Avascular necrosis (AVN) is a condition that happens when bone tissue dies due to a lack of blood supply to the bone. This causes the bones to decay and eventually collapse. The condition is most common in the hip or shoulder joints. AVN can begin in the teenage years and occurs in at least 40 percent of adults with sickle cell disease.
What causes AVN?
Sickling red blood cells may block the flow of blood to the bones in the joints. When bones do not get enough oxygen and nutrients from the blood supply, they begin to erode away. The joint eventually collapses.
What are the symptoms of AVN?
- Pain or stiffness in the joint
- Decreased range of motion
- Decrease in leg length
How is AVN diagnosed?
Early detection is important to prevent progression. An MRI detects early stages of AVN, often when few symptoms are noticed. An X-ray or CT scan may detect AVN in later stages.
How is AVN treated?
The first lines of treatment recommended are:
- Minimize bearing weight by resting in bed or using crutches
- No impact activities, such as running or jumping
- Physical therapy to increase range of motion, strengthen the surrounding muscles and increase circulation in the joint
- Anti-inflammatory medications, such as ibuprofen (narcotic pain medication can be prescibed for more severe pain)
- Hydroxyurea to decrease sickling of the red blood cells and minimize further bone damage
Surgery is an option, but it is not recommended until a patient has failed the first line of treatment therapy. Surgical options should be discussed with an orthopedic surgeon. Bone core decompression, osteotomy or total joint replacement may be considered at later stages of AVN.