The Effect of Knee Bracing After Anterior Cruciate Ligament Reconstruction

Abstract & Commentary

Synopsis: While bracing may have some minimal effect on the patient’s performance on a functional scale three months after surgery, the long-term benefit remains in question.

Source: Risberg MA, et al. The effect of knee bracing after anterior cruciate ligament reconstruction. A prospective, randomized study with two years’ follow-up. Am J Sports Med 1999;27(1):76-83.

For years, the inclusion of knee braces in post-op rehabilitation programs after anterior cruciate ligament (ACL) reconstruction has been considered standard of care. These braces have been designed to "protect against excessive motion and excessive loading on the healing ACL graft." However, controversy exists regarding the use of these post-op braces. There is a paucity of evidence concerning their effectiveness. The purpose of this study was to perform a prospective, randomized clinical trial to determine if the braces are effective. The subjects had an ACL injury that was either isolated or combined with a meniscus or MCL injury. All candidates had undergone a bone-patellar tendon-bone ACL reconstruction.

There were 60 subjects with a mean age of 28 years (range, 15 to 50 years). There were 28 women (47%) and 32 men (53%). The mean time from injury to operation was 31 months. All patients underwent the same rehabilitation program, which included CPM acutely. Isometric and passive extension exercises were also started immediately and continued. All subjects progressed following "closed kinetic chain principles." The patients were randomized into two groups, with and without braces. The brace group "utilized the DonJoy rehabilitative range of motion brace" (DonJoy, Smith & Nephew, Carlsbad, CA) for the first two weeks. They were instructed to wear the "DonJoy gold point functional knee brace" (DonJoy, Smith & Nephew) for the next 10 weeks. After 10 weeks the patients were instructed to use braces on an "as needed" basis.

Outcome measurements included knee joint laxity as measured by the KT-1000, range of motion, cross-sectional area of the thigh as measured by computer tomography and functional testing.

Data were recorded within 48 hours preoperatively and postoperatively at six weeks, three months, six months, one year, and two years, with the exception of knee laxity and function, which were measured at all times except six weeks. Preoperatively, there were no significant differences between the two groups. While there were some differences in associated pathologies between the two groups with respect to meniscal injuries, overall the groups were comparable. There were no significant differences between the two groups with regard to knee laxity or range of motion measurements at the follow-up visits. Cross-sectional area of the thigh was significantly decreased in the braced group at three months; however, this difference disappeared by six months. There were no significant differences with regard to isokinetic measures at each follow-up. Finally, there were no significant differences between the braced and nonbraced groups with respect to the functional knee test, except at three months after surgery, when the "Stairs Hopple Test" indicated that the braced group was significantly better functionally. In addition, follow-up MRIs revealed three new meniscal injuries in the braced group while the nonbraced group had none. There was also an increased number of degenerative changes in seven subjects of the braced group while the no-braced group had none.

Comment by Clayton F. Holmes, EdD, PT, ATC

This study is an attempt to determine the effectiveness of post-op bracing for ACL patients. Perhaps the most important finding relates to knee ligament laxity. Specifically, at no time, including two-year follow-up, was there an increase in knee joint laxity in patients who did not wear the brace postoperatively as compared with those who did. It should also be pointed out that early motion, early full-weight bearing, and an emphasis on closed kinetic chain exercises in the rehabilitation program have been reported as effective.1,2 These results regarding postoperative bracing may be different if a more conservative post-op rehabilitation approach is used. It is also important to note that at three months, bracing resulted in significantly more thigh atrophy while nonbraced subjects were more "functional" at three months. However, by six months there was no difference relative to thigh atrophy or function. Perhaps patients who have the brace "feel" more confident in their function despite having increased thigh atrophy. This study effectively dispels some of the myths concerning the possible benefits of bracing. Ultimately, while bracing may have some minimal effect regarding the patient’s performance on a functional scale at three months after surgery, the long-term benefit of post-op bracing remains in question. Furthermore, when cost is factored in, any benefit probably is not worth pursuing.

References

1. Shelbourne KD, Nitz P. Accelerated rehabilitation after anterior cruciate ligament reconstruction. Am J Sports Med 1990;18:292-299.

2. Schenck RC Jr, et al. A prospective outcome study of rehabilitation programs and anterior cruciate ligament reconstruction. Arthroscopy 1997;13:285-290.