An end-result study of ninety-three acetabular fractures in ninety patients followed for from one to twenty-seven years, or for an average of six years, is presented. These fractures were classified as undisplaced, posterior, inner-wall, and superior or bursting fractures. The prognosis would be different in the different types of fracture, but, in general, the prognosis was found to be more favorable than would be anticipated from current reports in the literature. The more favorable outlook for this fracture derived from this study is perhaps due to the fact that the patients studied were all those whose initial treatment was in one hospital. This gave a more representative balance between the good and poor results.

The outcome of the hip appeared to depend primarily on the condition of the dome or weight-bearing portion of the acetabulum, the condition of the femoral head, the adequacy of the reduction of the dislocation, and the stability of the joint after treatment. The clinical and roentgenographic findings in the affected hips one year after injury were found to be a most reliable guide to the ultimate prognosis of the hip, since definite changes were noted at one year in those hips that deteriorated.