Posterior spinal polyaxial locking lateral mass screw plate assembly
US5531746A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1995 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | May 22, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2310/00023
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The present invention is a polyaxial lateral mass locking screw plate assembly for immobilization of vertebral bones, via fixation to surfaces thereof. In one embodiment the invention includes a narrow elongate plate having a plurality of holes, which in one variation are threaded, into which holes coupling elements may be inserted, or correspondingly screwed. The coupling elements have a cylindrical exterior, and have an semi-spherical interior volume into which the semi-spherical head of a bone screw may be inserted, and therein polyaxially mounted. In one variation the coupling element is a 7/8ths ring including a single axial slot. In another variation the coupling element includes a plurality of slots in its lower portion. In either variation insertion of a coupling element into a corresponding hole causes the interior volume to be crush locked to the head of the screw. In a second embodiment, the present invention includes a similar plate, having holes which are, however, threaded part of the way through the plate. In this embodiment, the bottom portion of the holes of the plate, additionally, have a curved interior surface which forms an annular lip for supporting a semi-sph…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.