Histologic and mechanical evaluation of impaction grafting for femoral component revision in a goat model.

A goat model of revision hip arthroplasty was used to examine the histology and mechanical performance of impaction grafting using two femoral stems varying in stem surface finish. There were no significant mechanical or qualitative histologic differences between smooth, tapered, polished stems and step-cut, grit-blasted stems. Allograft distribution, bone incorporation, and cement mantle thickness were not uniform within the femoral canal. Efforts to improve the impaction grafting technique may be more important than stem design.