Osteoarthritis insights: an overview
Osteoarthritis is the most common form of arthritis, commonly affecting the hands, spine, knee or hip. A review from the National Institutes of Health (NIH) in the United States is attempting to dispel many of the myths associated with the condition, and may help educate people about the treatment options available to them.
The NIH review, published in the October and November 2000 issues of the Annals of Internal Medicine, offers insights into osteoarthritis — particularly risk factors and treatment options — that arose from the NIH's 1999 conference, ‘Stepping Away from OA: Prevention of Onset, Progression, and Disability of Osteoarthritis’.
The 2-part report discussed recent advances in osteoarthritis (OA), which are helping to change the common perception that treatment options are limited, and that OA is a simple disease.
OA and risk factors
The review indicated that OA may consist of several distinct conditions rather than being one single, and relatively simple, disease. This is supported by the following discoveries.
-
Hip and knee OA have different risk factors, meaning they could be separate diseases.
-
The cause of OA can be primary (unknown cause) or secondary (known cause).
-
There are hypertrophic (meaning abnormal enlargement) and atrophic (meaning degenerative) forms of OA of the hip.
-
Having OA in the family may be more important to the development of generalised OA than factors such as obesity, injury or muscle weakness.
The researchers confirmed that the risk of OA increases with age, and that gender can play an important role. Before the age of 50, the prevalence of OA in most joints is higher in men than women, although after the age of 50, OA of the hand, foot and knee becomes more prevalent in women.
Here are some other findings from the first part of the review, which focused on OA and its risk factors.
-
OA has been identified as the most common reason for total hip and total knee replacements.
-
The burden of OA is also a financial one: it contributes significantly to work absenteeism and early retirement.
-
The cause of pain in OA is unknown.
-
OA can be caused simply by a severe joint injury.
-
The review suggested that because antioxidants are protective against tissue injury, a high intake could have a protective effect against OA.
-
There is a high incidence of OA in women after the menopause, which may or may not be related to the protective effects of oestrogen.
-
High levels of vitamin C in the diet were associated with a reduction in the risk of progressive OA of the knee and with reduced risk for knee pain.
-
High levels of vitamin D have been shown to protect against new-onset and progressing osteoarthritis of the hip.
-
At least 50 per cent of OA in the hands and hips can be attributed to genetic factors.
-
Easily measured disease indicators (known as biomarkers) are being developed using synovial fluid, serum and urine. These may provide insights into development, progression and treatment of disease.
-
Weight loss can reduce the risk of OA: one study found that women who reduced their weight by an average of just under 5 kilograms decreased their risk of knee OA by 50 per cent.
-
There may be genes linked to the development of arthritis in specific areas of the body.
-
Participating in some competitive sports that involve direct joint impact can increase the risk of OA.
-
Moderate, regular running has low, if any, risk of leading to OA.
-
The risk of OA after a joint injury can be reduced if the injury is diagnosed and treated effectively and quickly, and rehabilitated completely.
-
The risk of OA is increased in people who do repetitive work that places strain on the joints and muscles. Work tasks account for between 15 and 30 per cent of knee OA in men.
Treatment approaches to OA
OA has no known cure, so treatment options centre around improving the pain control, comfort and quality of life of people with the condition.
Treatment options explored in the second part of the review included oral medications (those taken by mouth); creams and gels to rub in the skin; exercise; bracing and footwear; acupuncture; and surgery.
Here are some of the outcomes of the review.
-
In some people, mild to moderate joint pain can be treated effectively with paracetamol.
-
Non-steroidal anti-inflammatory drugs (NSAIDs) are a useful treatment option for people who don't get adequate pain relief from simple analgesics.
-
COX-2 inhibitors, or coxibs, such as celecoxib (Celebrex), can be a useful treatment option for doctors to consider: studies have shown that coxibs are just as effective as NSAIDs in treating arthritis pain and inflammation but have less risk of gastrointestinal side effects such as bleeding ulcers.
-
The COX-2 selective inhibitor meloxicam (Mobic) is another option for OA treatment that is also reported to have less risk of gastrointestinal side effects, compared to older NSAIDs.
(N.B. Since rofecoxib (Vioxx), one of the COX-2 inhibitor medications, was withdrawn from the market in September 2004, there has been further investigation into the safety of other coxibs and COX-2 selective inhibitors. Coxibs seem to be associated with an increased risk of cardiovascular events, such as heart attack and stroke, when taken in high doses. In February 2005, the Australian Therapeutic Goods Administration advised people taking more than 200 mg/day of celecoxib (Celebrex) or more than 15 mg a day of meloxicam (Mobic, Movalis) to review their treatment with their doctor. Celebrex should not be taken by people who are at high risk of cardiovascular disease. You can discuss the risks and benefits of treatment with these medications with your doctor, who will be able to tell you whether or not they are suitable for you.)
-
Topical analgesics (painkilling creams and lotions) can be used as an additional treatment in patients with OA of the hand or knee or as the only treatment.
-
Although the administration of glucosamine or chondroitin sulphate — touted by some sources as effective complementary therapy for osteoarthritis — has been shown to have favourable effects in some studies, there is considerable dispute about the quality and independence of many of the trials to date.
-
Exercise has been identified as an important factor in preventing arthritis. Failing to exercise if you have OA can increase the risk of obesity and heart disease.
-
Bracing and corrective footwear are simple and cost-effective treatment measures.
-
Many people who use complementary and alternative therapies use multiple remedies, without advising their doctor.
-
Research to date on the effectiveness of acupuncture as an arthritis treatment has been inconclusive, but shows promise.
The future for OA
The researchers concluded that OA is a ‘suprisingly complex’ condition, and the review described patient education as ‘the cornerstone’ of treatment for OA. Through increased awareness of the risk factors and treatment for OA, the quality of life and abilities of people with arthritis can be improved in the short-term, while the research for a definitive cure continues.
Sources: Annals of Internal Medicine 2000;133:635-646. Annals of Internal Medicine 2000; 133:726-737.
Last Reviewed: 16 May 2005
Sponsored links
