Intensive combined balneotherapy and aquatic exercise for knee osteoarthritis: short-term clinical and functional outcomes

Background: Knee osteoarthritis (OA) is a major cause of global disability, necessitating cost-effective interventions. While balneotherapy and acquatic exercise (AE) are established conservative treatments, evidence regarding their combined efficacy remains limited. This study evaluated the clinical impact of a combined program that include balneotherapy and AE in natural mineral waters - compared to balneotherapy alone in patients with mild-to-moderate knee OA in Health Resorts. Primary outcomes included pain intensity, joint range of motion (AROM/PROM), and functional indices [Western Ontario and McMaster Universities (WOMAC), Lequesne's Algofunctional Index for Knee (LAI-knee)]. Secondary outcomes encompassed quality of life (Short Form-12) and psychological well-being (Pittsburgh Sleep Quality Index and Psychological General Well-Being Index). Methods: 66 patients were allocated to either an experimental group (EG), receiving a combined two-week protocol of balneotherapy and AE in salt-bromine-iodine thermal water, or a control group (CG), receiving balneotherapy alone. Results: Both groups demonstrated significant short-term improvements in all the assessments included in study. However, the EG exhibited a superior reduction in pain intensity (31% vs. 13% in CG) and more consistent gains in bilateral active range of motion (AROM). Linear mixed-effects models confirmed significant time effects for WOMAC, LAI, and SF-12 Physical Component scores for both groups. Regression analysis revealed that higher BMI and age negatively correlated with mobility gains. Conclusion: A combined intervention significantly enhances the analgesic and functional benefits of standard balneotherapy. By leveraging physical properties of mineral water, the combined protocol addresses both the mechanical and biological components of knee OA. These findings support the integration of water exercise with balneotherapy in Health Resorts for degenerative joint diseases and the personalization of treatment based on patients age and BMI.