Patent ID: 9615869
Date: 2017-04-11
CPC Classifications: A61B

Claim:
1. An orthopedic implant device for compressing bone parts toward each other, comprising: an implantable bone screw having a shaft along a longitudinal axis, a tip at a first end of the shaft and a head opposite to the tip, said shaft having an external thread extending along the entire length of the shaft and partially along the head, the external thread having a constant crest diameter and a root diameter; wherein the head has a part-spherical lower side surface with a maximum diameter larger than the constant crest diameter, and having a first radius measured from the longitudinal axis to a first external side that is smaller than a second radius measured to a second external side diametrically opposed to the first side, and wherein the external thread having a constant crest diameter extends into the lower side surface of the head, the crest diameter in the lower side surface of the head being equal to the crest diameter along the shaft, and the root diameter gradually increases as the thread extends into the lower side surface of the head.