Effects of serial thermal brine hand baths on hand osteoarthritis: a randomized, double-blind, sham-controlled trial

BACKGROUND: Balneotherapy is used since ancient times, effects on hand osteoarthritis however are not well elucidated. AIM: To evaluate therapeutic effects of serial thermal brine hand baths (tbhb) in patients experiencing painful hand osteoarthritis (HOA). DESIGN: Randomized, double-blind, sham-controlled monocentric clinical trial. SETTING: Outpatient clinic, monocentric. POPULATION: Patients with painful bilateral painful HOA meeting the 1990 American College of Rheumatology classification criteria with a baseline pain level >30 mm on the Visual Analog Scale (VAS) and radiographic evidence of hand osteoarthritis in posteroanterior X-ray projection, classified as Kellgren and Lawrence grade ≥2. METHODS: Probands were randomized to the intervention group (IG) receiving tbhb or the control group (CG) receiving tap water hand baths (sham). Both hand baths (tbhb and sham) were performed 6 times in 3 weeks with 15 min/bath at a water temperature of 25 °C. OUTCOMES: The primary outcome was the change in pain intensity (VAS [mm]) following the intervention. Secondary outcomes were changes in the Australian Canadian Osteoarthritis Hand Index (AUSCAN), grip strength, functional parameters of microcirculation (by O2C method), vascular endothelial growth factor (VEGF) and safety. Outcomes were primarily analysed after the last intervention followed by secondary analysis of the follow-up visits 4 and 12 weeks after intervention and during intervention. RESULTS: A total of 38 patients successfully completed the trial. Pain intensity significantly decreased due to tbhb (P