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

Arthritis Rheum. 2007 Apr;56(4):1198-203. doi: 10.1002/art.22516.


Objective: In uncontrolled studies, a lateral-wedge 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 degrees lateral-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 lateral-wedge insole for knee OA was neither statistically significant nor clinically important.

Trial registration: ClinicalTrials.gov NCT00032240.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Bone Malalignment / complications
  • Bone Malalignment / physiopathology
  • Bone Malalignment / rehabilitation*
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Orthotic Devices* / economics
  • Osteoarthritis, Knee / complications
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / therapy*
  • Pain / physiopathology
  • Pain / prevention & control*
  • Pain Measurement
  • Shoes*
  • Treatment Outcome
  • Walking

Associated data

  • ClinicalTrials.gov/NCT00032240