Single-bundle versus double-bundle anterior cruciate ligament reconstruction: an up-to-date meta-analysis

The aim of this meta-analysis was to compare the results of arthroscopic single-bundle and double-bundle anterior cruciate ligament (ACL) reconstruction. We systematically searched electronic databases to identify randomised controlled trials (RCTs) in which arthroscopic single-bundle was compared with double-bundle for ACL reconstruction. The search strategy followed the requirements of the Cochrane Library Handbook. The outcomes of these studies were analysed in terms of graft failures, Lysholm score, negative pivot-shift test, KT1000 arthrometer measurements, knee extensor and flexor peak torques, knee extension and flexion deficit, and subjective and objective International Knee Documentation Committee (IKDC) final score. Methodological quality was assessed and data were extracted independently. Standard mean difference (SMD) or odds ratio (OR) with 95 % confidence interval (CI) was calculated by a fixed effects or random effects model. Heterogeneity across the studies was assessed with the I-square and chi-square statistic. Forest plots were also generated. We identified 17 RCTs comprising 1,381 patients who were treated by arthroscopic single-bundle versus double-bundle ACL reconstruction. The results of meta-analysis of these studies showed that arthroscopic double-bundle reconstruction was associated with a lower risk of graft failures (P = 0.002) and a lower rate of positive pivot-shift test (P < 0.0001). Compared with single-bundle reconstruction, double-bundle reconstruction had a lower KT1000 arthrometer measurement (P < 0.00001), a lower knee extension deficit (P = 0.006) and a higher subjective IKDC score (P = 0.03). There was no statistically significant difference between single-bundle and double-bundle reconstruction in Lysholm score (P = 0.91), knee extensor peak torques (P = 0.97), knee flexor peak torques (P = 0.96), knee flexion deficit (P = 0.30) and objective IKDC score (P = 0.18). Considering the more favourable outcomes of graft failures, knee joint stability and knee joint function in double-bundle reconstruction, we concluded that arthroscopic double-bundle reconstruction should be considered as the primary treatment in ACL reconstruction.