What Causes Knee Pain and Stiffness?
Disease and injury can damage the articular cartilage, causing it to wear or tear away from the bone. The remaining bare areas of bone rub against each other, resulting in pain and stiffness. Arthritis is the most common cause of long-term, disabling knee pain. Another cause is avascular necrosis. Osteoarthritis typically affects people who are more than 50 years old and have family members with this disease. It causes the articular cartilage to wear away slowly. Fig.7 Rheumatoid arthritis can affect people of any age. In this form of arthritis, your bodys immune system attacks the synovial membrane. It becomes inflamed (swollen) and produces too much synovial fluid, which causes the joint to swell. Fig.8 Over time, inflammation damages the articular cartilage. Traumatic arthritis results from a knee injury that directly or indirectly damages the articular cartilage. Indirect damage can occur over time after you fracture (break) a knee bone or tear a knee ligament. Avascular necrosis i
