Lateral wedge insoles and foot orthoses for medial knee osteoarthritis: a systematic review of pain and the knee adduction moment

Lateral wedge insoles and foot orthoses aim to unload the medial tibiofemoral compartment and reduce pain in medial knee osteoarthritis, but their clinical and biomechanical benefit remains uncertain. Randomized, crossover, quasi-experimental and cohort studies reporting pain, function or the knee adduction moment were included. Risk of bias was assessed with the RoB 2 tool and a checklist derived from JBI. A total of 630 records were identified, 345 were screened and 55 studies were included. Lateral wedge insoles consistently reduced the knee adduction moment immediately, most often by 4 to 25 percent at the first peak and with a dose response to wedge angle, but the effect varied widely between participants. Effects on pain were small and inconsistent: most placebo controlled trials found no advantage over neutral insoles, whereas one prescreened trial reported a reduction of 0.7 points on a 0 to 10 scale. Conclusions: Lateral wedge insoles and foot orthoses unload the medial compartment biomechanically but provide only small and inconsistent symptomatic benefit, and the response appears restricted to identifiable subgroups of patients.