Minor column structural acetabular allografts in revision hip arthroplasty

A minor column (shelf) allograft is used for uncontained defects that invol ve less than 50% of the acetabulum. The prospectively collected records and radiographs of 47 patients (51 hips) who had undergone minor column struct ural acetabular allograft reconstruction during revision hip arthroplasty w ere reviewed, The purpose was to identify the long-term results (minimum 5 Sears) and factors that may influence longevity of the allograft and predis pose the patient to subsequent acetabular component failure, The mean durat ion of followup was 119 months (range, 68-195 months), There was one periop erative death and sis patients were lost to followup. Eleven patients (22%) required additional surgery, Three acetabular cups could not be revised su ccessfully, despite multiple attempts, and the patients were treated with G irdlestone excisions, Eight patients underwent successful revision surgery with only three requiring a repeat structural allograft, Sur rival time for the acetabular cup as determined by Kaplan-Meier analysis was 153 months ( 95% confidence interval; range, 136-169 months). Cup failure was associated with more operative procedures performed before revision surgery (mean, 3. 2 procedures), and failure to restore the vertical center of hip rotation t o within 12 to 14 mm of the predicted value. The acetabular abduction angle was not a predictor for failure. The current study shows that good results can be achieved with structural acetabular allograft reconstruction with m id-term to long-term implant survival (cup aseptic survival, 80.4% and allo graft reconstruction survival, 94.1%), especially if there is restoration o f near normal hip biomechanics.