Comparison of clinical outcomes between hamstring tendon autografts and hybrid grafts in ACL reconstruction: a systematic review and meta-analysis

BackgroundHamstring tendon (HT) autografts have become a popular choice for anterior cruciate ligament (ACL) reconstruction. However, small-diameter grafts are inevitably encountered during surgery, which have poor biomechanical properties. Hybrid grafts (HGs) using an allograft combined with small diameter HT are gaining interest from surgeons.HypothesisThere would be no difference between the HT autograft and HG in terms of failure, knee stability, and patient-reported outcomes.Study designSystematic review and meta-analysis; Level of evidence, 4.MethodsThe PubMed, Embase, web of science and Cochrane databases were systematically searched from their inception until July 1, 2022. Clinical trials that compared HG and HT autografts were included. The quality of the included studies was assessed with the Cochrane Collaboration's risk of bias tool and the modified Newcastle-Ottawa Scale. Extracted data were pooled with fixed or random effects depending on the detected heterogeneity.ResultsA total of 14 eligible studies involving 1411 patients (HT: 863; HG: 548) were included in the quantitative meta-analysis. The mean age of the patients involved ranged from 14.6 to 40.4 years. Compared to patients who received HT autografts, patients receiving HGs had similar postoperative failure rate (OR, 0.99; P = 0.97; I2 = 41%), side-to-side difference (MD, -0.16; P = 0.13; I2 = 41%), Subjective IKDC (MD, 0.51; P = 0.58; I2 = 69%), Lysholm (MD, 2.79; P = 0.1; I2 = 79%), Tegner (MD, -0.88; P = 0.56; I2 = 0%). When the available data for failure rate were analyzed by the dose of irradiation, patient age, and mean diameter of the HT, the results of subgroup analyses did not change substantially.ConclusionThis review found no significant differences in failure rates, knee stability, or patient-reported outcomes between autologous HT and HG in ACLR. Surgeons should prioritize autografts of adequate size through optimized techniques and consider hybrid grafts as a last resort, considering the risks associated with allografts.