A patient of nephrotic syndrome taking steroids for 6 years presented with a limp gait and limitation of abduction and internal rotation. He MOST probably has:

Chronic intake of steroids in this patient has resulted in avascular necrosis of femoral head in this patient. Steroids inhibit angiogenesis and cause stenosis of vessels predisposing to this condition. Avascular necrosis is a condition which where interruption of blood supply leads to bone death. It usually affects the epiphysis of the hip leading to pain, loss of motion, and ahritis. It most commonly affects the hip joint. Patients usually presents with pain in groin, buttock or knee. They have difficulty with gait or weight bearing exercise. There is limitation of abduction and internal rotation. Risk factors: Hip fractures or dislocations Developmental hip dysplasia Alcoholism Use of coicosteroids Collagen vascular disease, vasculitis Sickle cell anemia Gaucher's disease Ref: Musculoskeletal, Spos, and Occupational Medicine By Ralph Buschbacher, Differential Diagnosis and Management for the Chiropractor: Protocols and By Thomas Souza page 355.