ACL reconstruction with double-bundle technique: a review of clinical results.

Anatomical and biomechanical studies have shown that the anterior cruciate ligament (ACL) primarily consists of 2 distinct bundles, the anteromedial (AM) and posterolateral (PL), which act separately during the knee's range of motion. Conventional ACL reconstruction techniques have focused on restoration of the AM bundle only, while giving limited attention to the PL bundle. The outcomes of these single-bundle techniques have been relatively good in ACL reconstruction. In recent years, many authors have developed double-bundle ACL reconstruction techniques to better replicate ACL anatomy and its 2 bundles. The purpose of this article is to analyze the clinical results of the double-bundle ACL reconstruction according to the current literature. The review focuses primarily on randomized controlled trials. According to the 14 randomized controlled trials published in the literature and included in this review, 4 (29%) trials did not find any significant differences in the results between double-bundle and single-bundle ACL reconstruction. Ten (71%) trials reported significantly better results with double-bundle technique than with single-bundle technique, of which 7 (50%) reported better rotational stability, 6 (43%) reported better anterior stability, 3 (21%) reported better objective knee scores, 3 (21%) reported better subjective knee scores, 2 (14%) reported fewer graft failures, and 1 (7%) reported less degenerative changes of the knee. In addition, none of the trials found the single-bundle technique to have better results in any of these evaluations when compared with the double-bundle technique. However, 13 (93%) of the 14 trials had only a short-term follow-up (1-3 years), and only 1 (7%) trial conducted long-term follow-up (8-10 years). Therefore, only through long-term follow-up studies will we be able to determine whether the double-bundle reconstruction is really better than the single-bundle technique.