Indications and limits of acetabular reimplantations using screwed prostheses

The clinical and radiographic results of 95 acetabular reimplantations performed between 1984 and 1992 are presented. A screwed acetabular prosthesis was used in 56 patients, the acetabulum was cemented in 15, and a press-fit acetabulum stabilized by screws (1 case without screws) was used in 24. Mean clinical follow-up was 35.6 +/- 24 months, ranging from 7 to 94 months. Clinical results were good and excellent (> or = 5 points according to Merle D'Aubigné) in 77% of the cases for pain, in 70% for walking, and in 71% for joint movement. Forty months after surgery 48% of the screwed acetabula and 44% of the cemented ones were osteointegrated. The incidence of loosening for the screwed acetabula was 24%. The preliminary results 24 months after the press-fit acetabula with screws had been inserted showed 100% osteointegration. Radiographic results of the screwed acetabula were satisfactory (92% osteointegration) only in reimplantations performed in patients with minimum acetabular osteolytic injury (Paprosky types I and IIA). The use of homoplastic bone grafts did not improve the radiographic results of the screwed acetabula in the cases with severe osteolysis: 57% of the acetabula screwed on grafts distributed throughout the acetabulum were, in fact, loosened.