Avascular Necrosis of the Hip (Osteonecrosis)
Avascular necrosis of the hip occurs when blood flow is cut off to the head of the femur or thighbone in the hip joint. This can be a temporary or permanent loss of blood, but ultimately the bone begins to die, and due to resultant weakness, collapses. While this can affect just about any bone in the body, longer bones tend to be affected more often and of those the hip is most often affected. In fact, over 20,000 people are admitted to hospital for treatment of an avascular necrosis of the hip in the United States.
The most common causes of avascular necrosis include injury, long-term steroid use, Gaucher or Caisson disease (decompression sickness/the bends), excessive alcohol use and a host of other diseases and conditions.
How Do I Know I Have Avascular Necrosis?
Early on, the symptoms of avascular necrosis are generalized and may mimic other conditions. Typically, patients only experience mild joint pain as the bone begins to die. However, as the bone weakens and starts to collapse (which may take several months to a year), the pain will become more significant and most patients will experience disability. Since avascular necrosis is not top of mind for most patients, they usually visit their doctor believing they have arthritis of the hip.
While just about anyone can experience avascular necrosis of the hip, it is most common in men between the ages of 40 and 65.
Diagnosing Avascular Necrosis
Dr. Manning will begin the diagnostic process with a full medical history and physical exam and understanding any potential injuries that may have contributed to hip dysfunction. From there, x-rays, CT scans or MRIs can all be used to visualize the bone in the hip joint. Early stage a vascular necrosis is better visualized on an MRI than x-ray. Other tests may be performed to rule out diseases and conditions with similar symptoms.
Treatment for Avascular Necrosis
The treatment for avascular necrosis may vary dramatically between patients as the degree of bone loss will differ. The goal is to use the least invasive possible treatment while offering patients a return to normal quality of life and minimize pain. The first course of action is medical therapy to control the pain. However, surgical intervention is the definitive answer to slowing the progression of the disease and ultimately implementing a solution.
Core decompression removes a layer of bone, minimizing pressure in the joint and slowing the degradation of bone. This can sometimes prevent the need for a total hip replacement, but only when avascular necrosis is diagnosed as an early stage. Successful patients will be back to normal activity within three months and will experience almost complete resolution of pain.
A bone graft takes bone from another part of the body to be transplanted into the hip joint. Typically, vascularized fibula bone is transplanted into a hole within the femoral neck and head. The fibula is transplanted with associated blood vessel structures which are reattached in the femur to promote healing and regrowth.
However, for many patients who have advanced avascular necrosis, a hip joint replacement may be the best option. Today’s hip replacements are safer and more successful than in past, and patients will experience almost immediate relief from joint pain. Further, replacement hip joints last for longer than ever before due to advanced materials.
Most importantly, the patient should have any hip pain evaluated at its earliest presentation to ensure that they have the widest range of treatment options available. A vascular crisis, like other joint issues in the hip have a multitude of treatment options