Playing with a knee brace after ACL reconstruction can affect your performance as an athlete.

I remember playing sports like soccer growing up as a kid; we would huddle in the middle of the field and devise a game plan to follow, to destroy the opposite team. You’d often hear expressions like:

• “Let’s play over the top and beat their back line with speed.”

• “Let’s split the through ball and have [insert cheekiest player’s name here] take them 1-on-1.”

• “Let’s exploit their weakness and attack the outside back with the knee brace.”

I’ve heard variations of these lines throughout my soccer career. Heck – I’ve probably said these lines all too many times.

Players who have used a knee brace after an ACL reconstruction know they can hinder their speed, power, and agility. They slow you down, but is it for a good reason to wear them?

Article Contents:

1. Why Athletes Should Wear Knee Braces After ACL Reconstruction
2. Types of Knee Braces
3. Return-to-Sport-Timeline
4. Costs of Knee Braces
5. Research on Bracing
6. Return-to-Sport Bracing After ACL Reconstruction

Why Athletes Should Wear Knee Braces After ACL Reconstruction

I posted a soccer-specific reactive cutting drill on my Instagram page not too long ago, so I got some blood-boiling responses. The athlete in the video was about eight months post-op and was not using a functional knee brace. We were in a controlled environment, and I dosed her activity accordingly. However, the video I posted seemed to have hit the nerve of other rehabilitation specialists.

While the video caused some banter that was exchanged back and forth in the comments section, it got me thinking. Although the verbiage “prophylactic” and “return-to-sport” are direct contradictions, possibly negating any validity of the aforementioned statement, it made me search out “said” research that advocates bracing.

Since then, I’ve done an extensive review of the literature on playing with knee braces, reading everything from randomized controlled trials to systematic reviews to meta-analyses. I’ll summarize what I found about playing with knee braces after ACL reconstruction below.

Types of Knee Braces

There are generally three types of knee braces that players returning-to-sport from ACL reconstruction can choose from:

• Rehabilitative

• Functional

• Prophylactic 

Rehabilitative Knee Braces 

Rehabilitative bracing allows early but the controlled motion of an injured limb. Think of your standard straight-leg brace or knee immobilizer immediately following surgery.

Functional Braces

Functional (or derotational bracing) provides stability for patients with post-operative or ACL-deficient knees, but only after a range of motion restrictions are lifted. Athletes use these braces when returning to sports from a significant injury.

Prophylactic Braces

Prophylactic bracing is used to prevent or reduce the severity of knee injury during high-risk sporting events. You have probably seen these strapped on the knee of a massive NFL lineman as he squares up to tackle an opposing player.

Return-to-Sport Timeline

According to Marx et al., nearly 60% of doctors surveyed by the American Academy of Orthopaedic Surgeons (AAOS) recommended a brace for the first six weeks following ACL reconstruction, while approximately 63% of them recommended a brace for participation in sports postoperatively. Other research from the American Orthopaedic Society for Sports Medicine (AOSSM) shows even higher numbers, with bracing used in approximately 85% of all cases following ACL reconstruction.

Decoster and Vailas revealed that only 13% of surgeons “never” prescribe functional bracing to their ACL reconstruction patients, with only 3% of surgeons “never” bracing ACL-deficient patients.

Costs of Knee Braces

With current injury rates (~200,000 per year/US), it is reasonable to assume more than 100,000 functional knee braces are prescribed annually in the United States. The average functional knee brace costing approximately $592 puts a significant financial burden of nearly $59,200,000 on our healthcare system, annually.

So, are you ready to put your money where your mouth is? Here’s what the research says.

Research on Bracing

Early Post-Operative Bracing

Early post-operative rehabilitative bracing is often performed following ACL reconstruction to protect the graft, limit the range of motion (while preserving extension), protect against excessive varus-valgus forces, and prevent anterior-posterior translation and/or rotation of the tibia.

Interestingly enough, Di Miceli et al. showed that bracing and delayed weight-bearing after ACL reconstruction might harm long-term functional outcomes according to IKDC score.

Bordes et al. published similar findings, revealing no significant difference in clinical outcomes between 969 patients assigned to early-bracing or non-bracing groups.7

Rodriguez-Merchán et al. found similar findings, stating that there was insufficient evidence to inform the current practice of routine knee brace immediately following ACL reconstruction.8

These three research articles also support the idea that accelerated rehabilitation, early weight-bearing, and early ROM are generally safe and beneficial to patient outcomes.

Not so fast! Before you unstrap your knee brace, continue reading.

Lowe et al. conducted a systematic review stating that early functional bracing may protect the implanted graft after ACL reconstruction without sacrificing function, range of motion, or proprioception.9

Other research by Fleming et al. showed that knee bracing could provide good protection against low-intensity anteroposterior displacement and sub-physiological rotational movements.10 

Beynnon et al. has also provided us with the knowledge that bracing can reduce ACL strain in response to a maximum of 140 N anterior tibial force (weight-bearing and non-weight-bearing) and 8 Nm internal tibial torques (non-weight-bearing). However, the protective effects of bracing are not observed with higher forces, weight-bearing tibial torques, isometric quadriceps contraction, or active flexion extension. 

I can see the validity in someone’s argument to immediately throw away their straight-leg brace or knee immobilizer upon leaving the hospital. Personally and professionally, however, if there is a way to possibly mitigate injury to that brand-new graft for two to three weeks, I’m all for it.

Return-to-Sport Bracing After ACL Reconstruction

We know knee braces can protect the ACL graft from anterior tibial translation up to 140 N and rotational torque up to 8 Nm. Athletic events, however, are comprised of unanticipated bursts of powerful movements, far exceeding these sub-physiological values. Is there any merit to functional knee bracing during athletics? The research below will address this.

McDevitt et al. conducted a prospective RCT to assess the effectiveness of functional knee bracing after ACL reconstruction. These researchers looked at 100 patients immediately placed in a straight-leg brace following ACL-R. After three weeks, both groups were discharged from the knee immobilizer.

One group was given a functional brace at the six-week mark and told to wear the brace with all activities up until six months post-surgery. At that time the functional brace was only to be applied during higher-level activities up until one-year post-op ACL surgery. The other group in the trial was given nothing. In the study, both groups of patients were followed up after two years, revealing no difference in knee stability, hop testing, range of motion, isokinetic strength, and International Knee Documentation Committee or Lysholm scores.

Birmingham et al. conducted a similar randomized controlled trial where researchers assigned 150 patients six-weeks post-op ACL reconstruction to a functional knee brace or neoprene sleeve group. Patients were followed up at one- and two-year marks when there were no significant differences in compliance or outcome measure (as recorded with ACL-QOL, KT1000 arthrometer, single-limb hop test, and Tegner activity scale.

Wright and Fetzer performed a systematic review of Level I evidence, revealing no evidence that pain, range of motion, graft stability, or protection from subsequent injury were affected by functional brace use.

Yang et al. concluded that no functional knee brace had been successfully validated to reduce re-injury risk after ACL reconstruction. As such, bracing for patients treated with ACL reconstruction should not be recommended routinely.

Smith et al. concluded that biomechanical and clinical evidence suggests current functional bracing technologies do not sufficiently restore normal biomechanics to the ACL-deficient knee, protect the reconstructed ACL, and improve long-term patient outcomes.

Pezzullo and Fadale concluded that using functional knee bracing to lower the risk of re-injury is not supported in the literature. Including as a component of the standard ACL rehabilitation protocol isn't easy.

There has been sufficient evidence that functional knee bracing effectively protects the graft from re-injury in skiers. Various studies show that skiers who are either ACL-deficient or have undergone ACL reconstruction are as much as six times more likely to sustain a knee injury when not wearing a brace. Injury rates for non-braced ACL reconstruction skiers have been reported to be as high as 13%, while bracing can reduce this to only 2%. Now, that’s some food for thought.

In my personal research, I have not found anything that supports using functional knee bracing to reduce the risk of re-injury in ACL reconstruction patients.

But that does not mean knee bracing to play sports is bad!

In many of the studies referenced, levels of subjective confidence and psychological readiness were positively affected by brace use. Wearing brace is excellent for reducing kinesiophobia and facilitating a return to previous confidence levels.

In Closing: Athletes Using Knee Braces After ACL Surgery

For the return-to-sport process from ACL reconstruction, knee braces are great during the 6-12 month mark. Like a security blanket, we need to prepare athletes for the moment when they get to leave their knee brace on the sideline. Personally, I like to prepare the athletes I work with for this moment in controlled environments, with appropriate dosing and monitoring of fatigue levels and biomechanics.

Nothing makes me crazier than people speaking in absolutes. Discrediting the clinical decision-making skills of “young” physical therapists is like discrediting the skill set of all physical therapists from the state of Massachusetts. You can’t possibly everyone into one basket. Experience and passion for learning and growth are not synonymous. 

References:

Yang, X., Feng, J., He, X., Wang, F. and Hu, Y. (2019). The effect of knee bracing on the knee function and stability following anterior cruciate ligament reconstruction: A systematic review and meta-analysis of randomized controlled trials. Orthopaedics & Traumatology: Surgery & Research, 105(6), pp.1107-1114.

Marx RG, Jones EC, Angel M, Wickiewicz TL, Warren RF. Beliefs and attitudes of members of the American Academy of Orthopaedic Surgeons regarding the treatment of anterior cruciate ligament in- jury. Arthroscopy. 2003;19:762–770.

Delay BS, Smolinski RJ, Wind WM, Bowman DS.Current practices and opinions in ACL reconstruction and rehabilitation: results of a survey of the American Orthopaedic Society for Sports Medicine. Am J Knee Surg 2001;14:85–91.

Decoster LC, Vailas JC (2003) Functional anterior cruciate lig- ament bracing: a survey of current brace prescription patterns. Orthopedics 26(7):701–706

Escamilla RF, Macleod TD, Wilk KE, Paulos L, Andrews JR (2012) Anterior cruciate ligament strain and tensile forces for weight-bearing and non-weight-bearing exercises: a guide to exercise selection. J Orthop Sports Phys Ther 42(3):208–220

Di Miceli R, Marambio CB, Zati A, Monesi R, Benedetti MG. Do knee bracing and delayed weight bearing affect mid-term functional outcome after anterior cruciate ligament reconstruction? Joints 2017;5:202–6.

Bordes P, Laboute E, Bertolotti A, et al. No beneficial effect of bracing after anterior cruciate ligament reconstruction in a cohort of 969 athletes followed in rehabilitation. Ann Phys Rehabil Med 2017;60:230–6.

Rodríguez-Merchán EC. Knee bracing after anterior cruciate ligament recon- struction. Orthopedics 2016;39:e602–9.

Lowe WR, Warth RJ, Davis EP, Bailey L. Functional bracing after anterior cruciate ligament reconstruction. J Am Acad Orthop Surg. 2017;25(3):239–249.

Fleming BC, Renstrom PA, Beynnon BD, Engstrom B, Peura G. The influence of functional knee bracing on the anterior cruciate ligament strain biome- chanics in weightbearing and nonweightbearing knees. Am J Sports Med 2000;28:815–24.

Beynnon BD, Johnson RJ, Fleming BC, Peura GD, Renstrom PA, Nichols CE, Pope MH (1997) The effect of functional knee bracing on the anterior cruciate ligament in the weightbearing and nonweightbearing knee. Am J Sports Med 25(3):353–359

Lowe WR, Warth RJ, Davis EP, Bailey L. Functional bracing after anterior cruciate ligament reconstruction. J Am Acad Orthop Surg. 2017;25(3):239–249.

McDevitt E, Taylor D, Miller M, et al. Functional bracing after anterior cruciate ligament reconstruction. A prospective, randomized, multicenter study. Am J Sports Med. 2004;32: 1887–1892.

Birmingham TB, Bryant DM, Litchfield RB, et al. A randomized controlled trial comparing the effectiveness of functional knee brace and neoprene sleeve use after anterior cruciate ligament reconstruction. Am J Sports Med. 2008;36:648–655.

Wright RW, Fetzer GB. Bracing after ACL Reconstruction—a systematic review. Clin Orthop Relat Res. 2007;455:162–168. doi: 10.1097/BLO.0b013e31802c9360.

Pezzullo DJ, Fadale P.  Current controversies in rehabilitation after anterior cruciate ligament reconstruction. Sports Med Arthrosc.  2010; 18: 43– 47.

Kocher MS, Sterett WI, Briggs KK, Zurakowski D, Steadman JR (2003) Effect of functional bracing on subsequent knee injury in ACL-deficient professional skiers. J Knee Surg 16(2):87–92.