<prompt> A 12 year old boy presents with chronic knee pain for 2 years. Knee x ray is shown. Probable diagnosis:Chronic osteomyelitisOsteosarcomaRicketsHyperparathyroidism  <response>: The x-ray shows lower end of femur with flaring and irregular margins but the epiphysis is normal. There is no white line in epiphysis, hence scurvy is ruled out. Absence of lytic lesions rules out hyperparathyroidism. Malignancy is ruled out as there is no periosteal reaction or bone growth is seen. Rickets shows flaring of metaphysis and widening of the growth 