Bath thermal waters in the treatment of knee osteoarthritis: a randomized controlled clinical trial.

Background: Osteoarthritis is a degenerative disease associated with pain, reduced range of motion, and impaired function. Balneotherapy or bathing in thermal or mineral waters is used as a non-invasive treatment for various rheumatic diseases.

Aim: To evaluate the effectiveness of hot sulfurous and non-sulfurous waters in the treatment of knee osteoarthritis.

Design: A randomized, assessor-blind, controlled trial.

Setting: A spa resort.

Population: One hundred and forty patients of both genders, mean age of 64.8±8.9 years, with knee osteoarthritis and chronic knee pain.

Methods: Patients were randomized into three groups: the sulfurous water (SW) group (N.=47), non-sulfurous water (NSW) group (N.=50), or control group (N.=43) who received no treatment. Patients were not blinded to treatment allocation. Treatment groups received 30 individual thermal baths (three 20-minute baths a week for 10 weeks) at 37-39 °C. The outcome measures were pain (visual analog scale, VAS), physical function (Western Ontario and McMaster Universities Osteoarthritis Index, WOMAC; Lequesne Algofunctional Index, LAFI; Stanford Health Assessment Questionnaire, HAQ), and use of pain medication. Patients were assessed before treatment (T1), at treatment endpoint (T2), and two months post-intervention (T3). Intra- and intergroup comparisons were performed at a significance level of 0.05 (P<0.05).

Results: A significant decrease in VAS pain scores (pain during movement, at rest, and at night) and use of pain medication, and improvement in WOMAC, LAFI and HAQ scores were observed from baseline to T2 and T3 within treatment groups (P<0.001), and between controls and both treatment groups at T2 and T3 (P<0.001). No significant differences in these variables were observed between treatment groups at T2, but patients in the SW group reported less pain and better functional status than those in the NSW group at T3, showing a lasting effect of sulfurous water baths.

Conclusions: Both therapeutic methods were effective in the treatment of knee osteoarthritis; however, sulfurous baths yielded longer-lasting effects than non-sulfurous water baths.

Clinical Rehabilitation Impact: Baths in thermal waters, especially those in sulfurous waters, are effective in reducing pain and improving physical function in patients with knee osteoarthritis.