Customized foot insoles have a positive effect on pain, function, and quality of life in patients with medial knee osteoarthritis

Background: Knee osteoarthritis (KOA) is a prevalent degenerative disease in older adults. Treatment strategies, including insoles, focus on reducing pain and physical disability. In medial KOA, insoles have been studied extensively with conflicting results, possibly due to heterogeneity in outcome measures and the intervention. We sought to investigate the effect of custom-made laterally wedged insoles on pain, function, and quality of life in patients with medial KOA. Methods: Fifty-one consecutive patients with medial KOA were prescribed custom-made insoles with arch support and a 5.0° to 8.7° lateral wedge. At follow-up, 42 of the 51 participants (22 men; mean age, 63 years; mean Kellgren-Lawrence, 3.4) participated. Retrospectively, participants were asked to rate the pain intensity in their affected knee before and after the intervention measured on a visual analog scale after 30 min of physical activity (primary outcome), at rest, at night, and after 50 m of walking. Additionally, they completed the Oxford Knee Score and the EQ-5D. The paired-samples t test was applied in the statistics. Results: The visual analog scale score after 30 min of physical activity was significantly reduced after the intervention (mean, 3.3 cm; 95% confidence interval, 2.1-4.5 cm; P <.001). The same significant changes were found in all of the secondary outcomes. Conclusions: There was a significant reduction in pain and improvements in function and quality of life with custom-made laterally wedged insoles with arch support in older adults with mild-to-severe medial KOA. The customization of laterally wedged insoles may be essential for the effect in medial KOA.