Avascular necrosis

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Avascular necrosis
Synonyms	Osteonecrosis, bone infarction, aseptic necrosis, ischemic bone necrosis
Pronounce	N/A
Specialty	Orthopedic surgery, Rheumatology
Symptoms	Joint pain, limited range of motion
Complications	Osteoarthritis, joint collapse
Onset	Gradual
Duration	Long-term
Types	N/A
Causes	Trauma, steroid use, alcoholism, sickle cell disease, Gaucher's disease, lupus
Risks	Smoking, radiation therapy, chemotherapy
Diagnosis	X-ray, MRI, CT scan
Differential diagnosis	Arthritis, fracture, bone infection
Prevention	Avoidance of risk factors
Treatment	Medication, physical therapy, surgery
Medication	Bisphosphonates, anticoagulants, statins
Prognosis	Variable, depends on stage and treatment
Frequency	10,000 to 20,000 cases per year in the United States
Deaths	N/A

Pronunciation

Ay-VAS-kyoo-ler neh-KROH-sis

Osteonecrosis femur

Definition

Avascular necrosis ( is a condition in which there is a loss of blood flow to bone tissue, which causes the bone to die.

Bones affected

It is most common in the hips, knees, shoulders, and ankles.

Causes

• It may be caused by long-term use of steroid medicines, alcohol abuse, joint injuries, and certain diseases, such as cancer and arthritis.
• It may also occur at some point in time after cancer treatment that included methotrexate, bisphosphonates, or corticosteroids.

Head of femur avascular necrosis ligamentum

Signs and symptoms

• Osteonecrosis may be asymptomatic when it first develops.
• As the disease gets worse, you may feel pain when you put your weight on a joint that is affected by osteonecrosis.
• Over time, you may feel pain in the joint even when you are resting.
• Pain caused by osteonecrosis may be mild or severe.
• If it causes your bone and joint to collapse, you may have severe pain and not be able to use the joint.

Crescent sign

Investigations

Investigations include imaging studies, blood work, bone scan and rarely bone biopsy.

• X-ray.
• Magnetic resonance imaging (MRI).
• Computed tomography (CT) scan.
• Bone scan.
• Bone biopsy.

Treatment

Treatment depends on the bone affected, and the persons age, and other medical conditions, and the cause. The goals of treatments include:

• Improve use of the joint.
• Stop further damage.
• Protect bones and joints.

Osteoradionecrosis

The treatment options may include surgery or nonsurgical treatments, such as medicines. Factors affecting treatment include:

• Your age.
• The stage of the disease.
• Where and how much bone has osteonecrosis.
• The cause, if known. If the cause is steroid or alcohol use, treatment may not work unless you stop using those substances.

Nonsurgical Treatments

Non-surgical treatments do not cure osteonecrosis, but they may help manage the disease. Your doctor may recommend one or more non-surgical treatments, especially if the disease is in its early stages.

Medications

• Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to reduce pain and swelling.
• If you have blood-clotting problems, blood thinners may be used to prevent clots that block the blood supply to the bone.
• If you take steroid medicines, cholesterol-lowering drugs may be used to reduce fat in the blood.

X-ray of pelvis with total arthroplasty

Taking Weight Off the Joint

Your doctor may suggest you limit your activity or use crutches to take weight off joints with osteonecrosis. This may slow bone damage and allow some healing. If combined with NSAIDs, it may help you avoid or delay surgery.

Range-of-Motion Exercises

Your doctor may recommend you exercise the joints with osteonecrosis to help improve their range of motion.

Electrical Stimulation

Your doctor may recommend electrical stimulation therapy to help bone growth.

Surgery

Most people with osteonecrosis eventually need surgery as the disease worsens. Some people with early stage disease may need surgery if non-surgical treatments do not help.

Necrotic bone

There are four types of surgery. Your doctor will decide if you need surgery and what type is best for you.

• Core decompression surgery, which lowers the pressure inside the bone. This increases blood flow to the bone.
• Osteotomy, which reshapes the bone. This reduce stress on the damaged joint.
• Bone graft, which takes healthy bone from one part of the body and uses it to replace diseased bone.
• Total joint replacement, which replaces the joint with a man-made one.

Other names

Also called aseptic necrosis, ischemic necrosis, and osteonecrosis.

Epidemiology

It is most common in men and people in their 30s, 40s, and 50s.