MSK ( 5% )

Question 1

16. Osteoporosis

• a. Always involves the entire skeleton
• b. Is associated with decreased IL-1 level
• c. Can be reliably detected on radiographs with 20% bone loss. Not detected until 40%
• d. Is associated with anticoagulant use
• e. May be caused by vitamin A deficiency

Answer 1

d. Is associated with anticoagulant use

• c. Can be reliably detected on radiographs only with >40% bone loss
• Can involve isolated portions of skeleton
• Associated with increased IL-1 and IL-6 levels

Question 2

9. Which of the following is true concerning rhabdomyolysis?

• a. It is caused by injury to smooth muscle
• b. Its diagnosis depends on the presence of characteristic physical findings
• c. The final common pathway of injury involves damage to the sarcolemma
• d. Renal failure is due to acute glomerular nephritis
• e. Occurs only in trauma

Answer 2

c. The final common pathway of injury involves damage to the sarcolemma

• Injury to skeletal muscle, diagnosis depends on characteristic biochemical findings.*
• Renal failure occurs due to accumulation of myoglobin in the nephons -> ATN*
• Occurs in trauma, some drug overdoses, metabolic conditions, exercise, ischaemia (eg compartment syndrome)*

Question 3

10. Which of the following tumours is benign?

• a. Chondrosarcoma
• b. Osteochondroma
• c. Chondroblastoma
• d. Ewing’s tumour
• e. None of the above

Answer 3

c. Chondroblastoma

Question 4

11. A 50 year old woman presents with back pain. Xrays suggest a malignant deposit in the 10th thoracic vertebra. The least likely primary site is

• a. Breast
• b. Ovary
• c. Thyroid
• d. Kidney
• e. Colon

Answer 4

b. Ovary

Question 5

12. Which of the following is a disturbance of mineralisation homeostasis?

• a. Ricketts
• b. Osteoporosis
• c. Pagets disease
• d. HPOA

Answer 5

a. Ricketts

• Occurs due to Vit D deficiency*
• Pagets is excess unorganised and structurally unsound bone*

Question 6

13. Osteomalacia

• a. Decreased osteoid matrix deposition
• b. Increased bone production
• c. Vitamin D deficiency
• d. Increased Ca absorption from the gut
• e. Decreased PTH

Answer 6

c. Vitamin D deficiency

Question 7

14. Bone metastases originate least often from carcinoma of

• a. breast
• b. prostate
• c. testis
• d. thyroid
• e. kidney

Answer 7

c. testis

And ovaries

Question 8

18. Fracture healing

• a. Involves formation of an osseous callus in the second stage.
• b. Occurs at the same speed for all types of fractures
• c. Is not affected by alignment
• d. Is better in comminuted fractures
• e. Involves organisation of haematoma in the first stage

Answer 8

e. Involves organisation of haematoma in the first stage

1. Haematoma formation (hours)
2. Procallus formation (days)
   
   1. Organisation of callus and fibrocartilagenous callus formation (1 week)
3. Callus ossification (2-3 weeks)
4. Bone remodelling

• a. Involves formation of a cartilagenous callus in the second stage.
• b. Occurs at different speed for all types of fractures
• c. Is affected by alignment
• d. Is worse in comminuted fractures - more pieces to move and fuck out I assume, with more interuppted blood supply

Question 9

19. Regarding fracture healing

• a. Bone callus offers no structural rigidity for weightbearing
• b. Cytokines stimulate production of osteoclasts and osteoblasts
• c. Complete fracture healing can be expected regardless of age
• d. Cartilage formation is not a feature
• e. Bony fracture fragments enhance healing

Answer 9

b. Cytokines stimulate production of osteoclasts and osteoblasts

Question 10

15. Stress facture of bone

• a. Occurs when the bone is subjected to large axial loads
• b. Is common in Paget’s disease
• c. Is caused by secondary hypoparathyroidism
• d. Is rapidly developed in athletes due to repetitive training.
• e. Develops slowly and is repaired without cartilage in the callus

Answer 10

e. Develops slowly and is repaired without cartilage in the callus​

• Develops gradually in athletes and other people*
• Pagets = pathological fractures*

Question 11

5. Stress fractures

• a. Do not incite a paracortical reaction
• e. result from repetitive stresses or abnormal axial loading

Answer 11

e. result from repetitive stresses or abnormal axial loading

Question 12

3. In bone healing

• a. Woven bone forms in the periosteum of the medullary cavity.
• b. Osteoblasts lay down woven bone over the procallus to repair the fracture line
• c. PTH acts directly on osteoclasts to increase absorption
• d. Haematoma at the fracture site plays little role in the development of procallus.
• e. Inadequate immobilization aids the formation of normal callus.

Answer 12

b. Osteoblasts lay down woven bone over the procallus to repair the fracture line

• a. Woven bone forms in the endosteum of the medullary cavity.
• c. PTH acts indirectly on osteoclasts to increase absorption
• d. Haematoma at the fracture site plays an important role in the development of procallus.
• e. adequate immobilization aids the formation of normal callus.

Question 13

1. Which occurs first in fracture healing?

• a. Neutrophil invasion
• b. Procallus formation
• c. Woven bone ossification
• d. Lamellar bone ossification
• e. Collagen deposition

Answer 13

1. a. Fibroblast and inflammatory cell invasion
2. b. Procallus formation
3. e. Collagen deposition
4. c. Woven bone ossification
5. d. Lamellar bone ossification

Question 14

Regarding fracture healing

• Conversion of the procallus to a fibrocartilaginous callus precedes haematoma organization
• Osseous callus precedes the fibrocartilaginous callus
• Almost perfect repair can be accomplished if the original weightbearing strains are restored
• Speed and perfection of healing does not depend on the type of fracture
• Comminuted fractures heal quicker than greenstick fractures

Answer 14

Almost perfect repair can be accomplished if the original weightbearing strains are restored

• Conversion of the procallus to a fibrocartilaginous callus follows haematoma organization
• Osseous callus follows the fibrocartilaginous callus
• Speed and perfection of healing does depend on the type of fracture
  
  • Presumably a massively comminuted, open fracture will hesal slower and less well
• Comminuted fractures heal slower than greenstick fractures - more bone needs to remodel and develop

Question 15

2. Subchondral necrosis

• a. Is rarely idiopathic
• b. Associated with diving injuries
• c. Rarely involves ischaemia.
• d. Caused by embolus
• e. Precursor to OA.

Answer 15

Apparently noted as b. Associated with diving injuries

However

e. Precursor to OA.

R&C states subchondral infarcts may lead to severe OA, and no mention is made of diving injuries

And a case could be made for d) too, so who knows.

• a. Is ?often idiopathic
• c. Often/always involves ischaemia.
• d. Caused by embolus - noted as a cause of osteonecrosis

Question 16

6. Avascular necrosis

• a. Occurs infrequently in those with sickle cell anaemia.
• b. Affects only cancellous bone and marrow.
• c. Is never painful
• d. May undergo malignant transformation
• e. Is improved by administration of corticosteroids.

Answer 16

b. Affects only cancellous bone and marrow.

Given as answer but R&C clearly states cortex can be involved ​

• a. Occurs frequently in those with sickle cell anaemia (about 50% of patients by age 35)
• c. Is often painful
• d. May undergo malignant transformation - Not mentioned in R&C or up to date
• e. Can be caused by administration of corticosteroids.

Question 17

The most common cause of avascular necrosis of bones is

• Radiation therapy
• Caisson disease
• Vasculitis
• Steroid induced necrosis
• Venous hypertension

Answer 17

Steroid induced necrosis

Question 18

7. In osteoarthritis

• a. There is a marked synovial reaction
• b. Chondrocytes play a role in cartilage destruction
• c. Osteophytes develop on top of the articular surface.
• d. Subchondral cysts are caused by collagenases
• e. Chondrocytes excrete digestive enzymes into the matrix in active forms

Answer 18

b. Chondrocytes play a role in cartilage destruction

• a. There is minimal/no synovial reaction
• c. Osteophytes develop on the edges of the articular surface (as you can see on x-rays)
• d. Subchondral cysts are caused by ???

Question 19

8. With regard to rheumatoid arthritis

• a. In the joint it is confined to the synovium and does not involve the articular cartilage
• b. Xrays of joints reveal marginal erosions
• c. Caseous necrosis is typical of rheumatoid nodules
• d. There is decreased vascularity in the pannus.
• e. It is confined to joints and skin.

Answer 19

b. Xrays of joints reveal marginal erosions

• a. In the joint it is involves destruction of hyaline cartilage, as well as synovial reaction
• c. ??if any necrosis is actually invovled, vs bony destruction
• d. There is increased vascularity in the pannus.
• e. It is not confined to joints and skin - there are Extra-articular manifestations like vasculitis

Question 20

17. Rheumatoid arthritis

• a. Is thought to be initiated by a microbial agent
• b. Is associated with IgE in 80% of patients
• c. Is an inflammatory synovitis triggered by an endogenous agent
• d. May lead to destructive proliferative synovitis initiated by eosinphils and/or neutrophils
• e. Is not shown to have genetic susceptibility

Answer 20

a. Is thought to be initiated by a microbial agent

This is the answer given, but I’m pretty sure this has been disproved and is no longer a theory.

• b. Is associated with rheumatoid factor in 80% of patients
• c. Is an inflammatory synovitis triggered by an arthritogenic/exogenous agent
  
  • ??if this is even still believed
• d. May lead to destructive proliferative synovitis initiated by CD4 cells and involving neutrophils, monocytes, and macrophages
• e. Does have genetic susceptibility

Question 21

regarding osteoarthritis

• incidence increases linearly with advancing age
• hips are characteristically involved in women
• characteristic pathological features include subchondral microcysts and subcutaneous nodules
• synovial inflammation is a predominant feature
• chondrocytes elaborate mediators such as TNFα and IL – 1

Answer 21

chondrocytes elaborate mediators such as TNFα and IL – 1

• incidence increases non-linearly with advancing age - likely has a large spike in the 50s/60s
• ?knees are characteristically involved in women
• characteristic pathological features include subchondral microcysts joint space narrowing, osteocytes
• synovial inflammation is not a feature