U.S. patent number RE49,138 [Application Number 16/989,263] was granted by the patent office on 2022-07-19 for ratcheted spinal devices.
This patent grant is currently assigned to ApiFix Ltd.. The grantee listed for this patent is ApiFix Ltd.. Invention is credited to Uri Arnin.
United States Patent |
RE49,138 |
Arnin |
July 19, 2022 |
Ratcheted spinal devices
Abstract
A spinal device including a variable-length member including a
ratchet mechanism that has an operative configuration that allows a
change in length of the variable-length member in one direction and
prevents a change in length of the variable-length member in an
opposite direction, wherein the variable-length member includes
polyaxial-joint attachment members for attachment to bone, which
permit pivoting movement of the attachment members about more than
one pivoting axis, characterized by a force applicator operative to
adjust or advance the ratchet mechanism.
Inventors: |
Arnin; Uri (Kiryat Tivon,
IL) |
Applicant: |
Name |
City |
State |
Country |
Type |
ApiFix Ltd. |
Carmiel |
N/A |
IL |
|
|
Assignee: |
ApiFix Ltd. (Yokneam Ilit,
IL)
|
Family
ID: |
48782067 |
Appl.
No.: |
16/989,263 |
Filed: |
August 10, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14370963 |
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PCT/US2013/020453 |
Jan 7, 2013 |
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61743418 |
Sep 4, 2012 |
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61690835 |
Jul 6, 2012 |
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61631667 |
Jan 9, 2012 |
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Reissue of: |
15394855 |
Dec 30, 2016 |
9980751 |
May 29, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/7014 (20130101); A61B 17/02 (20130101); A61B
17/7001 (20130101); A61B 17/7076 (20130101); A61B
17/7014 (20130101); A61F 2/4455 (20130101); A61F
2/4425 (20130101) |
Current International
Class: |
A61B
17/70 (20060101); A61B 17/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reip; David O
Attorney, Agent or Firm: Roberts; Gerald W. Daniluck; John
V. Dentons Bingham Greenebaum LLP
Claims
What is claimed is:
1. A system comprising at least one spinal device, said at least
one spinal device comprising: a variable-length member comprising a
ratchet mechanism that has an operative configuration that allows a
change in length of said variable-length member in one direction
and prevents a change in length of said variable-length member in
an opposite direction, wherein said variable-length member
comprises polyaxial-joint attachment members for attachment to
bone, which permit pivoting movement of said attachment members
about more than one pivoting axis, and a force applicator operative
to adjust or advance said ratchet mechanism, wherein said force
applicator comprises a cam which has a tooth that engages a ratchet
rack of said ratchet mechanism, and wherein by turning said cam,
said tooth of said cam forcefully moves said ratchet rack so that a
tooth of said ratchet rack, in which a pawl of said ratchet
mechanism is engaged, moves out of engagement with said pawl and
another tooth of said ratchet rack moves into engagement with said
pawl.
2. The system according to claim 1, wherein said at least one
spinal device comprises a pair of said spinal devices and a
connector assembly that forms a jointed connection between said
pair of spinal devices that permits multiple degree-of-freedom
movement of said pair of spinal devices.
3. The system according to claim 2, further comprising a connector
assembly that forms a jointed connection between said
variable-length members that permits multiple degree-of-freedom
movement of said variable-length members.
4. The system according to claim 3, wherein said connector assembly
comprises a bolt which passes through a first hinge member and a
second hinge member adjacent said first hinge member, and pivot
pins that pivotally connect said spinal devices to said first hinge
member and said second hinge member.
5. The system according to claim 4, wherein said connector assembly
permits rotation about a longitudinal axis of said bolt, and
independently about a longitudinal axis of each pivot pin, which
are perpendicular to the longitudinal axis of said bolt.
6. The system according to claim 1, wherein said cam of said force
applicator comprises a head configured for turning with a tool.
Description
FIELD OF THE INVENTION
The present invention relates generally to spinal implants and
prostheses, and particularly to spinal implants having ratchet
mechanisms, such as a spinal implant with joints that permit
movement in different degrees of freedom, or a spinal implant with
a force applicator to control a ratchet mechanism.
BACKGROUND OF THE INVENTION
Scoliosis is a spinal deformity affecting many people. Current
surgical treatment involves affixing long fusion rods to the spine
by pedicle screws. The rod system is intended to force the deformed
spine into a more healthy position. Other spinal disorders which
are often treated by fusion include hyperkyphosis and
hyperlordosis.
As an alternative to fusion, PCT Patent Application
PCT/US2011/035278 of the same inventor describes improved spinal
devices that can be lengthened or shortened using a ratchet
mechanism. The devices have a variable-length member that can be
connected to standard pedicle screws as well as to other spinal
rods, using appropriate connectors.
SUMMARY OF THE INVENTION
The present invention seeks to provide further improved spinal
devices.
In one embodiment, the spinal device is in the form of a spinal rod
(the term rod, or rod assembly, refers to one or more elongate
components that together function as a rod and which do not
necessarily have a cylindrical shape but can also be bars and other
shapes) that can be lengthened or shortened using a ratchet
mechanism. The rod is a variable-length member that can be
connected to standard pedicle screws as well as to other spinal
rods, using appropriate connectors. The variable-length member can
also be directly connected to, or be supported by, bony elements of
the spine.
In one embodiment of the invention, the device can be set to three
different configurations:
a. Ratchet mechanism active and the variable-length member (rod)
can change in length (extend or contract) in one direction.
b. Ratchet mechanism not active and the variable-length member can
move in opposite directions corresponding to the extending and
contracting directions.
c. Locked position, wherein the length of the variable-length
member is fixed.
In an embodiment of the invention, the selection of these
configurations can be done by rotating an internal element of the
assembly. For example, the rotation of the internal element can be
done using a worm gear mechanism. The worm gear can be activated by
a shaft, through a percutaneous procedure or by an implantable
mechanism such as an electric motor, magnet arrangement or other
means known to those skilled in the art.
In another embodiment of the present invention, the variable-length
member can have two portions with different rigidity. For example,
the variable-length member can have a flexible portion (e.g., when
the ratchet is built such that the rod can be only shortened) like
a flexible cable, a rope, a flexible mechanical joint and other
means known to those skilled in the art.
In another embodiment of the invention, useful when the rod is
supported directly by bone structure of the spine, the hook holding
against the bone can have a second hook to fix it to the optimal
position.
BRIEF DESCRIPTION OF DRAWINGS
The present invention will be understood and appreciated more fully
from the following detailed description, taken in conjunction with
the drawings in which:
FIG. 1 is a simplified pictorial illustration of a ratcheted spinal
device, constructed and operative in accordance with a non-limiting
embodiment of the invention;
FIG. 2 is a simplified pictorial illustration of a ratchet
mechanism of the ratcheted spinal device of FIG. 1;
FIG. 3 is a simplified illustration of a force applicator that can
adjust or advance the ratchet mechanism of the ratcheted spinal
device of FIG. 1;
FIG. 4 is a simplified pictorial illustration of a spinal device,
including two rod assemblies that are connected between three
vertebrae with three bone screws, constructed and operative in
accordance with a non-limiting embodiment of the present invention,
wherein there are connector assemblies that permit multiple
degree-of-freedom movement;
FIG. 5 is a simplified top view illustration of one preferred
embodiment of the connector assembly, in accordance with an
embodiment of the present invention;
FIG. 6A is a simplified cross-sectional illustration of the
embodiment of FIG. 5; and
FIG. 6B is a simplified cross-sectional illustration of a modified
version of the embodiment of FIG. 5.
DETAILED DESCRIPTION OF EMBODIMENTS
Reference is now made to FIGS. 1-3, which illustrates a ratcheted
spinal device 10, constructed and operative in accordance with
another non-limiting embodiment of the invention.
The ratcheted spinal device 10 includes a variable-length member
12. In the illustrated embodiment, the variable-length member 12 is
a rod. The term "rod" encompasses any slender element of any size
and cross-sectional shape, such as but not limited to, a rod, bar,
wire and the like.
As similarly described in PCT Patent Application PCT/US2011/035278,
spinal device 10 includes a ratchet mechanism 14 (FIG. 2), which
has an operative configuration that allows a change in length of
variable-length member 12 in one direction and prevents a change in
length of the variable-length member 12 in an opposite direction.
Ratchet mechanism 14 has ratchet teeth 16 (FIG. 3; also called
ratchet rack 16) formed along an axial portion of variable-length
member 12, and a pawl 18 (FIGS. 2-3) arranged to catch on one of
the teeth 16. Pawl 18 extends from a controller element 20 (FIG. 2)
mounted about a pivot 22 (FIG. 2) and provided with an eccentric
cam 24 (FIGS. 2-3). Rotation of eccentric cam 24 moves pawl 18 to
one of three positions: a) in ratchet engagement with teeth 16 so
that variable-length member 12 can incrementally move in one
direction, b) in locked engagement with teeth 16 so that
variable-length member 12 cannot move at all, and c) moved out of
engagement with teeth 16 so that variable-length member 12 can move
in both directions freely.
As seen in FIG. 1, one end 23 of variable-length member 12 is
arranged to linearly move through an aperture 28 formed in a
housing 30. Variable-length member 12 includes two polyaxial-joint
attachment members 32. Both polyaxial-joint attachment members 32
are used to attach device 10 to available bone structure of the
spine.
In contradistinction to PCT Patent Application PCT/US2011/035278,
in the present invention, spinal device 10 includes a force
applicator 40 to control ratchet mechanism 14. Force applicator 40
includes, without limitation, a cam 42 which has a tooth 44 (FIG.
3). The head 46 of cam 42 is shown in FIG. 2 (e.g., hexagonal
head); head 46 is not shown for simplicity in FIG. 3. By turning
head 46 with a suitable tool, such as a wrench (not shown), in the
clockwise direction of FIG. 3, the tooth 44 of cam 42 forcefully
moves ratchet rack 16 (upwards in the sense of FIG. 3), so that the
tooth in which pawl 18 is engaged moves out of engagement with pawl
18 and the next lower tooth of ratchet rack 16 moves into
engagement with pawl 18. Accordingly, force applicator 40 adjusts
or advances the ratchet mechanism 14.
Reference is now made to FIG. 4, which illustrates a spinal device
50, in accordance with an embodiment of the present invention.
In the illustrated embodiment, spinal device 50 includes two rod
assemblies 52 that are connected between three vertebrae 49 with
three bone screws 54. The rod assemblies 52 may be constructed,
without limitation, as ratcheted spinal devices 10 or other spinal
devices. Connector assemblies 56 form jointed connections between
rod assemblies 52. Connector assemblies 56 permit multiple
degree-of-freedom movement of rod assemblies 52 (e.g.,
variable-length members 12), as will be explained below.
It is noted that any number of vertebrae can be selected, since the
design of the system is modular. It is also noted that the middle
jointed connection of the two rod assemblies 52 does not have to be
connected to any vertebra, meaning one or more vertebrae can be
skipped, depending on the application. In the drawing figure, bone
screws 54 are inserted in the pedicles, but other insertion
locations can be used.
Reference is now made to FIGS. 5 and 6A, which illustrate one
preferred embodiment of the connector assembly 56, in accordance
with an embodiment of the present invention.
Connector assembly 56 includes a bolt 58 (e.g., a central threaded
bolt) having a head 60, and which passes through a hole formed in a
first hinge member 62 and a second hinge member 64, which may lie
on top of, or be adjacent to, first hinge member 62. Each hinge
member is formed with a receiver 66 (FIG. 6A) for receiving therein
a pivot pin 68 (FIG. 5). One of the pivot pins 68 is pivotally
received in an end 70 of one of the rod assemblies 52, and the
other pivot pin 68 is pivotally received in an end 72 of another of
the rod assemblies 52 (FIG. 5). Thus adjacent rod assemblies 52 can
pivot with respect to one another by means of connector assembly
56. A locking element 74 (such as a nut) secures pins 68 in place
(FIG. 6A). Another locking element 76 (such as a nut) is threaded
on the end of threaded bolt 58 to complete the assembly (FIG.
6A).
FIG. 6B illustrates a variation of the embodiment of FIG. 6A. Like
elements are designated by like numerals. The main differences are
the shape of locking element 74 and the receiver 66 of the first
hinge member 62 has a closed aperture instead of the open aperture
of FIG. 6A. Other variations are also possible within the scope of
the invention.
Connector assemblies 56 permit multiple degree-of-freedom movement
of rod assemblies 52. Rotation is permissible about the
longitudinal axis of central threaded bolt 58, and independently
about the longitudinal axis of each pin 68, which are perpendicular
to the longitudinal axis of central threaded bolt 58.
* * * * *