What type of arthritis developes when joint cartilage wears out?

Osteoarthritis (OA) is the most common form of arthritis. Arthritis causes inflammation and pain in one or more joints in the body. OA is also known as degenerative joint disease. According to the Centers for Disease Control and Prevention (CDC), about 27 million American adults over the age of 25 have osteoarthritis. That makes OA one of the leading causes of disability in adult Americans.

Cartilage, the smooth, rubbery connective tissue on the end of bones, cushions joints and helps them move smoothly and easily. A lifetime of walking, exercising, and moving takes a toll on your cartilage. The degeneration of cartilage can cause chronic inflammation in the joint. This inflammation can further break down the cartilage over time. The cartilage may wear away completely if it is left untreated.

A membrane called the synovium produces a thick fluid that helps keep the cartilage healthy and makes joints run smoothly. The synovium can become inflamed and thickened as OA progresses. The inflammation produces extra fluid within the joint, resulting in swelling.

As cartilage deteriorates, adjacent bones may no longer have sufficient lubrication from the synovial fluid and cushioning from the cartilage. Once the bone surfaces come in direct contact, this results in additional pain and inflammation to the surrounding tissues. As bones continually scrape one another, they can become thicker and begin growing osteophytes, or bone spurs. The joints most commonly affected by OA are in the hands, feet, spine, and weight-bearing joints, such as the hips and knees.

The older we get, the more common it is to experience mild soreness or aching when you stand, climb stairs, or exercise. The body does not recover as quickly as it did in younger years.

Another cause for the soreness: Cartilage naturally deteriorates. The smooth tissue that cushions joints and helps them move more easily disappears with age. In a sense, the body’s natural shock absorbers are wearing out, which means you begin feeling more of the physical toll your body is experiencing. In addition, we lose muscle tone and bone strength the older we get. That can make physically demanding tasks more difficult and taxing on the body.