Bone screw
AssigneeSynthes USA, LLC
InventorsAndre Frenk, Florian Beutter, Franco Cicoira
Life of this patent
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Abstract
A bone screw is provided having first and second threaded portions of different diameter separated by a middle portion that is unthreaded so that the bone screw may be inserted into a pair of adjacent bone fragments and used to compress the fragments together by driving the screw into a hole drilled in the fragments. An installation tool is also disclosed for threadably engaging one end of the bone screw and is used to initially drive the screw into the bone hole. Thereafter, a screwdriver may be inserted through the tool and into engagement with a recess in the bone screw and may be used to drive the screw fully into the bone and to separate the bone screw from the installation tool. A method of installation is further provided.
Claims8
A bone screw for connecting a plurality of bone fragments comprising:
- a shaft extending along a longitudinal axis, the shaft including a first end having a first threaded portion with a first core diameter, a first external diameter and a first pitch, the second end having a second threaded portion with a second core diameter, a second external diameter and a second pitch, the second end further having a tool engaging surface, wherein the first external diameter is no greater than the second core diameter, and the first and second pitches are substantially equal, and a non-threaded middle segment between the first and second threaded portions, an outer diameter of the middle segment being smaller than the first core diameter, and wherein the shaft includes a cannulation extending therethrough disposed coaxial with the screw longitudinal axis.
Dependencies are inferred from the claim text.