Chondrosarcoma c. Metastatic adenocarcinoma d. Osteosarcoma e. Giant cell tumor of bone

Answer 42

Answer: d. Osteosarcoma Huvos grade 1,2,3,4: grading for histological response to preoperative chemotherapy • grade-I : little or no necrosis (involving 50 per cent of the tumor or less); • grade-II : necrosis of more than 50 per cent but less than 90 per cent of the tumor; • grade-III : only scattered foci of viable tumor cells (necrosis of 90 to 99 per cent of the tumor) • grade-IV response, by no viable tumor (100 per cent necrosis). The histological response to preoperative chemotherapy was determined retrospectively by the same pathologist in a blinded fashion. Huvos grade 3,4 : kemo efektif.

Question 43

37. What is the most common clinical presentation of a patient with a malignant bone tumor ? a. Incidental finding b. Pain c. Pathologic fracture d. Deformity e. Presence of a mass

Answer 43

Answer: b. pain Ref. AAOS comprehensive orthopedic review. Pg 2. ## Footnote

Question 44

What is the current 5 year survival rate for patients with classic nonmetastatic, high grade osteosarcoma of the extremity ? a. 10% b. 20% c. 40% d. 70% e. 90%

Answer 44

Answer: d. 70% Ref. AAOS comprehensive orthopedic review. Pg 124.

Question 45

116. The scoring system for impending pathologic fractures devised by Mirels involves assessment of which of the following factors? 1. Lesion location, amount of pain, lesion type (lucent/blastic), lesion size 2. Patient’s functional status, lesion location, amount of pain, lesion size 3. Lesion type (lucent/blastic), patient’s functional status, lesion location, amount 4. of pain 5. Lesion size, lesion type (lucent/blastic), lesion location, patient’s functional status 6. 5- Amount of pain, patient’s functional status, lesion type (lucent/blastic), lesion size

Answer 45

Answer: 1. Lesion location, amount of pain, lesion type (lucent/blastic), lesion size ## Footnote Tabel Mirels Scoring System Variable 1 point 2 points 3 points Site Upper limb Lower limb Peritrochanteric Pain Mild Moderate Functional Lesion Blastic Mixed Lytic Extent \< 1/3 1/3 - 2/3 \> 2/3 A mean score of 7 or below, indicates a low risk of fracture; radiation therapy should be considered. A score of 8 or above suggest a substantial risk, and surgical intervention is recommended Reference : Operative Techniques in Orthopaedic Surgery. Vol 1. Pg 800. Lippicott William & Wilkins.

Question 46

118. What is the most common malignancy involving the hand? ## Footnote 1- Epithelioid sarcoma 2- Synovial sarcoma 3- Metastatic lung carcinoma 4- Chondrosarcoma 5- Squamous cell carcinoma

Answer 46

Answer 5. Squamous cell carcinoma Squamous cell carcinoma (SCC)—The most common malignancy of the hand is squamous cell carcinoma. It is usually seen in elderly men with premalignant conditions such as actinokeratosis or chronic osteomyelitis. The primary risk factor is excessive exposure to ultraviolet radiation. SCC is also the most common subungual malignancy. It has a higher metastatic potential than basal cell carcinoma. Treatment is with wide excision or Mohs micrographic surgery. Lymph node biopsy may be necessary. Reference : Miller’s Review of Orthopedic. 5th ed. Ch 7, Subch 15. Elsevier inc. 2008 Summary ; The most common benign soft tissue tumor in hand and wrist is ganglion The most common benign bone tumor in hand is enchondroma The most common sarcomas are epithelioid and synovial. Other common sarcomas of the upper extremity include liposarcoma and malignant fibrous histiocytoma The most common hand malignancy (metastases bone disease) is metastatic lung carcinoma, which is usually seen in the distal phalanx. The next most common primary sites of disease metastasizing to the hand are from the breast or kidney The most common malignant primary bone tumor of hand and wrist are chondrosarcoma, osteosarcoma, and Ewing sarcoma

Question 47

119. What is the most common bone tumor in the hand? ## Footnote 1- Periosteal chondroma 2- Subungual exostosis 3- Chondrosarcoma 4- Osteoid osteoma 5- Enchondroma

Answer 47

Answer ; 5. Enchondroma ## Footnote Enchondroma—The most common benign bone tumor of the upper extremity. It typically occurs in the second to fourth decades, and most cases are asymptomatic and discovered incidentally. The tumor arises from the metaphyseal medullary canal and spreads to the diaphysis. It is usually seen in the proximal phalanx and metacarpal (Fig. 7–58). Enchondroma causes symmetrical fusiform expansion of bone, with endosteal scalloping and intramedullary calcifications. It may present as a pathologic fracture. Histologically, enchondroma of the hand is characterized by benign cartilage of high cellularity. If mitotic figures are present, low-grade chondrosarcoma should be suspected. The recommended treatment is with curettage and bone grafting. Excision, intramedullary internal fixation, and bone cementing have also been successful in a small series. Reference : Miller’s Review of Orthopedic. 5th ed. Ch 7, Subch 15. Elsevier inc. 2008 Summary ; The most common benign soft tissue tumor in hand and wrist is ganglion The most common benign bone tumor in hand is enchondroma The most common sarcomas are epithelioid and synovial. Other common sarcomas of the upper extremity include liposarcoma and malignant fibrous histiocytoma The most common hand malignancy (metastases bone disease) is metastatic lung carcinoma, which is usually seen in the distal phalanx. The next most common primary sites of disease metastasizing to the hand are from the breast or kidney The most common malignant primary bone tumor of hand and wrist are chondrosarcoma, osteosarcoma, and Ewing sarcoma

Question 48

A 15-year old boy has haemophilic arthropathy of his knee. Radiographs showed widening of the intercondylar notch of femur and squaring off of patella. The next step in his management is A. Joint aspiration B. Synovectomy C. Replacement of factor VIII D. Traction in bed to correct flexion deformity. E. Total knee replacement.

Answer 48

Answer: c. replacement of factor VIII ## Footnote Joint aspiration : not mentioned whether there is any acute joint hemorrhage Traction in bed to correct flexion deformity : not recommended since it may worsen osteopenia Total knee replacement: not recommended for 15 years old Hemophilia—X-linked recessive disorder with decreased factor VIII (hemophilia A), abnormal factor VIII with platelet dysfunction (von Willebrand's disease), or factor IX (hemophilia B-Christmas disease); associated with bleeding episodes and skeletal/joint sequelae. Can be mild (5-25% of factor present), moderate (1-5% available), or severe (\< 1% of factor present). 1. Presentation and diagnosis—Hemarthrosis presents with painful swelling and decreased range of motion (ROM) of affected joints. The knee is the most commonly affected joint. Deep intramuscular bleeding is also common and can lead to the formation of a pseudotumor (blood cyst), which can occur in soft tissue or bone. Intramuscular hematomas can lead to compression of adjacent nerves (e.g., an iliacus hematoma may cause femoral nerve paralysis and may mimic bleeding into the hip joint). **Radiographic findings in hemophilia** include **squaring of the patellas and condyles, epiphyseal overgrowth with leg-length discrepancy, and generalized osteopenia with resulting fractures.** Fractures heal in normal time with proper clotting. Cartilage atrophy due to enzymatic matrix degeneration and chondrocyte death is frequent. 2. Treatment—Home transfusion therapy has reduced the severity of the arthropathy with the advantage of treatment when bleeding occurs. Treatment of the sequelae includes contracture release, osteotomies, open synovectomy, arthroscopic synovectomy (better motion, shorter hospitalization), radiation synovectomy (useful in patients with antibody inhibitors and poor medical management), and total joint arthroplasty. Mild to moderate hemophilia A can be treated with desmopressin. **Factor VIII levels should be increased for prophylaxis in the following situations: vigorous physical therapy (20%), treatment of hematoma (30%), acute hemarthrosis or soft tissue surgery (\> 50%), and skeletal surgery (approach 100% preoperatively and maintain over 50% for 10 days postoperatively)**. Tourniquets, ligated vessels rather than cauterized vessels, and rigid fixation of fractures decrease postoperative bleeding. Immunoglobulin G (IgG) antibody inhibitors are present in 4-20% of hemophiliacs and are a relative contraindication to surgery. Because of the amount of blood component therapy required to treat this disorder, a large percentage of older hemophiliacs are positive for human immunodeficiency virus (HIV).

Question 49

41. Eosinophillic granuloma frequently occurs as a solitary lesion in the tubular long bones. After biopsy, what is the best course of action ? a. Neoadjuvant chemotherapy b. En bloc resection c. Observation d. Amputation e. Chemotherapy followed by radiation therapy

Answer 49

Answer : c. observation ## Footnote Most lesions of eosinophilic granuloma are simply observed, but larger, aggressive lesions may require curettage and bone grafting. Frequently, biopsy is required to rule out malignant diagnosis. The differential diagnosis of eosinophilic granuloma is osteomyelitis, Ewing sarcoma of bone, or osteogenic sarcoma. The biopsy alone can be followed by spontaneous resolution. In some patients, low dose radiation therapy is used. Chemotherapy or amputation is not indicated for these benign lesions. Reference ; Simon M, Springfield D, et al: Common Benign Bone Tumors: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p200.

Question 50

42. Which fiber of the anterior cruciate ligament are thight in flexion ? ## Footnote a. Anteromedial b. Anterolateral c. Posteromedial d. Posterolateral e. Middle

Answer 50

Answer : a. anteromedial ## Footnote There are 2 bundles of anterior cruciate ligaments (ACL). The anteromedial bundle and posterolateral. The anteromedial tight in flexion, while in extension both bundle are tensioned. Reference : AAOS Comprehensive Orthopedic System Review. 2009. P 143

Question 51

43. Following harvesting of patellar tendon autograft, paresthesia most commonly occurs in which of the following location ? a. Medial to incision b. Lateral to incision c. First web space of the foot d. Medial foot e. Dorsal foot

Answer 51

Answer : b. lateral to incision ## Footnote The infrapatellar branch of the saphenous nerve often crosses over the anterior aspect of the knee and innervates the skin lateral to the anterior midline of the knee. An anterior midline incision, often result in incision of the terminal branches, resulting in lateral numbness. The superficial peroneal, deep peroneal, and saphenous nerve provide sensation to the foot are not at risk.

Question 52

86. According to the Third National Acute Spinal Cord Injury Study (NASCIS 3), what is the recommended protocol for a patient who sustained a spinal cord injury 7 hours ago ? 1. Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 23 hours 2. Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 48 hours 3. Dexamethasone 10 mg bolus, followed by 6 mg every 6 hour for 24 hours 4. Dexamethasone 10 mg bolus, followed by 6 mg every 6 hour for48 hours 5. No treatment

Answer 52

Answer: 2. Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 48 hours. ## Footnote Based on National Acute Spinal Cord Injury Study (NASCIS) 1 & 2: Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 23 hours. NASCIS 2 established the recommended doses of methylprednisolone for spinal cord injury : an initial bolus of 30 mg/kg over 1 hour, followed by an infusion of 5.4 mg/kg/hour for an additional 23 hours. If injury was more than 8 hours old, the methylprednisolone was not recommended. Based on National Acute Spinal Cord Injury Study (NASCIS) 3; The objectives of the third and final NASCIS were to investigate the interplay between timing of steroid administration and duration of therapy and to evaluate the efficacy of the 21-aminosteroid tirilazad mesylate, which purportedly had a better safety profile than methylprednisolone. Four-hundred ninety-nine patients were randomized into three treatment groups within 6 hours of injury: the first group received methylprednisolone according to the NASCIS II dosing for 24 hours, the second group received this dosing for 48 hours, and the third group received a methylprednisolone bolus of 5.4 mg/kg/hr followed by a maintenance infusion of tirilazad at 2.5 mg/kg IV every 6 hours for 48 hours. With outcome measures including motor function, sensory function, and functional independence; the NASCIS III revealed that increased duration of steroid administration (48 hours) resulted in statistically significant benefit only if treatment was initiated between 3 and 8 hours of injury. Infectious complications were more common in the 48-hour corticosteroid group but were statistically insignificant. There were no differences between the tirilazad group and the 24-hour methylprednisolone group. So, NASCIS 3 recommended changed the dosing schedule based on the time from injury. If the time from injury to treatment was less than 3 hours, the standard protocol was followed ( 30 mg/kg bolus followed by 5.4 mg/kg/hour for 23 hours). If the time from injury to treatment was between 3 – 8 hours, the infusion was continued at 5.4 mg/kg/hour for an additional 23 hours (48 hours total). Reference : Rothman-Simeone’ s The Spine. 6th ed. Ch : Basic Science of Spinal cord injury. Pg 1302.

Question 53

87. Injury to which of the following structures has been reported following iliac crest bone graft harvest? a. Superior gluteal artery from anterior crest harvest b. Superior cluteal artery from anterior crest harvest c. Inferior gluteal artery from posterior crest harvest d. Ilioinguinal nerve from a posterior crest harvest e. Lateral femoral cutaneous nerve from an anterior crest harvest

Answer 53

Answer : e. Lateral femoral cutaneous nerve from an anterior crest harvest ## Footnote Injury to the lateral femoral cutaneous nerve (Bernhardt's syndrome) or MERALGIA PARESTHETICA occurs after harvest of the bone from the anterior iliac crest. The lateral femoral cutaneous nerve is a terminal sensory nerve that originates from L2-L3 and innervates the skin of the thigh laterally. * Injury to the lateral femoral cutaneous nerve and the ilioinguinal nerve have both been described with an anterior iliac crest bone graft harvest. * The lateral femoral cutaneous nerve may be injured from retraction after elevating the iliacus muscle or from direct injury when the nerve actually cross over the crest. * Injury to ilioiguinal nerve has been reported from vigorous retraction of iliaus muscle after exposing inner table of anterior ilium. * A posterior crest harvest can injury the superior gluteal injury if a surgical instrument violates the sciatic notch. * Cluneal nerve injury may occur with posterior crest harvest, particularly if the skin incision is horizontal or extends more than 8 cm superolateral from the posterior superior iliac spine. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 226.

Question 54

88. A patient who sustained injuries in motocycle accident 30 minutes ago, has significant motor and sensory deficit corresponding to a C6 level of injury. A lateral radiograph obtained during the initial on scene evaluation reveals bilateral jumped facets as C5-C6, this appear to be an isolated injury. The patients is awake and alert. The next step in management of the dislocation should consist of : a. Immediate posterior surgical reduction and stabilization b. Immediate anterior discectomy and fusion c. MRI d. Reduction in Gardner-Wells tongs with serial traction e. Rigid collar immobilization until spinal shock resolves

Answer 54

Answer : d. Reduction in Gardner-Wells tongs with serial traction Surgical open reduction may increase the neurologic deficit if a disk herniation occur. Evidence from animal studies suggest, that rapid decompression of the spinal cord may improve recovery. Serially increasing traction weight to reduce dislocation has been shown to be safe when used in patient who are awake. Indication for MRI include patient who are unable to cooperate with serial examinations, the need for open reduction, and progression of deficit during awake reduction. Reference AAOS Comprehensive Orthopedic Review. 2009. Pg 226.

Question 55

89. A 64 year old man who underwent an L4-L6decompression approximately 1 year ago reported relief on his claudicatory leg pain initially, but he now has increasing low back pain and recurrent neurogenic claudication despite nonsurgical management. Radiograph shows show ney asymmetric collapse and spondylolisthesis at the decompressed segment, and MRI scans show lateral recess stenosis. The next most appropriate step in management should consist of 1. L4-5 discectomy 2. L4-5 discectomy and lateral recess decompression 3. Revision posterior decompression 4. Revision posterior decompression and posterolateral fusion 5. Anterior lumbar interbody fusion with cages

Answer 55

Answer: 4. Revision posterior decompression and posterolateral fusion ## Footnote When radiographic findings reveal postlaminectomy instability, procedures that do not include some type of fusion will fail to solve the problem. In fact, wider decompression or discectomy alone will only further destabilize the segment. Because there is radiographic, evidence of recurrent lateral recess stenosis and symptomatic neurogenic claudication, a revision decompression should be included. Since acces to the canal involves a posterior approach, the stabilization should be performed through the same approach. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 227.

Question 56

85. The longus colli muscle are directly anterior to which of the following structures ? ## Footnote a. Prevertebral fascia b. Pretracheal fascia c. Esophagus d. Vertebral arteries e. Cervical nerve root

Answer 56

Answer :d. vertebral arteries ## Footnote The longus colli muscle are posterior to the prevertebral fascia, pretracheal fascia, and esophagus. They are anterior to both the vertebral arteries and cervical nerve roots, but the later are posterior to the vertebral arteries. So the sequence structure from anterior to posterior are : • Longus colli muscle • Vertebral arteries • Cervical nerve roots Reference : AAOS Comprehensive Orthopedic Review. 2009. Pgg 224.

Question 57

92. What is the prognosis for ambulation, from best to worst, for patient with an incomplete spinal cord injury ? ## Footnote a. Central cord syndrome, anterior cord syndrome, brown sequard syndrome b. Central cord syndrome, brown sequard syndrome, anterior cord syndrome c. Brown sequard syndrome, anterior cord syndrome, central cord syndrome d. Brown sequard syndrome, central cord syndrome, anterior cord syndrome e. Anterior cord syndrome, central cord syndrome, brown sequard syndrome

Answer 57

Answer : d. Brown sequard syndrome, central cord syndrome, anterior cord syndrome ## Footnote Of the incomplete spinal cord injury, Brown Sequard syndrome has the best prognosis for ambulation. Central cord syndrome has a variable recovery. Anterior cord syndrome has the worst prognosis, with motor recovery rare below the level of injury. Reference ; AAOS Comprehensive Orthopedic Review. 2009. Pg 229.

Question 58

91. In the upright standing position, approximately what percent of the vertical load is borne by the lumbar facet joint? a. 0% b. 20% c. 40% d. 50% e. 80%

Answer 58

Answer: b. 20% ## Footnote Direct measurement and finite element modeling results show that approximately 20% of the vertical load is borne by the posterior structures of the lumbar spine in the upright position. Reference : AAOS Comprehensive Orthopedic review. 2009. Pg 229. Facet joint can carry up to 33% of dynamic axial loading. But when stand upright, 90% vertical load is borned by nucleus pulposus

Question 59

90. An elderly patient falls and sustain an extension injury to the neck that result in upper extremity weakness, spared perianal sensation, and lower extremity spasticity. These findings best describe what syndrome? a. Brown sequard b. Cauda equina c. Anterior cord d. Posterior cord e. Central cord

Answer 59

Answer: e. central cord ## Footnote * These findings indicate central cord syndrome, an injury that is more common in the older population who have some degrees of spondylosis. The physiologic insult can be a central spinal hematoma with result hematomyelia. Bowel and bladder function return, has agood prognosis, unlike the upper extremity motor loss. * Cauda equina syndrome generally involves injury at the lumbar level. With some degrre of lower extremity motor loss. * Posterior cord syndrome is characterized by preservation of motor function below the level of injury and position/vibration sensory loss. * Brown-Sequard syndrome, which is often produced by a penetrating injury, result in hypalgesia and ipsilateral weakness. * Anterior cord syndrome has a poor prognosis for functional return; lower extremity findings include loss of light touch, sharp/dull, and temperature sensation below the level of injury, as well as motor function.

Question 60

96. A type 2A Hangman’s fracture, which has the potential to overdistract with traction has which of the following hallmark findings ? ## Footnote a. Anterior translation of greater than 3 mm b. Severe angulation with minimal translation c. Extension at the fracture site d. Associated C 1 ring fracture e. Associated C2-3 facet dislocation

Answer 60

Answer: b. Severe angulation with minimal translation Classification (Levine and Edwards; Effendi) * Type I: Nondisplaced, no angulation; translation \<3 mm; C2-C3 disc intact (29%); relatively stable * Type Ia: Atypical unstable lateral bending fractures that are obliquely displaced and usually involve only one pars interarticularis, extending anterior to the pars and into the body on the contralateral side * Type II: Significant angulation at C2-C3; translation \>3 mm; most common injury pattern; unstable; C2-C3 disc disrupted (56%); subclassified into flexion, extension, and listhetic types * Type IIA: Avulsion of entire C2-C3 intervertebral disc in flexion with injury to posterior longitudinal ligament, leaving the anterior longitudinal ligament intact; results in severe angulation; no translation; unstable; probably caused by flexion-distraction injury (6%); traction contraindicated * Type III: Rare; results from initial anterior facet dislocation of C2 on C3 followed by extension injury fracturing the neural arch; results in severe angulation and translation with unilateral or bilateral facet dislocation of C2-C3; unstable (9%); type III injuries most commonly associated with spinal cord injury

Question 61

95. A 44 year old farmer involved in a rollover accident on his tractor sustained on a L1 burst fracture with a 20% loss of anterior vertebral body height, 30% canal compromise, and 15% kyphosis. He remains neurologically intact. The preferred course of action should consist of: a. Posterior spinal fusion with instrumentation b. thoracolumbalsacral orthosis (TLSO) extension brace and early mobilization c. Bed rest for 6 weeks followed by mobilization in a cast d. Anterior L1 corpectomy and fusion with instrumentation e. Anterior corpectomy followed by posterior fusion with instrumentation

Answer 61

Answer : b. thoracolumbosacral orthosis (TLSO) extension brace and early mobilization ## Footnote Surgical decompression is unnecessary in a patient with no neurologic deficit and canal compromise of less than 50%. A compression deformity of less than 50% and kyphotic of less than 30° may be successfully treated with a TLSO extension brace. Deformity in this range will reliably heal with minimal risk for late deformity or residual pain. Although some studies suggest 6 weeks of bed rest as treatment, early mobilization and bracing is preferred. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 232.

Question 62

94. A 19 year old man who sustained a spinal cord injury in a motor vehicle accident 3 days ago has 5/5 full strength in the deltoid and biceps bilaterally, 4/5 strength in wrist extension bilaterally, 1/5 triceps function on the right side, and 2/5 triceps function on the left side. The patient has no detectable lower extremity motor function. Based on the American Spinal Injury Association’ classification, what is the patient’s functional level ? a. C4 b. C5 c. C6 d. C7 e. C8

Answer 62

Answer: c. C6 ## Footnote By convention, when determining the motor level, the key muscle must be at least 3/5. The next most rostral level must be 4/5. Therefore, this patient’s function level is C6. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 232.

Question 63

85. The longus colli muscle are directly anterior to which of the following structures ? a. Prevertebral fascia b. Pretracheal fascia c. Esophagus d. Vertebral arteries e. Cervical nerve root

Answer 63

Answer :d. vertebral arteries ## Footnote The longus colli muscle are posterior to the prevertebral fascia, pretracheal fascia, and esophagus. They are anterior to both the vertebral arteries and cervical nerve roots, but the later are posterior to the vertebral arteries. So the sequence structure from anterior to posterior are : • Longus colli muscle • Vertebral arteries • Cervical nerve roots Reference : AAOS Comprehensive Orthopedic Review. 2009. Pgg 224.

Question 64

86. According to the Third National Acute Spinal Cord Injury Study (NASCIS 3), what is the recommended protocol for a patient who sustained a spinal cord injury 7 hours ago ? ## Footnote a. Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 23 hours b. Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 48 hours c. Dexamethasone 10 mg bolus, followed by 6 mg every 6 hour for 24 hours d. Dexamethasone 10 mg bolus, followed by 6 mg every 6 hour for48 hours e. No treatment

Answer 64

Answer: b. Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 48 hours. ## Footnote Based on National Acute Spinal Cord Injury Study (NASCIS) 1 & 2: Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 23 hours. NASCIS 2 established the recommended doses of methylprednisolone for spinal cord injury : an initial bolus of 30 mg/kg over 1 hour, followed by an infusion of 5.4 mg/kg/hour for an additional 23 hours. If injury was more than 8 hours old, the methylprednisolone was not recommended. Based on National Acute Spinal Cord Injury Study (NASCIS) 3; The objectives of the third and final NASCIS were to investigate the interplay between timing of steroid administration and duration of therapy and to evaluate the efficacy of the 21-aminosteroid tirilazad mesylate, which purportedly had a better safety profile than methylprednisolone. Four-hundred ninety-nine patients were randomized into three treatment groups within 6 hours of injury: the first group received methylprednisolone according to the NASCIS II dosing for 24 hours, the second group received this dosing for 48 hours, and the third group received a methylprednisolone bolus of 5.4 mg/kg/hr followed by a maintenance infusion of tirilazad at 2.5 mg/kg IV every 6 hours for 48 hours. With outcome measures including motor function, sensory function, and functional independence; the NASCIS III revealed that increased duration of steroid administration (48 hours) resulted in statistically significant benefit only if treatment was initiated between 3 and 8 hours of injury. Infectious complications were more common in the 48-hour corticosteroid group but were statistically insignificant. There were no differences between the tirilazad group and the 24-hour methylprednisolone group. So, NASCIS 3 recommended changed the dosing schedule based on the time from injury. If the time from injury to treatment was less than 3 hours, the standard protocol was followed ( 30 mg/kg bolus followed by 5.4 mg/kg/hour for 23 hours). If the time from injury to treatment was between 3 – 8 hours, the infusion was continued at 5.4 mg/kg/hour for an additional 23 hours (48 hours total). Reference : Rothman-Simeone’ s The Spine. 6th ed. Ch : Basic Science of Spinal cord injury. Pg 1302.

Question 65

69. Which of the following is considered the most reliable early clinical finding for hemorrhagic shock ? a. Decreased systolic blood pressure b. Decreased diastolic blood pressure c. Decreased hemoglobin level d. Low urine output e. Tachycardia

Answer 65

Answer : e. Tachycardia ## Footnote Because there are no laboratory tests to diagnose shock, the initial treatment of hemorrhagic shock is recognizing the problem. In most patients with hemorrhagic shock, tachycardia is the earliest measurable sign. Cutaneous vasoconstriction is also an early clinical finding. A drop in systolic blood pressure is often a late finding in hemorrhagic shock. As much as 30% of circulatory blood volume can be lost prior to any change in the systolic blood pressure. In an early state of shock, diastolic blood pressure is increased because of arterial vasoconstriction, which lead to narrow pulse pressure. A decreased hemoglobin level is uncommon finding in early state of hemorrhagic shock. If present, it may relatively preserved in the early state of shock. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 184.

Question 66

70. After undergoing a closed undreamed tibial nailing, a patient is diagnosed with an isolated anterior leg compartment syndrome. However, no treatment is initiated because the patient is thought to have a nerve palsy. Which of the following findings should be present at 2 weeks when the cast is removed ? a. Drop foot and numbness in the first web space of the foot b. Calcaneal deformity of the ankle c. Rigid equines deformity d. Plantar foot numbness e. Supple claw toes

Answer 66

Answer: a. Drop foot and numbness in the first web space of the foot Anterior compartment of cruris contain deep peroneal nerve which innervates tibialis anterior muscle, function in dorsiflexing the ankle, while its sensoric area is over the 1 st web space of the foot. In the acute phase, anterior leg compartment syndrome may look identical to a peroneal nerve palsy; however, with removal of the cast, the patient will most likely have a drop foot and numbness in the first web space of the foot. Calcaneal deformity of the ankle is unlikely to develop following anterior leg compartment syndrome. Deep posterior compartment syndrome most often result in a rigid equines deformity or claw toes. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 185.

Question 67

72. A patient with an acromioclavicular dislocation has a very prominent distal clavicle. Examination reveals that the deformity increases rather than reduces with an isometric shoulder shrug. Which of the following structures is most likely intact ? a. Trapezoid ligament b. Conoid ligament c. Acromioclavicular ligament d. Deltoid muscle origin e. Trapezius muscle insertion

Answer 67

Answer: e. Trapezius muscle insertion Severely displaced acrmioclavicular injuries disrupt the deltopectoral fascia and muscular origin in addition to the ligaments (acromioclavicular and coracoclavicular or trapezoid and conoid). When the deltoid is still attached to the clavicle, an isometric shoulder shrug will tend to reduce the displacement. When the deltoid is detached, but the trapezius is attached, this maneuver will increase the deformity, and surgery may indicated. Reference ; AAOS Comprehensive Orthopedic Review. 2009. Pg 86. Classification—Classified by extent of involvement of the ligamentous support and direction and magnitude of displacement * Type I—Sprain of AC joint * Type II—Rupture of AC ligaments and sprain of CC ligaments * Type III—Rupture of both AC and CC ligaments * Type IV—The clavicle is buttonholed through the trapezius posteriorly * Type V—The trapezius and deltoid are detached * Type VI—The clavicle is translocated beneath the coracoid

Question 68

73. Posterior sternoclavicular dislocation are most commonly associated with which of the following complication ? a. Chronic instability b. Brachial plexus palsy c. Pneumothorax d. Esophageal compression e. Tracheal compression

Answer 68

Answer: e. Tracheal compression Many complications have been reported secondary to the retrosternal dislocation: * right pulmonary artery laceration * transected internal mammary artery and lacerated brachiophalic vein * pneumothorax and laceration of the superior vena cava * respiratory distress * venous congestion in the neck * rupture of the esophagus with abscess and osteomyelitis of the clavicle * pressure on the subclavian artery in an untreated patient * occlusion of the subclavian artery late in a patient who was not treated Worman and Leagus, in their excellent review of the complications associated with posterior dislocations of the sternoclavicular joint, reported that 16 of 60 patients reviewed from the literature had suffered c_omplications of the trachea,_ esophagus, or great vessels Worman LW, Leagus C. Intrathoracic injury following retrosternal dislocation of the clavicle. Trauma 1967;7:416-423. Rereference : Rockwood & Green’s Fractures in Adult. 6th ed. Ch 36.

Question 69

74. During an anterior approach to the shoulder, excessive traction on the conjoined tendon is most likely to result in loss of a. Elbow flexion b. Shoulder flexion c. Shoulder internal rotation d. Shoulder abduction e. Forearm pronation

Answer 69

Answer : a. elbow flexion ## Footnote Conjoined tendon consist of biceps, coracobrachialis. The musculocutaneous nerve travels through the conjoined tendon approximately 8 cm distal to tip of acromion. The musculocutaneous nerve innervates the biceps muscle and the brachialis muscle, both of which responsible for elbow flexion. Shoulder flexion is facilitated by the anterior fibers of the deltoid muscle (axillary nerve), and the supraspinatus muscle (suprascapular nerve). The subsacpular muscle fascilitates internal rotation of the shoulder (upper and lower subscapularis nerve). Shoulder abduction is performed by the deltoid muscle (axillary nerve), and forearm pronation is fascilitated by the pronator teres (median nerve) Reference: AAOS Comprehensive Orthopedic System reviw. 2009. pg 187

Question 70

75. Which of the following ligaments is most commonly involved in posterolateral rotator instability of the elbow? a. Annular b. Lateral ulnar collateral c. Anterior band of medial collateral d. Radial part of the lateral collateral e. Posterior capsul

Answer 70

Answer: b. Lateral ulnar collateral ## Footnote Recurrent posterolateral rotator instability of the elbow is difficult to diagnose. Such instability can be demonstrated only by lateral pivot shift test. The cause for this condition is laxity for the ulnar part of lateral collateral ligament, which allow transient rotator subluxation of the ulnohumeral joint and a secondary dislocation of the radiohumeral joint. The annular ligament remain intact, so the radioulnar joint does not dislocate. Treatment consist of surgical reconstruction of the lax ulnar part of the lateral collateral ligament. The anterior band is the most important p[art of the medial collateral ligament which is lax in valgus instability of the elbow. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 189.

Question 71

76. Which of the following factors is considered most important when assessing an ankle fracture for surgical treatment? a. Level of fibular fracture b. Displacement of fibular fracture c. Size of posterior malleolus d. Position of the talus in the mortise view e. Rupture of the deltoid ligament

Answer 71

Answer:d. Position of the talus in the mortise view ## Footnote Although all of these factors may influence the decision to perform surgery, the most important is the position of the talus in the mortise. The goal of treatment of ankle fractures is to maintain the talus centered in the mortise. If it is in this position, the other factor do not enter into the decision intervene surgically. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 192.

Question 72

77. After stabilizing a bimalleolar fracture with a plate and lag screws foot the fibula and two interfragmental compression screws for the medial malleolus, a syndesmosis screw is indicated of the following situation a. In all suprasyndesmosis fibular fractures b. In all trans syndesmosis fibular fracture c. When there is increased medial clear space with external rotation stress d. If the deltoid ligament is ruptured e. If the posterior malleolus is fracture

Answer 72

Answer : c. When there is increased medial clear space with external rotation stress ## Footnote It is imperative to recognize the need for a position screw (syndesmosis screw) to hold the syndesmosis in proper alignment when surgically stabilizing an ankle fracture. Although many different fracture patterns are suspicious for a disrupted syndesmosis, the only way to asses the syndesmosis is to stress it with abduction and external rotation of the talus and attempt to displace the fibula from the incisura fibularis. Under fluoroscopy, the talus will move laterally and displace the fibula, show a valgus talar tilt, or show an increase medial clear space. If any of all of these signs occur, a syndesmosis screw is inserted after making sure that fibula is reduced into the incisura fibularis. This screw may transverse 3 or 4 cortices but must not act as a lag screw. It usually is inserted with the ankle in maximal dorsiflexion. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 193.

Question 73

78. A 32 year old man sustain an iliac wing fracture and a contralateral femur fracture. Twelve hours later he has shortness of breath with tachypnea, hypoxia, and confusion. A chest radiograph is normal. What is the most likely diagnosis ? a. Fat emboli syndrome b. Adult respiratory distress syndrome c. Pulmonary embolus d. Tension penumothorax e. Sepsis

Answer 73

Answer: a. Fat emboli syndrome ## Footnote Sevitt mayor criteria of fat emboli syndrome: • Hipoxia • Loss of consciousness • Ptechiea Sevitt minor criteria of fat emboli syndrome: • Tachypnea • Anemia • Trombositopenia • Fat macroglobulinuria

Question 74

79. The nerve that transverse the triangular internal (bounded by the teres major superiorly, the long head of triceps medially, and the humeral shaft laterally) supplies which of the following muscle ? a. Brachioradialis b. Flexor pollicis longus c. Deltoid d. Teres major e. Pronator teres

Answer 74

Answer : a. Brachioradialis ## Footnote The radial nerve and profunda brachii artery gain acces to the posterior aspect of the arm through the triangular interval. The radial nerve supplies the brachioradialis. Reference : Netter

Question 75

80. A 24 year old woman has a spleen laceration and hypotension. Radiographs reveal a pulmonary contusion and a displaced mid diaphyseal fracture of the femur. The trauma surgeon clears the patient for stabilization of the femoral fracture. What technique will offer the least potential complication? a. External fixation b. Plate fixation c. Unreamed unlocked intramedullary nailing d. Reamed statically locked intramedullary nailing e. Reamed unlocked nailing

Answer 75

Answer: a. External fixation ## Footnote A concern in the multiply injured patient who has a pulmonary contusion is the potential for further pulmonary compromise because of embolization of marrow, blood clot, or fat during manipulation of the medullary canal. Recent evidence has shown that the presence of a lung injury is the most important determining factor in future deterioration. However despite the lung injury and its potential consequences, this patient’s femur fracture needs stabilization. Damage control in the multiply injured patient requires a technique that can performed rapidly and consistently, the treatment of choice is application of an external fixator. This allow the patient to be resuscitated and treated at a later date when definitive management of the fracture can be carried out. There is little difference between plate fixation and IM nailing with reaming in mortality or ARDS following thoracic injury. Reference ; AAOS Comprehensive Orthopedic Review. 2009. Pg 195.

Question 76

123. The synonym for Paget's disease is: a. Osteitis fibrosa. b. Osteitis proliferans. c. Osteitis deformans. d. None of the above.

Answer 76

Answer : c. Osteitis deformans ## Footnote Paget’s disease—Elevated serum alkaline phosphatase and urinary hydroxyproline; virus-like inclusion bodies observed in osteoclasts. Can display both decreased and increased osteodensity (depending on the phase of the disease). Discussed in Chapter 9, Orthopaedic Pathology. a. Active phase (1) Lytic phase—Intense osteoclastic bone resorption (2) Mixed phase (3) Sclerotic phase—Osteoblastic bone formation predominates b. Inactive phase PA : Section from pagetic bone, showing the mosaic pattern due to overactive bone resorption and bone formation. The trabeculae are thick and patterned by cement lines. Some surfaces are excavated by osteoclastic activity whilst others are lined by rows of osteoblasts. The marrow spaces contain fibrovascular tissue. Marble or mosaic appearance Reference picture : Apley 9th ed. Ch 7. Pg 144

Question 77

124. Multiple myeloma tumor cells resemble: a. Granulocytes. b. Plasma cells. c. Lymphocytes. d. Chondrocytes.

Answer 77

Answer :b. plasma cells ## Footnote HistoPA: Eccentric round or oval cells nuclei membentuk roda pedati (tentiran dr Sjahjenny Sp.PA)

Question 78

127. The enzyme found in osteoclasts but not in osteoblasts is: a. Alkaline phosphatase. b. Acid phosphatase. c. Elastase. d. Cytochrome oxidase.

Answer 78

Answer : b. Acid phosphatase Osteoclast : Multinucleated, irregularly shaped giant cells originate from hematopoietic cells in the macrophage lineage (monocyte progenitors form giant cells by fusion). Possess a ruffled (“brush”) border (plasma membrane enfoldings that increase surface area. Osteoclasts synthesize tartrate-resistant acid phosphate. Bisphosphonates inhibit osteoclast resorption of bone (by preventing the osteoclast from forming the ruffled border necessary for expression of acid hydrolases) Reference : Miller’s Review of Orthopedic. 5th ed. Ch 1. Section 1.

Question 79

117. Healing of tuberculous arthritis can lead to: a. Calcification. b. Fibrous ankylosis. c. Bony ankylosis. d. None of the above.

Answer 79

Answer: b. Fibrous ankylosis. ## Footnote Tanda healing TB musculoskeletal : aspek klinis Dan radiologis. Klinis: keluhan nyeri(-), BB naik, KU baik Radiologis : spinal fusion Release from treatment setelah OAT 1 tahun,klinis, dan radiologis INH rifampicin, PZA : 3 bulan fase intensif INH, rifampicin : 9 bulan fase lanjutan

Question 80

112. What is not True of Brodie's abscess: a. A form of chronic osteomyelitis b. Intermittent pain and swelling. c. Common to diaphysis d. Excision is very often required.

Answer 80

Answer : c. Common to diaphysis.(common to metaphysis) ## Footnote The typical radiographic lesion is a circumscribed, round or oval radiolucent ‘cavity’ 1–2 cm in diameter. Most often it is seen in the tibial or femoral metaphysis, but it may occur in the epiphysis or in one of the cuboidal bones (e.g. the calcaneum). Sometimes the ‘cavity’ is surrounded by a halo of sclerosis (the classic Brodie’s abscess); occasionally it is less well defined, extending into the diaphysis. Metaphyseal lesions cause little or no periosteal reaction; diaphyseal lesions may be associated with periosteal new bone formation and marked cortical thickening. If the cortex is eroded the lesion may be mistaken for a malignant tumour. The radioisotope scan shows markedly increased activity. Curettage is also indicated if the x-ray shows that there is no healing after conservative treatment; this is always followed by a further course of antibiotics.

Question 81

100. A 54 year old man undergoes uneventful anterior cervical discectomy and interbody fusion at C4 -5 for focal disc herniation and C5 radiculopathy. At the 3 week follow up examination, the patient reports a persistent cough. Pulmonary evaluation reveals a mild but persistent aspiration. Laryngoscop reveals partial paralysis of the left vocal cord, most likely caused by: a. Entrapment of the superior laryngeal nerve during ligation of the superior thyroid artery b. Stretch of the recurrent laryngeal as it enters the esophageal tracheal groove c. Injury to the vocal cord during endotracheal intubation d. Displacement of the lanrynx against the endotracheal tube by retraction e. Retraction pressure on the laryngeal nerve in the esophageal groove

Answer 81

Answer : e. Displacement of the lanrynx against the endotracheal tube by retraction ## Footnote The exact anatomic event responsible for vocal cord paralysis associated with anterior cervical surgery remains a question Apfelbaum et al, in an excellent review of 900 anterior cervical surgeries, identified 30% with vocal cord paralysis, 3 of which were permanent. They showed that retractor placed under the longus colli for anterior cervical exposures can compress the laryngeal-tracheal branches within the larynx against the tented endotracheal tube rather than the recurrent laryngeal nerve which is extrinsic to the larynx. By releasing the endotrachela cuff and allowing the tube to recenter itself after placement of retractors, they were able to decrease vocal cord injury from 6.4% to 1.7%. Jewett et al suggested that a left sided approach may result in lower incidence of injury. Endotracheal intubation is the 2nd most common cause of vocal cord injury, with an incidence approximately 2%. Reference : AAOS Comprehensive Orthopedic review. 2009. Pg 236.

Question 82

96. A type 2A Hangman’s fracture, which has the potential to overdistract with traction has which of the following hallmark findings ? ## Footnote a. Anterior translation of greater than 3 mm b. Severe angulation with minimal translation c. Extension at the fracture site d. Associated C 1 ring fracture e. Associated C2-3 facet dislocation

Answer 82

Answer: b. Severe angulation with minimal translation Classification (Levine and Edwards; Effendi): * Type I: Nondisplaced, no angulation; translation \<3 mm; C2-C3 disc intact (29%); relatively stable * Type Ia: Atypical unstable lateral bending fractures that are obliquely displaced and usually involve only one pars interarticularis, extending anterior to the pars and into the body on the contralateral side * Type II: Significant angulation at C2-C3; translation \>3 mm; most common injury pattern; unstable; C2-C3 disc disrupted (56%); subclassified into flexion, extension, and listhetic types * Type IIA: Avulsion of entire C2-C3 intervertebral disc in flexion with injury to posterior longitudinal ligament, leaving the anterior longitudinal ligament intact; results in severe angulation; no translation; unstable; probably caused by flexion-distraction injury (6%); traction contraindicated * Type III: Rare; results from initial anterior facet dislocation of C2 on C3 followed by extension injury fracturing the neural arch; results in severe angulation and translation with unilateral or bilateral facet dislocation of C2-C3; unstable (9%); type III injuries most commonly associated with spinal cord injury

Question 83

95. A 44 year old farmer involved in a rollover accident on his tractor sustained on a L1 burst fracture with a 20% loss of anterior vertebral body height, 30% canal compromise, and 15% kyphosis. He remains neurologically intact. The preferred course of action should consist of: a. Posterior spinal fusion with instrumentation b. thoracolumbalsacral orthosis (TLSO) extension brace and early mobilization c. Bed rest for 6 weeks followed by mobilization in a cast d. Anterior L1 corpectomy and fusion with instrumentation e. Anterior corpectomy followed by posterior fusion with instrumentation

Answer 83

Answer : b. thoracolumbosacral orthosis (TLSO) extension brace and early mobilization ## Footnote Surgical decompression is unnecessary in a patient with no neurologic deficit and canal compromise of less than 50%. A compression deformity of less than 50% and kyphotic of less than 30° may be successfully treated with a TLSO extension brace. Deformity in this range will reliably heal with minimal risk for late deformity or residual pain. Although some studies suggest 6 weeks of bed rest as treatment, early mobilization and bracing is preferred. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 232.

Question 84

94. A 19 year old man who sustained a spinal cord injury in a motor vehicle accident 3 days ago has 5/5 full strength in the deltoid and biceps bilaterally, 4/5 strength in wrist extension bilaterally, 1/5 triceps function on the right side, and 2/5 triceps function on the left side. The patient has no detectable lower extremity motor function. Based on the American Spinal Injury Association’ classification, what is the patient’s functional level ? a. C4 b. C5 c. C6 d. C7 e. C8

Answer 84

Answer: c. C6 ## Footnote By convention, when determining the motor level, the key muscle must be at least 3/5. The next most rostral level must be 4/5. Therefore, this patient’s function level is C6. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 232.

Question 85

98. What spinal nerve in the cauda equine are primarily responsible for innervations of the bladder? ## Footnote a. L1,L2, and L3 b. L4 and L5 c. L5 and S1 d. S2, S3, and S4 e. Filum terminale

Answer 85

Answer : d. S2, S3, and S4 ## Footnote The spinal nerves primarily responsible for bladder function are the S2, S3, S4 nerve roots. With significant compression of the cauda equine by either disk herniation, tumor, or degenerative stenosis, bladder dysfunction may result. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 234.

Question 86

81. Which of the following is a long complication of ankle arthrodesis for post traumatic arthritis ? a. Progressive limb length discrepancy b. Contralateral ankle arthritis c. Ipsilateral hindfoot and midfoot arthritis d. Ipsilateral knee arthritis e. Talar osteonecrosis

Answer 86

Answer : c. Ipsilateral hindfoot and midfoot arthritis ## Footnote Ankle arthrodesis for posttraumatic ankle arthrosis provide reliable pain relief. However, the long term sequel of joint arthrodesis is the development of arthrosis in the surrounding joints. Over time, following ankle arthrodesis, the ipsilateral hindfoot and midfoot jints show sign of join space wear, and this may be symptomatic. With a stable ankle arthrodesis, progressive limb-length discrepancy or talar osteonecrosis is not expected. Ankle arthrodesis has not been definitely linked to ipsilateral knee arthritis or contralateral ankle arthritis. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 199.

Question 87

80. A 24 year old woman has a spleen laceration and hypotension. Radiographs reveal a pulmonary contusion and a displaced mid diaphyseal fracture of the femur. The trauma surgeon clears the patient for stabilization of the femoral fracture. What technique will offer the least potential complication? ## Footnote a. External fixation b. Plate fixation c. Unreamed unlocked intramedullary nailing d. Reamed statically locked intramedullary nailing e. Reamed unlocked nailing

Answer 87

Answer: a. External fixation ## Footnote A concern in the multiply injured patient who has a pulmonary contusion is the potential for further pulmonary compromise because of embolization of marrow, blood clot, or fat during manipulation of the medullary canal. Recent evidence has shown that the presence of a lung injury is the most important determining factor in future deterioration. However despite the lung injury and its potential consequences, this patient’s femur fracture needs stabilization. Damage control in the multiply injured patient requires a technique that can performed rapidly and consistently, the treatment of choice is application of an external fixator. This allow the patient to be resuscitated and treated at a later date when definitive management of the fracture can be carried out. There is little difference between plate fixation and IM nailing with reaming in mortality or ARDS following thoracic injury. Reference ; AAOS Comprehensive Orthopedic Review. 2009. Pg 195.

Question 88

58. A 21 year old man sustained a displaced pelvic fracture after falling 40 feet from examination reveals the presence of blood in the urethral meatus. Which of the following measures is most likely to complicate urologic management ? a. Intravenous pyelography b. Placement of a Foley catheter c. Placement of suprapubic catheter d. Rectal examination e. Retrograde cystogram

Answer 88

Answer: b. Placement of a Foley catheter ## Footnote

Question 89

82. A 18 year old man has a simple oblique fracture of the humeral shaft that require surgical stabilization to maintain reduction and facilitate mobilization. Which of the following methods will provide the best outcome ? ## Footnote a. Unreamed intramedullary nail b. Reamed statically locked intramedullary nail c. External fixation d. Plate fixation and interfragmentary compression e. Bridge plate stabilization

Answer 89

Answer: d. Plate fixation and interfragmentary compression ## Footnote The patient has a simple fracture pattern that can be reduce anatomically and stabilized with absolute stability by interfragmental compression and protection plating. This will guarantee a 95% - 98% union rate eith no radial nerve palsy. Intramedullary nailing does not equal these result in simple fracture pattern in humerus. Bridge palting is indicated for multifragmented fracture pattern when anatomic reductionand absolute stability cannot be achieved. External fixation is reserved for severe open fractures. Reference : AAOS Comprehensive Orthopedic Review. 2009. 202.

Question 90

101. Origin of bone is from: a. Ectoderm b. Mesoderm c. Endoderm d. All of the above

Answer 90

Answer: b. Mesoderm Fourth week of embryogenesis During this week, the limb buds become recognizable. Somites (mesoderm) differentiate into three dermatome, mtome, and sclerotome. The dermatome becomes skin, the myotome becomes muscle, and the sclerotome becomes cartilage and bone. Reference : Staheli. Practice of Pediatric Orthopedic. 2nd. 2006. Lippincott William & Wilkins. Ch 1

Question 91

103. Acute osteomyelitis usually begins at : a. Epiphysis b. Metaphysis c. Diaphysis d. Any of above

Answer 91

Answer: b. Metaphysis Reference: Apley 9th ed Predilection for this site has traditionally been attributed to the peculiar arrangement of the blood vessels in that area (Trueta, 1959): * the non-anastomosing terminal branches of the nutrient artery * twist back in hairpin loops before entering the large network of sinusoidal veins * the relative vascular stasis * consequent lowered oxygen tension

Question 92

104. What is not true of acute pyogenic osteomyelitis a. Trauma is a predisposing factor b. Common infecting agent is Staphylococcus aureus c. Infection is usually blood borne d. All are true

Answer 92

Answer: c. Infection is usually blood borne ## Footnote In adults, haematogenous infection accounts for only about 20% of cases of osteomyelitis, mostly affecting the vertebrae. Staphylococcus aureus is the commonest organism but Pseudomonas aeruginosa often appears in patients using intravenous drugs. Reference : Apley’s System of Orthopedic and Fractures. 9th ed, Ch 2: Pg 31.

Question 93

105. What is not true of Brodi’s abscess a. Form of chronic osteomyelitis b. Intermittent pain and swelling c. Common to diaphysis d. Excision is very often required

Answer 93

Answer: d. Common to diaphysis ## Footnote Brodie’s abscess, characteristic in subacute hematogenous osteomyelitis. The typical radiographic lesion is a circumscribed, round or oval radiolucent ‘cavity’ 1–2 cm in diameter. Most often it is seen in the tibial or femoral metaphysis, but it may occur in the epiphysis or in one of the cuboidal bones (e.g. the calcaneum). Sometimes the ‘cavity’ is surrounded by a halo of sclerosis (the classic Brodie’s abscess); occasionally it is less well defined, extending into the diaphysis. Reference : Apley’s System of Orthopedic and Fractures. 9th ed, Ch 2: Pg 31.

Question 94

116. The earliest sign of TB hip in X-ray is: a. Narrow joint space. b. Irregular moth eaten femoral head. c. Periarticular osteoporosis.(Apley Ch2) d. Dislocation.

Answer 94

Answer : c. Periarticular osteoporosis Tuberculosis – clinical and x-ray features (a) Generalized wasting used to be a common feature of all forms of tuberculosis. Nowadays, skeletal tuberculosis occurs in deceptively healthy-looking individuals. An early feature is peri-articular osteoporosis due to synovitis – the left knee in (b). This often resolves with treatment, but if cartilage and bone are destroyed (c), healing occurs by fibrosis and the joint retains a ‘jog’ of painful movement. Reference : Apley 9th ed. Ch 2.

Question 95

733. Which of the following is the most appropriate treatment for an acute comminuted radial head fracture, is associated with an Essex Lopresty injury (radioulnar dissociation) 1. Radial head preservation 2. Radial head excision 3. Suave-Kapandji procedure 4. Darrach procedure 5. Radioulnar synostosis

Answer 95

Answer: 1. Radial head preservation ## Footnote An Essex lopresti injury consist of a fracture of the radial head, disruption of the radioulnar interosseous membrane, and dislocation of the distal radioulnar joint. The diagnosis is frequently made late, ie after excision of comminuted radial head fracture, after pain develops at the distal radioulnar joint, and radiographs show progressive positive ulnar variance and/or dislocation due to proximal migration of radial shaft. Patient who have undergone reduction and internal fixation of the radial head or replacement have done better than those who had excision. Concurrent treatment should include reduction of the distal radioulnar joint and temporary stabilization. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 179.

Question 96

45. A posterior approach to the knee with an incision of the superficial fascia medial to the small saphenous vein avoids injury to what structure that line just lateral and adjacent to the small saphenous vein ? a. Popliteal vein b. Popliteal artery c. Tibial nerve d. Common peroneal nerve e. Medial sural cutaneous nerve

Answer 96

Answer : e. Medial sural cutaneous nerve Posterior approach by Burks and Schaffer Burks and Schaffer * With the patient prone, make a gently curved incision, with a horizontal limb near the flexion crease of the knee and a vertical limb overlying the medial aspect of the gastrocnemius muscle. * Carry the dissection to the deep fascial layer and incise it vertically over the medial head of the gastrocnemius. * Protect the medial sural cutaneous nerve (posterior cutaneous nerve of the calf), which usually perforates the deep fascia distal to the horizontal limb of the incision. * Identify the medial border of the medial gastrocnemius and bluntly develop the interval between it and the semimembranosus tendon, exposing the posterior joint capsule. The middle geniculate artery may be encountered near the midposterior capsule and can be ligated if necessary. By lateral retraction on the medial head of the gastrocnemius, no tension is directly applied to the motor branch to the medial head of the gastrocnemius, the only motor branch from the tibial nerve in the popliteal fossa that traverses medially. The thick muscle belly protects the neurovascular structures as the capsule is exposed. Dissection on this protected medial side of the popliteal fossa is therefore relatively safe. * Expose the posterior aspect of the proximal tibia and posterior margins of the femoral condyle. * If further lateral exposure is necessary, release a portion of the tendinous origin of the medial head of the gastrocnemius from the distal femur and joint capsule. Slight knee flexion will aid exposure, and complete sectioning of the medial head of the gastrocnemius rarely is needed. * Make a vertical incision through the posterior capsule to expose the contents of the posterior intercondylar notch and the tibial attachment of the posterior cruciate ligament. * Proceed as described by Berg * Suture the capsular incision, allow the gastrocnemius to settle into position, approximate the subcutaneous layers, and close the skin in a routine fashion.

Question 97

44. Patient with hip disease may report knee pain, which is primarily caused by irritation of which of the following branches of the obturator nerve ? a. Cutaneous continuation of the brach on the gracilis muscle b. Continuation of the branch to the adductor magnus c. Accessory obturator nerve branch d. Branch within the sartorius muscle e. Branch within the linea aspera

Answer 97

Answer: b. Continuation of the branch to the adductor magnus The branch of the obturator nerve to the knee is the continuation of the motor branch to the adductor magnus. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 144

Question 98

43. Following harvesting of patellar tendon autograft, paresthesia most commonly occurs in which of the following location ? a. Medial to incision b. Lateral to incision c. First web space of the foot d. Medial foot e. Dorsal foot

Answer 98

Answer : b. lateral to incision The infrapatellar branch of the saphenous nerve often crosses over the anterior aspect of the knee and innervates the skin lateral to the anterior midline of the knee. An anterior midline incision, often result in incision of the terminal branches, resulting in lateral numbness. The superficial peroneal, deep peroneal, and saphenous nerve provide sensation to the foot are not at risk. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 144.

Question 99

42. Which fiber of the anterior cruciate ligament are thight in flexion ? a. Anteromedial b. Anterolateral c. Posteromedial d. Posterolateral e. Middle

Answer 99

Answer : a. anteromedial There are 2 bundles of anterior cruciate ligaments (ACL). The anteromedial bundle and posterolateral. The anteromedial tight in flexion, while in extension both bundle are tensioned. Reference : AAOS Comprehensive Orthopedic System Review. 2009. P 143

Question 100

46. Which of the following tendons are topically harvested when performing anterior cruciate ligament reconstruction with double loop hamstring autograft? a. Semitendinosus and semimembranosus b. Sartorius and semitendinosus c. Gracilis and semimembranosus d. Gracilis and semitendinosus e. Biceps and semimembranosus

Answer 100

Answer : d. Gracilis and semitendinosus ## Footnote Because of the availability of long tendons and the minimal donor morbidity associated with the gracilis and semitendinosus tendons, they are currently considered the structures of choice for hamstring tendon autograft ACL reconstruction by most authors. The gracilis and semitendinosus are beneath and behind the sartorius (not a hamstring) at the tibial insertion of pes anserinus. They have long tendon and relatively small muscle bellies of vestigial muscles (in contrasts to the biceps and semimembranosus). With approximately 20 cm of tendon typically available, this allows the double loop technique to provide graft of sufficient strength. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 145.

Question 101

47. What tendon has an intra articular (intrasynovial) location in the knee joint ? a. Patellar b. Popliteal c. Semitendinosus d. Semimembranosus e. Biceps femoris

Answer 101

Answer : b. Popliteal The popliteal tendon arises from the posterior aspect of the tibia and courses through the knee joint through the popliteus hiatus of the lateral meniscus before attaching on the lateral femur, anterior to the lateral collateral ligament. It is the only tendon in knee joint that can be viewed directly on arthroscopy. Reference: AAOS Comprehensive Orthopedic Review. 2009. Pg 146.

Question 102

48. What is the most anatomic location for placement of the femoral tunnel anterior cruciate ligament reconstruction ? a. As far superior in the notch as possible b. As far posterior as possible on the lateral femoral condyle c. As far posterior as possible on the medial femoral condyle d. Directly across from the posterior cruciate femoral insertion e. At resident’s ridge

Answer 102

Answer: b. As far posterior as possible on the lateral femoral condyle ## Footnote It is critical for graft isometry and knee stability that the femoral tunnel be placed as far as posterior as possible on the lateral femoral condyle. Superiorly, the graft should be at the 1 o’clock position at the left knee. Resident’s ridge is a false posterior shelf that often seems like the extreme posterior cortex. Abnormal tunnel placement result in variety of complication, including an unstable knee, early graft failure, and joint stiffness. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 146.

Question 103

49. What neurovascular structure is most at risk when performing an inside out repair of the posterior horn of the medial meniscus ? a. Popliteal artery b. Peroneal nerve c. Saphenous nerve d. Tibial nerve e. Sciatic nerve

Answer 103

Answer: c. Saphenous nerve The saphenous nerve is located on the postero medial aspect of the knee, and must be protected when performing an inside out repair of the medial meniscus. The peroneal nerve is most at risk with lateral meniscus repairs. The other structures are usually are not at rick during meniscal repairs. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 147.

Question 104

50. A patient with no history of patellar instability sustains a traumatic lateral patellar dislocation. What structure most likely has been torn ? a. Vastus medialis obliquus b. Medial patellofemoral ligament c. Medial patellotibial ligament d. Medial retinaculum e. Quadriceps tendon

Answer 104

Answer: b. Medial patellofemoral ligament Any of the above structures may be involve in a lateral patellar dislocation. However, biomechanic studies have found that the medial patellofemoral ligament is the major soft tissue static restraint of lateral patellar displacement, providing at leqast 50% of this function Reference: AAOS Comprehensive Orthopedic Review. 2009. Pg 148.

Question 105

51. A 17 year old high scholl long distance runner is seeking advice before running a amarathon for the first time. What advice should be given regarding his fluid, carbohydrate, and electrolyte intake around the time of the race a. Restrict fluid intake 2 hours before the start of the race to avoid abdominal cramping b. Drink low osmolality (less than 10% solutions before, during, and after race) c. Drink fruit juice, such as orange juice, instead of water to replenish essential carbohydrates d. Drink high osmolality (greater than 10%) solutions before and during the race and low osmolality solutions after the race e. Avoid the use of glucose polymers because they slow down gastric emptying and may lead to abdominal cramping

Answer 105

Answer: b. Drink low osmolality (less than 10% solutions before, during, and after race) ## Footnote The goal of fluid replacement should be replace the sweat that has been lost. Sweat is mostly water, with a small concentration of salts and other electrolytes. Absorption is enhanced by solution of low osmolality. Scientific research has also shown that adding carbohydrates to the drink improves athletic performances. Carbohydrates such as glucose and maltodextrins (glucose polymers) stimulate fluid absorption by the intestines. Fructose slow intestinal absorption of fluids. Drinks that are high in fructose, such as orange juice, can lead to gastrointestinal distress and osmotic diarrhea. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 149.

Question 106

52. What artery is the primary blood supply to the humeral head ? a. Thoracoacromial b. Posterior humeral circumflex c. Anterior humeral circumflex d. Suprascapular e. Suprahumeral

Answer 106

Answer : c. Anterior humeral circumflex * The major blood supply is from the anterior and posterior humeral circumflex arteries. * The arcuate artery is a continuation of the ascending branch of the anterior humeral circumflex. It enters the bicipital groove and supplies most of the humeral head. Small contributions to the humeral head blood supply arise from the posterior humeral circumflex, reaching the humeral head via tendo-osseous anastomoses through the rotator cuff. Fractures of the anatomic neck are uncommon, but they have a poor prognosis because of the precarious vascular supply to the humeral head.

Question 107

53. A 25 year old man has a midshaft femoral fracture with 25% comminution and is undergoing closed intramedullary nailing. Proximal locking is performed uneventfully; however, during distal locking screw insertion, only one of the screws is noted to have bone purchase. Which of the following proceure is the best solution to this problem? a. Leave only one distal screw; this will provide adequate fixation b. Exchange the nail for one either longer or shorter, and relock at a new level c. Insert a screw through the hole either anterior or posterior to the intramedullary nail locking hole d. Insert a small diameter threaded pin at a different angle through the locking hole

Answer 107

Answer: a. Leave only one distal screw; this will provide adequate fixation For the majority of femoral diaphyseal fractures above the distal third, one distal locking screw is sufficient. Fractures located in the distal third, will often require the additional of a second locking screw. Reference : AAOS Comprehensive Orthopedic Review. 2009. Pg 174.

Question 108

54. Which of the following organism is most commonly isolated in acute necrotizing fasciitis? a. Group A streptoccus b. Group D streptococcus c. Pseudomonas aeruginosa d. Staphylococcus aureus e. Clostridium difficile

Answer 108

Answer: a. Group A streptoccus Many cases of acute necrotizing fasciitis involve a synergy of several organisms. The most commonly isolated organism, singly or in combination, is group A streptococcus. Reference : AAOS Comprehensive Orthoepdic review. 2009. Pg 175.

Question 109

55. What is the main disadvantage of using antibiotic impregnated polymethylmethacrylate beads to threat infected or contaminated wounds ? a. Local toxicity b. Systemic toxicity c. Inadequate antibiotic solution d. Foreign body reaction e. Allergic reaction

Answer 109

Answer: d. Foreign body reaction. ## Footnote Reference :Miller’s Review of Orthopedics. 5th ed. 2008. Elsevier inc. Antibiotic beads or spacers—PMMA impregnated with antibiotics (usually an aminoglycoside); useful when treating infected TJA or osteomyelitis with bony defects. Antibiotic powder is mixed with cement powder; the antibiotic used is guided by the microorganism, and dosage depends on the selected antibiotic and type of PMMA. Antibiotics that have been used with PMMA for infection are tobramycin, gentamicin, cefazolin and other cephalosporins, oxacillin, cloxacillin, methicillin, lincomycin, clindamycin, colistin, fucidin, neomycin, kanamycin, and ampicillin. Chloramphenicol and tetracycline appear to be inactivated during polymerization. Antibiotics elute from PMMA beads, with an exponential decline over a 2-week period, and cease to be present locally in significant levels by 6-8 weeks. Much higher local tissue concentrations of antibiotic can be achieved than those obtained by systemic administration but do not seem to cause problems in the doses typically used. (Extremely high local concentrations of antibiotics can decrease cellular replication or even result in cell death.) Increased surface area of PMMA (e.g., with oval beads) enhances antibiotic elution. Beads are inserted only after thorough débridement.Because PMMA may cause a foreign body reaction, the beads should always be removed. Antibiotic powder in doses of 2 g/40 g of powdered PMMA (simplex P) does not appreciably affect the compressive strength of PMMA. Much higher concentrations (4-5 g antibiotic powder/40 g PMMA) significantly reduce the compressive strength (important in cemented joint arthroplasties). Antibiotic-impregnated cement spacers help prevent soft tissue contracture after removing an infected TKA.

Question 110

56. Which of the following preoperative findings correlates best with results after operative fixation of the calcaneus ? a. Displacement of the sustentaculum tali b. Displacement of the lateral wall c. Number of major fragments of the posterior facet d. Diminution of Bohler’s angle e. Amount of heel varus

Answer 110

Answer: c. Number of major fragments of the posterior facet Satisfactory result correlate with fewer fragments of posterior facet. Two part fractures has a good outcome, whereas four-part fractures tend to do poorly. Varus and lateral wall displacement that occur postoperatively predict a poor result, but the presence of these findings preoperatively is common and indicate a need for surgery. Reference: AAOS Comprehensive Orthopedic Review. 2009. Pg 177.

Question 111

267. Ivory osteomata occur most often in the: a. Skull b. Spine c. Humerus d. Femur e. Tibia

Answer 111

Answer: a. skull **Introduction and Definition:** Osteoma is a benign bony outgrowth of membranous bones. They are found mostly on skull and facial bones. Incidence and Demographics: Large osteomas may develop on the clavicle, pelvis, and tubular bones (parosteal osteomas). Soft tissue osteomas may occur in the head, eye,and tongue,or in the extremities. The highest incidence is in the sixth decade. Some authors report that osteomas occur more often in women than men (3:1). Multiple osteomas are associated with Gardner's syndrome. The etiology of osteomas is unclear. They may be related to osteoblastomas or may simply be a developmental anomaly. The fact they are often found in the auditory canals of swimmers and divers who frequent cold water suggests that in some cases they are some type of inflammatory reaction. **Symptoms and Presentation:** Osteomas are slow growing lesions that are normally completely asymptomatic. They only present if their location within the head and neck region is causing problems with breathing, vision, or hearing. **X-Ray Appearance and Advanced Imaging Findings:** The radiological appearance of osteomas depends on their location. Central osteomas are well delineated sclerotic lesions with smooth borders, without surface irregularities or satellite lesions. Dr. Enneking describes the lesion as having the appearance of "one-half of a billiard ball" attached to the underlying bone. The adjacent cortex is not involved or weakened. Peripheral osteomas are radiopaque lesions with expansive borders that may be sessile or pedunculated. Osteomas need to be differentiated from enostosis which also appear as densely sclerotic well-defined lesions on x-ray. Bone scan will show increased uptake during the active phase of growth, which will diminish to background levels as the lesion becomes progressively less active. **Histopathology findings:** There are two types of osteomas microscopically. Compact or "ivory" osteomas are made of mature lamellar bone. They have no Haversian canals and no fibrous component. Trabecular osteomas are composed of cancellous trabecular bone with marrow surrounded by a cortical bone margin. Trabecular osteomas can be found centrally (endosteal) or peripherally (subperiosteal). **Treatment options for this tumor:** Treatment of osteomas is only necessary if they are symptomatic. Large osteomas should be evaluated to rule out other diagnoses. **Suggested Reading and Reference:** Bulloughs, Peter, Orthopaedic Pathologv (third edition), Times Mirror International Publishers Limited, London, 1997. Huvos, Andrew, Bone Tumors: Diagnosis, Treatment and Prognosis, W.B.Saunders, Co., 1991. Some text adapted from Dr. Enneking's site.

Question 112

259. Which one of the following statements is untrue concerning chondrosarcoma: a. Occurs most often between the ages 20 and 60 yrs b. Is always a primary malignant tumor of bone c. Most commonly affects scapula, pelvis, ribs & sternum d. Causes bone expansion and destruction with irregular opacities in the X-ray e. Is radioresistant

Answer 112

Answer: b. Is always a primary malignant tumor of bone CHONDROSARCOMA • Primary malignant tumour whose cells produce cartilage matrix • May arise de novo or secondarily to existing benign cartilaginous tumour (majority) Incidence • 17% of primary malignant bone tumours • Peak incidence 30-60 yrs • M:F 2:1 • Sites • Pelvis 30% • Femur 20% • Femoral head 10% • Ribs 10% Clinical • Most common malignant tumour of hands & face in middle aged patients • Usually occurs in metaphysis or diaphysis • Presents with constant ache or increased size of pre-existing lump • Metastatic deposits infrequent & usually go to lung X-rays • Variable appearance with 60-70% have calcification & 50% have subperiosteal new bone • May be a large cystic lesion with cortical destruction & central calcification, endosteal scalloping & cortical expansion. Popcorn lesions (rings, arcs, stipples) Chondrosarcoma can also be classified as Intramedullary, which generally arise from enchondroma • Patients with Ollier's disease (multiple enchondromatosis) or Maffucci's syndrome (multiple enchondromas & hemangiomas) are at much higher risk of chondrosarcoma than normal population Surface, which arise from osteochondroma • Malignant change in osteochondroma: increased size, fuzzy outline, cartilage cap \>1 cm thick, base \>6 cm diameter Pathology Cellular pleomorphism & increased cellularity with focally calcified matrix X-ray & CT of a chondrosarcoma involving the right hemipelvis & sacrum. Treatment * These tumours tend to metastasise late therefore attempt wide local excision initially * However, relatively resistant to chemotherapy & radiotherapy * Chemotherapy for occasional grade 3 dedifferentiated tumors * Radiotherapy useful for Rx of surgically inaccessible sites Prognosis Dependant on grade * \>90% grade 1 or 2 * Low grade - 65-85% 5-yr survival * High grade - 15-25% 5-yr survival

Question 113

258. The following statements about bone sarcoma are true except that it: a. Arises from osteoblasts of the periosteum or bone cortex b. Forms a fusiform mass ensheathing the bone c. Often invades the epiphyseal cartilage and neighbouring joint d. Produces characteristic new bone formation in the X-ray e. Disseminates rapidly by the blood stream

Answer 113

Answer: a. Arises from osteoblasts of the periosteum or bone cortex ## Footnote Sarcomas—These are malignant neoplasms of connective tissue (mesenchymal) origin. Sarcomas generally exhibit rapid growth in a centripetal fashion and invade adjacent normal tissues. Each year in the United States there are about 2800 new bone sarcomas. High-grade, malignant bone tumors tend to destroy the overlying cortex and spread into the soft tissues. Low-grade tumors are generally contained within the cortex or the surrounding periosteal rim. Bone sarcomas metastasize primarily via the hematogenous route, with the lungs being the most common site. Refrerence : Miller’e Review of Orthopedics. 5th ed. 2008 Ch 9.

Question 114

253. Which of the following is most common in the small bones of the hands and feet: a. Osteochondroma b. Enchondroma c. Osteoid osteoma d. Osteochondritis juvinelis e. Tuberculous osteitis

Answer 114

Answer: b. Enchondroma ## Footnote Enchondroma—The most common benign bone tumor of the upper extremity. It typically occurs in the second to fourth decades, and most cases are asymptomatic and discovered incidentally. The tumor arises from the metaphyseal medullary canal and spreads to the diaphysis. It is usually seen in the proximal phalanx and metacarpal. Enchondroma causes symmetrical fusiform expansion of bone, with endosteal scalloping and intramedullary calcifications. It may present as a pathologic fracture. Histologically, enchondroma of the hand is characterized by benign cartilage of high cellularity. If mitotic figures are present, low-grade chondrosarcoma should be suspected. The recommended treatment is with curettage and bone grafting. Excision, intramedullary internal fixation, and bone cementing have also been successful in a small series. Reference : Miller’s Review of Orthopedic. 5th ed. 2008. Ch 7.

Question 115

First treatment priority in patient with multiple injuries is: a. Airway maintenance b. Bleeding control c. Circulatory volume restoration d. Splinting of fractures e. Reduction of dislocation.

Answer 115

Answer: a. Airway maintenance A.B.C. (Airway, bleeding and circulation) are the priorities in management of seriously injured patient in that order

Question 116

A patient who has sustained open wound on leg is bleeding profusely. Before patient arrives in hospital the safest method to stop bleeding is: a. Elevation of leg b. Local pressure on wound and elevation of leg c. Ligation of bleeding vessel d. Use of tourniquet e. Pressure over femoral artery in groin.

Answer 116

Answer: b. Local pressure on wound and elevation of leg Local pressure on wound and elevation of leg is the safest and most effective method to stop bleeding. Tourniquet can be dangerous if not properly used. Elevation alone and local pressure on femoral artery is ineffective.

Question 117

Commonest cause of deformity in a long bone is: a. Osteoporosis b. Rickets c. Paget's disease d. Malunited fracture e. Fibrous dysplasia.

Answer 117

Answer: d. Malunited fracture Malunited fractures are the commonest cause of deformity in long bones since the incidence of fracture is much higher than congenital, developmental, metabolic, infective and neoplastic conditions.

Question 118

What is the second most important aspect in the treatment of fractures of long bones: a. Adequate nutrition of patient b. Accurate anatomical reduction c. Immobilization d. Restoration of bone alignment e. Antibiotics.

Answer 118

Answer: c. Immobilization First and foremost requisite to ensure healing of long bone fractures to restore function is the reduction of bone fragments into good alignment so that malunion does not occur. Accurate anatomical reduction is not necessary. Second important aspect is immobilization of the fracture.

Question 119

Which of the following is an absolute contraindicatiou of open reduction: a. Active infection b. Small sized fragment c. Very soft bone d. General medical complications e. Severe scarring of adjacent soft tissues.

Answer 119

Answer: a. Active infection Active infection is a contraindication for open reduction as this may lead to further complications and even more difficulty in salvage. In other conditions mentioned open reduction can produce problem and should not be lightly undertaken.

Question 120

Commonest cause of failure of internal fixation is: a. Infection b. Corrosion c. Metal reaction d. Immune deficient patient e. Stress fracture of implant.

Answer 120

Answer: a. Infection Most common and serious disadvantage of open reduction and internal fixation is infection which will ultimately lead to implant becoming loose and non union. Immune deficient patient does not behave differently as regards fracture healing. Corrosion, metal reaction and stress fracture of implant are rare.

Question 121

Which of the following fracture does not usually need open reduction and internal fixation: a. Mid shaft fracture of femur b. Pathological fractures c. Trochanteric fracture in elderly d. Displaced intra articular fractures e. Displaced fracture of both bones of forearm in adults.

Answer 121

Answer: a. Mid shaft fracture of femur Out of the fractures mentioned, femoral shaft fracture is least likely to need operative treatment. In this fracture operation is done to get patient out of traction early. All other fractures mentioned will almost always need open reduction and internal fixation

Question 122

8 Which of the following is the best way to preserve amputated part for replantation: a. Immersion in cold saline b. Immersion in cold ringer lactate c. Immersion in cold antibiotic solution d. Dry cooling with ice e. Deep freezing.

Answer 122

Answer: d. Dry cooling with ice Dry cooling with ice is the best way to preserve amputated part as this causes least alteration of tissue structures

Question 123

Death 3 days after pelvic fracture is most likely to he due to: a. Haemorrhage b. Pulmonary embolism c. Fat embolism d. Respiratory distress e. Infection.

Answer 123

Answer: c. Fat embolism Within first few hours after severe injuries death may occur due to hypovolaemia from haemorrhage and within 3 days from fat embolism. Pulmonary embolism usually occurs at about 3 weeks from injury. Respiratory distress is a part of fat embolism syndrome.

Question 124

Myositis ossificans is most commonly seen at: a. Hip b. Knee c. Shoulder d. Elbow e. Ankle

Answer 124

Answer: d. elbow Myositis ossificans can occur at any place following injury, vigorous massage or operative intervention, but is most common around the elbow joint

Question 125

Hyperbaric Oxygen is not used for which of following conditions in usual clinical practice: a. Gas gangrene b. Carbon monoxide poisoning c. Arterial gas embolism d. Decompression sickness e. Chronic osteomyelitis

Answer 125

Answer: e. Chronic osteomyelitis Hyperbaric Oxygen is not generally used in chronic osteomyelitis, although in experimental situations it has been shown to be effective by enhancing action of phagocytes, potentiating immune response and promoting both bone and soft tissue healing. HBO therapy allows patients to breathe 100% oxygen in a chamber under conditions of increased barometric pressure. It was first used in the late 1800s to treat caisson workers injured with decompression sickness (the “bends”) during construction of the Hudson River tunnel in NewYork. Subsequently the military used it to treat the bends and air gas emboli. Beginning in the 1960s, animal experimentation and clinical case reports indicated applications for HBO therapy in the management of both severe anemia and gas gangrene. **Most clinical hyperbaric medicine is practiced at 2 to 3 ATA**—that is, 1 or 2 atmospheres greater than ambient pressure. Each atmosphere is considered to be 760mmHg; thus, a patient receiving 100% oxygen at 3 ATA is exposed to a pO2 of 2,280mmHg (ie, 3 × 760mmHg). **Indication :**  Air or gas embolism  Carbon monoxide poisoning  Clostridial myositis and myonecrosis (gas gangrene)  Crush injury, compartment syndrome, or acute traumatic peripheral ischemia  Decompression sickness  Enhancement of healing in select problem wounds  Exceptional blood loss anemia  Intracranial abscess  Necrotizing soft-tissue infections  Osteomyelitis (refractory)  Delayed radiation injury (soft-tissue and bony necrosis)  Skin flaps and grafts (compromised)  Thermal burns Reference : Greensmith JE. Perspectives in Modern Orthopedic: Hyperbaric Oxygen Therapy in Extremity Trauma. J Am Acad Orthop Surg 2004;12:376-384

Question 126

Which of the following fracture is slowest to heal and often develops non union: a. Intracapsular femoral neck fracture b. Scaphoid c. Lower third of tibia d. Proximal humerus e. Distal femur.

Answer 126

Answer: a. Intracapsular femoral neck fracture Intracapsular femoral neck fractures are slowest to heal and develop non union in higher percentage of cases compared to scaphoid and distal tibial fractures, both of which also tend to heal slowly due to deficient blood supply of one fragment. Proximal humerus and distal femoral fractures do not usually go to delayed union.

Question 127

Which of the following is commonest cause of deformity in long bones: a. Bone dysplasias b. Metabolic disorders c. Bone tumours d. Infections e. Malunited fracture.

Answer 127

Answer: e. malunited fracture While all the conditions produce deformity of bone malunited fracture is statistically most important cause of bony deformity.

Question 128

15 Which of the following is most common cause of Volkmann's ischaemic contracture: a. Fracture of humeral shaft b. Dislocation of elbow c. Supracondylar fracture of humerus d. Brachial artery injury e. Tight bandage and plaster

Answer 128

Answer: e. Tight bandage and plaster Commonest cause of Volkmann's contracture is injudiciously applied tight plaster and bandages following injury, which result in compromise of circulation. This is followed in frequency by supracondylar fracture of humerus, dislocation of elbow and brachial artery injury. Fracture of humeral shaft does not usually produce this complication

Question 129

16 Development of gas gangrene can be prevented by: a. Prophylactic immunization b. Administration of intravenous antibiotics c. Proper debridement of wound d. Administration of hyperbaric oxygen e. Amputation.

Answer 129

Answer: c. Proper debridement of wound The only prophylaxis against development of gas gangrene is early and thorough debridment of open wounds, and wound should be left open. A wound left open after adequate debridment rarely develops gas gangrene. Immunization is of no value and all other methods of treatment are used when gas gangrene is developing or has developed.

Question 130

17 Commonest cause of failure of internal fixation of fracture is: a. Infection b. Fatigue fracture of implant c. Corrosion in implant d. Loosening of implant e. Metal reaction.

Answer 130

Answer: a. infection Infection following an open operation is the commonest cause of failure following internal fixation. All other factors can also lead to complications but. statistically they are not as important

Question 131

Most serious disadvantage of open reduction of fracture is: a. Delayed union b. Non union c. Infection d. Joint stiffness e. Cosmetic deformity.

Answer 131

Answer: c. Infection Introduction of infection in a closed fracture is most serious disadvantage of open reduction. Badly placed incisions produce cosmetic deformity. Excessive and injudicious stripping of soft tissues during operation can impair vascularity of bone and lead to delayed or non union. Scarring of muscles can lead to joint stiffness

Question 132

19 Which is commonest occasion in orthopaedic practice for use of bone grafts: a. Fresh fractures b. Non union c. For arthrodesis d. To bridge bone gap e. To fill cavities after curettage of tumours.

Answer 132

Answer: b. Non union Statistically non union is the commonest indication for use of bone grafts.

Question 133

20 Chemically Plaster of Paris is: a. Calcium carbonate b. Calcium phosphate c. Calcium sulphate d. Anhydrous calcium sulphate e. Hemihydrated calcium sulphate.

Answer 133

Answer: e. Hemihydrated calcium sulphate. Powder of plaster of Paris chemically is hemihydrated calcium sulphate : CaSO4. ½ H2O

Question 134

21 Most often open reduction of fracture is required in: a. Closed fracture with nerve injury b. Compound fracture c. Fracture in children d. Unsatisfactory closed reduction e. Non union.

Answer 134

Answer: d. Unsatisfactory closed reduction Unsatisfactory closed reduction is the commonest reason for performing open reduction. Next commonest reason for this is non union. Fractures in children rarely require open reduction. Compound fractures and fractures associated with nerve injury are also uncommon reasons

Question 135

22 In internal fixation of fracture, compression plating gives following advantages: a. Easier reduction as the exposure is longer b. It is simpler to use c. Provides more rigid fixation d. Induces osteogensis e. Increases vascular proliferation.

Answer 135

Answer: c. Provides more rigid fixation Only advantage of a compression plate fixation is more rigid fixation of fracture. Compression plating is neither simpler nor easier. Plate fixation has no influence on vascular proliferation or rate of osteogensis

Question 136

23 What is fracture disease: a. Non union b. Infection c. Joint stiffness d. Vascular damage e. Neurological damage.

Answer 136

Answer: c. Joint stiffness Joint stiffness and contractures along with poor muscle tone leading to functional impairment even after the fracture has united is termed fracture disease. This can be avoided by continuing physiotherapy while fracture is uniting.

Question 137

Concerning intra articular fractures at knee which of the following statement is true: a. Early knee mobilization is inadvisable b. Intercondylar fracture of femur quite often leads to avascular necrosis c. Non union of tibial condyle fracture is common d. Extraarticular adhesions play no role in producing joint stiffness e. Displaced intra articular fractures usually need open reduction

Answer 137

Answer: e. Displaced intra articular fractures usually need open reduction Joint congruity should be restored by accurate reduction of displaced intraarticular fractures, and early movements thereafter is the best course to regain joint mobility. Tibial and femoral condyle fractures occur in area of abundant cancellous bone where non union is extremely rare, and so is the incidence of avascular necrosis.

Question 138

25 Which of the following is not an absolute indication of open reduction: a. Non union b. Displaced intra articular fractures c. Fractures irreducible by manipulation d. Fractures associated with vascular injury e. Early mobilization.

Answer 138

Answer: e. Early mobilization Absolute indication : * Non union * Displaced intraarticular fractures * Fractures inreducible by manipulation * Fractures associated with vascular injury Relative indication : * Early mobilization * Improve nursing care in multiple injury patient * Tto reduce morbidity from prolonged immobilization * Delayed union

Question 139

26 A bone graft from same species and of identical histocompatibility of antigens is called a. Homograft b. Heterograft c. Allograft d. Isograft e. Autograft

Answer 139

Answer: d. Isograft When donor and receipient are same individual, graft is called autograft. When donor and receipient are of same species but not having compatible antigens, graft is called homograft. In same species between donor and receipient but not have identical histocompatibility of antigens, graft is called allograft. In same species when donor and receipient have histocompatibility of antigens graft is called isograft.

Question 140

27 What is the commonest cause of non union: a. Pathological fracture b. Inadequate immobilization c. Soft tissue interposition d. Infection e. Distraction at fracture site.

Answer 140

Answer: b. Inadequate immobilization Commonest cause of non union is inadequate, immobilization as repeated movements retard or even stop the process of fracture healing. All other factors mentioned also lead to non union but statistically their incidence is not so much.

Question 141

28 A prototype of external fixator was first devised by: a. Charnley b. Anderson c. Hoffman d. Muller e. Malgaigne

Answer 141

Answer: e. Malgaigne In 1853 Malgaigne devised a claw like device to compress fragments of fractured patella. Charnley and Anderson used the fixator for limited indications and laid down scientific principles. Hoffman and Muller are credited with making it versatile and popularizing this method

Question 142

29 In few days old fracture which of the following does not occur: a. Capillary proliferation b. Proliferation of osteogenic cells over endosteum and bone ends c. Local pH is acid d. Local pH is alkaline e. There is very little rise in level of alkaline phosphatase at fracture site.

Answer 142

Answer: d. Local pH is alkaline Upto a week after fracture local pH remains acidic and only after this period pH becomes alkaline and level of alkaline phosphatase markedly rises. All other statements are true.

Question 143

30 Modified Phemister bone grafting technique is: a. Extraperiosteal placement of bone grafts b. Subperiosteal placement of bone grafts c. Intramedullary placement of bone grafts d. Placing the grafts under osteo periosteal flap e. Patelling and placement of cancellous bone grafts under osteo¬periosteal flap.

Answer 143

Answer: e. Patelling and placement of cancellous bone grafts under osteo¬periosteal flap. Modified Phemister bone grafting includes both patelling of bone ends and placement of cancellous grafts under osteoperiosteal flap. Periosteum is not elevated separtely and neither is the central area of non union disturbed. Original Phemister technique was to place the grafts under periosteal flap only

Question 144

31 Last stage in fracture healing is a. Organisation of blood clot b. Vascular proliferation c. Osteoblastic proliferation d. Provisional calcification e. Remodelling of Haversian system.

Answer 144

Answer: e. Remodelling of Haversian system Remodelling of Haversian system is the last stage in fracture healing and it orientates bone formation along lines of normal stress. The process takes many months for completion.

Question 145

32 Fracture disease can he prevented by: a. Plaster immobilization of fracture b. Cast brace treatment of fracture c. Internal fixation of fracture d. External fixation of fracture e. Physiotherapy

Answer 145

Answer: e. Physiotherapy Fracture disease in some measure always occurs and none of the methods of treatment of fracture can prevent it. It can only be minimised by regular physiotherapy to reduce oedema, improve muscle tone and maintain functional movements in joints which have not been immobilized.

Question 146

33 In a healing fracture amount of cartilage formation is increased by: a. Rigid immobilization b. Movement at fracture site c. Necrosis of bone ends d. Compression plating e. Infection.

Answer 146

Answer: b. Movement at fracture site More the movement at fracture site, more will be cartilage formation and non union can occur. Compression plating helps in conversion of cartilage into bone and thereby fracture healing can occur in a delayed or non union. Infection retards all the stages of fracture repair.

Question 147

34 Cast syndrome is commonest after: a. Scoliosis surgery b. Hip surgery c. Spinal jacket application d. Hip spica application e. Halo traction

Answer 147

Answer: a. scoliosis surgery More than 50% cases of cast syndrome occur in scoliosis and spinal deformity correction, and majority of others occur in patients being treated for trauma to spine and hip. It is also seen after application of body jacket, shoulder and hip spica, the common denominator being extensive coverage of abdomen and chest.

Question 148

35 In cases of leg fractures, above knee plaster is applied, with knee slightly flexed for which of the following reason: a. To avoid stretching posterior capsule of knee joint b. To keep the cruciate ligaments relaxed c. To allow easier ambulation d. To prevent rotational movements being transmitted to the fracture site e. Plaster application is easier with knee slightly flexed.

Answer 148

Answer: d. To prevent rotational movements being transmitted to the fracture site In Complete extension knee locks and femur and tibia rotate as one, transmitting rotational stress to fracture site which will delay union. Therefore, knee is kept slightly flexed so that femoral rotation at hip can occur without movement being transmitted to proximal fragment of leg fracture.

Question 149

36 Which deformity in malunited fracture is most likely to correct with remodelling: a. Angular deformity in the middle of diaphysis in the plane of motion of nearby joint b. Angular deformity in plane of motion of nearby joint when deformity is in metaphyseal area c. Rotational malalignment d. Angular deformity near end of bone when angulation is in a plane 900 to the plane of motion of nearby joint. e. Shortening of bone length.

Answer 149

Answer: b. Angular deformity in plane of motion of nearby joint when deformity is in metaphyseal area Angular deformity in the plane of motion of nearby joint has maximum potential for remodelling. Remodelling is still better if deformity is near the end of bone. The process is rapid in growing children and slows down as the adulthood is reached. Rotational malalignment never corrects. Shortening of bone length, will to some extent correct in a growing child since the fracture induces little overgrowth in a long bone.

Question 150

37 In interfragmentary fixation screw works by producing: a. Compression b. Distraction c. Antiglide mechanism d. Increased shear e. None of above.

Answer 150

Answer: a. Compression Screw works by converting torsional stress (used during its insertion) into compressive force and this keeps fracture surfaces in close apposition. This is the basic mechanism on which screw works

Question 151

39 What is most important aspect of the treatment of crush syndrome involving an extremity: a. Amputation b. Fluid and electrolyte balance c. Dialysis d. Antibiotics e. Hyberbaric oxygen

Answer 151

Answer: b. amputation Amputation proximal to the level of injury is the most important aspect of treatment. At the same time maintenance of fluid balance is also important. Dialysis may be required. Antibiotics really are of prophylactic value. Hyperbaric oxygen has no role.

Question 152

40 Claw hand deformity of hand in Volkmann's ischaemic contracture is due to involvement of. a. Skin b. Fascia c. Nerves d. Muscles e. Tendons

Answer 152

Answer: d. Muscles Volkmann's ischaemia affects muscles and it is their fibrosis area contracture which produces the deformity of fingers.

Question 153

41 Which of the following is the earliest laboratory finding in a case of fat embolism: a. Increased serum cholestrol b. Increased serum lipase c. Increased serum fatty acids d. Lipouria e. Increased alkaline phosphatase.

Answer 153

Answer: d. Lipouria Presence of fat droplet in urine is the earliest laboratory finding in fat embolism. But it must be remembered that the diagnosis is mainly clinical and one should not wait for any investigations before instituting treatment

Question 154

42 Basic treatment of most non unions is: a. Compression plating b. Continuation of external splintage c. Electrical stimulation d. Bone grafting e. Phemister grafting.

Answer 154

Answer: d. Bone grafting In an established non union freshening of bone ends and bone grafting is the usual treatment. Electrical stimulation and compression plating is indicated in certain limited cases only. Phernister grafting is one method of bone grafting in cases where bone fragments are in good alignment

Question 155

43 External fixator is not indicated in: a. Comminuted fracture b. Fracture associated with severe soft tissue damage c. Infected fractures d. Simple closed fracture of humeral shaft e. Fracture associated with bums.

Answer 155

Answer: d. Simple closed fracture of humeral shaft Use of external fixator is contraindicated in an uncomplicated fracture. It is an indispensable method of treatment of fracture in association with infection, burn and severe soft tissue damage requiring repeated dressing and skin grafting. External fixator is also used extensively for purpose of limb lengthening.

Question 156

44 What is pathogenesis of cast syndrome: a. Recumbancy b. Psychological c. Constriction of stomach d. Intestinal obstruction e. Obstruction of duodenum

Answer 156

Answer: e. Obstruction of duodenum Cast syndrome, clinically known as superior mesenteric artery syndrome (SMAS), is gastric dilatation with partial or complete obstruction of the duodenum. Although rare, it is most frequently seen in orthopaedic patients who have had spinal surgery or who are in hip spica or body casts. Obstruction occurs when there is compression of the duodenum between the superior mesenteric artery anteriorly and the aorta and spinal column posteriorly. Obstruction can occur within days of surgery or casting or may not develop for several weeks. Treatment for SMAS varies from conservative nonoperative to operative procedures. Complications can be severe if symptoms are not quickly recognized and treatment instituted in a timely manner Reference : Sprague J. Cast Syndrome: Superior Mesenteric Artery Syndrome. Orthop Nurs. 1998 Jul-Aug;17(4):12-5; quiz 16-7.

Question 157

45 Which of the following is not seen in a case of fat embolism: a. Fat globules in urine b. Left heart strain on ECG c. Snow storm appearance on chest X Ray d. Normal carbon dioxide tension in arterial blood e. Low oxygen tension in arterial blood.

Answer 157

Answer: b. Left heart strain on ECG ECG will show right heart strain and not the left heart strain.

Question 158

46 What can happen if drill hole has been made too small while inserting Sherman bone screw: a. Non rigid fixation b. Very rigid fixation c. Fragmentation of bone while inserting the screw d. Screw will pull out easily later on e. Screw can never be removed.

Answer 158

Answer: c. Fragmentation of bone while inserting the screw If drill hole is too small either it will be impossible to insert the screw or bone can fragment while it is being inserted. If the drill hole is too large screw threads will have insecure purchase in bone

Question 159

47 Closed reduction with percutaneous K wire fixation is best suitable for: a. Bennett fracture b. Lateral malleolus fracture c. Media] malleolus fracture d. Lateral tibial condyle fracture e. Clavicle fracture

Answer 159

Answer: a. Bennet fracture Closed reduction followed by percutaneous K wire fixation is useful in unstable fractures like Bennett's, comminuted Colles and unstable supracondylar humeral fracture in child. All these are situations where internal fixation is required for a relatively short time

Question 160

48 Who first defined and applied tension band principle in fixation of fractures and non unions: a. Pauwels b. Muller c. Allgower d. Watson Jones e. Girdlestone

Answer 160

Answer: a. Pauwels This engineering principle of converting tensile force into compressive force in an eccentrically loaded bone was first defined and used by Pauwels. It has been popularized by the work of A.0. group notably Muller and Allgower

Question 161

49 Dual plate applied for fixation of diaphyseal fracture will have strongest fixation when: a. Both plates are superimposed on each other and applied on one side only. b. Each plate is applied on opposite side on bone c. Plates are applied at 900 to each other d. Plates are applied at 300 to each other e. Combination of two plates is always weaker than a single plate.

Answer 161

Answer: c. Plates are applied at 90 degrees to each other When plates are applied at 901 to each other fixation is strongest. It is less rigid when plates are on opposite sides of bone. Double plating is more rigid than single plate but to apply two plates soft tissue and periosteal stripping has to be much more extensive

Question 162

51 Which of the following is not the treatment of cast syndrome: a. Nasogastric suction b. Intravenous fluid c. Removal of plaster d. Laparotomy e. Antiemetic drugs

Answer 162

Answer: e. Antiemetic drugs Antiemetic drugs have no role. Most of the time conservative treatment by nasogastric suction and IN. drip succeeds after plaster has been removed. In rare cases not responding to conservative measures surgery is required to relieve or by pass the obstraction in duodenum.

Question 163

52 Which of the following is not seen in fat embolism: a. Altered mental state b. Petechial haemorrhages c. Bradycardia d. Hypotension e. Tachypnea.

Answer 163

Answer: c. Bradycardia Tachycardia occurs in fat embolism along with other clinical features mentioned.

Question 164

53 Which of the following is commonest material used to make orthopaedic implant: a. Titanium b. Stainless steel c. Polyethylene (UHMWPE) d. Methyl methacrylate e. Carbon.

Answer 164

Answer: b. stainless steel Most implants are made of stainless steel as it is comparatively cheap and can be easily cast into desired shape. Titanium is expensive and difficult to fashion into desired shape. Carbon and polyethylene implants are used only for some specific uses and methylmethacrylate is not made up into an implant as such. Orthopaedic implants are typically made of 316L (L = low carbon) stainless steel (iron, chromium, and nickel), “supermetal” alloys (e.g., Co-Cr-molybdenum (Mo) [65% Co, 35% Cr, 5% Mo] made with a special forging process), and titanium alloy (Ti-6Al-4V)

Question 165

54 Bone graft works by providing following mechanism: Which of these is most important. a. Bone induction factor b. Osteogenic cells c. Living osteoblasts d. Mineral scaffold for vascular proliferation e. Bridging the bone gap.

Answer 165

Answer: d. Mineral scaffold for vascular proliferation Provision of mineral scaffold into which newly forming vascular channels can grow is the most useful function of bone graft and that is why bank bone, heterogenous bone and homografts succeed. Bone inducing factor, osteogenic cells and living osteoblasts are supplied only by fresh autogenous grafts.

Question 166

56 What is chief disadvantage of pulsed electromagnetic induction of bone union: a. Difficult coil placement b. Danger of infection c. Can not be used in the presence of infection d. Equipment is not portable e. High cost.

Answer 166

Answer: d. Equipment is not portable Main disadvantage is that equipment is not portable. This method can be used even in the presence of active infection since it is totally non invasive

Question 167

57 What has been the maximum reported overall success rate when non union is treated by electrical stimulation: a. 5% b. 25% c. 50% d. 80% e. 100%.

Answer 167

Answer: d. 80% Maximum overall success rate in treatment of non union with electrical stimulation has been 80 85%

Question 168

58 The use of axial compression in promoting union of cancellous bone fractures was originally described by: a. Key b. Charnley c. Eggers d. Danis e. Muller.

Answer 168

Answer: a. Key This was originally described by Key and later popularized and put to practical use by Charnley. Eggers, Danis and Muller have late also worked on this principle to devise internal fixation appliances

Question 169

59 Commonest cause of refracture after removal of external fixator is: a. Pin tract infection b. Fracture through pin tract c. Absence of periosteal callus d. Destressing producing cancellization of cortex e. Avascular necrosis of bone fragments.

Answer 169

Answer: d. Destressing producing cancellization of cortex Removal of stress from bone by a rigid fixator produce osteoporosis and this is commonest cause of refracture. This car be prevented by staged removal of pin and fixator or giving additional external support after removal of fixator. Pin tract infection and fracture through pin tract will create a new additiona fracture and not refracture.

Question 170

61 Which is commonest complication when femoral shaft fracture is treated in cast brace: a. Varus angulation of fracture b. Valgus angulation of fracture c. Shortening d. Delayed union e. Neuro vascular impairment.

Answer 170

Answer: a. Varus angulation of fracture Varus angulation is the commonest complication, even when a preliminary period of traction has been used. When brace has been put on without a sufficiently long period in traction rotational deformity and shortening can also occur.

Question 171

60 Idea of dynamic compression plate was first used by: a. Muller b. Danis c. Hicks d. Egger e. Sherman

Answer 171

Answer: b. Danis Danis of Belgium was first to make use of a plate that actively compressed the fracture. In this a bolt was used to apply pressure against the end screw in plate. Modern dynamic compression plate utilizing the principle of gliding of screw head was made by Muller and co workers in A.0. group.

Question 172

61 Which is commonest complication when femoral shaft fracture is treated in cast brace: a. Varus angulation of fracture b. Valgus angulation of fracture c. Shortening d. Delayed union e. Neuro vascular impairment.

Answer 172

Answer: a. Varus angulation of fracture Varus angulation is the commonest complication, even when a preliminary period of traction has been used. When brace has been put on without a sufficiently long period in traction rotational deformity and shortening can also occur.

Question 173

62 Universal A.0. air drill used in orthopaedics normally consumes air at the rate of. a. 50 litres per minute b. 100 litres per minute c. 200 litres per minute d. 300 litres per minute e. 400 litres per minute.

Answer 173

Answer: d. 300 litres per minute For every minute of running time the universal A.O. air drill requires about 300 litres of air at pressure of 6 bar (90 psi). Oscilating bone saw uses same amount of air and pressure.

Question 174

\