Autograft versus nonirradiated allograft tissue for anterior cruciate ligament reconstruction: A systematic review

Background: An autograft has traditionally been the gold standard for anterior cruciate ligament reconstruction (ACLR), but the use of allograft tissue has increased in recent years. While numerous studies have demonstrated that irradiated allografts are associated with increased failure rates, some report excellent results after ACLR with nonirradiated allografts. The purpose of this systematic review was to determine whether the use of nonirradiated allograft tissue is associated with poorer outcomes when compared with autografts. Hypothesis: Patients undergoing ACLR with autografts versus nonirradiated allografts will demonstrate no significant differences in graft failure risk, laxity on postoperative physical examination, or differences in patient-oriented outcome scores. Study Design: Systematic review. Methods: A systematic review was performed to identify prospective or retrospective comparative studies (evidence level 1, 2, or 3) of autografts versus nonirradiated allografts for ACLR. Outcome data included graft failure based on clinical findings and instrumented laxity, postoperative laxity on physical examination, and patient-reported outcome scores. Studies were excluded if they did not specify whether the allograft had been irradiated. Quality assessment and data extraction were performed by 2 examiners. Results: Nine studies comparing autografts and nonirradiated allografts were included. Six of the 9 studies compared bone- patellar tendon-bone (BPTB) autografts with BPTB allografts. Two studies compared hamstring tendon autografts to hamstring tendon allografts, and 1 study compared hamstring tendon autografts to tibialis anterior allografts. The mean patient age in 7 of 9 studies ranged from 24.5 to 32 years, with 1 study including only patients older than 40 years and another not reporting patient age. The mean follow-up duration was 24 to 94 months. Six of 9 studies reported clinical graft failure rates, 8 of 9 reported postoperative instrumented laxity measurements, 7 of 9 reported postoperative physical examination findings, and all studies reported patient-reported outcome scores. This review demonstrated no statistically significant difference between autografts and nonirradiated allografts in any outcome measure. Conclusion: No significant differences were found in graft failure rate, postoperative laxity, or patient-reported outcome scores when comparing ACLR with autografts to nonirradiated allografts in this systematic review. These findings apply to patients in their late 20s and early 30s. Caution is advised when considering extrapolation of these findings to younger, more active cohorts.