Initial implant stability predicts migration but not failure in cementless acetabular revision with bone grafting.

Host bone contact of less than 50% is perceived but not proven to cause migration and loosening after acetabular revision. A prospective analysis of cementless acetabular revision cases with impaction grafting was performed to determine if this was an independent risk factor for these events. Sixty-two hips in 54 patients were assessed at a mean follow-up of 84.5 months (range 61-112) yielding a probability of 94.6% of retaining the acetabular component using revision for aseptic loosening as the end point. No single factor was independently causative for loosening, although Type III fixation was associated with migration (p=0.0159); subanalysis suggested that achieving host-bone contact in at least part of the dome and posterior column is important.