Hydrotherapy improves pain and function in older women with knee osteoarthritis: a randomized controlled trial

BACKGROUND: Currently, there is poor evidence of the effect of hydrotherapy alone on patients with hip or knee osteoarthritis. OBJECTIVES: The study aimed to assess the impact of hydrotherapy on pain, function, and muscle function in older women with knee osteoarthritis. METHODS: A randomized controlled trial was conducted to evaluate the efficacy of hydrotherapy in women with knee osteoarthritis. Seventy-three women aged 65 and older were randomized to hydrotherapy (n = 36) or a control group (n = 37). The hydrotherapy group received the intervention program in a heated pool (twice per week for six weeks) and an educational protocol while the control group received an educational protocol only. Primary outcomes (before and post-treatment) were pain intensity (0–100) and function (0–100), assessed with the WOMAC questionnaire. Secondary outcomes (before and post-treatment) were knee extensor and knee flexor muscle performance (strength, power, and endurance), assessed by an isokinetic dynamometer. The magnitude of change between the groups for the outcomes was calculated using linear regression models adjusted by baseline outcome values. RESULTS: The hydrotherapy group had better outcomes for pain (adjusted mean difference = 11 points, 95% CI: 3–18) and function (adjusted mean difference = 12 points, 95% CI: 5–18). Patients receiving hydrotherapy had better performance for knee flexor and extensor strength, knee flexor power, and knee extensor endurance. CONCLUSION: Older women with knee osteoarthritis are likely to have benefits from a course of hydrotherapy exercises. Registry of clinical trials (Trial number RBR-8F57KR) – http://www.ensaiosclinicos.gov.br/rg/RBR-8f57kr/.