Orthopaedic done screw apparatus
US5989255A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Aug 6, 2018 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2090/037
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A bone screw apparatus and method of implantation provides a bone screw having an elongated shaft of an oversized length with proximal and distal end portions. The distal end portion of the shaft has a cutting head. The proximal end portion of the shaft is sized and shaped to accept a driver tool, such as a drill chuck. The shaft is externally threaded along a majority of its length. A pair of opposed longitudinally extending circumferentially spaced flat surfaces are provided along the shaft. A removable head with a central opening enables the head to slide along the shaft proximally to distally. A ratcheting mechanism prevents movement of the head along the shaft in but one direction. A central opening of the head is shaped to conform to the shaped surfaces of the shaft, so that the head and shaft can be rotated as a unit by engaging and rotating the head. The tool receptive surface portion of the head includes intersecting external surfaces of the head spaced radially away from the shaft during use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.