Impacted particulate allograft for femoral revision total hip arthroplasty. In vitro mechanical stability and effects of cement pressurization.

The initial migration and micromotion of the revision femoral stem stabilized with morselized impacted cancellous allograft and bone-cement and the influence of cement pressurization on fixation of the cement/allograft composite to the host were examined with human cadaver femurs. The stability of the allograft/cemented reconstruction was found to be intermediate between those of conventional cemented and cementless stems. In most cases, the stability of the reconstruction was closer to that of cemented than to that of cementless stems. This may account for histologic findings of graft incorporation in experimental and retrieved specimens reported by other authors. Although increased cement pressurization led to greater penetration of cement into the graft bed, greater cement penetration did not increase fixation strength of the cement/allograft composite to the host.