Outcome of Single-Bundle versus Double-Bundle Reconstruction of the Anterior Cruciate Ligament

Abstract

Background The anterior cruciate ligament (ACL) has 2 anatomic bundles. Standard ACL reconstruction is with a single-bundle graft, but double-bundle reconstruction may better control knee rotational torque, a potential cause of failure after single-bundle reconstruction. The authors investigated outcomes of single-bundle versus double-bundle ACL reconstruction. Hypothesis There is no difference in outcomes of single-bundle versus double-bundle reconstruction. Study Design Meta-analysis. Methods The authors systematically identified randomized controlled trials (RCTs) comparing single-bundle versus double-bundle ACL reconstruction (secondary analysis includes nonrandomized trials). Outcomes reported in a majority of included trials were meta-analyzed. Results Four RCTs were included (secondary analysis including 5 additional trials yielded reassuringly similar results). Two outcome measures were reported (in a manner permitting meta-analysis) in at least 3 of 4 trials: KT-1000 arthrometer and pivot-shift testing. On average, KT-1000 arthrometer side-to-side difference was 0.52 mm closer to normal in patients treated with double-bundle reconstruction. This difference is demonstrated to be clinically insignificant. In addition, there was no statistical difference in the odds of having a normal or nearly normal pivot-shift result in patients treated with double-bundle versus single-bundle reconstruction. Conclusion Double-bundle reconstruction does not result in clinically significant differences in KT-1000 arthrometer or pivot-shift testing. The pivot-shift results have particular clinical relevance because the test is designed to evaluate knee rotational instability; the results do not support the theory that double-bundle reconstruction better controls knee rotation. Improved quality of future RCTs would allow meta-analysis of a greater number of outcome measures including measures of symptoms and disabilities most important to patients.