Review Question - QID 219440

This patient has sustained an irreducible posterior hip fracture-dislocation with an associated femoral head fracture. The use of a surgical hip dislocation with a trochanteric flip osteotomy allows for complete visualization of the femoral head and is associated with lower rates of post-traumatic osteoarthritis (Answer 4).

Femoral head fractures are rare traumatic injuries that are usually associated with concomitant hip dislocations. The incidence of these injuries is overall rare, and they are seen in approximately 12% of patients who sustain a hip dislocation. Due to an increase in the number of motor vehicle accidents worldwide, and improved resuscitative techniques, the incidence of these injuries is on the rise. These injuries can occur through direct impaction, avulsion, or with a shear-type mechanism. Up to 15% of patients who sustain a posterior hip dislocation will have a femoral head fracture, with the fracture occurring as the femoral head makes contact with the posterior rim of the acetabulum. These fractures are classified according to the Pipkin classification, which is based on the location of the fracture and the presence/absence of associated injuries. The treatment of these injuries is variable, but fractures with displacement following reduction are treated surgically. While a variety of surgical approaches can be utilized for the treatment of these fractures, a surgical hip dislocation with a trochanteric flip osteotomy allows for complete visualization of the femoral head.

Masse et al. report on the outcomes of patients with femoral head fractures treated through the use of a surgical hip dislocation with a trochanteric flip osteotomy. Their study included 13 patients with a mean follow-up of 77 months. Overall, the authors concluded that the use of a surgical hip dislocation with trochanteric flip osteotomy, when compared to non-osteotomy-based approaches, was associated with similar functional outcomes, similar rates of AVN, lower rates of post-traumatic arthritis but higher rates of heterotopic ossification.

Solberg et al. report on the use of a trochanteric flip osteotomy in the treatment of Pipkin IV femoral head fractures. Their study included 12 patients with a mean follow-up of 47 months. Overall, 11/12 patients had union of their femoral head fracture, with a single patient developing osteonecrosis. The authors note that the use of this approach allows for visualization of the entire femoral head and acetabulum.

Figure A is a posterior hip dislocation with an associated femoral head fracture. Illustration A is a chart outlining the Pipkin classification.

Incorrect Answers:
Answer 1: The utilization of a surgical hip dislocation with trochanteric flip osteotomy does not increase the rate of subsequent AVN.
Answer 2: Surgical hip dislocation with trochanteric flip osteotomy is associated with higher rates of heterotopic ossification compared to non-osteotomy-based approaches.
Answer 3: Surgical hip dislocation with trochanteric flip osteotomy allows for complete visualization of the femoral head.
Answer 5: The use of a surgical hip dislocation with trochanteric flip osteotomy does not negatively impact patient functional outcomes.