A bone member
fastener for closing a
craniotomy includes a cap and a base interconnected by a narrow cylindrical collar. The cap has an externally threaded stud that screws into an internally threaded bore of the collar, thereby allowing the cap and base to be brought into clamping engagement against the internal and external faces of a
bone plate and surrounding bone. In a particularly disclosed embodiment, the base of the
fastener is placed below a
craniotomy hole with the collar projecting into the hole, and the stud of the cap is screwed into the bore of the base from above the hole to clamp a bone flap against the surrounding cranium. This device provides a method of quickly and securely replacing a bone cover into a
craniotomy. The distance between the cap and base can be selected by how far the threaded stud of the cap is advanced into the internally threaded collar. The
fastener is therefore adaptable for use in several regions of the
skull having various thicknesses. An
insertion tool with a long
handle permits safe and convenient placement of the base between the brain and the internal face of the
bone plate. Some disclosed embodiments of the fastener have a cap and base that conform to the curved surface of the
skull, for example by having an
arcuate shape or flexible members that conform to the curvature of the
bone plate and surrounding
cranial bone as the fastener is tightened.