Laterally elevated wedged insoles in the treatment of medial knee osteoarthritis: a prospective randomized controlled study

Objective: To compare the clinical effects of laterally wedged insoles and neutrally wedged insoles (used as control) in patients with medial femoro-t ibial knee osteoarthritis (OA). Design: 6-month prospective randomized controlled study. Patients outpatien ts with painful medial femoro-tibial knee OA. Outcome measures: patient's overall assessment of disease activity (5 grade scale), WOMAC index subscales and concomitant treatments. Statistical analysis: Performed as an intention-to-treat analysis. Main cri terion: improvement in the patient's assessment of activity (defined as a r eduction of 1 grade or more at month 6 compared to baseline, and no intraar ticular injection or lavage during the study). Secondary criteria for asses sment: (a) improvement in the patient's assessment of activity at months 1 and 3 compared to baseline, (b) improvement in the WOMAC subscales at month s 1, 3 and 6, compared to baseline (defined as an improvement of at least 3 0%, and no intrarticular injection or lavage during the study) and (c) conc omitant therapies (analgesics and NSAIDs). Results: The baseline characteristics of the 156 recruited patients (41 mal es, 115 females, mean age 64.8 years) were not different in the two treatme nt groups. At months 1, 3 and 6 the percentages of patients with improvemen t in assessment of disease activity, in WOMAC pain, joint stiffness, and ph ysical functioning subscales were similar in the two groups. The number of days with NSAIDs intake during the previous 3 months was decreased at month 6 compared with baseline in the group furnished with laterally wedged inso les (14.1 days +/- 28 vs 9.9 days +/- 27, P=0.04, Wilcoxon paired test), wh ile it remained unchanged in the other group (15.5 days +/- 24 vs 15 +/- 28 , P=0.56). Compliance and tolerance were satisfactory. Compliance was diffe rent between the two groups at month 6, with a greater frequency of patient s who wore insoles permanently in the laterally wedged insole group than in the other group (87.8% vs 74.3%; P=0.032). Conclusion: This study failed to demonstrate a relevant short-term symptoma tic effect of laterally-wedged insoles in medial femoro-tibial OA. However, the decrease in NSAIDs consumption together with better compliance in the treated group are in favor of a beneficial effect of laterally-wedged insol es in medial femoro-tibial OA. (C) 2001 OsteoArthritis Research Society Int ernational.