Most knee pain experienced by patients results from the normal wear and tear from the aging process. As we age, the soft cartilage tissue holds less and less water, reducing the amount of cushion they provide and making them more susceptible to degradation. Injury and autoimmune diseases can also play a role in wearing down the cartilage. We call the breakdown of cartilage “arthritis” and it exists in three basic types that may affect the knee joint. Osteoarthritis, Post-traumatic arthritis, and Rheumatoid Arthritis.
Types of Knee arthritis
Osteoarthritis (OA) occurs more frequently than other forms of Arthritis. OA usually occurs slowly, as a progressive degenerative disease in which the joint cartilage gradually wears away. It mostly affects older patients. Avascular necrosis of the knee accelerates osteoarthritis and can even cause young patients to require surgical intervention to avoid it. Once the cartilage has sufficiently worn away, bone rubs on bone which causes pain and bone spurs that damage larger amounts of cartilage.
Rheumatoid arthritis (RA) destroys the joint cartilage by inflaming the tissues of the joint lining, and can occur at any age. RA generally affects multiple joints at the same time. Immediate treatment of RA may slow the progression of the disease and the damage it inflicts on the body. While orthopedic surgeons may identify and diagnose Rheumatoid arthritis, treatment of the condition requires specific type of specialist called a Rheumatologist.
Post-traumatic arthritis can develop after a knee injury. This type of arthritis appears the same as osteoarthritis and may only develop years after a ligament injury, fracture, or meniscus tear. In post-traumatic arthritis, the degradation of the joint accelerates after an injury jump starts a cartilage degradation feedback loop leading to the eventual failure of the cartilage in the joint.