Multi-axial screw
US5891145A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 14, 1997 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Jul 14, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/7032
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A spinal fixation assembly is provided that includes a bone engaging fastener and an elongated member, such as a spinal rod. The fixation assembly is a multi-axial assembly that permits fixation of the bone engaging fastener to the spinal rod at any of a continuous range of angles relative to the rod in three-dimensional space. The fixation assembly includes a receiver member having a bore therethrough, the walls of which are tapered near the bottom, and a channel communicating with the bore and having an upper opening at the top of the receiver member for insertion of a spinal rod. Also included are an outer wedge member and an inner wedge member, both of which have generally the shape of a washer and a bore therethrough. In each wedge member, the respective bore is not parallel to the central axis of the respective wedge member. Additionally, the outside surfaces of the wedge members may be tapered, and the respective bores may be tapered, so as to self-lock when seated and tightened. The bone engaging fastener fits within the bore of the inner wedge member, which in turn fits within the bore of the outer wedge member, which in turn fits within the tapered sides of the receiver m…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.