A prospective randomized study comparing double- and single-bundle techniques for anterior cruciate ligament reconstruction
Ahlden M, Sernery N, Karlsson J, and Kartus J. Am J Sports Med. 2013; [Epub Ahead of Print}
Take Home Message: Patients receiving single-bundle or double-bundle techniques for ACL reconstruction have similar favorable patient-reported and objective measures at 2 years post-surgery.
Despite development of both the single-bundle and double-bundle technique for reconstructions of anterior cruciate ligament (ACL) ruptures, a definitive gold-standard is still debated. Therefore, we need more clinical trials to identify which technique is most beneficial in terms of post-surgical knee stability. Therefore, Alden and colleagues completed a prospective, randomized controlled trial of 98 patients from 2 hospitals in western Sweden to investigate which surgical method had better clinical outcomes at 2 years post-surgery. The authors used the pivot-shift test to assess their primary outcome measure, which was the degree of rotational laxity. The secondary outcome measures were functional tests (1-legged hop test, square hop test, Lachman test and KT-1000 arthrometer) and patient-reported outcome measurements (Lysholm knee scoring scale, KOOS, and Tegner activity scale). The authors included patients who sustained a unilateral ACL injury, were 18 years of older, and failed nonsurgical treatment. Following inclusion, patients were randomized into either a single-bundle technique group (SBG) or double-bundle technique group (DBG). All patients, regardless of group, underwent a hamstring tendon graft and followed the same rehabilitation guidelines. One physical therapist, who was blinded to the type of surgical technique the patient received, assessed the patients at both the preoperative and 2 year follow-up examination. Overall, 38 of 50 (76%) patients in the SBG and 35 of 53 (66%) patients in the DBG had meniscal injuries either at the time of surgery or during the follow-up period. At the 2 year follow-up, the 2 groups had similar patient-reported outcomes (KOOS, Tegner activity level, Lysholm score), anterior knee laxity as measured by the KT-1000 arthrometer or Lachman test, and rotational laxity as assessed with the pivot-shift test (negative pivot-shift test: 67% and 79% of patients in the SBG and DBG, respectively).
Overall, the authors demonstrate that neither graft was more beneficial in terms of mitigating rotational laxity than the other. This is relevant since ligament laxity increases the risk of episodes of “giving away”. Therefore, clinicians must identify the best surgical technique to eliminate episodes of “giving away” and increase the patient’s ability to return to physical activity. While the authors found that neither group performed significantly better than the other, there were limitations. Firstly, patients had varying degrees of meniscal injury, which may lead to less stability in the joint. Secondly, the outcome measures (e.g., pivot-shift test and Lachman test) were fairly subjective. Future research on this topic should look to magnetic resonance imaging to better assess joint laxity. Finally, the indication for surgery in this study was failing nonsurgical treatment but there was no indication regarding how long after the injury the surgery was delayed. If the patient eventually failed nonsurgical treatment, then at least some patients subjected their joint to increase strain on the surrounding structures in episode of “giving away.” Ultimately this study presents data to support the idea that regardless of graft technique all patients, age 18 or older with unilateral ACL tears should respond well with regards to laxity following ACL reconstruction surgery.
Questions for Discussion: In your current setting do you often counsel your patients on choosing surgical options such as graft type, bundle type, etc.? Do you believe this data will have an impact on our ultimate goal of identifying a true gold-standard ACL reconstruction surgical method?
Written by: Kyle Harris
Reviewed by: Jeffrey Driban
Baseline Variables and Outcomes After ACL Surgery: The Swedish National Anterior Cruciate Ligament Register