Selectively expandable sacral fixation screw-sleeve device
US5713904A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1997 |
| Grant date | Feb 3, 1998 |
| Priority date | — |
| Expiry date | Feb 12, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B17/7055
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The present invention is a selectively expandable bone fixation screw-sleeve device which provides substantially greater holding strength in human bone than other bone screw devices. The sleeve element of this invention includes several embodiments, each having at least one corresponding screw element for selectively expanding a portion of the sleeve once it has been inserted into the bone. More specifically, in several embodiments, the sleeve includes a series of vertical slots in the end, or ends, of the cylindrical body of the sleeve. The slots define, therebetween, sections which are contiguous with the remainder of the cylindrical body, and which may rotate radially outward. In these embodiments, the sections are designed having a varying thickness, for example a single or double wedge profile, such that the insertion of the screw element into the sleeve deforms the shape of the sleeve by causing the sections to flair outward. In a different embodiment, the slots, and sections, are designed into the axially intermediate central portion of the cylindrical sleeve, and therefore flair outwardly therefrom upon insertion of a screw within the sleeve. As this invention is intended t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.