Impaction bone grafting for revision hip arthroplasty: biology and clinical applications.

Impaction bone grafting techniques are useful when the orthopaedic surgeon is faced with large cavitary acetabular defects or a large ectatic femoral metaphysis or diaphysis. Impaction bone grafting of the acetabulum involves packing of cavitary defects with compressed particulate graft, followed by insertion of either a cemented or cementless acetabular component. Impaction grafting of the femur involves retrograde filling of the femoral canal with impacted particulate graft, creating a neomedullary canal into which a cemented femoral stem can be placed. Use of the impaction allografting technique is appealing, especially in young patients, because of its potential to restore bone stock. The technically demanding nature of the procedure, the risk of complications, and the unknown long-term fate of the impacted allograft highlight the need for ongoing assessment of this technique for revision total hip arthroplasties.