Bone anchor and deployment device therefor

Abstract

A rivet-like bone anchor has a floating washer at its head that can adapt to an angled bone surface and, thereby, better secure a tissue thereto. The anchor includes a rivet, an expandable sleeve, and a washer. The rivet includes a head and an elongate body having proximal and distal ends, the head being mounted on the proximal end of the elongate body. The expandable sleeve has an inner bore adapted to receive the rivet body. The washer 'floats' at a proximal end of the sleeve. As the rivet is inserted into sleeve, the sleeve expands into an interference fit with the bone. The head of the rivet, moreover, forces the floating washer into contact with the tissue at an angle that conforms to that of the underlying bone surface. A deployment tool permits the anchor to be deployed without application of unnecessary counterforce. The tool includes an outer tube, the distal end of which can hold the anchor housing, e.g., via a screw fit. A rod, which is slidably disposed within the bore of the tube, can be used to push the rivet into the expandable sleeve so that the sleeve expands into the bone, so that the floating washer is forced into position against the bone surface, and so that anchor is broken away from the housing. This can be effected, for example, by squeezing the distal ends of the outer tube and the rod together, e.g., in the manner that the end of a syringe is squeezed.