Osteonecrosis, if this is the correct diagnosis, can be very serious and lead to destruction of the joint. It occurs when the blood supply is disrupted to the bones in the joint causing death of the bone. Fractures are the most common cause of this problem. Rarely, it is caused by blood disorders such as sickle cell anemia or disorders where the blood clots too much. I cannot second guess either the diagnosis of your orthopedic surgeon or the decision to adopt a wait and see approach. Given that this can be a serious problem, you may want to get more than one opinion.
About Alan Matsumoto, M.D.
Part-time Faculty, Division of Rheumatology
Johns Hopkins University