Single-bundle versus double-bundle arthroscopic reconstruction of the anterior cruciate ligament: what does the available evidence suggest?

The introduction of the double-bundle technique as a surgical option for primary anterior cruciate ligament (ACL) surgery stems from the hypothesis that replicating the double-bundle anatomy of the native ACL improves knee kinematics by supplying better rotational control. We performed a systematic review of the literature comparing double-bundle with standard single-bundle reconstruction methods. One RCT and three quasi- RCTs with a one- to two-year follow- up were included in this review. On the basis of these studies, ACL reconstruction with a double- bundle technique leads to less residual pivot-shift as assessed on manual and instrumented tests. Conflicting results exist as to whether the double-bundle technique leads to less side-to-side anterior tibial translation, and no significant differences were found regarding proprioception, flexorextensor peak torque and knee function as assessed with the International Knee Documentation Committee score. On the other hand, better subjective knee function was found in one quasi-RCT. However, there is a lack of correlation between these kinematic differences and an as yet unproven clinical effect. Uncertainties also exist regarding the mid- and long-term performances of the ACL reconstructed with a double-bundle technique. Comparison between the single- bundle and double-bundle techniques should be expanded to cover unresolved issues such as the rate of complications from a more challenging surgical technique, the risk of complicating revision surgery due to the presence of two tunnels, and the cost-effectiveness of a procedure with a higher consumption of fixation devices. The doublebundle technique should be further investigated by experienced knee surgeons in studies with higher methodological quality.