Biomechanical footwear may be effective for reducing pain in adults with knee degenerative joint disease

Reference

Reichenbach, S, Felson DT, Hincapie CA, et al. Effect of biomechanical footwear on knee pain in people with knee osteoarthritis. The BIOTOK randomized clinical trial. JAMA 2020;323(18):1802-1812.

Synopsis

A biomechanical footwear system consists of shoes with 2 convex pods on the outsoles, which can be individually calibrated to alter limb biomechanics and reduce stress on osteoarthritic knees. These investigators identified adults (N = 220), 40 years or older, with symptomatic radiologically confirmed knee DJD lasting at least 6 months. Eligible participants randomly received (via concealed assignment) either the biomechanical footwear or control footwear specifically designed to have a similar appearance but no capacity to be individually calibrated. Patients masked to their treatment group assignment self-assessed outcomes using validated pain, function, and quality-of-life scoring tools. Complete follow-up occurred for 96.8% of patients at 24 weeks. Using intention-to-treat analysis, the mean pain score improved from 4.3 at baseline to 1.3 in the biomechanical footwear group and from 4.0 to 2.6 in the control group (between-group difference, -1.3; 95% CI -1.8 to -0.9; range 0–10, where 0 = no symptoms and 10 = extreme symptoms). Significantly more patients in the biomechanical footwear group achieved a 50% reduction in pain scores compared with patients in the control footwear group (83% vs 42%; number needed to treat = 3; 1 - 4). Similar results occurred for function scores, but there were no significant between-group differences for overall quality-of-life improvement. Similarly, the rate of rescue analgesic use did not differ between groups.