Degenerative Joint Disease

Definition

Degeneration of cartilage and overgrowth of bone in joints associated with minimal inflammation. This type of arthritis is called osteoarthritis, OA, degenerative joint disease, DJD, or osteoarthrosis.

Description

The tissue involved most in osteoarthritis is the cartilage. This is the gristle material that faces the ends of the bones and forms the surface of the join on both sides. Gristle is tough, somewhat elastic, and very durable. The cartilage or gristle does not have a blood supply, so it gets its oxygen and nutrition from the surrounding joint fluid. In this, it is aided by being elastic and by being able to absorb fluid.

When we use a joint, the pressure expresses fluid and waste products out of the cartilage, and when the pressure is relieved, the fluid seeps back, together with oxygen and nutrients. Hence the health of the cartilage depends on use of the joint.

Over many years, the cartilage may become frayed and may even wear away entirely. When this happens, the bone surface on one side of the joint grates against the bone on the other side of the joint, providing a much less elastic joint surface. With time, the opposing bony surfaces may become polished, a process called eburnation.

There are three common forms of osteoarthritis, and many people have some of each type.

The first and mildest form causes knobby enlargement of the finger joints. The end joints of the fingers become bony and the hand begins to assume the appearance we associate with old age.

The second form involves the spine. Bony growths appear on the spine in the neck region or in the lower back. Usually the bony growths are associated with some narrowing of the space between the vertebrae.

The third form involves the weight-bearing joints, almost always the hips and knees.

These problems can be quite severe. Osteoarthritis of the weight-bearing joints, particularly the hip and knee, develops slowly and often involves both sides of the body. Pain in the joint may remain fairly constant or may wax and wane for a period of years. In severe cases, walking may be difficult or even impossible. Fluid may accumulate in the affected joint, giving it a swollen appearance, or a knee may wobble a bit when weight is placed on it.

Usually, in the knee, the osteoarthritis will affect the inner or outer half of the joint more than the other. This may result in the leg becoming bowed or splayed outward and cause difficulty in walking.

Causes and Risk Factors

Osteoarthritis is the most common form of joint disease, sparing no age, race, or geographic area. At least 20 million adults in the U.S. suffer from osteoarthritis. Symptomatic disease increases with age.

Hereditary and mechanical factors are most likely involved in the development of osteoarthritis. Osteoarthritis may occur secondary to an injury to the joint due to a fracture, occupational overuse, or metabolic disorders (e.g. hyperparathyroidism). Obesity is a risk factor for knee osteoarthritis and probably the hip as well. Recreational running does not increase the incidence of OA but participation in competitive contact sports does.

Symptoms

Initially there may be joint stiffness, seldom lasting more than 15 minutes. Later there may be pain on motion of the affected joint, which is made worse with activity or weight-bearing and relieved by rest.

There may be limitation of motion of the affected joint. Coarse crepitus (a creaking) may be felt in the joint. There is usually no joint swelling or tenderness.

Diagnosis

Diagnosis is based on the medical history and physical examination. Lab tests do not reveal signs of inflammation.

Treatment

Patients with mild to moderate osteoarthritis of weight-bearing joints (hips and knees) may benefit from a supervised exercise program such as walking. The most helpful exercises seem to be swimming and walking - activities that are easy, can be gradually increased, and are smooth rather than jerky.

A sensible, program of regular physical activity can strengthen the bones and ligaments surrounding the affected joints and preserve mobility in joints that are developing spurs. Many physicians believe that osteoarthritis may be prevented to a large extent by good health habits. Remain active, maintain a lean body weight, and exercise the muscles and joints regularly so as to nourish cartilage.

For many patients, acetaminophen (Tylenol) is as effective and has less side effects than other non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen.

Patients who fail to improve on acetaminophen may be treated with salicylates and other NSAIDs. Capsaicin cream 0.25% applied twice daily can reduce knee pain. Intra-articular (within the joint) injections of triamcinolone may also be helpful.

Surgery can be dramatically effective for patients with severe osteoarthritis of the weight-bearing joints. Total hip replacement and total knee replacement can be extremely effective. Although arthroscopic surgery for knee osteoarthritis is a common procedure, its long-term effectiveness is unclear.

Alternative & Complimentary Therapies

Experimental techniques to repair cartilage loss in the knee by transplantation of cartilage cells is promising.

Prevention

Weight reduction may reduce the risk of symptomatic knee osteoarthritis.

Questions to Ask Your Doctor

Are there signs of degenerative joint disease?

Where is this primarily focused?

Would exercise help?

How can this be done painlessly?

What medications do you recommend?

What are the side-effects?

Will surgery be required?

What can be done to retard the degenerative process?