Marginal impaction in posterior wall fractures of the acetabulum.

OBJECTIVE: The purposes of this study were to describe the CT features of isolated posterior acetabular wall fractures with associated marginal impaction and to discuss the potential therapeutic implications of recognizing this type of fracture. CONCLUSION: Marginal impaction is an important cause of articular incongruity that adversely affects prognosis. Radiologists should be capable of identifying posterior acetabular wall fracture patterns because they may be the first to suggest diagnoses.