Anterior cruciate ligament (ACL) injuries are commonly encountered by the orthopaedic surgeon, with approximately 250,000 ACL tears occurring annually in the United States. Surgical reconstruction of the ACL is considered the standard treatment for active patients with ACL injury, with the goals of surgery being restoration of knee stability and prevention of further intra-articular damage. The native ACL is composed of the functionally distinct anteromedial (AM) and posterolateral (PL) bundles. Cadaveric studies have suggested that double-bundle (DB) anterior cruciate ligament reconstruction (ACL-R) may provide improved anterior and rotational stability compared with single- bundle (SB) ACL-R. Improvements in femoral tunnel positioning for SB ACL-R to a more lateral position may negate the biomechanical stability benefits of DB ACL-R.

DB ACL-R has gained popularity because of an improved ability to replicate the normal anatomy of the AM and PL bundles of the ACL and the potential benefit of restoring more normal knee kinematics and stability than with SB ACL-R. Numerous clinical studies, including many prospective, randomized controlled trials, have been published to compare SB ACL-R and DB ACL-R. On the basis of the proliferation of clinical studies comparing SB and DB ACL-R, multiple authors have conducted systematic reviews and meta-analyses comparing SB ACL-R and DB ACL-R. Meredick conducted the first such meta-analysis in 2008, finding a small (0.52 mm) but statistically significant improvement in knee stability as determined by KT arthrometry (MEDmetric, San Diego, CA) in favor of DB ACL-R with no other differences between techniques. Although numerous overlapping meta- analyses have been performed to compare SB and DB ACL-R, the results of the meta-analyses have been discordant in their findings regarding the clinical outcomes and knee stability provided by these 2 techniques.

The purposes of this study were (1) to conduct a systematic review of meta-analyses comparing SB and DB ACL-R, (2) to propose a guide through the currently discordant best available evidence to provide treatment recommendations, and (3) to highlight gaps in the literature that require future research. The null hypothesis was that SB and DB ACL-R would exhibit similar clinical outcomes.

Full Article: Does Double-Bundle Anterior Cruciate Ligament Reconstruction Improve Postoperative Knee Stability Compared With Single-Bundle Techniques? A Systematic Review of Overlapping Meta-analyses