Avascular necrosis or AVN is the death in the bone tissue from losing the blood supply. It is also called ischemic bone necrosis, aseptic necrosis, or osteonecrosis. When not treated, AVN can make the bone collapse. In most people, the condition affects the hip. However, other possible sites are the ankles, knees, and the shoulder. Without necessary treatment, the space between two bones may collapse, and the bones may lose their smooth shape.
Causes
The bone’s blood supply disruption causes avascular necrosis. It happens because the bone does not get the vital nutrients and oxygen it needs. If the bone’s affected part is small and does not have a significant role in weight bearing, the body can repair the damage. In most cases, damage repair may not be possible and might lead to eventual bone collapse, bone erosion, and fracture development.
When an injury causes blood flow disruption, it is because of blood vessel damage. It is not yet understood how some factors unrelated to the injury disrupt the blood flow. But increased bone pressure constricting the blood vessels and blood clots that curtail circulation may also be responsible for the condition.
Risk factors
A few things that can amplify your risk of developing avascular necrosis. These include:
Serious injury that hampers the bone’s blood supply
Systemic lupus erythematosus is an autoimmune condition that involves tissue damage from inflammation
Some less prevalent risk factors associated with avascular necrosis are:
HIV
Blood disorders like sickle cell anemia distort RBCs
Organ transplant, typically a kidney transplant
Radiation therapy
Gaucher’s disease
Chemotherapy
Bisphosphonates
Decompression disease
High triglycerides, high cholesterol, or both
Pancreatitis
Lupus
Symptoms
During the early stages of AVN, some people may have no symptoms. As the condition aggravates, the affected joints may pain, normally when one puts weight on them. Over time, individuals may feel the pain even while lying down. The pain may be severe or mild but usually develops gradually. Pain from hip avascular necrosis centers on the buttock, thigh, or groin. Beyond the hip, it may also impact the knee, shoulder, foot, and hand. At times, people with avascular necrosis might have it on both sides, such as in both knees or both hips.
Treatment
Avascular necrosis treatment depends on the intensity of damage to the bones. Some prevalent options your doctor may recommend if your bone damage is curtailed to small bones that do not bear weight are:
Heat treatment
Cold packs
Physical therapy to lower joint tenderness and help with range of motion
Using crutches and canes as a walking aid
Treatment for advanced avascular necrosis forms
Typically, individuals will require surgery to treat avascular necrosis. Some prevalent surgical options include:
Joint replacement
The doctor will replace the damaged joint with an artificial one. Knee and hip replacements are almost 95 percent more effective at restoring mobility and relieving pain in people with avascular necrosis.
Core decompression
In this, the surgeon drills cores or tiny holes in the affected bone to increase blood flow in the area. This procedure is typically bundled with bone grafts or injections to promote healing.
