Polyaxial mechanism for use with orthopaedic implant devices
US5752957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1997 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Feb 12, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/7032
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A polyaxial orthopedic device for use with rod implant apparatus includes a hook or a screw having a recess which includes a lower portion and an upper portion, the up per portion is curvate. A rod receiving head having a channel formed therein, and a central bore which is curvately tapered at the inside bottom, and equivalently curvately tapered on the exterior surface, is polyaxially seated in the upper portion of the recess while a post element is inserted down through the head into the lower portion of the recess. The upper portion of the post is widened and curvate so that it seats in the curved lower interior of the bore of the head. The insertion of a rod into the head, onto the top of the post and the subsequent application of a downward force thereon by a nut causes the assembly to lock together, independent of the polyaxial angle of the head to the post and hook, or screw. The post may be held in the recess by means of a transverse dowel positioned in a co-linear transverse hole formed in the recess or post or by sweat locking the post into the recess; the process of sweat locking meaning the insertion of the post into the recess when there is a relative temperature diffe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.