Navicular Avascular Necrosis is the result of an insufficient flow of blood to the bone. This can happen to a carpal bone as a result of a trauma that disturbs the blood supply to the bone. It has also been associated with repetitive motion trauma.
Among some of the conditions associated with Navicular Avascular Necrosis include: Kienbock’s disease (Lunate Avascular Necrosis), Preiser’s Disease and Carpal Avascular Necrosis – each resulting from trauma to a different area of the carpal, though all accompanied by similar symptoms. Those suffering from the condition generally have a history of a single major wrist injury, or multiple minor occupational injuries. They suffer from chronic wrist pain, tenderness and swelling – and experience limited range of motion.
Kienbock’s disease
When the affected carpal bone is the lunate, patients are diagnosed with Kienbock’s disease or Lunate avascular necrosis – with pain and tenderness experienced in the middle finger. This is a rare condition, which is seen in patients from 20 to 40 years of age with a history of engaging in manual labor. Often there is a history of trauma.
Carpal Avascular Necrosis
Associated with scaphoid fractures, Carpal Avascular Necrosis can often go undetected. Patients frequently assume that the injury is a simple sprain and opt to let it heal on its own rather than seek medical attention.
In some cases the wrist does get better on its own, though often times the bone fails to heal and results in a non union. A simple non union consist of two pieces of a broken bone that fail to heal together. Another more serious type of non union consist of the lower half of the broken bone losing its blood supply and dying. This condition is called avascular necrosis.
There is only one small artery that enters the scaphoid bone – at the end closest to thumb – which if torn in a fracture deprives the bone of a necessary blood supply.
Diagnosis
While X-rays can often time times identify areas of vulnerability, ongoing pain in certain fingers will further indicate possible navicular avascular necrosis. X-rays in advanced stages will show changing bone shape and possibly bone fragmentation and collapse depending on the severity and stage of the condition.
Treatment
In the early stages, intermittent immobilization for several months may be indicated in order to allow for reconstitution of normal bone architecture. And a series of range of motion exercises are established.
In the later stages, surgery may be necessary to address bone fragments and collapse.