Spinal fixation system
US6280443A · kind A · utility
Inventors
Key dates
| Filing date | Nov 18, 1999 |
| Grant date | Aug 28, 2001 |
| Priority date | — |
| Expiry date | Nov 18, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/7041
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A spinal fixation system for use in the immobilization of a sequence of spinal bones, comprising a plurality of pedicle screws, a pair of rods, and connectors. The pedicle screw has a spherical head having a round portion at an upper portion of the spherical head, a threaded shaft for insertion through the pedicles, and a threaded stem on the top of the spherical head. The connector has a rod passage for receiving the rod therethrough, a set member bore formed in an upper portion of the connector, and a support portion having an opening formed for adapting the stem of the pedicle screw and a recessed hemispherical wall. A spherical joint at the pedicle screw and the connector allows the multi-directional adjustment capability of the connector so that the screws can be implanted in any angulation with no need of having the screws well aligned. The spherical head of the pedicle screw and the hemispherical wall have slightly different diameters which improve the locking power and provide a rigid fixation. A rigid coupling is achieved between the rod and the connector by making the cross-section of the rod passage as an imperfect circular shape which allows the three point contact betw…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.