What does ON mean in PHYSIOLOGY

The exact cause of osteonecrosis is unknown, but it most likely occurs as a result of poor blood circulation to the bones due to various factors including age-related changes in blood vessel structure, high-dose glucocorticoid use, an injury that damages the bone's vascular supply, alcohol misuse, infections within the bone or joint and certain medical conditions such as diabetes.

The main symptom of osteonecrosis is persistent joint pain. Other symptoms may include joint stiffness, swelling or tenderness around the joints. Over time, there may be increased deformity or collapse of part or all of a bone due to weakening from poor bone circulation or because some bony tissue has died before being replaced with new tissue.

Persons at higher risk for developing osteonecrosis include those with arthritis, alcohol abuse/misuse history, low body weight (anorexia), use of long-term corticosteroids (such as prednisone), lupus and other autoimmune diseases including rheumatoid arthritis and vasculitis (inflammation of blood vessels). Additionally individuals who have had hip replacements face an increased risk for osteonecrosis due to this surgery disrupting normal blood flow to the ball portion of the hip joint.

If your doctor suspects you may have osteonecrosis they will likely order imaging tests such as X-rays to look for signs like cysts on your bones or collapsed areas where tissue has already died off. Your doctor may also recommend an MRI scan which can provide more detailed images and reveal hidden areas that X-rays cannot detect. Blood tests may also be ordered to look for markers related to underlying conditions associated with ON such as inflammatory markers that indicate autoimmune disease activity.

Treatment usually involves supportive care measures such as rest and avoiding activities that put extra stress on affected joints. Pain medications (both over-the-counter medication or prescription medication) and physical therapy can also help manage symptoms associated with osteonecrosis whereas surgical procedures such as core decompression may be necessary in cases involving severe damage to the bones due to decreased circulation.