The Burch-Schneider cage: 9-year survival in Paprosky type 3 acetabular defects. Clinical and radiological follow-up.

Revision hip arthroplasty in cases with severe acetabular deficiency represents a technical challenge. The aim of this study was to determine: 1. The 9-year survival of the Burch Schneider anti-protrusio cage (BS-APC) in severe acetabular defects. 2. The migration of the cage and correlation of this with functional outcome. 3. The anticipated functional outcome users can expect in a district general hospital setting in the management of severe acetabular defects. A single-surgeon consecutive series of 30 complex acetabular reconstructions using the BS-APC was retrospectively reviewed. Clinical and radiological follow up at 5-9 years was obtained. Survival was established with revisions and further surgery as different end-points. A radiological analysis using ein bilt roentgen analyse (EBRA) was performed. At a mean follow-up of 85 months (range: 64-118) 26 patients (87%) were alive. Nine-year survival was 95% for revision of BS-APC as an end-point and 92% with any cause of further surgery as an end-point. The mean Oxford Hip Score was 34.5 and UCLA activity score was 4.4. All cases demonstrated evidence of significant migration, but no screws were found to be broken. There was no correlation between cup migration and Oxford hip score (p=0.07). Our non-specialist centre experience suggests the BS-APC should not be dismissed as a reconstruction option in the most severe acetabular defects.