Allograft failure in cruciate ligament reconstruction. Follow-up evaluation of eighteen patients.

Previous authors have reported the efficacy of cruciate ligament allograft reconstruction of the knee suggesting that allograft strength is not significantly different than that of autografts. The purpose of this study was to elicit the cause of a higher-than-expected failure rate in cruciate ligament allograft reconstructions. After clinical diagnoses, 12 male and 6 female patients with cruciate ligament instability underwent intraarticular allograft reconstruction followed by an aggressive rehabilitation program. Deep-frozen, freeze-dried, ethylene oxide-sterilized, bone-patellar tendon-bone allografts were rehydrated, prestressed, and implanted by an open or arthroscopically assisted technique. Results revealed 6 of 18 failures. Knee instability, postoperative complications, and roentgenographic changes were evident. Evaluation of procurement technique showed that graft failure was significantly correlated with time to implantation. A significant difference in mean time from procurement and deep freezing to freeze-drying and sterilization between failed-versus-successful grafts was 265.5 +/- 61.9 versus 66.8 +/- 43.8 days, respectively. Total mean time of failed grafts from procurement to implantation was significantly greater (528.3 +/- 75.1 versus 207.3 +/- 53.1 days) than for successful grafts. All graft failures came from the same batch number. These findings indicate that cruciate ligament allograft reconstruction can be successful; however, longer shelf life negatively affects graft integrity.