Single-bundle versus double-bundle reconstruction in anterior cruciate ligament: a meta-analysis

To systematically evaluate the clinical outcomes of single-bundle (SB) versus double-bundle (DB) anterior cruciate ligament (ACL) reconstruction and to provide evidence-based support for clinical surgical decision-making. A comprehensive search of English-language databases was conducted to identify randomized controlled trials (RCTs) comparing SB and DB ACL reconstruction. Two investigators independently performed literature screening, data extraction, and risk of bias assessment. The mean difference (MD) and odds ratio (OR) were used to pool effect sizes. Publication bias was evaluated using funnel plots, Egger’s test, and trim-and-fill analysis. Heterogeneity and result robustness were explored through subgroup analysis and sensitivity analysis. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was applied to assess the quality of evidence. A total of 41 RCTs comprising 3,568 patients (1,786 in SB group and 1,782 in DB group) were finally included. Pooled analysis showed no statistically significant difference between SB and DB groups in short‑term (MD = 0.26, 95% CI: -0.01 to 0.53, P = 0.06, I² = 60%, GRADE: low) or long‑term (MD = 0.15, 95% CI: -0.25 to 0.56, P = 0.46, I² = 68%, GRADE: low) KT‑1000 / KT‑2000 Knee Ligament Arthrometer (KT) side‑to‑side difference. The DB group demonstrated significantly higher rates of negative pivot‑shift test in both short‑term (OR = 0.62, 95% CI: 0.48 to 0.79, P < 0.001, I² = 44%, GRADE: moderate) and long‑term (OR = 0.37, 95% CI: 0.18 to 0.77, P = 0.007, I² = 68%, GRADE: moderate) follow‑ups compared with the SB group. No significant difference in short‑term Lysholm score was observed between the two groups (MD = -0.74, 95% CI: -3.05 to 1.58, P = 0.53, I² = 69%, GRADE: low). However, the DB group achieved a significantly higher long‑term Lysholm score (MD = -1.32, 95% CI: -2.21 to -0.42, P = 0.004, I² = 0%, GRADE: high). Subgroup analysis indicated that an anteromedial portal anatomical SB technique could offset the short-term rotatory stability advantage of DB reconstruction (interaction P = 0.01 for surgical approach; P = 0.002 for anatomic type); however, at long-term follow-up, the rotational stability advantage of DB reconstruction re-emerged (interaction P < 0.001), indicating that the offset effect did not persist over time. DB ACL reconstruction may offer statistically improvements in specific objective stability parameters and long-term Lysholm scores; nevertheless, current evidence does not indicate clinically meaningful superiority over SB reconstruction for most patients. SB reconstruction remains a reliable option for meeting short-term treatment needs. Consequently, surgical technique selection should be individualized based on patient age, activity demands, and surgeon expertise.