Background: Lateral wedge insoles have been used for the treatment of medial knee osteoarthritis (OA) and have been shown to reduce loading of the medial compartment of the knee. However, as the entire lower extremity acts as a single kinetic chain, altering the biomechanics of the knee may also have significant effects at the ankles or hips. We aimed to evaluate the effects of lateral wedge orthotics on ankle and hip joints, compared to neutral orthotics, by assessing the changes in joint space width (JSW) during 36 months of continuous use.
Methods: We prospectively enrolled 109 subjects with symptomatic osteoarthritis of the medial knee according to the American College of Rheumatology criteria. The trial was double blind and patients were randomized to either wedged or neutral orthotic shoe inserts. Hip and ankle JSWs were quantified using plain radiographies at baseline and at 36-months follow-up.
Findings: 45 patients completed the 36 month study. 31 of those who completed the study were using the lateral wedge versus 14 were using neutral orthotics. 2 patients in the wedge group had missing radiographs and were not included in the JSW analyses. There were no significant differences between the wedge and the neutral orthotics groups in the magnitude of JSW change at either the hip or the ankles at 36 month.
Interpretation: We found no significant adverse effects of the lateral wedges on ankles or hips. (ClinicalTrials.gov NCT00076453).
Keywords: Joint space widths; Orthotics; Osteoarthritis.
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