<prompt> In sickle cell crisis bone pain is due to:-Bone infarctionOsteroporosisOsteomalaciaPeriosteal reaction  <response>: - Abnormal shape of RBC - Occlusion of small vessels of bone - bone infarction - resulting in pain If bones of hand feet are involved - Hand foot syndrome Long bones - Avascular necrosis of femur veebral column - H shaped veebra cod fish veebra fish mouth veebra -X ray skull - crew cut appearance Hair on end appearance 