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US5478342A Expired / Lapsed US ⏱️ 0.0 years remaining

Reversible bone screw lock

Assignee: Zimmer Spine Inc
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Filing: 1994-06-30
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Granted: 1995-12-26
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Expires: 2014-06-30
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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 US
Data Source google_patents
Last Synchronized 2026-10-23 15:45
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: 3
Claim 1
Independent Claim 145 words
A reversible locking bone screw comprising: (a) a threaded shaft including a head at a proximal end for turning said screw, said screw including a cannula extending distally from said head into said threaded shaft; (b) a pair of opposing side openings formed through said threaded shaft to communicate with said cannula; (c) a spring wire shaped to define a vee having two spring ends normally spring-biased away from each other, each spring end of which may extend through said side openings; (d) said cannula including opposing spring guide grooves extending from said head to said side openings for guiding said spring ends to said side openings, said cannula extending from said head distally of said side openings such that said spring wire may be inserted past said side openings such that said spring wire ends may re-enter the cannula distally of the side openings.
Claim 2
Dependent Claim 145 words
A reversible locking bone screw comprising: (a) a threaded shaft including a head at a proximal end for turning said screw, said screw including a cannula extending distally from said head into said threaded shaft; (b) a pair of opposing side openings formed through said threaded shaft to communicate with said cannula; (c) a spring wire shaped to define a vee having two spring ends normally spring-biased away from each other, each spring end of which may extend through said side openings; (d) said cannula including opposing spring guide grooves extending from said head to said side openings for guiding said spring ends to said side openings, said cannula extending from said head distally of said side openings such that said spring wire may be inserted past said side openings such that said spring wire ends may re-enter the cannula distally of the side openings.
Claim 3
Dependent Claim 26 words
The reversible locking bone screw of claim 1 wherein said shaft includes a second pair of side openings spaced directly distally of said first side openings.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-12-25 1999-06-26 1999-12-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-12-25 2003-06-26 2003-12-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-12-25 2007-06-26 2007-12-26 $7700.00 Window Closed / Lapsed

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