A system for attaching first and second bone segments together may include a first component and a second component. The first component may have a first component bone engagement end implantable into a first bore formed in the first bone segment, and a first component attachment end. The second component may have a second component bone engagement end implantable into a second bore formed in the second bone segment, and a second component attachment end with a first projection that is movable, in response to a temperature change of the first projection, between insertion and locking configurations. In the insertion configuration, the first projection may be positioned to avoid interference with withdrawal of the second component attachment end from the first component attachment end. In the locking configuration, the first projection may be positioned to interfere with withdrawal of the second component attachment end from the first component attachment end.
