<prompt> 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 -Primary osteoarthritisAvascular necrosisTuberculosisAluminum toxicity  <response>: This patient has : -History of steroids intakePain in both hipDifficulty in walkingThe diagnosis is AVN of the hip.In 50 of idiopathic cases and 80 of steroid-induced AVN are bilateral.About other optionsTuberculosis of hip is usually unilateral.Primary osteoarthritis of hip does not occur at 45 years and has nothing to do with steroid intake.Aluminium toxicity does not cause bilateral hip pain. 