Patent ID: 6110172
Filing Date: 2000-08-29
Classification: A61B

Abstract:
An osteosynthesis apparatus adapted to engage a rod; said apparatus comprising:a) an implant having a head with an upwardly opening rod receiving channel formed therein and sized to receive a rod; said rod receiving channel separating a first branch of said head from a second branch; first and second tongue receiving grooves formed in said first and second branches respectively and opening into said upwardly opening rod receiving channel; each of said tongue receiving grooves including a downwardly opening undercut portion separated from said rod receiving channel by an overhanging lip; said first and second tongue receiving grooves extending from a first face to a second face of said head; a lower surface of each of said lips and a lower surface of each of said branches above said undercut portion of said tongue receiving groove being rectilinear;b) a cap having a central portion with a set screw receiving bore extending vertically therethrough and first and second tongues extending outwardly from opposite sides of said central portion; each of said tongues comprising a foot portion extending outward from said central portion and an upwardly extending leg extending upward from said foot portion and spaced apart from said central portion by a lip receiving groove; an upper surface of each of said upwardly extending legs and an upper surface of each of said foot portions below said respective lip receiving groove being flat; said cap including at least one upward extending structure on an insertion leading side thereof; said cap adapted for securement to said implant head such that said central portion extends across said rod receiving channel and said first and second tongues extend through said first and second tongue receiving grooves such that said upwardly extending legs extend in said respective undercut portions of said tongue receiving grooves and said lips extend into said respective lip receiving groove; a front surface of each of said first and second tongues curving downward and rearward to a flat bottom portion of said respective tongue; said cap having a downwardly opening rod receiving groove formed in a lower surface thereof between said first and second tongues; said insertion leading side having a lower radiused surface that allows said cap to be tilted during insertion to allow said upward extending structure to clear elements of said branches during insertion; said radiused surface extending not more than half way across the bottom of said cap and a trailing side of said cap opposite said leading side being generally squared with the bottom of said cap.