How often do you use an immobilizer after ACL reconstruction? The January 2009 issue of American Journal of Sports Medicine is out and there a few interesting articles I wanted to feature. The first of which discusses the use of knee bracing and immobilization postoperatively following ACL reconstruction using a hamstring tendon graft.
The Use of Postoperative Bracing Following ACL Reconstruction
In this study, 82 patients were randomized into two groups: 1) a group of patients that wore an unhinged knee immobilizer and 2) a control group that did not use a brace. At 2 week postoperatively, the authors report that there were no differences between groups for pain, medications consumed, complications, and range of motion.
The authors conclude that an unhinged postoperative knee brace is not recommended following ACL reconstruction for the purpose of pain control. That is the exact phrasing that was used. The last part of the sentence is significant, “for the purpose of pain control.” The paper is centered around pain control more than any other variable, it is even in the title of the paper.
There are a couple of methodological flaws that I found that are likely significant in the presentation of the results
- Compliance for brace use was extremely low and only documented by subjective reports. Only 86% of subjects in the immobilizer reported wearing their brace from day 7-13 and by day 14 only 26% of subjects reported wearing their brace as instructed. Since this is only self-reported, you can assume that these numbers are best-case scenario as I wouldn’t be surprised if a few subjects were not completely honest. Regardless, taking these numbers into consideration, you can argue that the brace group consisted of only 11 patients and the non-brace group had 73 subjects. Not sure that this low of compliance can lead to a good comparison.
- All of the patients were on pain medication consisting of either Percocet or Tylenol with codeine and naproxen. As previously mentioned, pain scales were of primary importance to the authors in the discussion section of the paper. However, it appears that pain was controlled with pharmaceuticals and likely has no correlation to brace use.
I am not sure that based on the results of this study, my choice to use a brace or not following ACL reconstruction will be influenced. Clinically, I have always used a postoperative knee brace following ACL reconstruction, though have always used a drop-lock hinged knee brace. This allows the patient to have the knee free to move throughout the day, however can lock the brace into full knee extension during ambulation.
While I feel that this is helpful for stability and protection of the knee postoperatively, these are not the reasons why I use a brace. For me, it is for a much more simplistic reason:
The quadriceps are susceptible to reflexive inhibition due to the pain and effusion associated with surgery.
Ambulating without full volitional control of the quadriceps encourages improper gait and makes the limb susceptible to “giving-way episodes” and potential harm.
The brace is utilized for the first 7-21 days depending on the patient and their ability to restore volitional control of the quad. Many factors will affect the duration of the brace use, including patient selection, age, and previous activity level. For example, an athlete that has an acute ACL reconstruction will likely restore their volitional control sooner than an older, sedentary patient. The key is to assess and individualize.
Another interesting fact that I took from this paper really has nothing to do with the topic of the study, but nevertheless was interesting to me. Look at the progression of reported pain on a VAS over the course of two weeks:
|1 hour postoperatively||20.0-20.8|
|Day 0 PM||29.3-30.8|
|Day 1 AM||28.7-34.1|
|Day 1 PM||41.9-45.5|
|Day 2 AM||35.1-40.8|
|Day 2 PM||32.6-35.2|
Pain appears to peak at 36 hours after surgery and remain high day 1 and day 2 postoperatively before gradually decreasing to a fairly tolerable level by week 14. This is important information for clinicians and patients. When I see a patient immediately postoperatively, I commonly tell them that the first few days are the worst and that it is not uncommon to feel worse days 2 or day 3. This helps assure them that they have not reinjured themselves when pain worsens.
This is also helpful regarding pain’s role in the inhibition of the quadriceps. Based on these numbers, it wouldn’t surprise me if a patient was having difficulty with volitional control of the quadriceps 1 week after surgery despite appropriate rehabilitation. If you were using a brace for this reason, as I suggest above, it looks like day 7 may be too early to discharge the brace and that 2 weeks may be more appropriate for many patients.
Food for thought either way I guess. How common do you use brace immediately after ACL reconstruction? What is the duration? What is your reasoning? Would love to hear what other centers are doing.
L. A. Hiemstra, S. M. Heard, T. M. Sasyniuk, G. L. Buchko, J. G. Reed, B. J. Monteleone (2008). Knee Immobilization for Pain Control After a Hamstring Tendon Anterior Cruciate Ligament Reconstruction: A Randomized Clinical Trial The American Journal of Sports Medicine, 37 (1), 56-64 DOI: 10.1177/0363546508322896