My Mom Has A Wound On Her Left Leg Directly

My mom has a wound on her left leg directly to the left of the kneecap. its a form of granulomatous but I don't remember all of it. she called me the other night and told me what appeared to be a round nail came out with the blood and yuck, she's had on before but it was on her him, and had cells from the kidney, liver and other organs. but this looks and feels like a nail coming from her leg, and doctors are giving us no real answers and wound care could only do so much, do you have any idea what causes this to happen?