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.