Evaluation and Management of Posterior Wall Acetabulum Fractures

Posterior wall acetabulum fractures typically result from high-energy mechanisms and can be associated with various orthopaedic and nonorthopaedic injuries. They range from isolated simple patterns to multifragmentary with or without marginal impaction. Determination of hip stability, which can depend on fragment location, size, and displacement, directs management. Although important in the assessment of posterior wall fractures, CT is unreliable when used to determine stability. The dynamic fluoroscopic examination under anesthesia (EUA) is the benchmark in assessment of hip stability, and fractures deemed stable by EUA have good radiographic and functional outcomes. In fractures that meet surgical criteria, accurate joint reduction guides outcomes. Joint débridement, identification and elevation of impaction, and adjunctive fixation of posterosuperior and peripheral rim fragments along with standard buttress plate fixation are critical. Complications of the fracture and surgical fixation include sciatic nerve injury, posttraumatic osteoarthritis, osteonecrosis of the femoral head, and heterotopic ossification. Although accuracy of joint reduction is paramount for successful results, other factors out of the surgeon's control such as comminution, femoral head lesions, and dislocation contribute to poor outcomes. Even with anatomic restoration of the joint surface, good clinical outcomes are not guaranteed and residual functional deficits can be expected.