A randomized crossover trial of a wedged insole for treatment of knee osteoarthritis

Abstract

Objective. In uncontrolled studies, a lateralwedge insole has reduced knee pain in patients with medial knee osteoarthritis (OA). The aim of this study was to test the efficacy of this simple, low-cost intervention for pain in patients with medial knee OA.Methods. We conducted a double-blind, randomized, crossover trial designed to detect a small effect of treatment. Participants were at least 50 years of age and had medial joint space narrowing on posteroanterior semiflexed radiographs and scores indicating moderate pain for 2 of the 5 items on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scale. Participants were randomized to receive a 5°l ateral-wedge insole or a neutral insole for 6 weeks. Following a 4-week washout period, participants crossed over to the other treatment for 6 weeks. Knee pain, the primary outcome, was assessed by the WOMAC pain scale (visual analog scale version). Secondary outcomes included the WOMAC disability subscale, overall knee pain, 50-feet walk time, chair-stand time, and use of medications for knee pain.Results. Ninety patients were randomized. The mean difference in pain between the 2 treatments was 13.8 points on the WOMAC pain scale (95% confidence interval ؊3.9, 31.4 [P ‫؍‬ 0.13]). We observed similar small effects for the secondary outcomes.Conclusion. The effect of treatment with a lateralwedge insole for knee OA was neither statistically significant nor clinically important.

Kinematic adaptations to a variable stiffness shoe: Mechanisms for reducing joint loading

“…The variable stiffness shoe results are in contrast to studies with laterally wedged insoles that in both healthy and subjects with OA have had mixed results (Baker et al, 2007;Bennell et al, 2011;Fang et al, 2006;Kakihana et al, 2007;Kutzner et al, 2011;Toda and Tsukimura, 2004). The mechanism by which the external adduction moment is reduced in the VS shoe is not clear.…”

The effect of laterally wedged shoes on the loading of the medial knee compartment‐in vivo measurements with instrumented knee implants

“…This dubiousness is supported by the fact that clinical studies about the effect of wedges come to controversial results. [8][9][10][11] Load reductions within or above 5-10% may also be achieved by other gait modifications such as increased lateral trunk lean, reduced walking speed or by using a contralateral crutch or cane. 33 Greater medial force reductions can also be expected when walking with (more inconvenient) valgus braces.…”

“…Some studies showed that the use of lateral wedges led to significant pain reduction, [5][6][7] but no pain-relieving effect of lateral wedges was found by other short-and long-term studies. [8][9][10][11] Reductions of the peak EAM when walking with lateral wedges have been shown by several studies.…”

Exercise, Gait Retraining, Footwear and Insoles for Knee Osteoarthritis

“…Most new biomechanical evaluations of lateral wedges published since 2011 agree with these findings [41][42][43]. Unfortunately, the assumption that the loadreducing effects of lateral wedges will translate into clinically meaningful reductions in pain in people with knee OA has not been borne out in the clinical trials conducted to date [44][45][46][47]. Of note, the latest RCT, involving 200 people with medial knee OA and published in BMJ in 2011 [48 •• ], demonstrated that lateral wedges worn over 12 months do not significantly reduce pain or slow structural disease progression (as measured via cartilage volume on MRI).…”