IMPLANT STABILITY IN REVISION TOTAL HIP-ARTHROPLASTY - ALLOGRAFT BONEPACKING FOLLOWING EXTENDED PROXIMAL FEMORAL OSTEOTOMY

One method of revising the femoral component in revision total hip art hroplasty in the presence of compromised femoral bone stock is to pack the upper femur with particulate allograft and then to cement the fem oral component into the allograft bed. This technique is being used cl inically with encouraging results. Additionally, surgical exposure of the femoral canal during revision total hip arthroplasty can be greatl y improved with an extended trochanteric osteotomy, which is subsequen tly repaired with wires or cables. To assess the feasibility of perfor ming the allograft bone packing technique following an extended trocha nteric osteotomy, the stability of this construct in a cadaver model w as measured, using micromotion sensing instruments and loads applied o n a materials testing machine. The stability of the cemented allograft impaction construct following extended trochanteric osteotomy was com parable to the stability of the control construct, which consisted of a similar impacted allograft construct without osteotomy. The stabilit y of the osteotomized side was comparable to that of the control side. It is concluded that the initial in vitro stability of the allograft impaction technique following extended proximal femoral osteotomy is a dequate to justify experimental in vivo use.