With surgical attempts to debride and stimulate formation of new cartilage, the new fibrocartilage is formed which consists of type I collagen. Lab tests are generally normal. There is usually no elevation of the sed rate. X-ray changes include bony sclerosis marginal osteophyte formation, and subchondral cysts. Mp symptoms may only be a small part of the disease.
Women are three times more likely than men to be affected.
The peak incidence is between the fourth and sixth decades. Genetic predisposition may occur especially with the HLA-DR4 haplotype. Rheumatoid arthritis is an autoimmune disease. The joint process is triggered in the subsynovial tissues and then secondarily affects the articular cartilage. Inflammatory cells proliferate in the synovial lining.