Tapered bone screw with continuously varying pitch
US5964768A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 3, 1998 |
| Grant date | Oct 12, 1999 |
| Priority date | — |
| Expiry date | Mar 3, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2017/0648
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A bone screw having a continuously varying pitch includes a tapered root portion having a relatively small diameter on a leading end of the screw and a larger trailing diameter. The pitch of the screw decreases between the leading and trailing ends thus causing the bone fragments in a fracture to be drawn together when the screw is installed across the fragments. The radially outer diameter of the threads increases between the leading and trailing ends thus causing each successive thread portion to cut into bone radially outwardly from the preceding thread portion thereby providing uncut bone in which the succeeding threads can gain purchase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.