A commentary on “Single-bundle versus double-bundle anterior cruciate ligament reconstruction in clinical and functional outcomes: an umbrella review and meta-meta-analysis”

Dear Editor, We read with great interest the recent umbrella review and meta-meta-analysis by Tang et al, which provides a comprehensive comparison between single bundle and double bundle anterior cruciate ligament reconstruction in terms of clinical outcomes, functional performance, and complication profiles[1]. By synthesizing data from 22 published meta-analyses and carefully addressing overlap using the GROOVE methodology, the authors offer one of the most methodologically rigorous and up-to-date summaries on this long-standing surgical debate. Their conclusion that neither technique demonstrates clear clinical superiority, despite small statistical advantages favoring double bundle reconstruction in certain patient-reported outcomes, represents an important and timely contribution to the literature. This work adheres to the TITAN 2025 guidelines on AI use and transparency[2] and complies with all related requirements. Beyond confirming the absence of clinically meaningful differences in objective stability and complication rates, this work implicitly highlights a broader issue in anterior cruciate ligament (ACL) research: the limited sensitivity of conventional outcome measures to capture nuanced functional recovery. While scores such as Lysholm or subjective International Knee Documentation Committee remain widely used, they may insufficiently reflect complex, sport-specific demands, neuromuscular control, and movement quality that ultimately determine return-to-sport success. Prior studies have suggested that biomechanical asymmetries, altered landing mechanics, and deficits in neuromuscular coordination persist even when traditional scores appear satisfactory, potentially contributing to reinjury risk or long-term joint degeneration[3,4]. Integrating such functional and biomechanical endpoints into future comparative studies may therefore be more informative than further refinements of bundle configuration alone. Another important aspect not fully explored in the current synthesis is patient heterogeneity. Increasing evidence indicates that age, activity level, generalized ligamentous laxity, and preinjury sport type substantially modify postoperative expectations and outcomes[5]. A “one-size-fits-all” comparison between single-bundle (SB) and double-bundle (DB) reconstruction may thus obscure meaningful subgroup effects. For instance, highly competitive pivoting athletes or patients undergoing revision surgery might benefit differently from anatomical reconstruction strategies than recreational athletes or older individuals. Future meta-analyses that stratify outcomes by patient phenotype rather than surgical technique alone could better support individualized decision making. In addition, the umbrella review underscores that surgical technique represents only one component of ACL reconstruction success. Emerging data emphasize the role of rehabilitation quality, psychological readiness, and biologic graft integration in determining long-term outcomes[6,7]. From this perspective, modest differences between SB and DB techniques may be overshadowed by variability in postoperative rehabilitation protocols or return-to-sport criteria. Shifting research priorities toward standardized, high-quality rehabilitation and biologic augmentation strategies may yield greater clinical gains than continued debate over bundle number. In summary, Tang et al provide a robust and methodologically sound synthesis that effectively closes the chapter on the question of global superiority between SB and DB ACL reconstruction. Our perspective extends their findings by suggesting that future progress in ACL surgery will likely come from refined patient stratification, advanced functional outcome assessment, and optimization of perioperative care rather than further technical comparison of reconstruction bundles. Such a shift could help translate statistical evidence into genuinely meaningful improvements for patients undergoing ACL reconstruction.