What Causes Pain And Burning Sensation At The Site Of Fracture?

i had wrist surgery to fix a broken scaphoid bone on dec. 17. about two weeks ago a pin sarted coming out and the doctor removed that one, while leaving the other two in. He then put a hard cast on whereas before I was in a splint. this was two weeks ago. Now im experiencing sharp pain in that area along with burning sensations that last a few seconds. This started a few das ago and has gotten worse each day. Could this be another pin that started to poke trhough the skin or a sore? Is this potentially a serious Problem?