Avascular Necrosis (AVN) Causes, Symptoms & Treatment

The hip is often referred to as a “ball and socket” joint. The ball, at the top of the thigh bone (called the femur), fits into the socket (the acetabulum) in the pelvic bone. The ball of the femur can occasionally lose its blood supply and, like a heart attack involving the heart muscle, the bone will die. This is called Avascular Necrosis (AVN) of the femoral head (also known as osteonecrosis). Approximately 20,000 people are diagnosed with AVN of the hip each year.

This condition is painful and left untreated, the femoral head can collapse and destroy the hip joint. This is not a condition related to repetitive trauma and as such, athletes in general are not at increased risk of AVN unless they suffer a severe traumatic injury.

Bones need continuous blood supply to be healthy. When blood flow to the femoral head is disrupted, the bone weakens and eventually dies. A severe injury to the hip, such as a dislocated or fractured hip, can cause AVN because the trauma to the bone disrupts the blood supply. High energy collision sports where this type of trauma can occur present a risk for AVN. Other causes include excessive alcohol use or long-term systemic use of corticosteroids (drugs used to reduce inflammation). Certain medical conditions are also associated with AVN, such as sickle cell disease and Crohn’s disease.

Because of the nature of the sport, AVN of the hip is most common in these sports:

• Soccer
• Football
• Basketball
• Rugby
• Volleyball

AVN develops gradually, and in its first stages, athletes may not recognize any symptoms. Over time, hip pain may be noticed, particularly during play. As the disease progresses, common symptoms include:

• Constant pain in the hip, even at rest
• Severe pain in the groin, thigh or buttocks
• Difficulty walking without a limp
• Stiffness and difficulty moving the hip

Athletes should see their doctor if they injure their hip after a serious fall or some other major trauma, especially if hip pain does not go away. During your examination, your doctor may ask you to move your hip in different positions to assess your condition. Patients in the early stages of AVN may not have clinical findings and typically have good range of movement because the bone damage to the femoral head has not progressed. It’s important to share with your doctor any injuries you’ve experienced, as well as your medical history and habits. All are important for helping your doctor make a correct diagnosis.

After the physical examination, your doctor may recommend an x-ray, and if AVN is suspected, a magnetic resonance imaging (MRI) test. These imaging tests provide detailed pictures of the hip and help determine if there is AVN and how much bone has been affected. Damage to bone structure typically doesn’t show up on x-rays until later stages of the disease but MRIs can detect the beginning stages of AVN.

If detected early, conservative treatment of AVN can be effective in relieving pain, slowing or even halting the progression of the disease. Your doctor may recommend a number of non-surgical treatment options including:

• Rest
• Using crutches and limited weight bearing for up to six weeks
• Nonsteroidal anti-inflammatory (NSAID) medication like ibuprofen, to reduce pain
• Gentle exercises such as stationary bike or water walking in a pool

Try these exercises to help address your condition:

Below is a PDF of the Exercise Program

Avascular Necrosis

For many patients with AVN, surgery is the best course of treatment. If AVN is identified early, before the femoral head collapses, there are surgical procedures your doctor may recommend that can preserve your hip. One procedure, called core decompression surgery, involves drilling holes into the diseased bone, providing a path for new blood vessels to improve the blood supply and replace dead bone with new healthy bone. Other procedures rebuild affected bone with bone grafts of healthy bone tissue from another part of your body or even a donor (cadaver bone).

If your AVN has advanced to the point where the femoral head has collapsed, you may be a candidate for a total hip replacement. This procedure involves removing the damaged joint and replacing it with an artificial ball and socket.

Core decompression and total hip replacement are common procedures used to treat AVN. The outcome of core decompression depends on the stage of the AVN when it is performed (the earlier the better). Total hip replacement for AVN generally leads to a successful outcome. Athletes who undergo these procedures can expect relief from pain and restored function. Recovery time after these procedures can take months and include physical therapy as part of your rehabilitation. A variety of factors, such as age, fitness level, and intensity of their sport, will influence an athlete’s ability to return to their full or modified level of athletic activity. Your doctor can guide you throughout your recovery process.