Damage from mechanical stress with insufficient self repair by joints is believed to be the primary cause of<unk> . Sources of this stress may include misalignments of bones caused by congenital or pathogenic causes; mechanical injury; excess body weight; loss of strength in the muscles supporting a joint; and impairment of peripheral nerves, leading to sudden or uncoordinated movements. However exercise, including running in the absence of injury, has not been found to increase the risk of knee<unk> . Nor has cracking one's knuckles been found to play a role. Primary The development of<unk>  is correlated with a history of previous joint injury and with obesity, especially with respect to knees. Changes in sex hormone levels may play a role in the development of<unk> , as it is more prevalent among post-menopausal women than among men of the same age. Conflicting evidence exists for the differences in hip and knee<unk>  in African Americans and Caucasians. Occupational Increased risk of developing knee and hip<unk>  was found among those who work with manual handling (e.g. lifting), have physically demanding work, walk at work, and have climbing tasks at work (e.g. climb stairs or ladders). With hip<unk> , in particular, increased risk of development over time was found among those who work in bent or twisted positions. For knee<unk> , in particular, increased risk was found among those who work in a kneeling or squatting position, experience heavy lifting in combination with a kneeling or squatting posture, and work standing up. Women and men have similar occupational risks for the development of<unk> . Secondary This type of<unk>  is caused by other factors but the resulting pathology is the same as for primary<unk> : * Alkaptonuria * Congenital disorders of joints * Diabetes doubles the risk of having a joint replacement due to<unk>  and people with diabetes have joint replacements at a younger age than those without diabetes. * Ehlers-Danlos syndrome * Hemochromatosis and Wilson's disease * Inflammatory diseases (such as Perthes' disease), (Lyme disease), and all chronic forms of arthritis (e.g., costochondritis, gout, and rheumatoid arthritis). In gout, uric acid crystals cause the cartilage to degenerate at a faster pace. * Injury to joints or ligaments (such as the ACL), as a result of an accident or orthopedic operations. * Ligamentous deterioration or instability may be a factor. * Marfan syndrome * Obesity * Joint infection
Osteoarthritis
Fibromyalgia
Oligoarthritis
Bunion
Osteochondropathy
Septic arthritis
Bursitis
Plantar fasciitis