Posterior rod system
US7163538B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2003 |
| Grant date | Jan 16, 2007 |
| Priority date | — |
| Expiry date | Jul 15, 2023 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/7037
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention provides a rod assembly for implantation into the spine which includes a bone anchor assembly providing two points of angulation for the connection between the point of fixation and the rod. Further, the distance of offset between the point of fixation and the rod can be varied. The invention uses a bone screw having a pronged cage with a recess that accommodates the head of a post member. The cage can be tightened around the head by the camming surfaces of a locking cap that is drawn down around the compressible cage as the head is screwed upward in the recess by the engagement of the threads of the post by a locking nut. Further, the locking cap has a slotted bushing that is positionable in the elongated slot of a rod connector member. The locking nut includes an external taper that expands the bushing outward to lock it into position in the slot. In a further embodiment, the head has an internal hollow that receives a spindle journaled in a cavity in the recess to limit the amount of play in the assembly prior to tightening.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.