Clariance

Bruno Sauvage

Guy Viart

Alain Tornier

Jean Yves Leroy

Brice Krier

Nicolas Virgaux

Pascal Rokegem

Andrew Clavenna

Andrew Clevenna

A discontinuously double-threaded bone screw includes a drive head and anchoring body consisting of a cylindro-conical core over which extend at least two cylindro-conical threads, the anchoring body including anchoring portions of different profiles, ensuring an anchoring corresponding to different bone hardnesses and strengths, the anchoring body including, below the drive head, a first anchoring portion with a conical core and two threads with cylindrical profile and identical pitch, a second anchoring portion with a cylindrical core and a single cylindrical thread over &#xbc; turn, a third anchoring portion with a cylindrical core and two threads with cylindrical profile over &#xbd; turn, a fourth anchoring portion including a cylindrical core and a single thread with cylindrical profile n turn based on total length of the bone screw, and a fifth anchoring portion including a conical core and two threads with conical profile forming the tip of the bone screw.

Double-threaded bone screw

Disclosed is a polyaxial screw including a friction element () positioned between the head () of the threaded bone anchoring portion () and the head () of the mechanical thread anchoring portion () on the one hand, and a retaining element () ensuring that the anchoring portions () cannot separate from each other while guaranteeing that the anchoring portion with the mechanical thread () is free to move in vertical translation and angular pivoting with respect to the threaded bone anchoring portion () so as to be able to axially preposition the mechanical thread anchoring portion () with respect to the axial anchoring position of the threaded bone anchoring portion ().

Polyaxial screw with mechanical thread and its friction device

Growing community of inventors

Frevin Capelle, France

Bruno Sauvage