The purpose of this study was to examine the methodological integrity, sample size requirements, and short-term preliminary clinical outcomes of manual and manipulative therapy (MMT) in addition to a rehabilitation program for symptomatic knee osteoarthritis (OA).
This was a pilot study of an assessor-blinded, randomized, parallel-group trial in 2 independent university-based outpatient clinics. Participants with knee OA were randomized to 3 groups: 6 MMT sessions alone, training in rehabilitation followed by a home rehabilitation program alone, or MMT plus the same rehabilitation program, respectively. Six MMT treatment sessions (provided by a chiropractic intern under supervision or by an experienced chiropractor) were provided to participants over the 4-week treatment period. The primary outcome was a description of the research methodology and sample size estimation for a confirmatory study. The secondary outcome was the short-term preliminary clinical outcomes. Data were collected at baseline and 5weeks using the Western Ontario and McMasters Osteoarthritis Index questionnaire, goniometry for knee flexion/extension, and the McMaster Overall Therapy Effectiveness inventory. Analysis of variance was used to compare differences between groups.
Eighty-three patients were randomly allocated to 1 of the 3 groups (27, 28, and 28, respectively). Despite 5 dropouts, the data from 78 participants were available for analysis with 10% of scores missing. A minimum of 462 patients is required for a confirmatory 3-arm trial including the respective interventions, accounting for cluster effects and a 20% dropout rate. Statistically significant and clinically meaningful changes in scores from baseline to week 5 were found for all groups for the Western Ontario and McMasters Osteoarthritis Index (P ≤ .008), with a greater change in scores for MMT and MMT plus rehabilitation. Between-group comparison did not reveal statistically significant differences between group scores at week 5 for any of the outcome measures (P ≥ .46).
This pilot trial suggests that a confirmatory trial is feasible. There were significant changes in scores from baseline to week 5 across all groups, suggesting that all 3 treatment approaches may be of benefit to patients with mild-to-moderate knee OA, justifying a confirmatory trial to compare these interventions.