1
Q
Bone Function
A
- Stability
- Mobility
- Hematopoiesis
- Protection of vital organs
2
Q
Bone Layers
A
Cortex
- Hard, outer layer
- Covered by the periosteum
> Thick
> Contains vessels, nerve endings, & cells
> Repairs fracturesCancellous bone
- Soft, inner layer
- Covered by the endosteum
3
Q
Physis
A
Regions of long bone growth
- Highly vascular
- Prone to infections & fractures
4
Q
Metaphysis
A
- Largely consists of spongy, cancellous bone
- Most susceptible region to compression fractures
5
Q
Diaphysis
A
- Thick cortical bone
- Provides most of the structural support
6
Q
Fracture
A
A disruption in the continuity or structural integrity of bone
- Occurs when stress applied to the bone is greater than the bone’s intrinsic strength
- Bone withstands high compressive force (BUT, susceptible to breaks from tension/torsion)
- Fractures involve the bone & surrounding soft tissue (e.g. periosteum, muscles, & vessels)
- open fractures = skin involvement*
7
Q
Fracture Classifications
A
- Location
- Orientation
- Extent of fracture lines
- Amount of displacement
- Skin integrity
8
Q
Clinical Sxs of Fractures
A
- Pain
` Worsened by movement
` May limit weight-bearing capacity - Swelling
- Decreased function
- Visible deformity w/ displaced fractures
- Numbness/tingling w/ injury to nerves or vessels
9
Q
Open vs. Closed Fracture
A
Closed
- Skin over & near fx is intact
Open
- Skin over & near fx is lacerated or abraded by the injury
10
Q
Types of Fracture Displacement
A
Non-displaced
*Fragments in anatomic alignment
Displaced
*Fragments NOT in usual alignment
Angulated
*Fragments are malaligned
*Displaced from midline
Bayonetted ("shortened")
*Distal fragment overlaps proximal fragment
Distracted
*Gap b/t distal & proximal fragments
11
Q
Orientation of Fracture Lines
A
- Transverse
- Comminuted
- Oblique
- Segmental
- Spiral
- Intra-articular
- Torus
- Greenstick
12
Q
Transverse Fx
A
A fracture that is perpendicular to the shaft of the bone
13
Q
Comminuted Fx
A
A fracture in which there are more than 2 fracture fragments
14
Q
Oblique Fx
A
An angulated fx line
15
Q
Segmental Fx
A
A type of comminuted fx in which a completely separate segment of bone is bordered by fx lines
16
Q
Spiral Fx
A
A multiplanar & complex fx line
17
Q
Intra-articular Fx
A
The fx line crosses the articular cartilage & enters the joint
18
Q
Torus Fx
A
An incomplete buckle fx of one cortex, often seen in children
19
Q
Greenstick Fx
A
An incomplete fx w/ angular deformity, often seen in children
20
Q
Types of Fractures
A
- Impaction
- Compression
- Depression
- Stress (Fatigue)
- Stress (Insufficiency)
- Pathologic
21
Q
Impaction Fx
A
A fracture that occurs when 1 bone hits or impacts an adjacent bone
22
Q
Compression Fx
A
A type of impaction fx that occurs in the vertebrae, resulting in depression of the end plates
23
Q
Depression Fx
A
A type of impaction fx that occurs in the knee when the femoral condyle strikes the softer tibial plateau
24
Q
Stress (Fatigue) Fx
A
A fracture in normal bone that has been subjected to repeated or cyclical loads that alone are not sufficient to cause a fx
25
Stress (Insufficiency) Fx
A fx in weakened bone that has been subjected to a load insufficient to fx normal bone
26
Pathologic Fx
A fx through bone weakened by tumor, metabolic bone disease, or osteoporosis
27
Physical Exam Findings: Fracture
- Swelling
` extreme may --> compartment syndrome
- Ecchymosis
- Deformity
- Skin lacerations/abrasions
- Palpation (+/- tenderness, crepitus, or compartment tightness)
28
Diagnostic Testing: Fracture
X-Ray
- initial test for suspected fx
- minimun, AP & lateral projections
- always includes joints above/below injury
CT
- indicated for evaluation of bony anatomy
- suspected joint involvement or bone loss
- MC used w/ spine, scapula, foot & hand
MRI
- indicated w/ soft tissue injury
- necessary for non-displaced or stress fx
29
Complications of Fractures
- Delayed union, non-union, or malunion (fx that heals w/ poor alignment -> poor functioning)
- Joint fx -> stiffness or contractures
- Osteonecrosis d/t compromised blood supply (MC in bones w/ tenuous blood supply, e.g. talus, scaphoid, & femoral head)
- Open fx -> soft tissue loss, infection, or osteomyelitis
- Compartment syndrome (pain w/ passive stretching of involved muscle & significant swelling)
30
Fracture Treatment
- 1st: manipulation, reduction, & urgent stabilization
- Immobilization
`Cast, splint, or sling (extremities)
`Bed rest (axial fx-hip, pelvis, spine)
- Surgery (displaced/unstable fx)
- Open Fx: copious irrigation & dressing, splinting, IV antibiotics, tetanus prophylaxis, & urgen surgery
- Following healing --> rehabilitation d/t muscle atrophy & joint stiffness
31
Factors that Improve Stability or Prognosis of Fractures
- Skeletal immaturity: thick periosteum, potential for remodeling, faster healing
- Non-displaced fx
- Single bone fx of forearm (radius/ulna) or lower leg (tibia/fibula)
- Thoracic spine fractures (support of rib cage provides added stability)
32
Factors that Worsen Stability or Prognosis of Fractures
- Skeletal maturity: little remodeling ability, thin periosteum, slower healing
- Marked displacement or segmental (indicates soft-tissue stripping)
- Intra-articular fractures
- Nerve or vascular injury
- Compartment syndrome
- Osteonecrosis
- Oblique fracture pattern
33
Fracture Healing
Structural regeneration
- Complex biologic cascade mediated by a variety of cells & proteins
- Clinical evidence = absence of tenderness & motion at the fracture site
- Radiographic evidence = union--amount of bridging callus or obliteration of the fracture line
34
Risk Factors for Impaired Fracture Healing
```
Smoking
Indolent infection
Inadequate immobilization
Malnutrition
NSAID use
Significant soft tissue injury
```
35
Phases of Fracture Healing
Three overlapping phases
1: inflammation
- hematoma forms
2: repair
- fibrocartilaginous callus forms
- bony callus forms
3: remodeling
- bone remodeling occurs
36
Fracture Healing: Phase 1
- begins w/ bleeding from fracture site & surrounding soft tissue
- peaks after several days
- formation of granulation tissue
37
Fracture Healing: Phase 2
- formation of new blood vessels
- removal of necrotic tissue & debris by phagocytes
- production of new collagen by fibroblasts
- soft cartilaginous callus produced -> mineralized -> converted to woven (immature) bone
38
Fracture Healing: Phase 3
- overlaps w/ repair phase (occurs at 6-10 wks)
- can continue for several months
- woven bone replaced w/ mature lamellar bone
39
Primary Fracture Healing Pattern
Direct re-establishment of bony cortex
- requires very small gaps
- occurs almost exclusively w/ surgical anatomic restoration w/ rigid internal fixation
- osteoclasts on 1 fragment show a tunneling resorptive response
- no intermediate callus forms
40
Secondary Fracture Healing Pattern
Indirect bone healing through a cartilaginous callus intermediate
- does not require absolute stability (allows for relative stability--controlled fracture motion)
- immobilized by splints, casts, or certain intramedullary fixation devices
- periosteum provides progenitor cells, which differentiate into healing cells
41
Malunion
= An inadequately aligned union of a fracture
- MCC's-inadequate fx reduction, immobilization, or surgical error in alignment
- May result in loss of function or poor cosmesis
42
Delayed Union
= Prolongation time to union (beyond 16-20 weeks)
43
Non-Union
= Failure of normal fracture healing
(1) fx unhealed after 6 months of tx
(2) fx w/o healing process on x-rays for 3 consecutive months
Tx: bone grafting
44
Delayed Union & Non-Union Presentation
- Persistent pain
- Etiology: compromised biologic environment, infection, insufficient immobilization, inadequate reduction, or extensive surgical disruption of the surrounding vascular supply
45
Hypertrophic Nonunion
Cause: inadequate stability
Tx: revision to more stable fixation
46
Atrophic Nonunion
Cause: inadequate biologic conditions
Tx: bone grafting
47
Fibrous Nonunion
```
Cause:
- inadequate reduction
- inadequate biologic conditions
- inadequate stability
Tx:
- debridement
- bone grafting
```
48
Oligotrophic Nonunion
Cause: inadequate reduction
Tx: revision of reduction
49
Septic Nonunion
Cause: infection
Tx: debridement, antibiotics
50
Nonsurgical Tx of Fractures
Indicated w/ stable fracture patterns that can be immobilized w/ a splint or cast
- require follow-up radiographs
- loss of reduction or a lack of healing may require surgical interventions
- electrical & ultrasound stimulation may enhance healing in fractures prone to impaired healing
51
Surgical Tx of Fractures
Indicated for unstable fractures & fractures that fail to respond to nonsurgical tx
- open fx: debridement to reduce infection
- intraarticular fx: reduce articular cartilage & minimize future posttraumatic arthritis
- malunion: osteotomy, or bone cuts
- nonunion: debridement & bone grafting
