Original Research

Efficacy of Unloader Bracing in Reducing Symptoms of Knee Osteoarthritis

Am J Orthop. 2016 July;45(5):306-311

References

1. Michaud C, McKenna M, Begg S, et al. The burden of disease and injury in the United States 1996. Popul Health Metr. 2006;4:11.

2. Lawrence RC, Felson DT, Helmick CG, et al; National Arthritis Data Workgroup. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part II. Arthritis Rheum. 2008;58(1):26-35.

3. Woolf AD, Pfleger B. Burden of major musculoskeletal conditions. Bull World Health Organ. 2003;81(9):646-656.

4. London NJ, Miller LE, Block JE. Clinical and economic consequences of the treatment gap in knee osteoarthritis management. Med Hypotheses. 2011;76(6):887-892.

5. Hochberg MC, Altman RD, April KT, et al; American College of Rheumatology. American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthritis Care Res. 2012;64(4):465-474.

6. McAlindon TE, Bannuru RR, Sullivan MC, et al. OARSI guidelines for the non-surgical management of knee osteoarthritis. Osteoarthritis Cartilage. 2014;22(3):363-388.

7. Gallelli L, Galasso O, Falcone D, et al. The effects of nonsteroidal anti-inflammatory drugs on clinical outcomes, synovial fluid cytokine concentration and signal transduction pathways in knee osteoarthritis. A randomized open label trial. Osteoarthritis Cartilage. 2013;21(9):1400-1408.

8. Pollo FE, Jackson RW. Knee bracing for unicompartmental osteoarthritis. J Am Acad Orthop Surg. 2006;14(1):5-11.

9. Ramsey DK, Russell ME. Unloader braces for medial compartment knee osteoarthritis: implications on mediating progression. Sports Health. 2009;1(5):416-426.

10. Zhang W, Moskowitz RW, Nuki G, et al. OARSI recommendations for the management of hip and knee osteoarthritis, part II: OARSI evidence-based, expert consensus guidelines. Osteoarthritis Cartilage. 2008;16(2):137-162.

11. Richmond J, Hunter D, Irrgang J, et al; American Academy of Orthopaedic Surgeons. American Academy of Orthopaedic Surgeons clinical practice guideline on the treatment of osteoarthritis (OA) of the knee. J Bone Joint Surg Am. 2010;92(4):990-993.

12. Kellgren JH, Lawrence JS. Radiological assessment of osteo-arthrosis. Ann Rheum Dis. 1957;16(4):494-502.

13. Dugdale TW, Noyes FR, Styer D. Preoperative planning for high tibial osteotomy. The effect of lateral tibiofemoral separation and tibiofemoral length. Clin Orthop Relat Res. 1992;(274):248-264.

14. Weinstein AM, Rome BN, Reichmann WM, et al. Estimating the burden of total knee replacement in the United States. J Bone Joint Surg Am. 2013;95(5):385-392.

15. Ramsey DK, Briem K, Axe MJ, Snyder-Mackler L. A mechanical theory for the effectiveness of bracing for medial compartment osteoarthritis of the knee. J Bone Joint Surg Am. 2007;89(11):2398-2407.

16. Haim A, Wolf A, Rubin G, Genis Y, Khoury M, Rozen N. Effect of center of pressure modulation on knee adduction moment in medial compartment knee osteoarthritis. J Orthop Res. 2011;29(11):1668-1674.

17. Pollo FE, Otis JC, Backus SI, Warren RF, Wickiewicz TL. Reduction of medial compartment loads with valgus bracing of the osteoarthritic knee. Am J Sports Med. 2002;30(3):414-421.

18. Shelburne KB, Torry MR, Steadman JR, Pandy MG. Effects of foot orthoses and valgus bracing on the knee adduction moment and medial joint load during gait. Clin Biomech. 2008;23(6):814-821.

19. Lewek MD, Ramsey DK, Snyder-Mackler L, Rudolph KS. Knee stabilization in patients with medial compartment knee osteoarthritis. Arthritis Rheum. 2005;52(9):2845-2853.

20. Lewek MD, Rudolph KS, Snyder-Mackler L. Control of frontal plane knee laxity during gait in patients with medial compartment knee osteoarthritis. Osteoarthritis Cartilage. 2004;12(9):745-751.

21. Draganich L, Reider B, Rimington T, Piotrowski G, Mallik K, Nasson S. The effectiveness of self-adjustable custom and off-the-shelf bracing in the treatment of varus gonarthrosis. J Bone Joint Surg Am. 2006;88(12):2645-2652.

22. Barnes CL, Cawley PW, Hederman B. Effect of CounterForce brace on symptomatic relief in a group of patients with symptomatic unicompartmental osteoarthritis: a prospective 2-year investigation. Am J Orthop. 2002;31(7):396-401.

23. Brouwer RW, van Raaij TM, Verhaar JA, Coene LN, Bierma-Zeinstra SM. Brace treatment for osteoarthritis of the knee: a prospective randomized multi-centre trial. Osteoarthritis Cartilage. 2006;14(8):777-783.

24. Larsen BL, Jacofsky MC, Brown JA, Jacofsky DJ. Valgus bracing affords short-term treatment solution across walking and sit-to-stand activities. J Arthroplasty. 2013;28(5):792-797.

25. Hewett TE, Noyes FR, Barber-Westin SD, Heckmann TP. Decrease in knee joint pain and increase in function in patients with medial compartment arthrosis: a prospective analysis of valgus bracing. Orthopedics. 1998;21(2):131-138.

Discussion

We conducted this study to determine the efficacy of a medial unloader brace in reducing the pain and symptoms associated with varus knee OA.

Although TKA is an option for patients with significant end-stage knee OA, mild OA and moderate OA typically are managed with nonoperative modalities. These modalities can be effective and may delay or eliminate the need for surgery, which poses a small but definite risk. Delaying surgery, especially in younger, active patients, has the potential to reduce the number of wear-related revision surgeries.¹⁴

Braces designed to off-load the more diseased medial or lateral compartment of the knee have been used in an effort to provide relief from symptomatic OA. There is a lack of appropriately powered, randomized controlled studies on the efficacy of these braces. With the evidence being inconclusive, the American Academy of Orthopaedic Surgeons is unable to recommend for or against use of a brace in medial unicompartmental OA.¹¹ More research on the efficacy of these braces is needed. In the present study, we asked 2 questions: Does use of an unloader brace lessen the pain associated with knee OA? Is the unloader brace an acceptable and valid treatment modality for knee OA?

The 2 clinical outcome tools used in this study showed significant improvement in pain in brace patients compared with control patients. KOOS results showed reduced pain and arthritis symptoms. VAS results showed less pain experienced throughout the day. Pain reduction is probably the most important benefit of any nonoperative modality for knee OA. Pain typically is the driving force and the major indication for TKA. Other investigators have found pain reduced with use of unloader braces, but few long-term prospective randomized trials have been conducted. Ramsey and colleagues¹⁵ compared a neutral stabilizing brace with a medial unloading brace and found that both helped reduce pain and functional disability. This led to discussion about the 2 major potential mechanisms for symptom relief. One theory holds that bracing unloads the diseased portion of the joint and thereby helps improve symptoms.^16-18 According to the other theory, bracing stabilizes the knee, reducing muscle cocontractions and joint compression.^15,19,20 Draganich and colleagues²¹ found that both off-the-shelf and adjustable unloader braces reduced pain. In a short-term (8-week) study, Barnes and colleagues²² found substantial improvement in knee pain with use of an unloader brace. In one of the larger, better designed, prospective studies, Brouwer and colleagues²³ found borderline but significant improvements in pain. Larsen and colleagues,²⁴ in another short-term study, found no improvement in pain but did report improved activity levels with use of a medial unloader brace.

In addition to demonstrating pain reduction, our results showed that, compared with control patients, brace patients had fewer arthritis symptoms, better ability to engage in ADLs, and increased activity levels. Other studies have identified additional benefits of bracing for knee arthritis. Larsen and colleagues²⁴ found that valgus bracing for medial compartment knee OA improved walking and sit-to-stand activities. Although pain relief results were modest, Brouwer and colleagues²³ found significantly better knee function and longer walking distances for patients who used a medial unloader brace. Hewett and colleagues²⁵ found that pain, ADLs, and walking distance were all improved after 9 weeks of brace wear.

Our study had a few limitations. Although injections and narcotic pain medications were not allowed, NSAIDs, home exercises, and other modalities were permitted. We did not think it was reasonable to eliminate every nonoperative modality during the 6-month study period. Therefore, it is possible that some of the study population’s improvements are attributable to these other modalities, which were not rigidly controlled.

Patient enrollment was difficult because of the strict inclusion and exclusion criteria used. The result was a smaller than anticipated patient population. Although there were many excellent study candidates, most declined enrollment when they learned they could be randomized to the control group. These patients were not willing to forgo injections or bracing for 6 months. We thought it was important to maintain our study design because it allowed us to evaluate the true effect of brace use while eliminating confounding variables. Nearly equal numbers of brace and control patients dropped out of the study. The majority of control group dropouts wanted more treatment options, indicating that NSAIDs and exercises alone were not controlling patients’ symptoms. This finding supports recommendations for a multimodal approach to treatment. As expected, some patients dropped out because their brace was uncomfortable—an important finding that should be considered when counseling patients about treatment options for OA.

Not all patients are candidates for braces. Braces can be irritating and uncomfortable for obese patients and patients with skin or vascular issues. Some patients find braces inconvenient. As discussed, a multimodal OA treatment approach is encouraged, but not every mode fits every patient. Physician and patient should thoroughly discuss the benefits and potential problems of brace use before prescribing. Our study results showed trends toward better improvements for brace patients (compared with control patients) in quality of life, ability to engage in sport and recreation, ability to sleep, and need for NSAIDs. Had we enrolled more patients, we might have found statistical significance for these trends. Despite the challenges with patient enrollment and study population size, the data make clear that unloader braces can benefit appropriate patients.

Our findings support use of a medial unloader brace as an acceptable and valid treatment modality for mild and moderate knee OA. The medial unloader brace should be considered a reasonable alternative, as part of a multimodal approach, to more invasive options, such as TKA.