Impaction allografting and the Kerboull acetabular reinforcement device: 35 Hips followed for 3-7 years

Background: The incidence of acetabular loosening with segmental and cavitatory bone loss increases as the number of total hips implanted increases. Revision hip arthroplasty using impacted bone graft and an acetabular reinforcement device is one solution to this problem. Patients and methods: Clinically and radiographically, we assessed 35 hips in 33 patients who had undergone revision hip arthroplasty using impaction grafting and the Kerboull acetabular reinforcement device. Mean follow-up was 5 (3-7) years. Results: The mean Mayo score preoperatively was 30, which improved to a mean score of 85. Good to excellent clinical results were seen in 25 patients. The 8 individuals scoring below 80 had significantly more co-morbid conditions than the others. No acetabular reconstruction required re-revision. Aseptic loosening occurred in 6 patients. Graft resorption occurred in 5 cases, resulting in inferior hook fracture of the Kerboull device. This was noted at a mean of 13 months after surgery. Further follow-up showed this to be non-progressive, with incorporation of the remaining graft to the host bone. These patients all had good to excellent Mayo hip scores. Interpretation: Early results of revision acetabular surgery using impaction grafting and the Kerboull shell in patients with severe osteolysis have shown good functional outcome. However, 6 of 35 patients had radiographic evidence of aseptic loosening without progression for 4 years. Long-term follow-up is required to ensure that this loosening does not result in failure.