Purpose: We wanted to evaluate the clinical and radiologic results of acetabular revision using the acetabular reinforcement ring and also the allograft impaction in the acetabulum having deficient bone stock.
Material and Methods: Nineteen hips revision arthroplasty were performed in 18 patients (9 males and 9 females) with using an acetabular reinforcement ring and allograft between July 1993 and December 2003. The patients were followed for an average of 64 months (range: 24-153). The mean age at the time of arthroplasty was 59 years old (range: 34-76). The causes of revision were aseptic loosening of the acetabular component in 16 cases, severe progressive osteolysis around the acetabular component in 2 cases and Girdlestone state after infected total hip arthroplasty in one case. The acetabular deficiency was type II in 5 hips, type III in 13 hips, and type IV in one hip according to the AAOS classification. The clinical results were evaluated using the modified Harris hip score, and the radiologic results were evaluated by assessing the preoperative and serial follow-up radiographs.
Results: The mean preoperative Harris hip score of 47 was improved to 86 points at the latest follow-up. Periacetabular osteolysis was found in 2 cases, which did not progress at follow-up. The anatomic hip center was restored after revision arthroplasty (p<0.05). Complications were dislocation in 2 cases, breakage of the hook of the Ganz ring in one case, heterotopic ossification in one case and femoral artery injury in one case. All cases showed stable fixation of the acetabular component and good remodelling of the impacted allograft. There was neither recurrence of dislocation nor progression of the acetabular component loosening on the radiographs.
Conclusion: Acetabular revision with acetabular reinforcement ring and allograft impaction showed satisfactory clinical and radiologic results with restoration of the hip center and consolidation of the allograft.

Keywords: Acetabular defect, Allograft, Acetabular reinforcement ring, Acetabular revision