Avascular Necrosis of the Knee

Avascular Necrosis

Avascular Necrosis is a disease that develops from the temporary or permanent loss of the blood provided to the bones. Bone tissue needs blood otherwise it will die causing the bone to breakdown. This can occur from trauma, non-traumatic or even pressure within the bone. Other names for Avascular necrosis include ischemic bone necrosis, osteonecrosis and aseptic necrosis.

There are also other sites for avascular necrosis to occur such as the femur, shoulder, upper arm bone and ankles. The disease may impact just one bone, multiple bones at the same time or multiple bones at separate times

Normally after an injury, a bone can heal itself by breaking down and restoring itself along with the old bone that gets drawn in and is exchanged with new bone, however if this doesn't take place and the bone is losing blood circulation then Avascular Necrosis presents itself.

At the beginning of this disease, a patient may not have any indication that they have Avascular Necrosis but as it advances the patients encounter joint pain. The pain first starts in the joint when weight is placed on the joint and then it continues on even in a relaxed state. The pain begins slowly and steadily increases to severe. The severity of this pain can restrict a persons range of motion.

After an orthopaedic doctor has completing a physical exam and has assessed the patients history, they can determined what tests are needed to diagnose the patient as having Avascular Necrosis. X-rays can help decide if more test need to be performed to evaluate if further test are required for their diagnosis. Other diagnostic tests include MRI, CT, Bone Scan, Biopsy and Functional Evaluation of Bone.

To choose the most suitable treatment, the doctor takes into consideration the patients age, at what stage the disease is in, where the affected bone is located and its size, and what is the primary cause of Avascular Necrosis. Conservative treatment such as corticosteroid is usually given to patients first, however, these hardly ever give permanent improvement. So, more than likely the patient will have to have surgery.