초록 ▼

A bone screw annd assembly are described wherein the bone screw has a dual lead thread that is provided as an offset thread. The bone screw has two leads starting less than 180.degree. apart. Because the leads start less than 180.degree. apart, the leads appear to spiral together along the shaft of

A bone screw annd assembly are described wherein the bone screw has a dual lead thread that is provided as an offset thread. The bone screw has two leads starting less than 180.degree. apart. Because the leads start less than 180.degree. apart, the leads appear to spiral together along the shaft of the bone screw, creating a large groove and a small groove. The offset dual lead thread of the present invention provides enhanced pullout resistance by overcoming machining limitations to produce a bone screw with increased thread depth while maintaining or decreasing thread pitch. The bone screw may also be provided together with a bone plate to comprise a bone fixation assembly.

대표청구항 ▼

[ What is claimed is:] [1.] A bone screw comprising:a head, a tip, and a shaft extending between the head and the tip, the shaft including a dual lead threaded section, the dual lead threaded section having a first lead and a second lead each in the form of helix, wherein the second lead starts betw

[ What is claimed is:] [1.] A bone screw comprising:a head, a tip, and a shaft extending between the head and the tip, the shaft including a dual lead threaded section, the dual lead threaded section having a first lead and a second lead each in the form of helix, wherein the second lead starts between about 90.degree. and 150.degree. after the first lead.