Which Graft Is Associated With Better Outcomes in ACL Reconstruction? A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

Abstract

Background: In clinical practice, different surgical methods, including autografts, allografts, and artificial ligaments, have been used in reconstruction after ACL injuries. However, the available evidence is conflicting in terms of which approach has yielded better patient-reported outcomes, joint stability, and risk of graft reinjury. A network meta-analysis allows the comparison of approaches that have not been compared head-to-head in individual RCTs. Although several network meta-analyses have been performed on this topic, they are hampered by methodological limitations.

Questions/purposes: We performed an updated network meta-analysis of RCTs to answer the following questions: Considering different grafts applied in ACL reconstruction, which graft is superior in terms of (1) patient-reported outcomes (International Knee Documentation Committee [IKDC] objective score, Lysholm score, and Tegner score), (2) knee stability results (Lachman test, pivot-shift test, and KT-1000/2000 arthrometer side-to-side difference), and (3) risk of graft reinjury?

Methods: We searched the PubMed, Embase, Cochrane Library, and Web of Science databases from January 2000 to November 2024 for completed studies. We reviewed 30,976 papers, and 27 met inclusion criteria, which were as follows: RCTs published in English, RCTs that involved ACL reconstruction with different grafts (autografts, allografts, and artificial ligaments) with fully described surgical techniques, RCTs that reported on at least one of the relevant outcome measures (preoperative and postoperative IKDC objective score, Lysholm score, Tegner score, Lachman test, pivot-shift test, KT-1000/2000 arthrometer side-to-side difference, and risk of graft reinjury), and RCTs that reported a minimum follow-up period of 12 months with at least 80% follow-up completeness. The Cochrane risk-of-bias tool (RoB 2.0) was used to assess the quality of the included studies, with 18 studies judged as being at a low risk of bias and 9 studies assessed as being at an unclear risk of bias. In total, 2572 patients were treated with 16 different types of grafts. The mean length of follow-up was 47 months. The mean age of the included patients was 28 years, and 71% of the patients were male. A Bayesian network meta-analysis was performed via the "gemtc" and "coda" packages of R Studio, version 4.2.1, and the "networkplot" command of Stata 15 software was used to plot network relationships for direct and indirect comparisons between different interventions. The surface under the cumulative ranking curve (SUCRA) was calculated to rank the intervention effects of different interventions. A SUCRA value approaching 1 (100%) indicates a greater probability that the corresponding treatment is superior in terms of efficacy or safety. The most common treatment comparisons were the single-bundle 4-strand semitendinosus with gracilis tendon autograft versus the bone-patellar tendon-bone autograft and the single-bundle 4-strand semitendinosus with gracilis tendon autograft versus the double-bundle 4-strand semitendinosus with gracilis tendon autograft.

Results: Although there were no differences when comparing different grafts for traditional pairwise comparisons of patient-reported outcomes, joint stability, and graft reinjury, the network meta-analysis allows ranking of interventions by efficacy or safety through the SUCRA. In terms of patient-reported outcomes, the double-bundle 4-strand semitendinosus with gracilis tendon autograft had the highest ranking for the IKDC objective score (SUCRA 77%), the single-bundle 3-strand semitendinosus tendon autograft was ranked most favorably for the Lysholm score (SUCRA 78%), and the single-bundle 4-strand semitendinosus with gracilis tendon autograft with synthetic artificial ligament had the highest ranking for the Tegner score (SUCRA 90%). Concerning knee stability, the double-bundle 4-strand semitendinosus with gracilis tendon autograft ranked first (SUCRA 58%) on the Lachman test, the single-bundle 5-strand semitendinosus with gracilis tendon autograft ranked first (SUCRA 64%) in terms of the pivot-shift test, and the bone-patellar tendon-bone autograft was ranked most favorably for the KT-1000/2000 arthrometer side-to-side difference (SUCRA 91%). The most effective treatment in terms of graft reinjury was the double-bundle 4-strand semitendinosus with gracilis tendon autograft (SUCRA 70%). Again, a higher SUCRA value (close to 1) represents higher probability of a treatment being ranked among the most effective interventions.

Conclusion: In ACL reconstruction, based on the results of SUCRA rankings, patients should be counseled that the double-bundle 4-strand semitendinosus with gracilis tendon autograft and the bone-patellar tendon-bone autograft represent potentially superior surgical techniques for simultaneously enhancing patient comfort, restoring knee anterior stability, and having low reinjury risk, and the single-bundle 5-strand semitendinosus with gracilis tendon autograft has the potential advantage in restoring rotational knee stability. To achieve best patient-reported outcomes, the single-bundle 3/4-strand semitendinosus tendon autograft and the single-bundle 4-strand semitendinosus with gracilis tendon autograft with synthetic artificial ligament are also recommended. Further comparisons of different grafts should be performed to determine whether meaningful differences exist between men and women in terms of these surgical outcomes.

Level of evidence: Level I, therapeutic study.