Bi-fed offset pitch bone screw
US6129730A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1999 |
| Grant date | Oct 10, 2000 |
| Priority date | — |
| Expiry date | Feb 10, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/863
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.