Traditionally, rheumatologists offer significantly effective treatment for so-called “inflammatory” forms of arthritis, but find limited success in treating “wear-and-tear” arthritis.
The latter condition, known medically as osteoarthritis (or simply “OA”), is a ubiquitous source of disability among older Americans. For example, by age 60, most people will have X-ray evidence of OA, although most of these findings are incidental and do not indicate the presence of overt significant pain. On the other hand, patients with minimal disease on X-ray may have very troublesome pain. So osteoarthritis remains an enigma.
Probably the greatest intervention in the history of arthritis treatment is the total joint replacement, which can return a patient to active living after a knee or hip joint becomes severely arthritic. As a rheumatologist who prescribes pills and injections for pain, I must tip my hat to our colleagues in orthopedic surgery who actually replace defective joints. Hip and knee replacements, in particular, often give patients a new lease on life. Joint surgeries to replace smaller joints are also improving with time.
The cornerstone of OA treatment, I believe, is patient education. For example, exercise seems to diminish arthritic pain through various mechanisms. One involves up-regulation of natural morphine-like pain-blocking molecules in the brain, called endorphins. Unlike the morphine-like molecules available pharmaceutically, these natural chemical messengers represent more of a “runner’s high” phenomenon, without the side effects of a drug, per se.
The problem is that if you have OA in your hips or knees, it is painful to exercise. Elliptical training, stair climbing, walking, swimming, yoga and low-impact aerobics represent alternative exercise options, assuming that your health care provider feels you can handle these activities from a general health standpoint. Traumatic injuries, obviously, are not helpful. Indeed, a football player with a damaged knee ligament may develop secondary osteoarthritis in that joint.
Although we typically recommend acetaminophen as a first-line agent for the treatment of OA, this medication can cause liver toxicity. Anti-inflammatory medications, such as ibuprofen, are probably the cornerstone of OA treatment, but these pills potentially cause stomach irritation, ulcers and other side effects.
Glucosamine and chondroitin may provide modest pain relieve for knee OA. Cortisone-like compounds may be injected into painful joints, although repeated use of cortisone injections can also accelerate the development of arthritic deformities in some cases. Artificial joint fluids, designed to lubricate creaky joints, are now available as proprietary medications that can be injected into arthritic knees.
None of these remedies, however, will alter the natural history of OA.
Historically, the term “disease-modifying” was reserved for agents that dampen inflammation in other arthritic conditions, such as rheumatoid disease. Research to improve therapeutic options for OA is emerging, however.
We know, for example, that Nerve Growth Factor, a cellular messenger, is released in inflamed joints that are becoming arthritic. Could agents that inhibit the activity of NGF slow down the progression of degenerative joint disease? One such agent, an artificial antibody called tanezumab, is undergoing clinical trials. Such research has prompted some to predict development of so-called “disease-modifying osteoarthritis drugs” in coming years.
Arthritis is the leading cause of disability in the United States, according to the Senate Special Committee on Aging. Our nation’s economy loses more than $100 billion annually due to decreased economic activity caused by arthritis, according to Centers for Disease Control and Prevention estimates.
Economic considerations alone, therefore, would appear to justify continued research into prevention, and treatment, of osteoarthritis. Organizations devoted to battling arthritis include the American College of Rheumatology, the Arthritis Foundation and the National Institutes of Health.
Disease prevention is critical. Untreated obesity, for example, increases the risk of knee osteoarthritis.
Scott T. Anderson, M.D., Ph.D. (email@example.com) is clinical professor of medicine, UC Davis. This column is informational, and does not constitute medical advice.