Wedge shaped suture anchor and method of implantation
A suture anchor is described which in one form may be easily fabricated from extruded material by angular cuts and bore holes which provide an offset pulling force to the suture. In an alternate and preferred embodiment the suture anchor is injection molded having an annular displaced corner and abutment wall which act to seat the suture anchor firmly within a bore hole. Novel application means are also disclosed which hold the suture anchor on a frangible shaft for insertion and upon completion of the insertion permit fracture of the frangible portion and removal of the instrument. In another form of the invention, the suture anchor comprises a substantially wedge-shaped body having a smaller distal end and a larger proximal end, means thereon for retaining a suture, and means thereon for releasable connection to an inserter shaft; a boundary surface and a plow surface of the body intersecting to form a biting edge at the proximal end of the body; and the boundary surface and an abutment surface of the body intersecting to form a cam surface at the proximal end of the body; and the biting edge being adapted to be in engagement with a first wall portion of a bore in a bone and the cam surface being adapted to be in engagement with a second wall portion of the bore opposed to the first wall portion; wherein tension on the inserter shaft is operable to move the cam portion along the bore second wall portion and rotate the body in the bore such that the biting edge bites into the bore first wall portion to lock the body in the bore.
1. A method for disposing a suture anchor in a bone, the method comprising the steps of:
providing a suture anchor comprising a generally wedge-shaped configuration defined by a ledge surface at a first end thereof, a protuberance upstanding from the ledge surface, an abutment surface depending from the protuberance, a rounded cam surface defined by a juncture of the protuberance and the abutment surface, and a plow surface depending from the ledge surface and angled toward the abutment surface to form therewith a rounded distal end surface, the plow surface and the ledge surface defining a biting edge, the protuberance being provided with a recess off-set from a center of the anchor first end, the anchor further being provided with a through-hole extending therethrough from side to side;
providing an inserter comprising a shaft having a tip portion, and a handle;
releasably mounting the suture anchor on the inserter shaft tip portion by engaging the protuberance recess with the inserter shaft tip portion;
extending a suture through the anchor through-hole;
by manipulation of the inserter, inserting the anchor, distal end surface first, into a bore in the bone until the biting edge is adjacent a first wall portion of the bore, and the cam surface is adjacent an opposite second wall portion of the bore;
pulling the inserter to cause the cam portion to move along said second wall portion and the anchor to rotate in the bore, and the biting edge to bite into said bore first wall portion, to bind the anchor in the bone bore with the suture extending from the bore; and
releasing the anchor from the shaft tip.