Patent Number: 6,168,597

Title: Bone screw

Abstract: A bone screw (1) having a threaded shaft portion (2) and a head (3) is provided. In order to ensure a good fastening capability of the bone screw even in soft bone material the bone screw has a longitudinal bore (5) extending along the longitudinal axis of the threaded shaft portion (2) and having a portion (7) which flares towards the free end (6) opposite to the head (3). Slits (8) extending parallel to the longitudinal axis are provided in this portion of the threaded shaft portion. An expanding member (20) comprises a top portion (22) forming the top (22) of the bone screw (1) and a shaft (21) adjacent thereto extending into the longitudinal bore (5). The threaded shaft portion is provided with notches at its inner wall adjacent to the flared portion (7) of the longitudinal bore (5), the notches surrounding the longitudinal bore (5) in a defined region thereof. When expanding the bone screw within the bone, the top portion (22) is pulled into the longitudinal bore (5) in such a manner that a peripheral edge (25) at the top portion (22) engages the notches (9) of the threaded shaft portion (2). This expands the end of the bone screw (1) screwed into the bone.

Inventors: Biedermann; Lutz (D-78048 VS-Villingen, DE), Harms; Jurgen (D-76337 Waldbronn, DE)


International Classification: A61B 17/86 (20060101); A61B 17/68 (20060101); A61B 017/56 ()

Expiration Date: 01/02/2018