Osteonecrosis cause and treatment
January 20 2016 by Ray Sahelian, M.D.

Osteonecrosis literally means dead bone. It is known by many other names, such as avascular necrosis or ischemic necrosis. Osteonecrosis occurs because of a decrease in blood supply to specific parts of bones. This decreased circulation causes cells in the bone and bone marrow to begin to die. Eventually the dead section of bone weakens and collapses.

What causes Osteonecrosis?
Injuries such as fractures or dislocations of certain bones, such as in the wrist or hip, can produce osteonecrosis if the arteries supplying blood to these areas are damaged. Blocked blood vessels, of any cause, will result in osteonecrosis. For example, abnormal red blood cells (sickle cell anemia or thalassemia) or expanding nitrogen bubbles (commercial deep-sea divers or tunnel workers who do not decompress properly) can block blood vessels leading to osteonecrosis. Taking corticosteroid medications such as prednisone, particularly in high doses, also can reduce the bone blood flow by increasing the pressure with bone marrow and blood flow. Recently, osteonecrosis has been reported in those using bisphosphonates such as Actonel for prolonged periods.
 

Who Gets this bone condition?

The following people are most at risk:

Those with certain fractures of the hip

Alcoholics

Those taking corticosteroids

Individuals with sickle cell anemia, lupus or pancreatitis

Those who take bisphosphonates. Medication-related osteonecrosis of the jaw (MRONJ) is a well-recognized severe complication of bisphosphonate treatment in patients with osteoporosis or metastatic cancer. Microbiological infection has been hypothesized as a contributing factor to bisphosphonate related osteonecrosis of the jaw (BRONJ). Despite infection being present in BRONJ patients, there is no clear data as to whether infection plays a role in the pathophysiology.

 

Go Natural with Osteoporosis Prevention - Bisphosphonates are a class of drugs that inhibit the resorption or breakdown of bone tissue. Bisphosphanates are used for the prevention and treatment of osteoporosis, multiple myeloma and other conditions that involve bone fragility. In the last 10 years, millions of patients have taken biphosphanates for the prevention of osteoporosis and bone thinning from cancer. Bisphosphantes once seemed safe, but lately concerns have been raised. Many women have been taking bisphosphantes thinking that these drugs were okay since their doctors probably did not caution them on potential risks. However, bisphosphante use is now believed to be associated with osteonecrosis of the jaw. Osteonecrosis of the jaw is an uncommon complication, but it is estimated that among the 500,000 American cancer patients who take the drugs because their disease is affecting their bones, 1 to 10 percent may develop the problem. Some dentists are refusing to treat patients taking the drugs, fearful that the dental work will induce a case of osteonecrosis, and lawyers are lining up to sue the drugs' makers, saying they failed to give patients adequate warning. Cancer patients, mostly those with multiple myeloma and breast cancer whose disease has spread to their bones, generally take one of two bisphosphonates, Zometa or the older Aredia, intravenously. Osteoporosis patients usually take bisphosphonates as pills, in much lower doses that patients with cancer. Those bisphosphanate drugs Fosamax, Actonel and Boniva reduce the risk of fractures of the spine or hip, injuries that can create a steady downward spiral in patients' condition.
 
 My thoughts: It may be too early to know for certain how prevalent and serious are the risks from bisphophanates, including osteonecrosis, but if you are taking them, ask your doctor if you really need them and whether the risks are worth the potential benefits. In previous issues I mentioned that calcium supplements at 600 mg to 1200 mg a day are beneficial, and, of course, exercise and weight lifting are the most helpful.

Craniomaxillofac Trauma Reconstr. 2013. Pathologic Fractures in Bisphosphonate-Related Osteonecrosis of the Jaw-Review of the Literature and Review of Our Own Cases. Bisphosphonates are powerful drugs used for the management of osteoporosis and metastatic bone disease to avoid skeletal-related complications. Side effects are rare but potentially serious such as the bisphosphonate-related osteonecrosis of the jaws (BRONJ). BRONJ impairs the quality of life and can even lead to pathologic fractures of the mandible.

Research
Bisphosphonates and oral cavity avascular bone necrosis: a review of twelve cases.Anticancer Res. 2006. Intravenous bisphosphonates are the current standard of care for the treatment of hypercalcemia of malignancy and for the prevention of skeletal complications associated with bone metastases. Recently, retrospective case studies have reported an association between long-term bisphosphonate therapy and osteonecrosis of the jaws. Based on the patients' respective histories, clinical presentations and responses to surgical and antibiotic treatments, it appears that the pathogenesis of this osteonecrosis is most consistent with localized vascular insufficiency. In our opinion, the mechanism by which bisphosphonates compromise bone vascularity may be related to their effect on the osteoclasts. The potent bisphosphonate -mediated inhibition of osteoclast function serves to decrease bone resorption and inhibit normal bone turnover remodeling, resulting in microdamage accumulation and a reduction in some mechanical properties of the bone.

Clinical and diagnostic imaging of bisphosphonate-associated osteonecrosis of the jaws.Dentomaxillofac Radiology. 2006.It is important to recognize osteonecrosis of the jaw in patients treated with bisphosphonates because an early diagnosis can make a significant difference to the outcome of the disease. The aim of this study is to describe the radiological features of bisphosphonate osteonecrosis in order to aid its prompt recognition. 99Tc(m)-MDP three-phase bone scan was the most sensitive tool to detect the osteonecrosis at an early stage. 99Tc(m)-MDP three-phase bone scans who could be used as a screening test to detect subclinical osteonecrosis in patients who have received bisphosphonates. CT scans and MRI are useful in defining the features and extent of osteolytic lesions.

Bisphosphonate-associated osteonecrosis: a long-term complication of bisphosphonate treatment. Lancet Oncol. 2006. Department of Diagnostic Sciences, Nova Southeastern University College of Dental Medicine, Fort Lauderdale, FLWe present current knowledge of bisphosphonate -associated osteonecrosis, a new oral complication in oncology. It was first described in 2003, and hundreds of cases have been reported worldwide. The disorder affects patients with cancer on bisphosphonate treatment for multiple myeloma or bone metastasis from breast, prostate, or lung cancer. Bisphosphonate -associated osteonecrosis is characterised by the unexpected appearance of necrotic bone in the oral cavity. Osteonecrosis can develop spontaneously or after an invasive surgical procedure such as dental extraction. Patients might have severe pain or be asymptomatic. Symptoms can mimic routine dental problems such as decay or periodontal disease. Intravenous use of pamidronate and zoledronic acid is associated with most cases. Other risk factors include duration of bisphosphonate treatment (ie, 36 months and longer), old age in patients with multiple myeloma, and a history of recent dental extraction.

Emails
Q. My wife was saved pain and a horrible experience! She was to have dental implants after 3 back teeth were removed. She also has been taking Fosamax for 8 years. She balked at the mannerisms of the dental surgeon when on the first visit he was ready to remove the 3 teeth and estimated $14,000 for all work including implants and new teeth. She went for a 2nd opinion and the surgeon made her aware of potential serious problems with taking Fosemax and osteonecrosis. I researched the Internet and found Dr. Sahelian's article "Bisphosphonates". Floored and happy she was spared over a year and many be longer. So many thanks. By the way the 2nd surgeon had my wife take blood tests to confirm she had osteonecrosis. Needlessly to say she has quit Foxemax. We have also notified out family doctor of the Dr. article and the problem. Many, many thanks. I researched this situation further and found that this is one scary situation. The first legal hearings will occur August 2009 on bisphosphonate complications. I sent an email to a legal firm asking for any information. We initially were not interested in getting involved legally but I have to admit if my wife has osteonecrosis and she is affected like some of the pictures I saw we will need help. I talked to a lawyer involved in the field. His most informative bit of info is that the CTX test that my wife took is not a "go" or "no go' gage as to whether you will have problems. It is only a measure of healing. (After she went to a second surgeon he had her take the blood test and confirmed she was positive). The lawyer suggested that we obtain a written diagnosis from a surgeon. Some facts the lawyer presented: The effects of Fosamax in the system can be as much as 10 years, so just because she stopped taking Fosamax she still may have some serious problems. This disease is called "Dead Jaw" because the bone figuratively turns to stone, blood vessels are marbleized and any invasive procedure is a major, major problem. Since blood flow is reduced or eliminated she would be open to bacteria infections of sorts. Existing teeth can crumble, fall out, become loose (Which is what my wife had experienced - she has been having problems getting her mouth guard adjusted and feels like one tooth keeps floating up). Medicare may or may not cover costs even though this disease is a drug reaction problem and not a dental problem.He added his editorial in that he believes the drug companies hid this problem and somehow got FDA approval in spite of this problem being around for many years. (I understand one can get this from a broken jaw from a car wreck or radiation when bone rebuilding medication is used like Zometa, Aredia, Bonefos and so on are used. Do not know exactly what we are going to do. My wife is having no problems other than what I noted..... importantly she has no pain. At 75 I have grown so cynical in this new society I find it hard to trust anybody.

I am wondering whether you have any natural supplements that can reverse the osteonecrosis of the lunate bone in a patient with Kienbock's disease. Do you expect serrapeptase to be effective in achieving this?
   I am not familiar with treatment of Kienbock's disease.