Comparison between Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction

Abstract

Background Double-bundle ACL reconstruction popularity is increasing with the aim to reproduce native ACL anatomy and improve ACL reconstruction outcome. However, to date, only a few randomized clinical studies have been published. Purpose The aim of this study was to prospectively compare the clinical results of single- and double-bundle ACL reconstruction. Study Design Randomized controlled clinical trial; Level of evidence, 1. Methods Seventy patients with a chronic unilateral ACL rupture who underwent arthroscopically assisted ACL reconstruction using a hamstring graft were randomized to receive a single- (SB) or double-bundle (DB) reconstruction. Both groups were comparable with regard to preoperative data. A double-incision surgical technique was adopted in both groups. The graft was fixed by looping the hamstring tendons around a bony (DB) or a metallic (SB) bridge on the tibial side and with interference screws reinforced with a staple on the femur. The same rehabilitation protocol was adopted. Outcome assessment was performed by a blinded, independent observer using the visual analog scale (VAS) score, the new International Knee Documentation Committee (IKDC) form, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and KT-1000 arthrometer evaluation. Results All the patients reached a minimum follow-up of 2 years. No differences between the 2 groups were observed in terms of KOOS and IKDC subjective score. A statistically significant difference in favor of the DB group was found with the VAS (P < .03). The objective IKDC final scores showed statistically significantly more “normal knees” in the DB group than in the SB group (P = .03). There was 1 stability failure in the DB group and 3 in the SB group. The KT-1000 arthrometer data showed a statistically significant decrease in the average anterior tibial translation in the DB group (1.2 mm DB vs 2.1 mm SB; P < .03). The incidence of a residual pivot-shift glide was 14% in DB and 26% in SB (P = .08). Conclusion In the 2-year minimum follow-up, DB ACL reconstructions showed better VAS, anterior knee laxity, and final objective IKDC scores than SB. However, longer follow-up and accurate instrumented in vivo rotational stability assessment are needed.