Osteonecrosis (Avascular Necrosis)

Osteonecrosis at a glance

  • Osteonecrosis occurs when the blood supply to a bone is interrupted, causing the bone tissue to die.
  • Avascular necrosis can be caused by dislocations and fractures, certain medical conditions, or long-term use of corticosteroids or alcohol.
  • Over time, symptoms may include pain in the groin, thigh or buttock, especially when putting weight on the affected leg, and limping.
  • Treatment for osteonecrosis includes medication, specific exercises, or electrical stimulation. Eventually, most people with osteonecrosis will need to have surgery.

Causes of osteonecrosis

Osteonecrosis, also known as avascular necrosis, occurs when the normal supply of blood flow to a bone is reduced or cut off, causing that part of the bone to die. Traumatic injuries to the hipbone, such as fractures or joint dislocations, are common causes of osteonecrosis.

In some cases, other medical conditions like sickle cell anemia or Gaucher’s disease can cause avascular necrosis. These diseases make it hard for blood to move through the bone because they increase the amount of pressure inside the bone. HIV, lupus, and diabetes also increase a person’s chances of developing osteonecrosis.

People who take high doses of corticosteroids for long periods of time are at a higher risk for developing osteonecrosis. Cancer treatments (particularly radiation), organ transplants, and dialysis also can contribute to osteonecrosis developing. Heavy, long-term alcohol use can also cause this painful condition.

Symptoms of osteonecrosis

In many cases, avascular necrosis is not detected until the disease is quite advanced because there may be no discernible symptoms in the early stages of the condition. As it worsens, there may be pain in the hip joint during weight-bearing activities. Eventually, hip pain will occur during movement and sometimes even when at rest.

Hip pain caused by osteonecrosis may occur in the hip, groin, thigh, or buttock. Avascular necrosis can also develop bilaterally, in both hips.

Treatment for osteonecrosis

Treatment options for avascular necrosis depend on the severity of the bone damage. Over-the-counter anti-inflammatory drugs may help to relieve the pain. Talk to your pharmacist before purchasing anti-inflammatories as these medications may be contraindicated as they may interact with other medications and medical conditions.

In some cases, drugs that are commonly used to treat osteoporosis may help to slow the progression of osteonecrosis. Additionally, cholesterol drugs can help keep the blood vessels that flow into the bones from becoming blocked.

Restricting physical activity and limiting the amount of weight placed on the hip joint can help slow the development of further damage to the hip bones.

While being treated for avascular necrosis, it may be necessary to use crutches for several months to avoid further damage. Physical therapy exercises may also help maintain the range of motion in the hip joint.

Electrical stimulation is one technique used to treat osteonecrosis. Electrical currents stimulate the body through electrodes attached to the skin, encouraging new bone growth to replace damaged bone. This procedure can also be performed directly to the damaged area during surgery.

Surgery is a common treatment for osteonecrosis because in many cases the condition is far advanced by the time it has been detected. Surgeons may remove or reshape part of the damaged bone, or graft a healthy section of bone from another part of the body.

Joint replacement surgery may be necessary if the bone has already collapsed.

If you are experiencing hip pain and the symptoms associated with avascular necrosis, contact us to request an appointment with our orthopedic specialists to learn about your treatment options.