My mom was recently diagnosed with osteonecrosis of her hip and I’ve been told that it’s hereditary.  Do I need to be worried about this?  

Although the underlying pathology is not quite understood there are multiple factors that must occur to develop femoral osteonecrosis.  The primary risk factors are excessive corticosteroid or alcohol use, trauma, or a blood clotting disorder.  The blood clotting disorder can be hereditary, but does not necessarily mean that you will develop the disease process as your mom did.  Do keep in mind, however that the earlier femoral osteonecrosis is detected, the better the prognosis.