Posterior Wall Acetabular Fractures

Abstract

Acetabular fractures with impaction/comminution of the posterior wall (AO type A1.3 c3) in older patients result in a posterior wall void > 1 cm3; a collapse of the posterior wall can often be observed despite open reduction and internal fixation (ORIF) with cancellous bone grafting. Due to inferior results using ORIF in older patients (> 60 years of age), this study was initiated to assess the clinical utility of a high strength, injectable, calcium phosphate bone cement that hardens in vivo. Ten patients, all > 60 years, were treated with Norian SRS® in a prospective study and compared to a historical patient group. The posterior wall was reconstructed with plates and screws, and the large comminuted region was filled with Norian SRS® via a screw hole or small cortical gap. Ten patients were treated with conventional ORIF and Norian SRS® cement. Return to normal range of motion in the Norian SRS® cement-treated patients was after 5 (range 4–6) weeks compared to 8 (6–10) weeks in the conventionally treated patients. Full weight bearing without pain occurred within 10 (8–11) weeks in the former compared to an average of 14 (12–16) weeks in the latter group. Poor results following posterior wall fracture of the acetabulum are due to a variety of reasons. Bone implant construct stability may be significantly enhanced by structural augmentation of regions of comprised cancellous bone. These early clinical results support previous biomechanical investigations and suggest that high-strength cements may be useful in treating these difficult acetabular fractures.