Disclosed is a fastener that can be mounted to a bone of a patient and can foreshorten and swell of a desired period of time. The fastener can include a head portion and a body portion extending from the head portion. At least one of the head portion and the body portion has a first width that changes to a second width greater than the first width and collectively the head portion and the body portion have a first length that changes to a second length shorter than the first length upon the head portion and the body portion being exposed to a temperature below a glass transition temperature of a polymeric material forming the head portion and the body portion.