Osteoarthritis (OA) isalready the most prevalent disorder of joints in the world and is likely to increase in prevalence. Although the exact mechanism of OA is still not fully known, it appears to be the result of an imbalance between synthesis and degradation of articular cartilage, its extracellular matrix and subchondral bone, thus leading to loss of integrity. The most common sites of OA are the hands, knees, hips, cervical and lumbrosacral spine and less frequently the shoulders and elbows. Joint involvement is usually unilateral and systemic manifestations are rare. Current treatment of OA is dominated by drug therapy, with paracetamol and selective and non-selective nonsteroidal antiinflammatory drugs. It is becoming more evident that drug treatment is inappropriate for OA, as symptoms are mostly driven by mechanical and psychosocial factors.

There are efforts for improving recent management strategies of OA including American College of Rheumatology (ACR) Subcommittee on Osteoarthritis Guidelines and a task force for the European League Against Rheumatism (EULAR) Standing Committee for Clinical Trials. The recommended approach to the medical management of hip or knee OA by the Subcommittee on OA Guidelines of ACR includes nonpharmacological modalities and drug therapy. The components of nonpharmacological therapy do not specifically include balneotherapy or spa therapy. But some modalities are also components of contemporary complex spa therapy such as patient education, aerobic and muscle-strengthening exercises. Recommendations of the EULAR Task Force reflect an evidence-based approach to key clinical questions concerning the treatment of knee OA. Spa therapy is included among the nonpharmacological interventions selected for assessment. A total of four OA papers were assessed and of which, three of them reported positive results compared to control. In one study, effect size could be calculated as 0.47 but the quality of trials was moderate (median: 14.5, range: 12-17, possible max. score 28). Category of evidence was assessed according to study design which reflected susceptibility to bias. Evidence for spa therapy for knee OA was categorized as 1B reflecting strong evidence obtained from at least one randomised controlled trial. But the strength of recommendation for spa therapy was graded C (range A-D) by the four members of editing subcommittee of the task force. This is an extrapolated recommendation from category 1 or 2 evidence and seems to be an underestimated one. Finally, overall opinion of all experts on the usefulness of spa therapy (expressed by a VAS scale of 0-100 ) reveals that spa therapy is not strongly recommended (mean VAS score 30). This is not in accordance with good evidence (1B) that spa therapy is beneficial in the management of knee OA.

Balneotherapy and/or spa therapy are the oldest form of therapy that have been used for centuries in the management of musculoskeletal disorders. Balneotherapy of modern times may be defined as “the therapeutic use of mineral and thermal waters, usually through water immersion of part or all of the body, but also through drinking certain amount of water and inhaling the vaporized or dispersed water. “Balneo” comes from the Latin word for bath- “balneum”. It refers to bathing in thermal or mineral waters.

Almost all ancient civilizations used natural thermal and mineral water therapies, which later became a central focus of many health-promoting establishments such as spas. In English language “Spa” is a specific word for ‘place with thermal baths’ or ‘health resorts’. One of the most important activities that take place at a traditional or modern spa is balneotherapy. In addition to balneotherapeutic use of waters, gases such as CO2 and radon, muds such as peat or clay and climatic factors such as atmospheric temperature or UV light are often used as part of a complex spa therapy. A ‘natural’ approach to health and healing has developed by using these components which are specific to spas for therapeutic purposes. These watering places evolved the term spa therapy.

There have been many anecdotal claims of beneficial effects of balneotherapy and/or spa therapy especially for pain relief in arthritic conditions such as osteoarthritis. But, until recently, there have not been many trials on the efficacy of balneotherapy and spa therapy in general for osteoarthritis that apply modern clinical trial methodology and standardized outcome measures. Last decade, several randomised controlled trials (RCTs) have published in peer-reviewed journals in English reporting modest short and long-term effects in reducing pain and improving functional indexes. Most of these trials have studied the effects of spa therapy in patients with knee OA. Currently, there are scarce RCTs on hip, spine and hand osteoarthritis that report positive results on the effectiveness of spa therapy.

It is hoped that in the near future, there will be more pharmacological and nonpharmacological options available in the management of OA. Balneotherapy and spa therapy is such an option which may gain more importance and acceptance when more scientific evidences are available to explain their effects on the pathophysiology of osteoarthritis and to confirm their therapeutic efficacy in osteoarthritis and musculoskeletal conditions.