Femoral head fractures are rare injuries that are usually associated with hip dislocation (10%). In a posterior hip dislocation, the femoral head hits the posterior rim of the acetabulum and fractures. On the other hand, anterior dislocation causes impaction or indentation fractures of the head. Treatment may be non-operative or operative, depending on the location of the fracture and displacement.
Pipkin classification of femoral head fracture
| Classification | Description | Treatment |
|---|---|---|
| Type I | Fracture is inferior to the fovea. Does not involve the weight-bearing portion of the femoral head. | Excision of a small fragment, fixation if the fragment is large |
| Type II | Fracture is superior to the fovea. Involves the weight-bearing portion of the femoral head. | Open reduction internal fixation |
| Type III | Type I or II with associated femoral neck fracture. Has a high incidence of avascular necrosis. Closed reduction may displace the neck fracture | Stabilize the femoral neck fracture before attempting to reduce or fix the dislocated head |
| Type IV | Type I or II with associated acetabular fracture (posterior wall fracture) | Fixation if the fragment is large |
- Mechanism of injury
- High-energy, e.g., MVA (dashboard injury), fall from height, or sports
- Associated injuries
- Knee instability due to posterior cruciate ligament injury (dashboard injury)
- Femoral neck fracture
- Acetabular fracture
- Avascular necrosis of the femoral
- Sciatic nerve injury
- Signs and symptoms
- Hip pain
- Inability to bear weight
- Shortening
- Flexion, adduction, and internal rotation (posterior hip dislocation)
- Flexion, abduction, and external rotation (anterior hip dislocation)
- Signs of sciatic nerve injury
- Investigations
- Emergency treatment
- Reduce hip dislocation within 6 hours (unless there is an associated femoral neck fracture)
- Indications for non-operative treatment
- Pipkin I
- Non-displaced pipkin II < 1mm step off
- Stable hip joint
- Indications for operative treatment
- Non-operative treatment
- Touch down weight bearing for 4 – 6 weeks
- Restrict adduction and internal rotation
- Operative treatment
- Comlpications
- Post-traumatic osteoarthritis (50%)
- Avascular necrosis (20%)
- Heterotopic ossification
- Sciatic nerve injury
- Reduced internal rotation
- Malunion
- Non-union