US4537185A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cannulated fixation screw
Assignee: Ace Orthopedic Co Inc
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Filing: 1983-06-10
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Granted: 1985-08-27
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Expires: 2003-06-10
Abstract
Abstract A self-tapping, self-drilling orthopedic fixation screw includes a cannula through the shaft of the screw for placement over a guide pin mounted in a guide hole in a bone to drill and tap a hole at predetermined location in the bone.
Inventors
- 👤 Denis P. Stednitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:01
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/84; A61B17/86; A61B17/8625; A61B17/8635; A61B17/864
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
151 words
A cannulated fixation screw for use in orthopedic surgery comprising; an elongate hollow shaft defining a cannula through the center of the shaft; self-tapping threads adjacent the distal end of the shaft formed by a plurality of flutes arcuately spaced apart around the circumference of the shaft having lands therebetween, each of said lands having a plurality of threads thereon and a heel, the flutes forming a plurality of self-tapping cutting edges on each of said threads, each thread having a maximum thread height at the cutting edge thereof, and a mimimum thread height at the heel of the land in which the thread is located; and means on the distal tip forming a plurality of teeth projecting from said distal tip, each of said teeth forming a drilling edge formed by the intersection of the cutting face of the corresponding land, the cannula and the exterior of the corresponding land.
Claim 2
Dependent Claim
151 words
A cannulated fixation screw for use in orthopedic surgery comprising; an elongate hollow shaft defining a cannula through the center of the shaft; self-tapping threads adjacent the distal end of the shaft formed by a plurality of flutes arcuately spaced apart around the circumference of the shaft having lands therebetween, each of said lands having a plurality of threads thereon and a heel, the flutes forming a plurality of self-tapping cutting edges on each of said threads, each thread having a maximum thread height at the cutting edge thereof, and a mimimum thread height at the heel of the land in which the thread is located; and means on the distal tip forming a plurality of teeth projecting from said distal tip, each of said teeth forming a drilling edge formed by the intersection of the cutting face of the corresponding land, the cannula and the exterior of the corresponding land.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-26 | 1989-02-25 | 1989-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-26 | 1993-02-25 | 1993-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-26 | 1997-02-25 | 1997-08-27 | $7700.00 | Window Closed / Lapsed |