Following is a summary of a 2005 study conducted by the Cholesterol Center, Jewish Hospital, Cincinnati, OH; and the Department of Orthopaedics, Cincinnati, Veterans Administration Hospital, Cincinnati, OH. Authors include: Charles J. Glueck, MD, Richard A. Freiberg, MD, Luann Sieve, BS, and Ping Wang, PhD.

Before I go into the explanation of the summary it is important for me to first clarify the difference between primary osteonecrosis (avascular necrosis) and secondary osteonecrosis (avascular necrosis). Primary osteonecrosis, often referred to as idiopathic osteonecrosis (avascular necrosis), is when the disease is associated or thought to be caused by, thrombophilia (inherited clotting disorders) or hypofibrinolysis (an abnormal rate of the breakdown of protein in blood clots). Osteonecrosis (avascular necrosis) is referred to as secondary osteonecrosis when it is caused, for example, by: alcoholism, corticosteroid use, chemotherapy or is secondary to such diseases as: Lupus, Multiple Sclerosis, other autoimmune diseases or AIDS.

In the 2005 study it was hypothesized that taking 60mg a day of enoxaparin sodium (trade name: Lovenox) for 12 weeks could prevent the progression of Stages I and II in patients with primary osteonecrosis. Two groups of patients were treated with enoxaparin sodium. One group consisted of patients with primary osteonecrosis of the hips, in Stages I and II, caused by inherited clotting disorders. The rationale for the studying the disease in those with thrombophilia factors was based on the idea that anticoagulation could possibly improve the restriction of blood supply to tissues, therefore allowing for the rebuilding of bone. The other group consisted of patients with secondary osteonecrosis in the hips, in Stages I and II, caused by corticosteroid use.

Patients self administered the enoxaparin sodium twice a day in pre-loaded syringes.  The disease was tracked in all patients from the beginning of the study up to a period of 108 weeks. Every 36 weeks radiographs were taken of each patient and the results were interpreted by a blind committee.

At the end of the 108 weeks it was found that ON (AVN) in patients with primary osteonecrosis did not progress from Stages I and II. However, osteonecrosis (avascular necrosis) in patients with secondary osteonecrosis progressed to Stages III and IV. Therefore, it was concluded that if enoxaparin sodium is started in the early ficat stages I and II of ON in patients with primary hip Osteonecrosis, associated with thrombophilia or hypofibrinolysis or both, the ON (AVN) may be safely arrested or possibly reversed, ultimately decreasing the incidence of total hip replacement.

If you wish to download the entire study please click here: Enoxaparin Prevents Progression of Stages I and II Osteonecrosis of the Hip

This is just one study, it was significant to me because enoxaparin has reversed my ON (AVN). Dr. Glueck continues to do research on osteonecrosis for patients with both primary and secondary osteonecrosis.

Note: I am not a doctor, if you need more clarification concerning the study the best thing to do is to take the paper to your doctor, in the hopes that he will read it (I know they often say they “don’t have time”).