Unitary locking cap for use with a pedicle screw
US5667508A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 1996 |
| Grant date | Sep 16, 1997 |
| Priority date | — |
| Expiry date | May 1, 2016 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2017/867
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A unitary locking cap mechanism, which is used with pedicle screws and other orthopaedic implant devices which couple bones to rods, includes rim and post portions which are rotationally freely coupled to one another to permit independent motion relative to one another. The rim element has a cylindrical body with an open end and a closed end; the closed end alternatively having a concentric hole defined by an inwardly directed flange. In one embodiment, the flange includes a series of slots, dividing into a plurality of wedge-shaped pie sections. In another embodiment, the sidewall of the cylindrical portion of the rim includes an annular recess. The post is a cylindrical shaft having surface elements at one end which provide for mutual engagement with the rim. These surface elements may be deflecting arms which seat into the annular recess of the rim, or an annular recess in the shaft into which the wedge-shaped pie sections of the flange portion may be resiliently snapped into. In an alternative embodiment, the shaft and the rim are coupled together through the concentric hole by a retaining ring which is placed around the shaft, in an annular recess therein, after the insertion …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.