Double-bundle versus single-bundle anterior cruciate ligament reconstruction: a prospective randomized study with 5-year results

Abstract

Background: Surgical technique is essential in anterior cruciate ligament (ACL) reconstruction.

Purpose: This randomized 5-year study tested the hypothesis that double-bundle ACL reconstruction with hamstring autografts and aperture screw fixation has fewer graft ruptures and rates of osteoarthritis (OA) and better stability than single-bundle reconstruction.

Study design: Randomized controlled trial; Level of evidence, 1.

Methods: Ninety patients were randomized: double-bundle ACL reconstruction with bioabsorbable screw fixation (DB group; n = 30), single-bundle ACL reconstruction with bioabsorbable screw fixation (SBB group; n = 30), and single-bundle ACL reconstruction with metallic screw fixation (SBM group; n = 30). The following evaluation methods were used: clinical examination, KT-1000 arthrometer measurement, and International Knee Documentation Committee (IKDC) and Lysholm knee scores. Additionally, radiographic evaluation was made by a musculoskeletal radiologist who was unaware of the patients' clinical and surgical data. A single orthopaedic surgeon performed all the operations, and clinical follow-up assessments were made in a blinded manner by an independent examiner.

Results: Preoperatively, there were no differences between the groups. Eleven patients (7 in the SBB group, 3 in the SBM group, and 1 in the DB group) had a graft failure during the follow-up and went on to ACL revision surgery (P < .043). Of the remaining 79 patients, a 5-year follow-up was performed for 65 patients (20 in the DB group, 21 in the SBB group, and 24 in the SBM group) who had their grafts intact. At 5 years, there was no statistically significant difference in the pivot-shift or KT-1000 arthrometer tests. In the DB group, 20% of the patients had OA in the medial femorotibial compartment and 10% in the lateral compartment, while the corresponding figures were 33% and 18% in the single-bundle groups, again an insignificant finding. Further, no significant group differences were found in the knee scores.

Conclusion: The double-bundle surgery resulted in significantly fewer graft failures and subsequent revision ACL surgery than the single-bundle surgeries during the 5-year follow-up. Knee stability and OA rates were similar at 5 years. In view of the size of the groups, some caution should be exercised when interpreting the lack of difference in the secondary outcomes.