While more than half of patients older than 65 years of age have osteoarthritis changes in the their knees on x-ray, osteoarthritis is not considered a "normal" part of aging.

Certain activities and occupations increase the likelihood of osteoarthritis. For instance baseball players have an increased incidence of osteoarthritis in the elbows and shoulder. Football players have an increased incidence of osteoarthritis in the hips and knees. And ditch diggers have an increased incidence of osteoarthritis in their wrists.

Obesity is a risk factor for osteoarthritis developing in the knees.

Osteoarthritis is a disease that arises from biochemical changes in cartilage which include a decrease in glycosoaminoglycans, an important constituent of collage, an increase in water content, and an increase in the content of destructive enzymes such as matrix metalloproteinases.

These changes lead to structural weakening of cartilage. Small fissures develop, then larger cracks and irregularities also occur. Ulceration of cartilage and further deterioration occurs. The end result is a premature wearing away of cartilage with exposure of underlying bone. Along with this wearing away of cartilage is an increase in inflammation of the lining of the joint, the synovium.

The joints that are affected most in osteoarthritis are weight-bearing areas such as the neck, low back, hips, and knees.

Stiffness and pain are the moist common symptoms.

On physical exam, there are signs that point towards the diagnosis including bony swelling, and distribution of joint problems.

Laboratory testing is usually normal. X-rays may show changes.

Treatment for osteoarthritis is aimed at five primary goals. They are relief of pain, maintenance of function, prevention of disability, control of co-morbid conditions, and avoidance of medication side effects.

Non-drug therapies include patient education, physical therapy, thermal modalities, weight loss if indicated, and exercise.

Drug therapies include non-steroidal anti-inflammatory agents, injections of glucocorticoids or viscosupplements (lubricants), and disease-modifying drugs.

Alternative therapies such as acupuncture, balneotherapy (spas), glucosamine/chondroitin, massage, chiropractic, etc. all have their advocates.

One area that has received much attention is the use of mechanical shifting devices that can unload specific joints. For instance osteoarthritis of the knee, a common problem, has received much scrutiny lately.

A recent study showed that the use of shoes that mimic barefoot walking may help because there is more pressure placed on the middle of the knee joint when people wear shoes as opposed to when they walk barefoot.

Also, the use of a simple device like a cane also reduced the load on the knees.
(Kemp G, et al Arthritis Care and Research 2008; 59: 609-614).

Other studies have found that lateral wedge insoles worn inside shoes can also reduce the load on the medial side of the joint.

Until the day comes when new cartilage can be grown... and that day may be closer than we think, particularly with the emphasis on stem cell research, the above modalities may have to do.