EP0767631B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Reversible bone screw lock
Assignee: Zimmer Spine Inc
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Filing: 1995-06-30
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Granted: 2000-12-27
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Expires: 2015-06-30
Abstract
Abstract A medical bone screw including a lock to lessen the possibility of pull-out or screw-out. The screw may be any bone screw including a cannula. A wire spring is inserted partially into the cannula prior to use. Once in position, the wire spring is pushed further down the cannula until its ends may project out side openings in the screw. These projections lock the screw in place. Further depression of the wire spring disengages them so the screw may be removed.
Inventors
- 👤 Douglas W. Kohrs
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 03:25
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/84; A61B17/86; A61B17/8685; A61B17/74; A61B17/742; A61B17/88; A61B17/8872; A61B2017/00831; A61B2017/00867; A61B17/04; A61B17/0401; A61B2017/0409; A61B2017/8655
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
147 words
A reversible cannulated bone screw (10) including a threaded shaft (11), a head (18) for
turning said screw and a cannula (16) extending from said head along the length of
said screw, characterized by: a) at least one side opening (24, 26) formed through said threaded shaft to
communicate with said cannula, b) a spring (12) including at least one spring end (28, 30) inserted into
said screw cannula, said spring being constructed and arranged such
that depression of said spring down said cannula away from said head
causes at least one spring end to project through at least one of said side
openings, said spring further being constructed and arranged such
that once inserted into said cannula, no portions extends above the screw head,
and that by further depressing the spring distally, the spring disengages the
bone so that the screw may be removed or repositioned.
Claim 2
Dependent Claim
39 words
The bone screw of claim 1, wherein said at least one side opening includes a pair
of opposed side openings (24, 26), said spring including two spring ends
(28, 30), each of which may extend through a side opening.
Claim 3
Dependent Claim
33 words
The bone screw of claim 2, wherein said cannula includes locating means (20, 22,
38, 40) for inserting said spring within said screw such that said spring
ends align with said side openings.
Claim 4
Dependent Claim
15 words
The bone screw of claim 3, wherein said spring is a generally V-shaped
spring wire.
Claim 5
Dependent Claim
74 words
The bone screw according to one of the claims 1 to 4, characterized in that said
cannula includes opposing spring guide grooves (20, 22, 38, 40) extending from
said head to said side openings (24, 26; 44, 46) for guiding said spring ends (28, 30) to
said side openings, said cannula extending from said head distally of said side
openings such that said spring ends may re-enter the cannula distally of the
side openings.
Claim 6
Dependent Claim
32 words
The bone screw according to one of the claims 1 to 5, wherein said shaft includes
a second pair of side openings (46) spaced directly distally of said first side
openings (44).
References Cited (Backward Citations)
No citation records indexed.
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