AVN: A Complicated Diagnosis

AVN is Complicated

Dennis M. Lox M.D., has treated Avascular Necrosis (AVN) for over 25 years.
He has seen the confusion over how to treat AVN, what caused it, and what to do about it. Patients from around the world, have traveled to treat with Dr. Lox at his Tampa Bay, Florida office, and at his Los Angeles metropolitan area office, located in Beverly Hills, California office.

What is AVN?

Avascular necrosis (AVN) is a complicated condition in which the blood supply to a region of bone becomes impaired. This leads to ischemia of the area of bone.

The ensuing lack of oxygen to the living bone tissue, causes bone cell death or necrosis. This is similar to a heart attack, in which blood flow to an area of cardiac muscle tissue is lost, and living cardiac tissue dies.

A severe heart attack can occlude enough tissue to result in the person dying. This can not occur with AVN. However, obviously more loss of blood flow to more bone cells, results in more necrosis, and the larger area of AVN on the bone. AVN is complicated and can occur in practically any bone, but it is most common in the hips, shoulders, and knees.

Dr. Lox has treated patients with AVN of the wrist, ankle, and foot, as well as the hips, shoulder, and knees.

AVN and Other Names

There are many names some people, or doctors prefer to use for avascular necrosis. They all refer to the same thing. Probably the most common name besides Avascular Necrosis, is Osteonecrosis. Other terms include, Aseptic Necrosis, and Bone Infarction.

Some names are used for individual bones typically the physician who first described it on x-rays over a century ago.

Examples are children with hip or femoral head AVN is referred to as Legg-Calve-Perthes Syndrome.

The foot navicular bone is called Koehler’s Disease, the wrist lunate bone is called Kienbock Disease, the wrist scaphoid bone is called Preiser’s Disease, the spine vertebral body AVN is called Kummel’s Disease.

There are other names that refer to what precipitated the developmental AVN. These include Caisson’s Disease for decompression sickness, where nitrogen bubbles occlude the blood supply. Gaucher’s Disease is the development of AVN from a lipid or fat storage disease, which results in occlusion of blood flow from the fatty deposits. This is more information than most need, unless you have it, and further understanding is beneficial.

Causes Of AVN

Trauma is the leading cause of the development of AVN. The next most commonly seen type of AVN is Idiopathic. This means unknown causation.

This is frustrating for all involved, because everyone wants a clear cut answer, and by necessity, excluding other possible causes is prudent medical care.

This is because if a yet unknown causative factor is present, it should be diagnosed. Dr. Lox had a patient with Gaucher’s Disease. Undiagnosed vasculitis or Lupus needs to addressed.

By far the most commonly seen causative factor behind trauma, is high dose corticosteroids (cortisone). There is a much higher incidence of AVN, with intravenous corticosteroids for treatment of lung or autoimmune problems, however oral corticosteroids have often been the culprit.

Just like excessive alcohol consumption, the exact amount of what excessive is for for alcohol and corticosteroids, varies for different people for unknown reasons. There are many alcoholics who never develop AVN, and many patients who have taken high levels of corticosteroids, who do not develop AVN. However with the development of AVN, these substances should be avoided if possible.

Autoimmune disorders, such as Lupus and Rheumatoid Arthritis have a risk factor for the development of AVN. The risk goes up for them if also treated with high does corticosteroids. Vasculitis, AIDS, Sickle Cell Disease, chemotherapy and Radiation therapy all are risk factors.

Multi-Joint AVN

As if AVN was not confusing enough, it can occur in more than one site. This is called multi-joint AVN. The hip is most commonly seen as occurring in both hips. However, one hip and one knee may be seen, or any pattern.

The expert physician should be alerted to any pain complaints in an AVN diagnosed patient, that is not specifically from localized trauma. Localized trauma such as a dislocated hip, is what ended the legendary professional Football and Baseball player Bo Jacksons career. Bo Jackson ended up with a hip replacement. Though Bo Jackson never played professional Football again, he did play one season of professional baseball after his hip replacement surgery.

Multi- joint AVN typically occurs from a systemic process. It unfortunately ends most athletes careers, disrupts occupations and quality of life. Dr. Lox has treated severe cases involving both hips, knees and ankles. The femur had islands of AVN from hip to knee, which makes joint replacement impossible.

This was due to excessive corticosteroids.

AVN Proposed Treatment Options

Wait and see…. Unfortunately it often is recommended.

This is highly uncomfortable for young patients, athletes, and those who which to avoid joint replacement surgery.

A list of treatment options will be given, however no one thing is the right answer for everyone. This is an individualized case by case decision based upon the patient’s needs, goals, desires, quality of life, age, and degree of AVN.

• Core decompression or micro-fracture
• Free Fibular Vascular Graft
• Core Decompression with Bone Marrow Aspirate Concentrate (Stem Cell Transfer)
• Cell Transfer Alone
• Non Weight Bearing
• Joint Replacement or Fusion

How Does Someone Decide Which Treatment is Right?

Be proactive and talk to an expert. Some physicians have little experience in the treatment of AVN.

Some well known physicians only take some patients, with a certain degree of AVN to have good success rates.

AVN is complicated, with no easy answer for everyone. There are so many factors involved that discussing each patient’s situation is needed to fully clarify all the important issues.