Advanced polyaxial locking screw and coupling element device for use with rod fixation apparatus
US5549608A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1995 |
| Grant date | Aug 27, 1996 |
| Priority date | — |
| Expiry date | Jul 13, 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; a recess formed in its side for receiving the rod of the implant apparatus; and an exterior threading disposed on its upper portion for receving thereon a top locking nut. A locking ring is disposed about the exterior of the lower portion of the coupling element, and provides an inward force on the outwardly tapered portion upon downward translation thereof, thereby causing the interior chamber to crush lock the screw head therein, thus eliminating the polyaxial nature of the screw-element coupling. In addition, a hollow cylindrical rod securing sleeve fits over the coupling element and locks the rod to the coupling element. In a first embodiment, the locking nut seats against the top of the sleeve, which seats against the top of the locking ring, and causes the sleeve to lock the rod and the screw in the interior chamber. In a second embodiment, the locking ring and the bottom of the coupling element have threa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.