 Hi everybody, I would like to spend a couple of minutes talking about avascular necrosis or osteonecrosis are also known as bone back. This is the condition that occurs in a bone when the blood supply to that particular part is obstructed or cut off. It can occur in different parts of the body like the head of the humerus, the scaffold, the talus and couple of other places but the most common part is the head of the femur that has this particular condition called avascular necrosis. Avascular necrosis is occurring because of the unique nature of the blood supply to that particular part of the bone. Once this blood supply is obstructed or cut off and the blood supply to that is obstructed then the part degenerates or necrosis or dies so the terminology osteonecrosis or bone death. Indeed we have these conditions prevailing ever since the human being has been there but we should also know the causes for the cause of avascular necrosis. Trauma or injury to the blood vessels that carry the blood supply to that particular part of the bone or sometimes because of certain diseases like sickle cell anemia, gauchus disease in certain conditions like alcohol abuse, diabetics, long term use of steroids and non-steroidal anti-inflammatory drugs. The latest hum in the field is because of the burst or spike in the number of cases of avascular necrosis that have been reported recently after the COVID in fall. In COVID the basic management or the baseline of management has been the use of steroids for long term and high doses of steroids. Long term steroids and high doses of steroids prevent or obstruct the blood supply to the head of the femur or that particular part of the bone. Why does steroid affect the blood supply? We are not sure but there is a hypothesis that the lipids increase in the blood level and they cause clogging of the vessels that supply blood to that part of the bone. So this latest pandemic of COVID-19 and the use of steroids in these patients have led to a spike in the condition called avascular necrosis, austere necrosis or bone death. So can we prevent it? Unfortunately no because we have to save lives by using the use of steroids for long duration and in high doses. Of course we can prevent the damage if it is recognized very early by operative methods like cold decompression. In later cases when this is identified at a later stage we have to salvage the procedure or we have to do a hip replacement surgery. So this is in short about avascular necrosis and austere necrosis are also known as bone death. Thank you.