Impaction grafting for bone defects in revision total knee arthroplasty.

UNLABELLED: Bone loss in revision total knee arthroplasty is a complex and challenging problem. Frequently, the defects encountered are irregular in size and shape. Since 1998, we have been using impaction bone allografting for constrained and unconstrained defects in revision total knee arthroplasty. We prospectively studied the mid-term results of 48 consecutive revision total knee arthroplasties with substantial bone loss treated with impaction allograft. Average followup was 3.8 years. Knee Society scores improved from a preoperative average of 57.0 to a postoperative average of 89.8 points (p < 0.001). Knee Society functional scores improved from a pre-operative average of 52.3 to a postoperative average of 80.3 points (p < 0.001). There have been no mechanical failures of the revisions and all radiographs have shown incorporation and remodeling of the bone graft. There were six complications out of the 42 revisions available for followup (14%); two periprosthetic fractures, one early infection salvaged with irrigation and antibiotics, one late infection resulting in fusion, and two patellar clunk syndromes. Though time consuming and technically demanding, impaction grafting for bone loss in revision total knee arthroplasty has excellent durability and versatility. It has become our preferred technique for the management of substantial bone loss in revision total knee arthroplasty. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series).