Clinical outcomes of double- vs single-bundle anterior cruciate ligament reconstruction: A systematic review of randomized control trials

J. Kongtharvonskul, J. Attia, S. Thamakaison, C. Kijkunasathian, P. Woratanarat,  A. Thakkinstian
Scand J Med Sci Sports. 2012 Jan 31

Without question, anterior cruciate ligament (ACL) tears are one of the most common knee injuries sustained by athletes at all levels.  ACL reconstruction is the standard of care to treat patients with complete ruptures.  However, currently there are two surgical techniques to commonly used reconstruct the ACL (single and double bundle).  Previous meta-analyses have compared single vs. double bundle ACL reconstructions examining both anterior-posterior translation and rotational stability as measured by the KT1000/2000, but other factors such as functional outcomes and heterogeneity sources (i.e., age, gender, sex, injury grade, use of instrument assessment) have gone largely unexamined.  Therefore, the purpose of this systematic review was to determine which ACL reconstruction technique (single vs. double bundles) improves both anterior-posterior and rotational stability as well as functional outcomes, while controlling for several factors.  One final area that was examined was complications associated with the respective reconstruction.  The authors conducted searches on multiple online databases and identified 286 articles but only 13 were used based upon the following criteria: patients >18 years of age, single versus double-bundle reconstruction clinical outcome comparison, minimum 1 year post-op outcome (rotational laxity measured by pivot-shift test, anterior laxity measured by KT1000/2000 arthrometer and functional outcomes as measured by International Knee Documentation Committee (IKDC), Tegner, Lysholm or Cincinnati scores and complications (revision, reflex sympathetic dystrophy, infection, re-tear).  After data extraction and comparison, it was found that patients undergoing double-bundle reconstruction were 4 times more likely to have a normal pivot-shift and twice as likely to have improved IKDC scores than the single bundle patients.  The double-bundle reconstruction also had a trend toward decreased anterior translation, but it didn’t reach significance.  There was no statistical difference between the 2 techniques regarding functional outcomes and complications, even though IKDC scores were slightly improved (non-significant) in the double-bundle patients.

These results are interesting for a handful of reasons.  First and foremost, the fact that the double-bundle patients had improved rotational stability as elicited by the pivot-shift test is a major benefit.  When considering the roles of the ACL’s bundles, this makes complete sense.  The single bundle technique reconstructs the anteromedial bundle of the ACL, which is taut during knee flexion and resists anterior knee translation. The posterolateral bundle, which resists rotation during knee flexion, is absent in this reconstruction.  Upon post-op examination and scoring, it stands to reason that single-bundle reconstruction would have inferior rotational stability outcomes.  Another interesting result found from this meta-analysis is the fact that there was no significant difference regarding functional outcomes as measured by the 4 knee scores.  There were differences between subjective and objective IKDC scores, but not statistically significant.  With the added rotational stability afforded by the double-bundle reconstruction, it is surprising that functional outcomes were no different between the 2 reconstruction types.  That begs the question, if functional outcomes are not improved by the double bundle reconstruction, would a single bundle reconstruction be advised for non-athletes?  What techniques are your team physicians using for ACL reconstructions, and what kinds of outcomes are you seeing?  Are there any complications, and what do you see most often?

Written by:  Mark Rice
Reviewed by:  Stephen Thomas

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Kongtharvonskul J, Attia J, Thamakaison S, Kijkunasathian C, Woratanarat P, & Thakkinstian A (2012). Clinical outcomes of double- vs single-bundle anterior cruciate ligament reconstruction: A systematic review of randomized control trials. Scandinavian Journal of Medicine & Science in Sports PMID: 22288837