Dr. Lox on Avascular Necrosis or AVN
Dennis M. Lox M.D. is an expert in Sports and Regenerative Medicine. Dr. Lox also has special expertise in the treatment of Avascular Necrosis or AVN. Patients from all around the world have consulted with Dr. Lox in his Clearwater, Florida, and his Beverly Hills, California office for all types of AVN.
What is AVN?
Avascular necrosis (AVN) is sometimes referred to as osteonecrosis.
When a region of bone loses its blood supply, a portion of the bone dies. Avascular, refers to the loss of blood supply, and necrosis refers to the bone cell death. It is somewhat similar to a heart attack when the blood supply to the cardiac tissue is disrupted, a myocardial infarction occurs. This is the same principle. Cardiac tissue death from ischemia or lack of blood flow leads to areas of necrotic cardiac tissue. Similarly, other terms for AVN are bone infarction or ischemic necrosis. All terms mean the same underlying pathology.
What Causes AVN?
Avascular necrosis most commonly is caused by trauma. Traumatic injuries, and commonly sports trauma can disrupt the blood flow to the bone. A case example was the Legendary Professional Baseball and Football Player Bo Jackson. Jackson was tackled from behind, catching his leg he fell hard and dislocated his hip. It spontaneously relocated, but the shearing force of the dislocation caused some of his hip blood vessels to tear, disrupting the blood flow to his hip. Football is a grueling painful sport, and accidental injuries happen so fast, the first impulse is to attribute the pain from being tackled hard. He was helped off the field, however, it was a playoff game the Oakland Raiders lost, and the Football season was over. Injuries can nag and take time to heal. Unfortunately, for Bo Jackson it was not diagnosed quickly, and he ultimately had a hip replacement, after his hip joint collapsed. This is the most feared outcome of AVN, the necrotic bone collapses, and rapid joint destruction ensues. Bo Jackson never played Professional Football again, but he did play another season of Baseball, after his hip replacement surgery. A true tragedy for one of the most extraordinarily gifted athletes of all time.
AVN Many Causations
The next most common cause of AVN after trauma is idiopathic or unknown etiology. It may be also referred to as, spontaneous AVN. It is troubling for the patient, as there are so many other potential factors which may cause or contribute to AVN, that the other possible causes should be excluded before stating that it is idiopathic, or of unknown cause. Missing an underlying condition by not looking for a cause is fraught with error.
The next most commonly seen cause of AVN in Dr. Lox’s practice is excessive cortisone or corticosteroid use. This is usually seen with high doses, though rarely smaller doses can result in it. Most patients who take Cortisone tablets or injections never get AVN, however, when it occurs it can be disastrous if not treated properly. Sometimes even with the best of care it is diagnosed late, or just is not responsive to treatment.
There are numerous other potential causes, such as excessive alcohol consumption. Just like with excessive cortisone, many severely excessive alcohol consumers and alcoholics never develop AVN. So it is paradoxical and unpredictable. Rheumatologic conditions such as, Lupus, Rheumatoid Arthritis, and others may develop AVN. However, it becomes more complicated when some of the Rheumatologic medications, including cortisone that is commonly used to treat these disorders, may also cause or contribute to the development of avascular necrosis.
Chemotherapy and radiation therapy, also may predispose to the development of AVN or Osteonecrosis.
There are many other rarer causes, such as decompression sickness, and Gaucher’s disease a lipid (fat) storage disorder. Sickle cell disease, when a sickle cell crisis occurs it may cause the sickling cells to occlude the blood vessels. Vasculitis is also known to cause disruption of blood flow.
Dr. Lox has treated nearly every type of AVN, except decompression sickness to date.
Why is AVN so Significant?
Due to the bone cell death, it may remain stable or if in less fortunate cases collapse into the joints, leading to rapid joint destruction. This is what typically leads to recommendations for joint replacement surgery or joint fusion. Not what most patients or any athlete wishes to hear.
Avascular necrosis may also preset unusually. The hip is the most commonly affected joint. However, especially with idiopathic AVN, it may occur in both hips. Also, excessive corticosteroid use can preset in multi-joints, again, most commonly in both hips. However it may be seen in one hip and knee, or other atypical patterns. This also occurs with the systemic causative factors like excessive corticosteroids, chemotherapy or radiation therapy, and the autoimmune Rheumatologic disorders. Having a high index of suspicion in a patient with known AVN, when an unexplained severe pain develops in another joint must allude the expert in the management of AVN or Osteonecrosis, that multi-joint AVN May be present or is developing. Dr. Lox once saw an excessive corticosteroid AVN case that manifested initially in both ankles, a year later it was in both hips, then both knees. An unusual trauma is typically one joint that was injured, thus it is straight forward.
How Can Regenerative Medicine and Stem Cell Therapy be an Option?
Early detection of the presence of AVN, may find the necrotic region of bone is well localized, not involving the joint. At this point there becomes depending on which doctor or orthopedic surgeon evaluates the patient many different answers on treatment of early AVN, from wait and see if the bone collapses then it’s a hip replacement surgery, to core decompression, non-weight bearing, and even some medications with no scientific data to support its effectiveness in AVN. Regenerative Medicine and Stem Cell Therapy, has become an increasingly popular consideration with AVN patients, mostly because it is proactive and has the potential to heal the AVN. Once more and equally important, Regenerative Medicine and Stem Cell Therapy may potentially avoid rapid joint destruction.
Stem cells are your bodies own healing cells. They just are not found in joints, thus we cannot self-repair, and develop degenerative arthritis. AVN is like a rapidly progressive degenerative arthritis. The theoretically scientific rationale for how stem cells can heal AVN range from helping grow new blood vessels to improve blood flow, replacing the dead necrotic bone with new bone cells, and deter degenerative arthritis progression. A condition called Legg Cathes Perthes Disease occurs in newborns to age two roughly, it is bilateral spontaneous hip AVN. Most of these young children can self heal the AVN with immobilization. In this young age group they are capable of doing amazing things due to their extremely young and growing cells. Yet, not all of these young children heal. Some develop early-onset hip degenerative arthritis in their 20’s. If we could predicate those who do not heal or follow them closely perhaps Regenerative Medicine would be a useful prevention measure for degenerative hip arthritis in them.
However, Dr. Lox has also noted more frequent complete AVN resolution of necrotic bone without joint destruction, after Stem Cell Therapy in teen athletes with one joint AVN. Obviously, older patients with disease states causing the AVN in many areas is a less favorable prognosis. It is important for early AVN assessment with an expert skilled in the evaluation and treatment of all types of avascular necrosis, such as Dennis M. Lox M.D. to understand treatment options and provide early intervention. Dr. Lox has literally had patients fly into his Beverly Hills, California office, and his Tampa Bay, Florida office from throughout the country, and even from around the world for treatment under his guidance. This is truly humbling and an honor to help these patients, who often are given little hope. Especially, returning young athletes to their sport. Several teen athletes with AVN who were told to have surgery which would end their sports career, successfully underwent Stem Cell Therapy with Dr. Lox, and excelled in high school sports, and later obtained college sports scholarships. Truly rewarding for a medical doctor.
Dr. Lox treats patients in the Tampa Bay, Florida area, and in the metropolitan Los Angeles area, at his office in Beverly Hills, California.
