internal fixation, any method of holding together the fragments of a fractured bone without the use of appliances external to the skin. After open reduction of the fracture, smooth or threaded pins, Kirschner wires, screws, plates attached by screws, or medullary nails may be inserted through an appropriate incision to stabilize the fragments. In some instances the device is removed at a later operation, but it may remain in the body permanently. Compare external pin fixation.
