Surgical results and factors influencing outcome in patients with posterior wall acetabular fracture.

The purpose of this study was to evaluate the results of open reduction and internal fixation in a large series of posterior wall fractures of the acetabulum and to identify the factors that affect the outcomes in this case series. One hundred twenty-one patients who had undergone open reduction and internal fixation of a fracture of the posterior wall of the acetabulum were assessed at a mean of 53 months (range, 24-163) after surgery. The functional outcome was evaluated with use of the modified Merle d'Aubigne scoring system, the Harris Hip Score (HHS), and the Short Form-36 Health Survey (SF-36) questionnaire. Final follow-up radiographs were graded according to Matta's radiologic criteria. Patient, fracture, and radiographic variables were analyzed to identify possible associations with functional and radiographic outcome. The quality of fracture reduction on postoperative radiographs was anatomical in 115 hips (95.0%), satisfactory in 6 cases (5.0%), and unsatisfactory in none. Final modified d'Aubignè scores were excellent in 45 hips (40.2%), good in 52 (46.4%), fair in 7 (6.3%), and poor in 8 (7.1%). Mean HHS was 91.5±8.9 (48-100). The SF-36 scores were similar with respect to age and sex-matched norms, but physical domains in males remained lower in comparison with the normal population. The early reduction of an associated hip dislocation and quality of surgical reduction were strong positive predictors of functional and radiographic outcomes at follow-up, whereas associated injuries and the existence of pre-operative nerve palsy were negative predictors of patients' functionality. This study of surgically treated fractures of the posterior wall of the acetabulum has shown that functional and radiographic results are satisfactory in most patients, provided that prompt reduction of an associated hip dislocation and anatomical reduction of the fracture are carried out. Associated injuries and nerve lesions affect the final functional outcome.