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Minimal, if any, benefit from lateral wedge insoles for medial knee OA

Clinical Question:
Is a lateral wedge insole effective in the treatment of pain in adults with medial knee osteoarthritis?

Bottom Line:
There is minimal, if any, benefit to using a lateral wedge insole to reduce pain in adults with predominantly medial knee osteoarthritis. (LOE = 1a-)

Parkes MJ, Nasimah M, Lunt M, et al. Lateral wedge insoles as conservative treatment for pain in patients with medial knee osteoarthritis. A meta-analysis. JAMA 2013;310(7):722-730.  [PMID:23989797]

Study Design:
Meta-analysis (randomized controlled trials)


Various (meta-analysis)

Medial osteoarthritis is a common subtype of knee osteoarthritis. Reducing medial loading with a lateral wedge insole is thought to ease physical stress and reduce pain. These investigators thoroughly searched multiple databases including EMBASE, MEDLINE, the Cochrane Register, and CINAHL Plus. They also manually searched reference lists of relevant articles and contacted experts in the field to locate potential unpublished trials. No language restrictions were applied. Eligible studies included randomized controlled trials that evaluated the use of various lateral wedge treatments, including shoes, insoles, or both, with at least 5 degrees to 15 degrees of angulation in adult patients with predominantly medial compartment knee osteoarthritis confirmed either radiologically or using standard international clinical criteria. Controls included either neutral or flat insoles or shoes, or no treatment. Two reviewers independently assessed study inclusion criteria and quality using standard methodologic criteria. Disagreements were resolved by consensus. A total of 12 studies (N = 885) met inclusion criteria with an average treatment duration of 2 weeks to 2 years. The methodologic quality of the individual trials ranged from medium to high. Overall, use of a lateral wedge insole significantly reduced pain, with an average difference of -2.12 on a 0 to 20 pain scale. However, because the effects were highly heterogeneous, the authors grouped the trials according to the control treatment (neutral insole vs no treatment) and those studies comparing the lateral wedge only to a neutral insole reported no significant difference in pain scores. Formal analyses for publication bias did detect a benefit favoring the lateral wedge insole (meaning that smaller studies with negative findings were less likely to be published). Studies with the largest sample sizes found no benefit to lateral wedge insole treatment.


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