Patent EP0195455A1 successfully refreshed from Google Patents.
EP0195455A1
Expired / Lapsed
EP
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Cranial screw
Assignee: Codman and Shurtleff Inc
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Filing: 1986-03-21
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Granted: —
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Expires: 2006-03-21
Abstract
Abstract A cranial screw (10) transparent to X-ray or magnetic fields so that it is compatible with CT or MR scanning techniques. The screw (10) has a hollow shank (12) with a threaded distal portion (22) for insertion into a hole in the cranium and an emergency removal drive (14) head spaced proximally from an insertion drive head (16) by a frangible connecting portion (18), so that if excessive torque is placed on the screw during insertion, it will break at the frangible portion (18) leaving the emergency removal drive head (14) and the threaded distal portion (22) intact so that they can be removed using the emergency removal drive head (14).
Inventors
- 👤 Robert George Kraus
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 03:49
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/84; A61B17/86; A61B17/864; A61B5/00; A61B5/03; A61B5/031; A61B90/00; A61B90/10; A61B90/11; A61B2017/00831; A61B2017/00902; A61B90/03; A61B2090/037; A61B2090/103; A61B2562/00; A61B2562/16; A61B2562/17
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
164 words
1 . A hollow screw adapted for insertion into a hole through the cranium comprising: a hollow shank having a lumen for providing access to the interior of the cranium, having a distal end adapted for insertion into said hole and having a proximal end extending outside of said cranium: said distal end having a threaded portion: an emergency removal drive head integrally disposed about the exterior of said shank adjacent said threaded portion: an insertion drive head integrally disposed about the exterior of said shank spaced proximally from said emergency removal drive head: a frangible portion of said shank integrally connecting said emergency removal and said insertion drive heads: whereby, if excess torque is placed on said screw during insertion into the hole in the cranium, said shank will break preferably at said frangible portion leaving said emergency removal drive head and said threaded portion intact so that the remainder of said broken screw can be removed using said emergency removal drive head.
Claim 2
Dependent Claim
164 words
1 . A hollow screw adapted for insertion into a hole through the cranium comprising: a hollow shank having a lumen for providing access to the interior of the cranium, having a distal end adapted for insertion into said hole and having a proximal end extending outside of said cranium: said distal end having a threaded portion: an emergency removal drive head integrally disposed about the exterior of said shank adjacent said threaded portion: an insertion drive head integrally disposed about the exterior of said shank spaced proximally from said emergency removal drive head: a frangible portion of said shank integrally connecting said emergency removal and said insertion drive heads: whereby, if excess torque is placed on said screw during insertion into the hole in the cranium, said shank will break preferably at said frangible portion leaving said emergency removal drive head and said threaded portion intact so that the remainder of said broken screw can be removed using said emergency removal drive head.
Claim 3
Dependent Claim
31 words
The screw of Claim 1 wherein said screw is made of a uniform material which will not show up on an X ray or a magnetic resonance scan of the cranium.
Claim 4
Dependent Claim
23 words
3 . The screw of Claim 1 wherein said frangible section is made of a different material from the remainder of said screw.
Claim 5
Dependent Claim
13 words
The screw of Claim 1 wherein said threaded portion includes a self-tapping thread.
Claim 6
Dependent Claim
14 words
The screw of Claim 1 wherein said distal tip is chamfered for easy insertion.
Claim 7
Dependent Claim
14 words
The screw of Claim 1 wherein said lumen is slightly tapered to facilitate molding.
Claim 8
Dependent Claim
28 words
. The screw of Claim 1 wherein said proximal end extends proximally from said insertion drive head and is adapted for connection to equipment external to the cranium.
Claim 9
Dependent Claim
16 words
The screw of Claim 7 wherein said extending proximal end includes a standard luer lock connection.
Claim 10
Dependent Claim
42 words
The screw of Claim 1 wherein the distal end of said emergency removal drive head is formed into a circular flange: and, further including washer to provide a tight seal between said -f lange and the cranium when said screw is tightened.
Claim 11
Dependent Claim
29 words
The screw of Claim 1 wherein said distal end includes a first wall thickness and said frangible portion includes a second wall thickness less than said first wall thickness.
References Cited (Backward Citations)
FR2328876A1
Cited
DE2621909A1
Cited
US4206762A
Cited
US4068555A
Cited
FR2389362A1
Cited
WO1983003190A1
Cited
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