Porous coated bone screw
US5098434A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1990 |
| Grant date | Mar 24, 1992 |
| Priority date | — |
| Expiry date | Nov 28, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S606/907
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A bone screw is disclosed for joining bone fragments or for mounting a prosthetic component onto an underlying bone. The bone screw includes a head and an elongated cylindrical shank which is integral with and extends from the head. The shank includes a threaded member and a shoulder member connecting the threaded member and the head, the shoulder member having an outer surface with a porous medium thereon for encouraging bone ingrowth fixation. The outer diameter of the shoulder member is greater than the diameter of a bore of the bone into which the screw is to be threadedly engaged. The head of the screw is provided with a coupling member engageable by a tool for selectively rotating the shank to advance the screw into the bone. As the bone screw is advanced toward a fully seated position, the shoulder member with the porous medium thereon engages the bone in a fitting manner which may be described as a "scratch fit". Initial loosening of the bone screw due to the viscoelastic relaxation of the bone tissue following fixation is thereby largely inhibited and long term loosening of the bone screw is also inhibited by providing an interface onto which or into which bone tissue can …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.