To compare the influence of concomitant heeled footwear when wearing a lateral wedged insole for medial compartment of osteoarthritis (OA) of the knee, between everyday walking shoes for outdoor use and socks or flat footwear without a heel for indoor use.
A total of 227 outpatients were prospectively randomized and treated with a neutral wedged insole inserted into shoes (placebo with shoes; n=45), a wedged insole inserted into shoes (inserted insole with shoes; n=45), a sock-type ankle supporter with a wedged insole when wearing socks or flat footwear (inserted insole without shoes; n=46), a subtalar strapped insole when wearing shoes (strapped insole with shoes; n=45), and the strapped insole with socks or flat footwear (strapped insole without shoes; n=46). The Lequesne index of knee OA at week 12 was compared with the baseline in each treatment group.
Twenty patients withdrew from the study, and the 207 patients who completed the 12-week study were evaluated. At the final assessment, participants wearing the inserted insole without shoes (P=0.003), the strapped insole with shoes (P<0.0001), and the strapped insole without shoes (P<0.0001) demonstrated significantly improved Lequesne index scores in comparison with their baseline assessments. No significant differences were found in the placebo (P=0.16) or the inserted insole with shoes (P=0.2) groups.
Concomitant heeled footwear may decrease the efficacy of an inserted lateral wedged insole. The optimal usage of a lateral wedged insole for knee OA would be the combination with socks or flat footwear without heels.