PRINCIPLES OF BONE-GRAFTING IN REVISION TOTAL HIP-ARTHROPLASTY - ACETABULAR TECHNIQUE

Multiple revisions of the acetabulum ultimately lead to severe loss of bone stock. Each bone loss type requires a specific method of allogra ft reconstruction struction to achieve acetabular component stability. A series of 316 acetabular revisions in which 69 required support all ograft were followed for a mean of 5.1 years (range, two to ten years) . Support allograft was required when radiographs showed superior comp onent migration greater than 2 cm. Severe ischial lysis was indicative of posterior column insufficiency. Distal femurs were used instead of femoral heads as support for porous-coated cups. If in addition to th e radiographic findings, Kohler's line also was violated (which was in dicative of anterior column deficiency as well), then whole acetabular allografts were used with cemented polyethylene cups. Biologic fixati on of a porous-coated cup and support allograft were not possible in t hese cases. All of the distal femoral allografts united to host bone, and there was no migration of porous-coated components at a mean of 5. 1 years when Kohler's line was intact. When Kohler's line was not inta ct, 70% of the porous cups had migrated more than 4 mm and were consid ered failures. Conversely, when whole acetabular allografts with cemen ted polyethylene cups were used in these cases, air 14 showed graft un ion and no change in the cement-graft interface at a minimum follow-up period of 24 months. The postoperative clinical results using the D'A ubigne and Postel rating scales were 10.1 of 12, with 76% good to exce llent results. This study indicates that better results with support a llografts can be achieved at similar periods than has previously been reported.