Sports Medicine Research: In the Lab & In the Field: Single- and Double-bundle Techniques Lead to Similar Outcomes Following ACL Surgery (Sports Med Res)


Wednesday, September 25, 2013

Single- and Double-bundle Techniques Lead to Similar Outcomes Following ACL Surgery

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

Related Posts:

Ahldén M, Sernert N, Karlsson J, & Kartus J (2013). A Prospective Randomized Study Comparing Double- and Single-Bundle Techniques for Anterior Cruciate Ligament Reconstruction. The American Journal of Sports Medicine PMID: 23921339


Anonymous said...

As a collegiate athletic trainer, we see many of these each year. When having discussions with my athletes about choices regarding graft type, etc. I try to assure them that the best option for them is always what the surgeon is most comfortable doing. Each type of graft has it's strengths and weaknesses compared to the other (location of pain, rejection in the case of a cadaver graft, etc.) but in the research that I've seen, each graft type is strong enough to do the job that we are asking of it.
Therefore, if the grafts themselves are all capable of performing the tasks, we leave it up to the surgeon to install it properly and make sure that it is fixated with the utmost quality. On that line of reasoning, it makes sense that we would want a surgeon to perform a technique that they are confident with in order to get the best results possible.

Joey Lopez said...

Something that sparks my interest but also something I have been questioning for years is what information does a doctor go off of when choosing an anatomical structure for an ACL surgery. What will an athlete get a graft of when getting his/her ACL reconstructed? How about someone who is just physically active? Or how about the average person who just goes on with normal daily activity (i.e. work, cleaning etc.)? Also, if neither graft reduced rotational laxity, how would you differ on what structure to graft based on that?

Kyle said...


Thanks for the comment, and a great one it is. I think you have a very valid point. I too counsel my patients and encourage them to trust the surgeon in their choice of graft, technique, etc. I think not only does the research support this as we see in the study above, but I also feel that in throwing support behind the surgeon we further support our fellow members of the sports medicine team. Now with this all being said. I do encourage them to educate themselves with current literature, and ask many questions of the surgeon. I do this, not to cause doubt, but make the patient feel as comfortable as possible with their situation. I find in doing this, patients have a much more realistic expectation of their recovery process and overcome setbacks much better. Is this something that you do as well?

Kyle said...


Lots of excellent questions posed here. Firstly, I should acknowledge my limitations. I'm not a surgeon so I cannot say definitively all that goes into the decision of surgical details. With many studies providing conflicting results, and seemingly endless variable to look at, surgeons do have a wealth of knowledge to decipher. Hopefully some of these professionals who see this post will comment to help foster our understanding. The information I can speak to with knowledge is your question surrounding patients varying levels of physical activity. Although not as popular in the US right now, conservative treatment (no reconstruction) of ACL ruptures is growing in popularity. Not getting a ruptured ACL reconstructed in some literature, suggests that even when surgery is carried out, it does not meet the goals it sought to remedy (instability, return to preinjury biomechanics, etc.). With that being said, patients who are highly active may not be good candidates for this treatment simply due to the stresses placed on the knee joint during rigorous physical activity. There is also data our there which suggests that it may also fall on the individuals ability to stabilize the knee joint through cocontraction of the hamstring and quadriceps. For more information on these patients I would suggest, Eastlack ME, Axe MJ, Snyder-Mackler L: Laxity, instability, and functional outcome after ACL injury: copers versus noncopers. There is also some interesting research currently being done by Richard Frobell and colleagues using a randomized-controlled trial study design. This study is the first of its kind and I think provides some strong evidence for both treatment options given the patient is screened properly. I hope this gives you a little more insight into some of the questions you had. Keep the great comments coming.

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