Osteoarthritis: New Perspectives

Abstract

Osteoarthritis (OA) is the most common and frequent disease in rheumatology. Aging and obesity are the two main risk factors linked to OA, and because of the aging population and the increasing rates of obesity, the number of OA patients stands to increase dramatically. To date, 46 million adults in the United States—more than 50 percent of adults aged 50 and over—have been diagnosed with OA: it is predicted that by the year 2030, that figure will rise to around 70 million [1]. In the last two decades, many mechanisms have been discovered about this disease. Cartilage, which previously was considered inactive tissue, is now actively studied as the main active tissue of joints; it is being studied as part of the whole joint, including other tissues as subchondral bone, synovium and tendons. OA mainly targets the major joints (knee, hip, and back) but commonly affects the hands, elbows, and ankles. Osteoarthritis is a degenerative disease caused by the loss of cartilage and inflammation: it is often—but not always— accompanied by pain and sometimes occurs subsequent to an injury as primary or secondary OA. The disease results in an imbalance between catabolic and anabolic factors in cartilage. Chondrocytes, osteoblasts, and synoviocytes seem to cross-talk and be part of the process. Current molecular and genetic approaches have led to the identification of more complex mechanisms. The practical questions this paper addresses are: how should we treat OA in the next 10 years, and how can we help aging patients manage their arthritis? Although the ultimate goal for the treatment of OA would be to halt the disease progression and restore cartilage damage and relieve pain, effective cures are not currently available and recommendations for treatment vary. The European League Against Rheumatism (EULAR), the OsteoArthritis Research Society International (OARSI) and the American College of Rheumatology (ACR) have developed various recommendations for treating OA, depending on its location [2–8]. Roddy and Doherty have written a critical review of EULAR’s and ACR’s recommendations for treating OA, which are generally similar, combining non pharmacological and pharmacological approaches [9]. Rannou et Poiraudeau recently published an exhaustive list of nonpharmacological treatments for OA, echoing the work done by Felson et al. [10] on malalignment: treatment regimens range from orthosis to exercise, patient education, and diet, depending on OA location [10–13]. The recent study by Richette et al. [14] concerning obesity and diet and OA highlighted the importance of such non pharmacological treatments [14]. Briefly, non pharmacologic treatment include orthosis (such as using insoles and specific shoes, depending on the location), moderate excercise (specific postural exercises, swimming, walking), acupuncture, thermotherapy, and walking aids such as canes crutches, frames, wheeled walkers, and walking sticks. Diet and weight loss are also recommended, although these are a challenge and a difficult process for obese patients. Defining a weight objective could lead to improvement not only with OA but also with metabolic and cardiovascular diseases. No matter the recommended treatment, education and information are vital for effecting patient compliance. Physicians and therapists play an important role in providing such education during time spent with their patients: regular phone calls may help as well. The pharmacological approach for the treatment of OA differs from Europe to the U.S., although both approaches share the common goal of managing pain while also managing disability. Pharmacological guidelines for the management of OA recommend acetaminophen up to 4g/day as first-line therapy. Alternative pharmacological therapy should be used only in the presence of an inadequate response and severe pain. If acetaminophen cannot control symptoms or if inflammation signs are detected, the use of NSAIDs at the lowest dose is recommended, with consideration of a gastro-protective agent. OARSI and EULAR guidelines recommend that if patients don’t respond to oral analgesics, they should receive intra-articular injections of either corticosteroids or hyaluronate followed by the use of opioids and narcotics only when all other pharmacological options have been considered. Surgery, including joint replacement, is recommended only as the last option [15]. Finally, the use of topical NSAIDs, capsaicin, and SYSADOA (SYmptomatic Slow-Acting Drugs for OA, which includes avocado/soybean unsaponifiables (ASU), chondroitin, diacerein, and glucosamine) is recommended by EULAR and OARSI.