Degenerative Joint Disease

A degeneration or ‘wear and tear’ of articular (joint surface) cartilage usually accompanied by an overgrowth of bone (osteophytes), narrowing of the joint space, sclerosis or hardening of bone at the joint surface, and deformity in joints. OA is not usually associated with inflammation, although swelling of the joint does frequently occur in OA. This type of arthritis is called osteoarthritis, OA, degenerative joint disease, DJD, or osteoarthrosis. Other forms of arthritis (rheumatoid, post-traumatic, and other inflammatory disorders) frequently may have OA as the end-stage, making differentiation difficult.

Causes

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. Many patients may have OA seen on x-rays, but not be overly symptomatic.

Hereditary, injury, fractures around a joint surface, and overuse factors are most frequently involved in the development of osteoarthritis. Osteoarthritis may occur secondary to an injury to the joint due to a fracture, repetitive or overuse injury, or metabolic disorders (e.g., hyperparathyroidism). Additionally, gout and other forms of crystalline joint disease may lead to OA of a joint. Obesity or being overweight is a risk factor for knee osteoarthritis more commonly in females; this is less commonly seen in the hip joint. Recreational running does not increase the incidence of OA, but participation in competitive contact sports does. Specifically, impact sports that repetitively load a joint increase the injury to a joint. If cartilage in a joint is injured, it cannot regenerate, and the new forces that are created are abnormal, leading to further stresses, and the cycle may propagate.

Treatment

Treatment of OA depends upon multiple factors including patient age, activities, medical condition, and x-ray findings. Patients with mild to moderate osteoarthritis of weight-bearing joints (hips and knees) may benefit from a supervised exercise program such as walking. Non-impact activities such as swimming, cycling, and walking tend to be more comfortable for patients with OA. In a younger patient with signs or symptoms of OA, other causes of arthritis such as deformity, medical conditions, or bone disorders should be carefully sought for in order to rule out other conditions.

A program of regular physical activity can strengthen the muscles, tendons, and ligaments surrounding the affected joints and preserve mobility in joints that are developing bone spurs. Many physicians believe that osteoarthritis may be prevented by good health habits. Remaining active, maintaining an ideal body weight, and exercising the muscles and joints regularly so as to nourish cartilage.

A first line of simple treatment - acetaminophen (Tylenol) is as effective and has less side effects than other non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen, naproxen, or aspirin.

Glucosamine-chondroitin sulfate may be prescribed by your doctor. This medication, when taken over a period of months, may reduce pain and symptoms by restoring or replenishing nutrition to diseased cartilage cells. It tends to be more effective in earlier stages of OA. The dosage and combination of each ingredient is an important aspect of the therapy, as not all preparations and brands are the same. Patients who fail to improve on acetaminophen or glucosamine may be treated with salicylates and other oral anti-inflammatories ( NSAIDs). Previously, medications such as Vioxx, Celebrex, and Bextra (Cox-2 NSAIDS) were preferred due to less gastrointestinal side effects (ulcers) and improved pain relief for arthritis. However, currently the use of these medications should be reviewed with your doctor, as concerns about their use in certain patients has been recently reported. More traditional NSAIDS (ibuprofen, naproxen, etc.) are available over the counter, and they also provide excellent relief of symptoms. Capsaicin cream 0.25% applied twice daily may reduce knee pain. Intra-articular (within the joint) injections of steroids may also be helpful, although the duration and amount of pain relief is often unpredictable, especially in more advanced stages of OA. Alternative injections of hyaluronic acid peparations (sodium hyaluronate) are also available and may be very useful in the treatment of OA. These injections are indicated for OA of the knee, and typically require an injection once a week, over a period of three to five weeks (i.e., three to five injections). The hyaluronic acid is injected into the knee joint, and similar to oral glucosamine, may provide nutrition to the diseased cartilage cells and collagen within the cartilage. The fluid is a gel-like material that appears to act initially like a lubricant for the joint. However, studies have shown that the lubricant aspect plays little role and, in fact, the fluid is absorbed quickly by the cartilage cells.

Bracing, splinting, and other orthotic treatments may be useful in managing or “unloading” an arthritic joint surface. These nonoperative treatments are simple, often effective, however cost and ease of use are factors in their selection in treatment.

Surgery may be dramatically effective for patients with severe osteoarthritis of the weight-bearing joints. Total hip replacement and newer hip resurfacing replacements and total knee replacement or unicompartmental (partial) knee replacement can be extremely effective. Joint replacement is now being performed in younger patients also. The concerns about wear of the prosthetic joint surface in younger patients make this the most challenging aspect of future research in this area. Newer joint surfaces for joint replacement including highly cross-linked polyethylene, metal on metal bearing, ceramic bearings, and others have emerged and currently are available in the U.S.

Although arthroscopic surgery for knee osteoarthritis is a common procedure, its long-term effectiveness is unclear, and may be best for symptoms such as catching, locking, or those that have been present for only a short duration. In addition, not all patients that have arthritis should have an arthroscopy, as this may not improve their symptoms.

In younger patients, hip and knee preserving procedures should be considered, in order to avoid a hip or knee replacement. Although performed less frequently, hip and knee preserving procedures, such as osteotomy (cutting the bone and realigning the bone or joint surface), may restore a joint to a normal alignment and be an excellent alternative to joint replacement.