U.S. patent application number 13/776479 was filed with the patent office on 2013-09-26 for triple lead bone screw.
The applicant listed for this patent is AMEDICA CORPORATION. Invention is credited to David Crook, Peter Harris, Chester Sharps.
Application Number | 20130253596 13/776479 |
Document ID | / |
Family ID | 43356770 |
Filed Date | 2013-09-26 |
United States Patent
Application |
20130253596 |
Kind Code |
A1 |
Crook; David ; et
al. |
September 26, 2013 |
TRIPLE LEAD BONE SCREW
Abstract
Pedicle screw assemblies and related bone screws. In some
embodiments, the bone screw may comprise a head portion and an
axial shaft. The axial shaft may comprise a threaded portion
comprising a triple lead thread disposed about the axial shaft. The
axial shaft may further comprise a tapering portion and a
non-tapering portion. The tapering portion may comprise multiple
tapering portions tapering at differing rates, and may be
positioned adjacent to a tip of the axial shaft. Each of the three
leads may extend coextensively along at least a majority of the
length of the axial shaft, the threaded portion, the tapering
portion, and/or the non-tapering portion.
Inventors: |
Crook; David; (Mineaola,
TX) ; Harris; Peter; (Boca Raton, FL) ;
Sharps; Chester; (Manakin-Sabot, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AMEDICA CORPORATION |
Salt Lake City |
UT |
US |
|
|
Family ID: |
43356770 |
Appl. No.: |
13/776479 |
Filed: |
February 25, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12818749 |
Jun 18, 2010 |
8382811 |
|
|
13776479 |
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61218574 |
Jun 19, 2009 |
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Current U.S.
Class: |
606/308 ;
606/315 |
Current CPC
Class: |
A61B 17/7037 20130101;
A61B 17/7032 20130101; A61B 17/863 20130101; A61B 17/8625
20130101 |
Class at
Publication: |
606/308 ;
606/315 |
International
Class: |
A61B 17/86 20060101
A61B017/86; A61B 17/70 20060101 A61B017/70 |
Claims
1. A pedicle screw assembly, comprising: a bone screw comprising a
head portion and a threaded portion, wherein the threaded portion
comprises an axial shaft and a triple lead thread disposed about
the axial shaft, wherein the axial shaft comprises a tapering
portion and a non-tapering portion, wherein the tapering portion is
positioned adjacent to a tip of the axial shaft, wherein the triple
lead thread comprises three distinct thread leads, wherein each of
the three leads terminates at a different point along a tapering
portion of the axial shaft, and wherein each of the three leads
extends coextensively along at least a majority of the length of
the threaded portion; and a rod retention member selectively
coupled to the head portion of the bone screw.
2. The pedicle screw assembly of claim 1, wherein the rod retention
member comprises a U-shaped member comprising a hole for receiving
the head portion of the bone screw.
3. The pedicle screw assembly of claim 2, wherein the head portion
is configured to be pivotably seated in the U-shaped member.
4. The pedicle screw assembly of claim 1, wherein each of the three
leads extends coextensively along at least substantially the entire
length of the threaded portion.
5. The pedicle screw assembly of claim 1, wherein the axial shaft
further comprises a second tapering portion.
6. The pedicle screw assembly of claim 5, wherein the second
tapering portion is positioned between the tapering portion and the
non-tapering portion.
7. The pedicle screw assembly of claim 6, wherein the tapering
portion tapers more steeply than the second tapering portion.
8. The pedicle screw assembly of claim 5, wherein at least one of
the three leads terminates at a point along the second tapering
section.
9. A bone screw, comprising: a head portion; and a threaded
portion, wherein the threaded portion comprises an axial shaft and
a triple lead thread disposed about the axial shaft, wherein the
axial shaft comprises a tapering portion and a non-tapering
portion, wherein the tapering portion is positioned adjacent to a
tip of the axial shaft, wherein the triple lead thread comprises
three distinct thread leads, wherein at least two of the three
leads terminate at a different points along the tapering portion of
the axial shaft, and wherein each of the three leads extends
coextensively along at least a majority of the length of the axial
shaft.
10. The bone screw of claim 9, wherein at least one of the three
thread leads comprises a biting surface.
11. The bone screw of claim 10, wherein each of the three thread
leads comprises a biting surface.
12. The bone screw of claim 10, wherein the biting surface
comprises a notch formed within the at least one of the three
thread leads.
13. The bone screw of claim 9, wherein the three thread leads start
with about 120 degrees of separation.
14. The bone screw of claim 9, wherein at least one of the three
thread leads originates at a different point along the threaded
portion than the other two thread leads.
15. The bone screw of claim 9, wherein the axial shaft further
comprises a reduced diameter portion, and wherein the reduced
diameter portion is positioned adjacent to the head portion.
16. The bone screw of claim 9, wherein the axial shaft further
comprises a second tapering portion.
17. The bone screw of claim 16, wherein the second tapering portion
is positioned between the tapering portion and the non-tapering
portion.
18. The bone screw of claim 16, wherein the tapering portion tapers
more steeply than the second tapering portion.
19. The bone screw of claim 9, wherein each of the three leads
terminates at a different point along the tapering portion of the
axial shaft.
20. A bone screw, comprising: a head portion; an axial shaft; and a
tip, wherein the axial shaft comprises a tapering portion and a
non-tapering portion, wherein the axial shaft further comprises a
triple lead thread disposed about the axial shaft, wherein the
triple lead thread comprises three distinct thread leads, wherein
the tapering portion is positioned adjacent to the tip, and wherein
each of the three leads extends coextensively along at least a
majority of the length of the non-tapering portion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of U.S. patent
application Ser. No. 12/818,749, filed on Jun. 18, 2010, and titled
"TRIPLE LEAD BONE SCREW," which claims the benefit of U.S.
Provisional Patent Application No. 61/218,574, filed on Jun. 19,
2009, and also titled "TRIPLE LEAD BONE SCREW." Both of the
aforementioned applications are incorporated by reference herein in
their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a triple lead
bone screw for use in surgical applications. More specifically, the
present invention relates to a triple lead bone screw for use in
spinal surgical applications, such as pedicle screw applications
and the like.
BACKGROUND OF THE INVENTION
[0003] Triple lead screws are used in a variety of applications,
including bone screw applications. These screws utilize three
thread starts/leads between the distal end (i.e. tip) of the screw
and the proximal end (i.e. head) of the screw. The three thread
starts are typically spaced apart by about 120 degrees. The screws
may be used to engage bone, or, more often, the triple lead portion
is used to engage an anatomical plate or other implant structure.
The advantage of triple lead screws relative to single or double
lead screws is that triple lead screws are advanced farther with
fewer turns, i.e. they are placed more quickly and with less
effort. The disadvantage of triple lead screws relative to single
or double lead screws is that triple lead screws typically have a
lower pullout or backout strength, i.e. they may become dislodged
more easily and with less effort.
[0004] What is still needed in the art is a triple lead pedicle
screw or the like that overcomes the above mentioned
disadvantage.
BRIEF SUMMARY OF THE INVENTION
[0005] In various exemplary embodiments, the present invention
provides a triple lead pedicle screw or the like that is capable of
being placed quickly with minimal effort and that resists pullout
or backout at least as effectively as comparable single or double
lead screws. This triple lead bone screw is ideally suited for the
surgical correction of spinal deformities and other similar
surgical procedures in which multiple screws must be placed. In
such surgical procedures, a surgeon may be come fatigued and time
is of the essence.
[0006] In one exemplary embodiment, the present invention provides
a pedicle screw assembly, including: a bone screw having a head
portion and a thread portion, wherein the thread portion includes
an axial shaft and a triple lead thread disposed about the axial
shaft; and a rod retention member selectively coupled to the head
portion of the bone screw. Optionally, the triple lead thread of
the thread portion of the bone screw includes leads that start with
about 120 degrees of separation. Optionally, the triple lead thread
of the thread portion of the bone screw includes leads that
originate at different points along the axial shaft of the thread
portion of the bone screw. Optionally, the triple lead thread of
the thread portion of the bone screw includes leads that terminate
at different points along the axial shaft of the thread portion of
the bone screw. Optionally, the axial shaft of the thread portion
of the bone screw includes a first tapering portion proximate a tip
of the axial shaft of the thread portion of the bone screw.
Optionally, the axial shaft of the thread portion of the bone screw
includes a second tapering portion proximate the tip of the axial
shaft of the thread portion of the bone screw. Preferably, the
second tapering portion tapers more steeply than the first tapering
portion. Optionally, the axial shaft of the thread portion of the
bone screw includes a reduced diameter portion proximate the head
portion of the bone screw. Optionally, the axial shaft of the
thread portion of the bone screw includes one or more tapering
portions proximate the head portion of the bone screw. Preferably,
the rod retention member is selectively pivotably coupled to the
head portion of the bone screw.
[0007] In another exemplary embodiment, the present invention
provides a bone screw, including: a head portion; and a thread
portion, wherein the thread portion includes an axial shaft and a
triple lead thread disposed about the axial shaft. Optionally, the
triple lead thread of the thread portion of the bone screw includes
leads that start with about 120 degrees of separation. Optionally,
the triple lead thread of the thread portion of the bone screw
includes leads that originate at different points along the axial
shaft of the thread portion of the bone screw. Optionally, the
triple lead thread of the thread portion of the bone screw includes
leads that terminate at different points along the axial shaft of
the thread portion of the bone screw. Optionally, the axial shaft
of the thread portion of the bone screw includes a first tapering
portion proximate a tip of the axial shaft of the thread portion of
the bone screw. Optionally, the axial shaft of the thread portion
of the bone screw includes a second tapering portion proximate the
tip of the axial shaft of the thread portion of the bone screw.
Preferably, the second tapering portion tapers more steeply than
the first tapering portion. Optionally, the axial shaft of the
thread portion of the bone screw includes a reduced diameter
portion proximate the head portion of the bone screw. Optionally,
the axial shaft of the thread portion of the bone screw includes
one or more tapering portions proximate the head portion of the
bone screw.
[0008] In a further exemplary embodiment, the present invention
provides a bone screw, including: a head portion; and a thread
portion, wherein the thread portion includes an axial shaft and a
triple lead thread disposed about the axial shaft, wherein the
axial shaft of the thread portion of the bone screw includes a
first tapering portion proximate a tip of the axial shaft of the
thread portion of the bone screw, and wherein the axial shaft of
the thread portion of the bone screw includes a second tapering
portion proximate the tip of the axial shaft of the thread portion
of the bone screw, wherein the second tapering portion tapers more
steeply than the first tapering portion. Optionally, the triple
lead thread of the thread portion of the bone screw includes leads
that originate at different points along the axial shaft of the
thread portion of the bone screw. Optionally, the triple lead
thread of the thread portion of the bone screw includes leads that
terminate at different points along the axial shaft of the thread
portion of the bone screw. Optionally, the axial shaft of the
thread portion of the bone screw includes a reduced diameter
portion proximate the head portion of the bone screw. Optionally,
the axial shaft of the thread portion of the bone screw includes
one or more tapering portions proximate the head portion of the
bone screw.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention is illustrated and described herein
with reference to the various drawings, in which like reference
numbers are used to denote like screw components, as appropriate,
and in which:
[0010] FIG. 1 is a planar side view of one exemplary embodiment of
the triple lead pedicle screw assembly of the present invention,
including the triple lead bone screw of the present invention and
an associated rod retention member;
[0011] FIG. 2 is a perspective view of the triple lead pedicle
screw assembly of FIG. 1;
[0012] FIG. 3 is a perspective view of one exemplary embodiment of
the bone screw of the present invention;
[0013] FIG. 4 is a planar side view of the bone screw of FIG.
3;
[0014] FIG. 5 is another planar side view of the bone screw of FIG.
3;
[0015] FIG. 6 is a perspective view of another exemplary embodiment
of the bone screw of the present invention;
[0016] FIG. 7 is a planar side view of the bone screw of FIG. 6;
and
[0017] FIG. 8 is another planar side view of the bone screw of FIG.
6.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Again, in various exemplary embodiments, the present
invention provides a triple lead pedicle screw or the like that is
capable of being placed quickly with minimal effort and that
resists pullout or backout at least as effectively as comparable
single or double lead screws. This triple lead bone screw is
ideally suited for the surgical correction of spinal
deformities/anomalies/trauma and other similar surgical procedures
in which multiple screws must be placed. In such surgical
procedures, a surgeon may be come fatigued and operative time is of
the essence.
[0019] Referring to FIGS. 1 and 2, in one exemplary embodiment, the
triple lead pedicle screw assembly 10 of the present invention
includes a triple lead bone screw 12 and a rod retention member
14.
[0020] The triple lead bone screw 12 includes a head portion 16 and
a threaded portion 18. The head portion 16 of the triple lead bone
screw 12 consists of an enlarged structure, such as a wholly or
partially spherical structure, a wholly or partially cylindrical
structure, or the like, having one or more tool receiving recesses
20 manufactured into the top surface thereof, by which the triple
lead bone screw 12 is grasped and/or turned. Optionally, three such
tool receiving recesses 20 are utilized and are spaced apart by
about 120 degrees, although it will be readily apparent to those of
ordinary skill in the art that other suitable configurations may be
utilized. The threaded portion 18 of the triple lead bone screw 12
consists of three thread starts/leads between the distal end (i.e.
tip) 22 of the screw 12 and the proximal end (i.e. head) 24 of the
screw 12. Optionally, the three thread starts are spaced apart by
about 120 degrees, although it will be readily apparent to those of
ordinary skill in the art that other suitable configurations may be
utilized. Optionally, the three thread starts/leads also originate
and/or terminate at different positions along the length of the
screw 12. In other words, the three thread starts/leads may or may
not coincide along the length of the screw 12 and may be spaced
apart by any desired constant or variable distance. Finally, one or
more of the three thread starts/leads may be selectively broken or
notched to create a biting surface, such as near the tip 22 of the
screw 12 so that the screw will advance into bone from the first
tum. Any suitable thickness, pitch, or other dimensions may be
utilized, as well as any suitable materials (e.g. a biocompatible
metal, ceramic, or plastic, bony material, etc.).
[0021] The rod retention member 14 consists of a U-shaped member 26
having a hole in the bottom. The threaded portion 18 of the bone
screw 12 is disposed through this hole, with the head portion 16 of
the bone screw being pivotably seated in the interior bottom of the
U-shaped member, prior to the screw 12 being driven into bone. The
rod retention member 14 includes a plurality of internally
threaded, concentrically arranged, vertically extending arm members
28 between which a stabilizing rod or other similar stabilizing
structure (not illustrated) is selectively disposed. This
stabilizing rod is then "locked" into place via the engagement of
an externally threaded cap (not illustrated) into the internal
threads of the arm members 28, thereby "locking" the orientation of
the rod retention member 14 with respect to the head portion 16 of
the triple lead bone screw 12, as the stabilizing rod is in direct
or indirect contact with the head portion 16 of the triple lead
bone screw 12. It will be readily apparent to those of ordinary
skill in the art that various other structures may also be disposed
between the stabilizing rod and either or both of the externally
threaded cap and the head portion 16 of the triple lead bone screw
12. In this manner, screws 12 may be placed in different anatomical
structures, or different parts of the same anatomical structure,
and securely joined by stabilizing structures in a predetermined
configuration and alignment.
[0022] Referring to FIGS. 3-5, in one exemplary embodiment, the
triple lead bone screw 12 of the present invention includes a head
portion 16 and a threaded portion 18. The head portion 16 of the
triple lead bone screw 12 consists of an enlarged structure, such
as a wholly or partially spherical structure, a wholly or partially
cylindrical structure, or the like, having one or more tool
receiving recesses 20 manufactured into the top surface thereof, by
which the triple lead bone screw 12 is grasped and/or turned.
Optionally, three such tool receiving recesses 20 are utilized and
are spaced apart by about 120 degrees, although it will be readily
apparent to those of ordinary skill in the art that other suitable
configurations may be utilized. The threaded portion 18 of the
triple lead bone screw 12 consists of three thread starts/leads
between the distal end (i.e. tip) 22 of the screw 12 and the
proximal end (i.e. head) 24 of the screw 12. Optionally, the three
thread starts are spaced apart by about 120 degrees, although it
will be readily apparent to those of ordinary skill in the art that
other suitable configurations may be utilized. Optionally, the
three thread starts/leads also originate and/or terminate at
different positions along the length of the screw 12. In other
words, the three thread starts/leads may or may not coincide along
the length of the screw 12 and may be spaced apart by any desired
constant or variable distance. Finally, one or more of the three
thread starts/leads may be selectively broken or notched to create
a biting surface, such as near the tip 22 of the screw 12 so that
the screw will advance into bone from the first tum. Any suitable
thickness, pitch, or other dimensions may be utilized, as well as
any suitable materials (e.g. a biocompatible metal, ceramic, or
plastic, bony material, etc.).
[0023] Referring specifically to FIG. 5, the threaded portion 18 of
the screw 12 includes an axial shaft 30 that may have a
non-tapering portion 32, a first tapering portion 34, and a second
tapering portion 36 disposed, in order, between the head portion 16
of the screw 12 and the rounded or pointed tip 38 of the screw 12.
Preferably, the taper of the second tapering portion 36 is greater
than the taper of the first tapering portion 34, with the second
tapering portion sweeping a 45-degree arc, a 60-degree arc, etc.
The threads are disposed about these various segments of the screw
12.
[0024] Referring to FIGS. 6-8, in another exemplary embodiment, the
triple lead bone screw 12 of the present invention includes a head
portion 16 and a threaded portion 18. The head portion 16 of the
triple lead bone screw 12 consists of an enlarged structure, such
as a wholly or partially spherical structure, a wholly or partially
cylindrical structure, or the like, having one or more tool
receiving recesses 20 manufactured into the top surface thereof, by
which the triple lead bone screw 12 is grasped and/or turned.
Optionally, three such tool receiving recesses 20 are utilized and
are spaced apart by about 120 degrees, although it will be readily
apparent to those of ordinary skill in the art that other suitable
configurations may be utilized. The threaded portion 18 of the
triple lead bone screw 12 consists of three thread starts/leads
between the distal end (i.e. tip) 22 of the screw 12 and the
proximal end (i.e. head) 24 of the screw 12. Optionally, the three
thread starts are spaced apart by about 120 degrees, although it
will be readily apparent to those of ordinary skill in the art that
other suitable configurations may be utilized. Optionally, the
three thread starts/leads also originate and/or terminate at
different positions along the length of the screw 12. In other
words, the three thread starts/leads may or may not coincide along
the length of the screw 12 and may be spaced apart by any desired
constant or variable distance. Finally, one or more of the three
thread starts/leads may be selectively broken or notched to create
a biting surface, such as near the tip 22 of the screw 12 so that
the screw will advance into bone from the first tum. Any suitable
thickness, pitch, or other dimensions may be utilized, as well as
any suitable materials (e.g. a biocompatible metal, ceramic, or
plastic, bony material, etc.).
[0025] Referring specifically to FIG. 8, the threaded portion 18 of
the screw 12 includes an axial shaft 30 that may have a
non-tapering portion 32, a first tapering portion 34, and a second
tapering portion 36 disposed, in order, between the head portion 16
of the screw 12 and the rounded or pointed tip 38 of the screw 12.
Preferably, the taper of the second tapering portion 36 is greater
than the taper of the first tapering portion 34, with the second
tapering portion sweeping a 45-degree arc, a 60-degree arc, etc.
The threads are disposed about these various segments of the screw
12. In this exemplary embodiment, a reduced diameter portion 40 and
one or more tapering portions 42 are also disposed along the axial
shaft 30 between the head portion 16 and the threaded portion 18 of
the screw 12.
[0026] Axial pullout testing of the triple lead bone screw 12 of
the present invention demonstrated performance comparable to that
of a conventional single lead bone screw.
[0027] Although the present invention has been illustrated and
described herein with reference to preferred embodiments and
specific examples thereof, it will be readily apparent to those of
ordinary skill in the art that other embodiments and examples may
perform similar functions and/or achieve like results. All such
equivalent embodiments and examples are within the spirit and scope
of the present invention, are contemplated thereby, and are
intended to be covered by the following claims.
* * * * *