Lateral wedge shoe insoles may improve knee pain in individuals with painful medial knee osteoarthritis (OA), according to a study published in Arthritis & Rheumatology.
A total of 62 patients with medial knee OA (average age, 64 years) were asked to wear a 5° lateral wedge insole or a neutral insole for 8 weeks, followed by a washout period (8 weeks), after which study participants switched to the other type of insole for another 8 weeks.
Patients with patellofemoral OA were excluded from the study. Study participants were asked to wear the insoles for at least 4 hours per day. They were evaluated for pain level and secondary outcomes at baseline and at 8, 16, and 24 weeks. A total of 56 participants completed both treatment periods.
Participants reported lower knee pain intensity when wearing lateral wedge vs neutral insoles (mean difference, 0.7 on a 0-10 scale; P =.02). Both groups reported comparable average Knee Injury and Osteoarthritis Outcome Scores.
A minimally important improvement in pain and function was reported by 28% and 22% of participants wearing lateral wedge and neutral insoles, respectively (odds ratio, 1.35; P =.49). Lateral wedge insoles were not found to offer a significant effect on medial bone marrow lesion volume or total bone marrow lesion volume in the knee.
“[W]e found, for the first time, that lateral wedge insoles may be modestly effective in reducing pain in persons with medial knee OA. However, the treatment effect was small and most treated patients did not achieve conventional levels of minimal important response. Future modifications of the treatment or of the screening strategy might offer greater levels of efficacy,” noted the study authors.
Felson DT, Parkes M, et al. The efficacy of a lateral wedge insole for painful medial knee osteoarthritis after prescreening: A randomized clinical trial [published online January 7, 2019]. Arthritis Rheumatology. doi: 10.1002/art.40808.