Polyaxial locking screw and coupling element assembly for use with side loading rod fixation apparatus
US5584834A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 14, 1995 |
| Grant date | Dec 17, 1996 |
| Priority date | — |
| Expiry date | Jul 14, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/7034
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate head and a coupling element. The coupling element has a tapered lower portion including a slotted interior chamber in which the curvate head is initially polyaxially disposed. The coupling element further includes a recess formed in its side for receiving a rod of an implant apparatus, and an exterior threading disposed on its upper portion onto which a locking nut may be downwardly translated. A hollow cylindrical rod securing sleeve fits above the rod receiving recess, having a pair of grooves formed in its lower surface for seating against the rod. A locking collar is disposed below the rod receiving recess, having a pair of grooves in its top surface for receiving thereon the rod. Both the sleeve and the collar are axially translatable along the exterior surface of the coupling element. The downward translation of the collar provides an inward force on the outwardly tapered portion upon downward translation thereof, thereby causing the vertical slots to close, and crush locking the screw head within the interior chamber. The downward translation of the locking nut locks the rod be…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.