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 w ith 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 averag e of 14 (range 12-20) months: after surgery. All of them had a good clinica l outcome, with an average postoperative Hip Society Score of 89 (range 65- 98) and no evidence of radiolucency or subsidence on direct radiography. Sc intigraphic examination demonstrated that the area corresponding to the all ograft had a remarkable radioactivity accumulation suggesting new bone form ation. The allograft in total hip revision using the impaction grafting tec hnique undergoes a significant neovascularization and new bone formation. T his study suggests than when vigorous impaction is used, freeze-dried cance llous allograft can be used for impaction grafting.