Patient Outcomes After Anterior Cruciate Ligament (ACL) Reconstruction With Hybrid Allograft Augmentation Compared With Isolated Autografts: A Systematic Review and Meta-Analysis.

Anterior cruciate ligament reconstruction (ACLR) is a common orthopedic procedure involving the replacement of a torn anterior cruciate ligament (ACL) with a graft, and current literature comparing the outcomes of different graft types remains inconclusive. The aim of this study was to compare isolated autografts and hybrid allograft/autograft grafts of various sizes to determine whether allograft augmentation provides a clinically significant benefit during ACLR by assessing patient-reported outcome measures (PROMs) and rates of graft failure. A comprehensive systematic review and meta-analysis was performed, with the search conducted across three databases (PubMed, Embase, and Cochrane Reviews). Quantitative data were collected regarding PROMs and rates of re-tear/revision, and a meta-analysis was performed to assess Lysholm, International Knee Documentation Committee (IKDC), and Tegner scores and rates of graft failure. The initial search yielded 249 studies, of which 17 met the final inclusion criteria; the included studies were published between 2015 and 2025, and 15 of the 17 were retrospective cohort studies. In terms of pooled patient outcomes, there were no clinically significant differences between hybrid grafts and isolated autografts across any of the analyzed clinical scores. Lysholm scores were statistically higher in the autograft group (weighted mean difference (WMD) 3.77, 95% CI 1.47-6.07, p=0.0013), though this difference remained below the established minimal clinically important difference; IKDC (p=0.80) and Tegner (p=0.28) scores did not differ significantly between groups. The pooled relative risk of graft failure was slightly higher in patients with hybrid grafts (risk ratio (RR) 1.24, 95% CI 0.84-1.84); however, this difference was not statistically significant (p=0.28). At the individual study level, there is literature to both support and refute the viability of hybrid ACL grafts in augmenting an autograft of insufficient diameter. However, following a comprehensive review of the literature and meta-analysis, we report a lack of clinically meaningful or statistically significant differences in clinical outcome scores and overall rates of graft failure.