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EP0276153A2
Expired / Lapsed
EP
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Bone screw
Assignee: Ethicon Inc
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Filing: 1988-01-21
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Granted: —
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Expires: 2008-01-21
Abstract
Abstract The invention relates to a bone screw with a threaded part and a screw head, characterized in that a head plate (3) is provided between shank (5) and screw head (1) and on whose centre is located said screw head and that the transition zone (2) between the head plate and the screw head is constructed as a predetermined shearing zone, which shears at a torque corresponding to 0.2 to 0.4 times the pulling off force for separating head plate (3) and shank (5).
Inventors
- 👤 Lothar Schilder
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 11:56
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/16; F; F16; F16B; F16B31/00; F16B31/02; F16B31/021; A61B17/56; A61B17/58; A61B17/68; A61B17/84; A61B17/86; A61B17/866; A61B2017/00004; A61B90/00; A61B90/03; A61B2090/037; F16B23/00; F16B23/0061
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
85 words
Bone screw comprising a threaded part, whose shank terminates in one piece in a screw head, characterized in that a head plate (3) is provided between shank (5) and screw head (1) and on whose centre is located said screw head and that the transition zone (2) between the head plate and the screw head is constructed as a predetermined shearing zone, which shears at a torque corresponding to 0.2 to 0.4 times the pulling off force for separating head plate (3) and shank (5).
Claim 2
Dependent Claim
85 words
Bone screw comprising a threaded part, whose shank terminates in one piece in a screw head, characterized in that a head plate (3) is provided between shank (5) and screw head (1) and on whose centre is located said screw head and that the transition zone (2) between the head plate and the screw head is constructed as a predetermined shearing zone, which shears at a torque corresponding to 0.2 to 0.4 times the pulling off force for separating head plate (3) and shank (5).
Claim 3
Dependent Claim
26 words
Bone screw according to claim 1, characterized in that the predetermined shearing zone has a cross-sectional surface 60 to 80% smaller than that of the shank.
Claim 4
Dependent Claim
36 words
Bone screw according to claim 2, characterized in that two or more vertical bores or recesses (4) for receiving the pins of a box spanner are provided in the outer peripheral region of head plate (3).
Claim 5
Dependent Claim
18 words
Bone screw according to claim 1, characterized in that the screw head is constructed as a hexagonal stump.
Claim 6
Dependent Claim
28 words
Bone screw according to claims 1 to 3, characterized in that the bone screw is made from a resorbable plastic from the group of polylactides, polyglycolides and/or polydioxanones.
Claim 7
Dependent Claim
40 words
Bone screw according to claim 4, characterized in that the torque of the desired shearing point of a M4 screw is in the range 55 to 85 Nmm in the case of a predetermined shearing zone diameter of 1.8 mm.
References Cited (Backward Citations)
No citation records indexed.
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