Effect of biomechanical footwear on knee pain in people with knee osteoarthritis : the BIOTOK randomized clinical trial

Reichenbach, S; Felson, DT; Hincapié, CA; Heldner, S; Bütikofer, L; Lenz, A; da Costa, BR; Bonel, HM; Jones, RK; Hawker, GA; Jüni, P

Abstract

Importance:
Individually calibrated biomechanical footwear therapy may improve pain and physical function in people with symptomatic knee osteoarthritis, but the benefits of this therapy are unclear.
Objective:
To assess the effect of a biomechanical footwear therapy vs control footwear over 24 weeks of follow-up.
Design, Setting, and Participants:
Randomized clinical trial conducted at a Swiss university hospital. Participants (N = 220) with symptomatic, radiologically confirmed knee osteoarthritis were recruited between April 20, 2015, and January 10, 2017. The last participant visit occurred on August 15, 2017.
Interventions:
Participants were randomized to biomechanical footwear involving shoes with individually adjustable external convex pods attached to the outsole (n = 111) or to control footwear (n = 109) that had visible outsole pods that were not adjustable and did not create a convex walking surface.
Main Outcomes and Measures:
The primary outcome was knee pain at 24 weeks of follow-up assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscore standardized to range from 0 (no symptoms) to 10 (extreme symptoms). The secondary outcomes included WOMAC physical function and stiffness subscores and the WOMAC global score, all ranging from 0 (no symptoms) to 10 (extreme symptoms) at 24 weeks of follow-up, and serious adverse events.
Results:
Among the 220 randomized participants (mean age, 65.2 years [SD, 9.3 years]; 104 women [47.3%]), 219 received the allocated treatment and 213 (96.8%) completed follow-up. At 24 weeks of follow-up, the mean standardized WOMAC pain subscore improved from 4.3 to 1.3 in the biomechanical footwear group and from 4.0 to 2.6 in the control footwear group (between-group difference in scores at 24 weeks of follow-up, -1.3 [95% CI, -1.8 to -0.9]; P < .001). The results were consistent for WOMAC physical function subscore (between-group difference, -1.1 [95% CI, -1.5 to -0.7]), WOMAC stiffness subscore (between-group difference, -1.4 [95% CI, -1.9 to -0.9]), and WOMAC global score (between-group difference, -1.2 [95% CI, -1.6 to -0.8]) at 24 weeks of follow-up. Three serious adverse events occurred in the biomechanical footwear group compared with 9 in the control footwear group (2.7% vs 8.3%, respectively); none were related to treatment.
Conclusions and Relevance:
Among participants with knee pain from osteoarthritis, use of biomechanical footwear compared with control footwear resulted in an improvement in pain at 24 weeks of follow-up that was statistically significant but of uncertain clinical importance. Further research would be needed to assess long-term efficacy and safety, as well as replication, before reaching conclusions about the clinical value of this device.

• Journal Article Type: Article
• Acceptance Date: Mar 3, 2020
• Online Publication Date: May 12, 2020
• Publication Date: May 12, 2020
• Deposit Date: May 13, 2020
• Publicly Available Date: Nov 12, 2020
• Journal: The Journal of the American Medical Association (JAMA)
• Print ISSN: 0098-7484
• Electronic ISSN: 1538-3598
• Publisher: American Medical Association
• Volume: 323
• Issue: 18
• Pages: 1802-1812
• DOI: https://doi.org/10.1001/jama.2020.3565
• Publisher URL: https://doi.org/10.1001/jama.2020.3565
• Related Public URLs: http://jama.jamanetwork.com/
• Additional Information: Funders : Maxi Foundation