Osteoarthritis (OA) is a common chronic disease that affects more than 300 million people worldwide that imparts a high societal cost and has few and suboptimal management options. With no approved disease-modifying drugs available for OA, current pharmacological treatment options are limited to analgesics, intra-articular corticosteroids, and non-steroidal anti-inflammatory drugs (NSAIDs). While these medications have only a mild-to-moderate effect size for pain relief, they are associated with gastrointestinal, renal, and cardiovascular complications. Furthermore, OA is mostly a disease of older adults, and OA patients often have comorbidities, which makes many of these medications contraindicated. Consequently, the global demand for safe and effective therapeutic options for OA has refocused the interest from conventional drugs to complementary and alternative medicines (CAMs). Forty percent of OA patients have tried at least one complementary medicine over the last year, and there is increasing evidence from well-conducted studies on the therapeutic potential of CAMs.

Currently, there are no approved disease-modifying drugs available for OA. The current treatment guidelines include exercise and patient education as first-line treatments, often followed by pain medications such as topical and oral NSAIDs. The most commonly used analgesic, paracetamol, has been shown to have minimal effect compared to placebos and is not recommended in recent guidelines. Furthermore, oral NSAIDs have shown moderate pain relief compared to placebos, however their use carries an increased risk of cardiovascular toxicity. The efficacy of other therapies, such as intra-articular corticosteroid injections, remains questionable due to the short-term benefits and the overall low-quality evidence. New efficacious and safe therapeutic options are therefore required for the management of OA. Recent studies on CAMs such as collagen hydrolysate, passion fruit peel extract, Curcuma longa extract, Boswellia serrata extract, pycnogenol, L-carnitine, undenatured type II collagen, avocado soybean unsaponifiables, methylsulfonylmethane, pharmaceutical grade glucosamine and chondroitin, and balneotherapy have demonstrated clinically important effects on pain and function in patients with hand, hip, or knee OA in the short term. However, the quality of the evidence demonstrating the efficacy of CAMs in OA is very low.

The aim of this Special Issue is to publish exceptional, high-quality, and original research papers presenting cutting-edge evidence on the role of CAMs in the management of OA. The need for a safe and effective option for OA treatment has transferred the focus of research from conventional drugs to CAMs. Furthermore, CAMs have acceptability among OA patients, and a substantial number of OA patients have reported trying at least one CAM for the management of OA. Over the years, increasing evidence is being generated from well-conducted studies on the therapeutic potential of CAMs for OA treatment. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Safety and efficacy of medicinal plants, herbal extracts, vitamins, minerals, marine oils, or isolated compounds for the treatment of osteoarthritis, including but not limited to knee, hip, or hand osteoarthritis, and related symptoms and structure modifications
• Safety and efficacy of traditional healing systems of different regions for the treatment of osteoarthritis
• Safety and efficacy of various non-pharmacological management options such as yoga or Tai-chi for the treatment of osteoarthritis
• Semi-synthetic or pharmaceutical grade formulations extracted from the above sources for the treatment of osteoarthritis
• Standardization of CAMs for the treatment of osteoarthritis
• Health economic, cost-effectiveness, and cost-benefit analysis of CAMs for the treatment of osteoarthritis
• Systematic reviews, meta-analysis, or review articles evaluating the efficacy and safety of medicinal plants or isolated compounds for the treatment of osteoarthritis