Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Fractures ?
    ### Response:
    A fracture is a break, usually in a bone. If the broken bone punctures the skin, it is called an open or compound fracture. Fractures commonly happen because of car accidents, falls, or sports injuries. Other causes are low bone density and osteoporosis, which cause weakening of the bones.
    