To evaluate the results of surgical treatment of posterior wall fractures of the acetabulum and to determine the factors affecting the results.

Thirty-one posterior wall fractures were reviewed; 7 type A1-1, 19 type A1-2 and 5 type A1-3 by AO classification. Postoperatively, the accuracy of the reduction was evaluated. At the final follow-up, clinical and radiographic results were evaluated with medical records and radiographs. The factors affecting the results were determined.

The reduction was graded as anatomical in 22 patients, imperfect in seven and poor in two. The clinical result was excellent in 21 hips, good in six, fair in three and poor in one. The quality of the reduction was strongly associated with the clinical result. The radiographic result was excellent in 22 hips, good in five, fair in two and poor in two. The clinical result was related closely to the radiographic result. Complications were osteoarthritis in three patients, osteonecrosis of the femoral head in one, heterotopic ossification in one, penetration of a screw into the joint in one and iatrogenic sciatic nerve injury in one. The factors affecting the clinical results were fracture patterns, the surgeon's experience, the accuracy of the reduction and late complications.

In this present series of posterior wall fractures, as their prognosis depends on the severity of the injury and the accuracy of the reduction, satisfactory result can be obtained by anatomical reduction with thorough preoperative planning and the surgeon's experience.