The use of structural allograft for uncontained defects in revision total knee arthroplasty: a minimum fiveyear review

Background: To our knowledge, the medium to long-term outcome after revision knee arthroplasty with structural allograft augmentation for reconstruction of uncontained defects has not been determined. The purpose of the present study was to assess the outcome for patients managed with such a procedure. Methods: We prospectively followed fifty patients who had fifty-two revision knee replacements with sixty-six struc-tural grafts performed at three institutions. Twenty-nine knees (twenty-seven patients) were independently evalu-ated at a mean of 96.9 months (range, sixty to 189 months) by an investigator who had not been involved in the index procedure. Twelve knees (23%) had a repeat revision at a mean of 70.7 months (range, twenty-six to 157 months). The allograft was retained in two of these patients. Eleven patients died at a mean of ninety-three months (range, sixty-one to 128 months) after the procedure; the structural allograft and implants were intact, and the patients were not awaiting revision at the time of death. Results: Clinical evaluation revealed that the mean modified Hospital for Special Surgery knee score had improved from 32.5 points preoperatively to 75.6 points at the time of the review and the mean range of motion had increased from 60.5 ° preoperatively to 88.6°. Failure was defined as an increase of less than 20 points in the modified Hospital for Special Surgery knee score at the time of the review or the need for an additional oper-ation related to the allograft. Thirteen knee replacements failed, yielding a 75 % success rate. Five knees ha