What Is Osteoarthritis and What Can Be Done About It?

Osteoarthritis (OA) is the most common form of arthritis and affects approximately 28 million Americans. While it was initially viewed as a "wear and tear" phenomenon, it has become quite clear that it is a disease that is multifactorial in its development.

It is not a benign disease because, in addition to the pain, OA leads to functional disability as well as interference with activities of daily living. Eventually, though, it is the pain that brings the patient to the physician.

The joint is a dynamic structure where anabolic (building) activities are counterbalanced by catabolic (destructive) activities.

With OA, the catabolic activities gradually overtake the anabolic ones. While there are attempts at repair, these attempts are dysfunctional, leading to the formation of bony spurs, called osteophytes.

There are three major risk factors for the development of osteoarthritis. They are genetic (usually a family history is prominent), constitutional (obesity in the case of OA of the knee, and aging), and finally local components (injury, ligamentous laxity, congenital abnormalities).

The development of osteoarthritis starts with an initial injury to cartilage. Cartilage consists of cells called chondrocytes that sit inside a "soup", a matrix, which consists of collagen and proteoglycans.

The injury may trigger an inflammatory response leading to the synthesis of cartilage matrix degrading enzymes, produced by chondrocytes. Over time, the catabolic activities override anabolic activities and abnormal repair mechanisms lead to the formation of osteophytes, while cartilage continues to degrade.

The treatment for osteoarthritis is primarily symptomatic. Analgesics (pain relievers), non-steroidal-anti-inflammatory drugs (NSAIDS), weight loss, exercise, assistive devices such as wedge insoles, braces, canes, walkers, and such. Injection of glucocorticoids and viscosupplements (lubricants derived either from rooster combs or from bacteria) may also be helpful.

Nonetheless, eventually patients will require surgery in the form of joint replacement. Joint replacement surgery has come a long way, but there are still concerns about them. The first is the possibility of a surgical complication such as blood clot or infection. The second issue is the finite lifespan of the prosthesis. They usually last 10 to 15 years but this is a function of activity and joint replacement patients do have restrictions on their activity level. Persistent pain due to particle induced inflammation can also be a problem.

Finally, the chance of faulty prosthetic devices such as the recent Johnson & Johnson metal-on-metal hip debacle, makes the choice of total joint replacement less attractive. In future articles I will discuss an alternative, the use of autologous stem cells to help cartilage regeneration.