Osteoarthritis, also known as degenerative joint disease, is the most common joint disorder. It is characterized by damage of the joint cartilage and abnormalities of the bones surrounding the joint. Unlike in rheumatoid arthritis, inflammation is usually minimal in osteoarthritis. In severe cases, the entire joint surface may be destroyed, with resultant pain and disability.

The most common joints to be involved are the knees, hips, and vertebrae. The joints of the hand are also commonly affected. The most common symptom is stiffness within the joint, typically lasting less than 15 minutes per day. Over time, the stiffness progresses to pain.

Most cases of osteoarthritis occur in the absence of underlying diseases. However, several medical disorders predispose a person to osteoarthritis. These include endocrine abnormalities (e.g., hypothyroidism, diabetes, or mellitus), other joint diseases (e.g., rheumatoid arthritis, gout, or joint infection), and bone diseases (e.g., avascular necrosis or Paget's disease).

Risk Factors

• Obesity: Obesity increases risk of osteoarthritis of the knee and hip joints.
• Age: The condition is rare in young people, but common in middle-aged and older adults. One-third of people over 65 years old have evidence of osteoarthritis in the knee on X-rays
• Female gender
• Occupation: Hands, hips, and knees are vulnerable
• Genetics: An identical twin of an individual with hand or knee osteoarthritis has double the risk of having the same condition, compared with a fraternal twin.
• Trauma: Repetitive acts increase the risk.
• Pre-existing or anatomical joint abnormality

Osteoarthritis: Diagnosis and Treatment

Diagnosis

• The evaluation begins with a medical history and a physical examination.
• There is no laboratory test specific for osteoarthritis.
• X-rays or CT scan of the affected joints may suggest the diagnosis.

Treatment

• Weight loss, low-impact exercise, physical therapy, and shoe inserts or braces/splints are the first line of therapy.
• Over-the-counter medications that have been shown to be useful include capsaicin cream, acetaminophen (Tylenol), nonsteroidal anti-inflammatory drugs (e.g., ibuprofen, Celebrex), and glucosamine and chondroitin sulfate.
• Joint injections can be effective in many cases that do not respond to medications.
• Surgery, which may include joint replacement, is reserved for severe cases that limit activities of daily living.

Osteoarthritis: Nutritional Considerations

• The role for nutrition in osteoarthritis is mainly related to the effects of diet on body weight. Obesity increases the risk for osteoarthritis of the hip, knee, and possibly the joints of the hand. Weight loss was found to significantly improve pain and function in individuals with osteoarthritis. Some evidence suggests that a reduction in body fat, independent of body weight, may help relieve symptoms. A low-fat, high-fiber diet in combination with exercise prevents weight gain, and may also prove useful in treatment. See How to Lose Weight.
• The combination of glucosamine sulfate (1500 milligrams a day) and chondroitin sulfate (1200 milligrams a day) may improve symptoms. Early studies suggested that these supplements improve symptoms in patients with knee osteoarthritis. Subsequent controlled trials, however, have been less favorable. At this time, further study is necessary.
• Reducing serum cholesterol may decrease osteoarthritis risk. Elevated serum cholesterol was independently associated with osteoarthritis in two studies.
• Vitamin D may play a role in osteoarthritis. Individuals with lower blood levels of vitamin D appear to have greater risk for progression of osteoarthritis.
• Ginger may provide significant pain relief for osteoarthritis patients. Effective doses range from 170 milligrams ginger extract three times per day to 250 milligrams four times per day.