Scintigraphic evaluation of impaction grafting for total hip arthroplasty revision.

To determine the fate of an impacted allograft after a minimum follow-up of 1 year, we examined 9 of 40 patients who underwent revision arthroplasty with the impaction grafting technique. The allograft used in this study was morselized cancellous freeze-dried allograft. We examined these 9 patients with technetium-99 m methylene diphosphonate bone scintigraphy at an average of 14 (range 12-20) months after surgery. All of them had a good clinical outcome, with an average postoperative Hip Society Score of 89 (range 65-98) and no evidence of radiolucency or subsidence on direct radiography. Scintigraphic examination demonstrated that the area corresponding to the allograft had a remarkable radioactivity accumulation suggesting new bone formation. The allograft in total hip revision using the impaction grafting technique undergoes a significant neovascularization and new bone formation. This study suggests than when vigorous impaction is used, freeze-dried cancellous allograft can be used for impaction grafting.