Polyaxial pedicle screw having a compression locking rod gripping mechanism
US5810819A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1997 |
| Grant date | Sep 22, 1998 |
| Priority date | — |
| Expiry date | Jun 23, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/7041
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate ball top, a polyaxial head member having a socket into which the head of the screw is initially polyaxially nested, a vertical slot which renders the socket compressible, and a horizontal through hole having a tapered portion on one side of the vertical slot. A rod gripping cross-bar member, which is mounted through the through hole includes an axial split which permits the first end thereof to grip a rod, and then to be clamped onto the rod when the axial slot is narrowed. A nut is provided on the end of the cross-bar member which extend out from the through hole on the opposite end from the rod gripping mechanism. The advancement of the nut causes the cross-bar member to be compressed by the taper of the front portion of the through hole, thereby locking the rod in the gripping end thereof, and further provides the compression force necessary to compression lock the interior socket of the head against the ball top of the screw.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.