By definition, avascular necrosis is “death of bone tissue due to lack of blood supply.” This can lead to small breaks in the bone, eventually causing the bone to collapse. This condition most often affects the top of the thigh bone, the femur, resulting in hip pain. However, it can affect other bones as well.
How is the blood supply to the bone impaired? There are a number of reasons, such as injuries sustained, long-term use of steroid medications, and excessive alcohol intake. Other terms that are synonymous with avascular necrosis are osteonecrosis, aseptic necrosis or ischemic bone necrosis. This is a progressive disease and will most likely worsen over time. Managing it is a lifelong process.
Sometimes, avascular necrosis will not present any symptoms. Some patients, however, may notice pain or a loss of range of motion in the affected joint. If this condition is in the hip, it may cause pain in the groin. The pain may radiate down the leg to the knee. The pain tends to intensify when one is standing or walking. If avascular necrosis is in the wrist, the patient may notice pain in the wrist and weakness in the fingers. The more the hand is moved, the more intense the pain can become. When this condition is in the femur, more than likely the patient will experience knee pain. When in the shoulder, pain and stiffness in that area are evident.
The most common cause of avascular necrosis is some sort of injury to the bone, such as a fracture or a dislocated joint. As a result of the trauma, the blood vessels that deliver blood to the bone can be damaged. The bone is then left without a means to obtain oxygen or nutrients. Eventually, the bone cells die, which in turn weaken the bone.
Other reasons cited include long-term use of steroids. While it is uncertain as to how these anti-inflammatory medications cause avascular necrosis, it can be a contributing factor. Also, individuals who drink heavily are at risk of suffering from avascular necrosis. If one were to consume several alcoholic drinks per day for many years, that can cause fatty deposits to form in the blood vessels, thereby restricting the flow of blood to the bones.