Is double-bundle anterior cruciate ligament reconstruction superior to single-bundle? A comprehensive systematic...

To describe current evidence on single- and double-bundle anterior cruciate ligament (ACL) reconstruction, in terms of differences in knee kinematics, functional outcomes, patient-reported outcomes and graft failures.

An electronic search was made using PubMed (MEDLINE), EMBASE and Cochrane Library. Studies published from January 1995 to August 2011 were included, and an updated search was made in PubMed in July 2012. Therapeutic studies, level of evidence I-III, for isolated primary ACL tears written in English comparing single- and double-bundle reconstruction reporting clinical outcome were included. Quality appraisal based on Cochrane Collaboration's tool for assessing risk of bias was performed.

Of 7,154 potentially eligible studies, 60 papers were included (25 randomised controlled trials, 21 prospective comparative studies, 14 retrospective comparative studies), comprising 4,146 patients (2,072 single-bundle, 2,074 double-bundle). Minor differences were found between study types. An analysis of graft failures revealed fewer re-ruptures in double-bundle reconstruction than single-bundle, 19 and 44, respectively. Up to 45 % of the studies reported a superior outcome in double-bundle reconstruction in terms of antero-posterior laxity, measured with the Lachman, anterior drawer, KT-1000/2000 and navigation. Measurements of rotatory laxity revealed superior results in double-bundle reconstruction measured with pivot shift and navigation in 18/42 (8/15 anatomically reconstructed) and 9/20 studies, respectively. Patient-reported outcome measures and functional outcomes did not differ to a large extent; however, differences when identified were almost exclusively in favour of double-bundle reconstruction.

Based on current evidence, double-bundle reconstruction appears to have fewer re-ruptures and less antero-posterior and rotatory laxity. Furthermore, no differences were found in short-term patient-reported outcome measures or objective findings. However, detailed statistical analyses of the included studies divided into homogeneous groups are needed to avoid reporting bias and to confirm any statistical difference.