What Causes Severe Pain In Hand After Removal Of Fracture Cast?

hi my daughter was 9 in january she is waiting for a scan on her left hand.She is in plaster with a suspected scarfoid break the x ray didn't show a break.The cast was on for 8 day's and has been changed when removed was in a lot of pain .She is afraid of having the scan can she be left in plaster the cast didn't go on until 10 day's after the accident.