Hybrid graft vs autograft in anterior cruciate ligament reconstruction: a meta-analysis

Purpose: We conducted this meta-analysis to evaluate the efficacy of hybrid grafts in anterior cruciate ligament reconstruction (ACLR). Methods: We performed an electronic search of the Cochrane Library, PubMed, Embase, and ScienceDirect from the inception of these databases to February 2018, based on the terms "anterior cruciate ligament or ACL reconstruction", "autograft", "hybrid", and "augment". Relevant journals and conference proceedings were searched manually. Quality assessment, data extraction, and calculation of data from the included studies were conducted independently by two reviewers using RevMan 5.1. Results: One randomized controlled trial and eight nonrandomized controlled trials met inclusion criteria. Larger graft diameters were found in the hybrid-graft group (mean difference -1.47, P= 0.0001). There was no significant difference in failure rate (OR 2.13, P= 0.21), retearing (OR 2.23, P= 0.12), revision of ACLR (OR 1.05, P= 0.87) or reoperation (OR 1.27, P= 0.35). Subgroup analysis showed that hybrid-graft patients with meniscus injury suffered more revision (OR 4.10, P= 0.02) and reoperation (OR 5.74, P= 0.001). Both autografts and hybrid grafts performed similarly in most knee-score systems. However, autograft patients had better KT-1000 (mean difference 0.24, P= 0.05) and quality-of-life results on the Knee Injury and Osteoarthritis Outcome Score measure (mean difference 7.23, P= 0.05). Conclusion: This meta-analysis of the current literature indicates similar performance of hybrid or autologous grafts in ACLR, though hybrid grafts had larger diameters than autografts. Other potential factors to influence failure, revision, or postoperative knee function, such as irradiation, age at reconstruction, meniscus injury/treatment, and hybrid-graft remodeling, should be investigated further.