A 45 year old was given steroids after renal transplant. After 2 years he had difficulty in walking and pain in both hips. Which one of the following is most likely cause -: (A) Primary osteoahritis, (B) Avascular necrosis, (C) Tuberculosis, (D) Aluminum toxicity
Answer is B. High dose coicosteroid & alcohol abuse are the commonest causes of avascular necrosis,the commonest site being femoral head.the mechanism is intravascular thrombosis-hyperlipidemia & fatty degeneration of liver;fat embolism give rise tocapillary endothelial damage,platelet aggregation & thrombosis. reference:Apleys,9th edition,page no104