The clinical effect of an unloader brace on patients with osteoarthritis of the knee, a randomized placebo controlled trial with one year follow up

Hjörtur F Hjartarson, Sören Toksvig-Larsen, Hjörtur F Hjartarson, Sören Toksvig-Larsen

Abstract

Background: Treatment of patients with knee osteoarthritis is challenging. Unloader braces have been developed with various success. Unloader One® Knee Brace is light, easily-fitted and shown to be effective by the unloading of the affected compartment. The aim of the study was to assess the clinical outcome of the brace vs. a placebo on patients with knee osteoarthritis.

Methods: Initially 150 patients were randomized to receive either the Unloader brace or a control placebo group look-alike brace where the active strips had been removed. The patients were followed up at 6,12,26 and 52 weeks with Knee Society Score (KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS). The reason for dropout was recorded.

Results: A total of 149 patients were included, 74 in the study and 75 in the control group. The mean age was 59.6 vs. 60.2, BMI was 27.5 vs. 26.9, 37% vs. 44% were women in the study vs. control group. Both groups showed improvement in KSS over 52 weeks, with the study group showing higher improvement in mean scores. KSS increased from 64.3 to 84.0 for the study group and from 64.0 to 74.6 for the control group (p = 0.009). The study group improved in KSS function from 67.0 to 78.6 (p < 0.001) and KOOS for knee related symptoms increased/improved from 64.3 to 72.4 (p < 0.001). Activity of daily living increased/improved from 65.3 to 75.2 and Sports/Recreation from 24.6 to 40.2 (p > 0.001) whereas the control group did not show significant improvements in any of the scores. The dropout was higher in the control group, 40 vs. 25.

Conclusions: The brace seems to be more effective and better tolerated than the placebo.

Trial registration: The trial was retrospectively registered with ClinicalTrials.gov ( NCT03454776 ) on March 6th 2018.

Conflict of interest statement

Ethics approval and consent to participate

The regional ethics committee in Lund, Sweden approved the study (Reference 2011/2). The participants in the study all gave a written consent.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests. Neither of the authors, nor anyone in their immediate families have any financial ties to Össur.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Unloader One® brace, Ossur, Iceland
Fig. 2
Fig. 2
Participant flow. KSS and KOOS show how many participants were evaluated for KSS or turned in KOOS questionnaires at that follow-up
Fig. 3
Fig. 3
Predictive margins of KSS with 95% CI at baseline 6,12,24 and 52 weeks
Fig. 4
Fig. 4
Predictive margins of KSS Function with 95% CI at 6,12,24 and 52 weeks

References

    1. Bay-Jensen AC, Hoegh-Madsen S, Dam E, Henriksen K, Sondergaard BC, Pastoureau P, Qvist P, Karsdal MA. Which elements are involved in reversible and irreversible cartilage degradation in osteoarthritis? Rheumatol Int. 2010;30(4):435–442. doi: 10.1007/s00296-009-1183-1.
    1. Neogi T, Zhang Y. Epidemiology of osteoarthritis. Rheum Dis Clin N Am. 2013;39(1):1–19. doi: 10.1016/j.rdc.2012.10.004.
    1. Woolf AD, Pfleger B. Burden of major musculoskeletal conditions. Bull World Health Organ. 2003;81(9):646–656.
    1. Zhang W, Moskowitz RW, Nuki G, Abramson S, Altman RD, Arden N, Bierma-Zeinstra S, Brandt KD, Croft P, Doherty M, et al. OARSI recommendations for the management of hip and knee osteoarthritis, part II: OARSI evidence-based, expert consensus guidelines. Osteoarthr Cartil. 2008;16(2):137–162. doi: 10.1016/j.joca.2007.12.013.
    1. Petersen W, Ellermann A, Zantop T, Rembitzki IV, Semsch H, Liebau C, Best R. Biomechanical effect of unloader braces for medial osteoarthritis of the knee: a systematic review (CRD 42015026136) Arch Orthop Trauma Surg. 2016;136(5):649–656. doi: 10.1007/s00402-015-2388-2.
    1. Rannou F, Poiraudeau S, Beaudreuil J. Role of bracing in the management of knee osteoarthritis. Curr Opin Rheumatol. 2010;22(2):218–222. doi: 10.1097/BOR.0b013e32833619c4.
    1. Ostrander RV, Leddon CE, Hackel JG, O'Grady CP, Roth CA. Efficacy of unloader bracing in reducing symptoms of knee osteoarthritis. Am J Orthop (Belle Mead NJ) 2016;45(5):306–311.
    1. 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. Osteoarthr Cartil. 2006;14(8):777–783. doi: 10.1016/j.joca.2006.02.004.
    1. Steadman JR, Briggs KK, Pomeroy SM, Wijdicks CA. Current state of unloading braces for knee osteoarthritis. Knee Surg Sports Traumatol Arthrosc. 2016;24(1):42–50. doi: 10.1007/s00167-014-3305-x.
    1. van Raaij TM, Reijman M, Brouwer RW, Bierma-Zeinstra SM, Verhaar JA. Medial knee osteoarthritis treated by insoles or braces: a randomized trial. Clin Orthop Relat Res. 2010;468(7):1926–1932. doi: 10.1007/s11999-010-1274-z.
    1. Duivenvoorden T, Brouwer RW, van Raaij TM, Verhagen AP, Verhaar JA, Bierma-Zeinstra SM: Braces and orthoses for treating osteoarthritis of the knee. Cochrane Database Syst Rev 2015(3):CD004020. 10.1002/14651858.CD004020.pub3.
    1. Kellgren JH, Lawrence JS. Radiological assessment of rheumatoid arthritis. Ann Rheum Dis. 1957;16(4):485–493. doi: 10.1136/ard.16.4.485.
    1. Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the knee society clinical rating system. Clin Orthop Relat Res. 1989;(248):13–4.
    1. Roos EM, Roos HP, Lohmander LS, Ekdahl C, Beynnon BD. Knee injury and osteoarthritis outcome score (KOOS)--development of a self-administered outcome measure. J Orthop Sports Phys Ther. 1998;28(2):88–96. doi: 10.2519/jospt.1998.28.2.88.
    1. Dupont WDPW. Power and sample size calculations: a review and computer program. Control Clin Trials. 1990;11:116–128. doi: 10.1016/0197-2456(90)90005-M.
    1. 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.
    1. Kirkley A, Webster-Bogaert S, Litchfield R, Amendola A, MacDonald S, McCalden R, Fowler P. The effect of bracing on varus gonarthrosis. J Bone Joint Surg Am. 1999;81(4):539–548. doi: 10.2106/00004623-199904000-00012.
    1. Sattari S, Ashraf AR. Comparison the effect of 3 point valgus stress knee support and lateral wedge insoles in medial compartment knee osteoarthritis. Iran Red Crescent Med J. 2011;13(9):624–628. doi: 10.5812/kowsar.20741804.2252.
    1. Pham T, Van Der Heijde D, Lassere M, Altman RD, Anderson JJ, Bellamy N, Hochberg M, Simon L, Strand V, Woodworth T, et al. Outcome variables for osteoarthritis clinical trials: the OMERACT-OARSI set of responder criteria. J Rheumatol. 2003;30(7):1648–1654.

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