Friday, March 18, 2011

Maximizing Treatment for Osteoarthritis: A 3 Part Story (2011 Abstract of Lecture)

Treatment of Osteoarthritis remains a challenge, and reviewing data from the mid 1990’s to present, the advances in understanding the disease have not been matched with advances in treatment,  compared to that seen in rheumatoid arthritis, for instance.
This symposium has 3 parts, namely, new concepts in pathogenesis and pathology that has fueled research in targeted therapy, use of OA treatment guidelines and the future of OA treatment.
Part 1: Osteoarthritis as a disease is a heterogenous entity, with incongruence in its anatomic, radiographic and clinical characteristics. Osteoarthritis in the spine, hands, hips and knees can be different diseases, with different risk factors and remain radiographic entities for extended periods before they manifest clinically as pain. Pain is generated by various mechanisms, the recent concept being, bone marrow lesions (BMLs) that are consistent anatomically with pain and progression of cartilage disease. Inflammatory elements are established in synovium, subchondral bone and periarticular fat pad, triggering studies on new targets of treatment.
Part 2: Treatment has focused on pain control and prevention of disability. Clinical practice guidelines abound, by specialty, country, by advocacy. Adherence to these expensive projects is in question. Western data show low adherence to recommendations on exercise and weight loss, and instead, drug prescription and surgery are resorted to more often than necessary. Non-pharmacologic treatment remains by evidence, the first line treatment for the control of pain and for preserving function. Drug treatment starts with analgesics. The GAIT study shows a rather big placebo effect for OA pain and the effects of many of drugs are small over that of placebo.
Part 3: Targeted treatment and newer approach to control pain and preserve function continue to be explored. Disease modifying OA drugs have long been in the market with inconsistent evidence. Diacerein, avocado unsaponifiables, chondroitin sulphate, glucosamine salts have known anti- metalloproteinase and anti -cytokine effects. The clinical effects of disease modification are difficult to measure. Current studies on monoclonal antibodies are promising for the control of pain, but again, these modalities would suffer from cost considerations.
In summary, treatment for OA can be maximized by considering the patient as a whole, keeping them functional and pain free, in the safest way possible. For now, clinical practice guidelines contain recommendations that have been judiciously studied for evidence of efficacy and safety and should therefore help the clinician achieve the objectives of treatment.