U.S. patent number RE48,250 [Application Number 16/545,644] was granted by the patent office on 2020-10-13 for rod reducer, compressor, distractor system.
This patent grant is currently assigned to K2M, Inc.. The grantee listed for this patent is K2M, Inc.. Invention is credited to Clint Boyd, Larry E. McClintock.
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United States Patent |
RE48,250 |
McClintock , et al. |
October 13, 2020 |
Rod reducer, compressor, distractor system
Abstract
A compressor/distractor system for operating on a spine is
disclosed. The system includes two rod reducers which each advance
a spinal rod into the shoulder portion of a pedicle screw. Each rod
reducer includes an inner member, an outer member, and a pair of
gripping members. Each outer member receives and advances the
spinal rod into the pedicle screw. The outer member also includes a
through slot which receives the proximal end of each of the pair of
gripping members which may limit the longitudinal translation of
the outer member with respect to the inner member. The
compressor/distractor system may include a compressor/distractor
device which has a compressing, a distracting, and a neutral
configuration. A method for using the minimally invasive rod
reducers with the compressor/distractor system to secure at least
two pedicle screws in desired positions on a spinal rod is also
disclosed.
Inventors: |
McClintock; Larry E. (Gore,
VA), Boyd; Clint (Winchester, VA) |
Applicant: |
Name |
City |
State |
Country |
Type |
K2M, Inc. |
Leesburg |
VA |
US |
|
|
Assignee: |
K2M, Inc. (Leesburg,
VA)
|
Family
ID: |
48780504 |
Appl.
No.: |
16/545,644 |
Filed: |
August 20, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
13741934 |
Sep 8, 2015 |
9125703 |
|
|
|
61586928 |
Jan 16, 2012 |
|
|
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Reissue of: |
14828909 |
Aug 18, 2015 |
9737351 |
Aug 22, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/7086 (20130101); A61B 17/7077 (20130101); A61B
17/7079 (20130101); A61B 17/708 (20130101); A61B
17/88 (20130101); A61B 17/88 (20130101); A61B
17/7085 (20130101); A61B 17/7079 (20130101); A61B
17/708 (20130101); A61B 17/7085 (20130101); A61B
17/7086 (20130101) |
Current International
Class: |
A61B
17/88 (20060101); A61B 17/70 (20060101) |
References Cited
[Referenced By]
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Other References
Charles Hartjen; The Atavi System, Surgical Technique Brochure.
Endius, p. 1-17, undated. cited by applicant .
Diapason, Surgical Texchnique Catalog, Diapasan Spinal System, Jan.
2002. cited by applicant .
Kambin et al, "Percutaneous Posterolateral Lumbar Discectomy and
Decompression with a 6.9-millimeter cannula", The Journal of Bone
and Joint Surgery, pp. 822-831, Jul. 1991. cited by applicant .
Kambin, Minimally Invasive Techniques in Spinal Surgery Current
Practice, Neurosurgical Focus, wwwspineuniversecom, 16 pages,
printed Aug. 24, 2005. cited by applicant .
Leu et al., Percutaneous Fusion of the Lumbar Spine, State of the
Art Reviews, vol. 6, No. 3, pp. 593-604, Sep. 1992. cited by
applicant .
Pathfinder; Minimally Invasive Pedicie Fixation System. Spinal
Concepts Product Brochure p. 1-4, May 2003. cited by
applicant.
|
Primary Examiner: Reip; David O
Attorney, Agent or Firm: Lerner, David, Littenberg, Krumholz
& Mentlik, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is .Iadd.an application for the reissue of
U.S. Pat. No. 9,737,351, which is .Iaddend.a divisional of U.S.
patent application Ser. No. 13/741,934, filed .[.Jun..]. .Iadd.Jan.
.Iaddend.15, 2013, which claims the benefit of, and priority to,
U.S. Provisional Application Ser. No. 61/586,928, filed on Jan. 16,
2012. The entire contents of each of the above applications are
incorporated herein by reference.
Claims
What is claimed:
1. A method for manipulating vertebrae comprising: accessing the
spinal area of a patient having a pedicle screw secured to each of
at least two vertebrae; engaging each pedicle screw with an inner
member having distal and proximal ends defining a longitudinal axis
therebetween, the distal end of each inner member receiving a head
of the pedicle screw; advancing an outer member having distal and
proximal ends distally along each of the inner members by rotating
the proximal end of each of the outer members relative to each
inner member, a pair of receiving slots on the distal end of each
outer member receiving a portion of a spinal rod, each pair of
receiving slots advancing the spinal rod into a saddle portion of
the head of each pedicle screw; attaching a force applying device
and a fulcrum to an outer surface of each outer member, the force
applying device including first and second hook members and having
a compressing configuration when the first and second hook members
are attached to each outer member with each of the outer members
between the first and second hook members and a distracting
configuration when the first and second hook members are attached
to each outer member with the first and second hook members between
each of the outer members; manipulating each outer member with the
force applying device until each of the pedicle screws is in a
desired position with respect to the spinal rod; and securing each
pedicle screw to the spinal rod with a set screw.
2. The method of claim 1, wherein the force applying device further
includes a neutral configuration and the second hook member
includes a switch assembly having a first, a second, and a third
position, each position corresponding to a configuration of the
force applying device.
3. The method of claim 1, wherein the first and second hook members
each include a hook portion, each hook portion having a compressing
hook and a distracting hook.
4. The method of claim 1, wherein the fulcrum is attached to a
gripping portion of each outer member.
5. The method of claim 1, wherein the step of advancing further
includes attaching an anti-torque handle to a distal segment of
each outer member and attaching a turning handle to a proximal
segment of each outer member.
6. The method of claim 1, wherein the method further includes the
step of inserting at least one set screw through an inner member
and at least partially locking the rod to at least one of the
pedicle screws before the step of manipulating the each outer
member.
7. A method for manipulating vertebrae comprising: securing a first
elongate member to a first pedicle screw that is secured in a first
vertebra; securing a second elongate member to a second pedicle
screw that is secured in a second vertebra; and manipulating the
first and second elongate members with a force applying device
until the first and second pedicle screws are in a desired
position, the force applying device having first and second hook
members, each hook member having a distracting hook and a
compressing hook.
8. The method according .[.of.]. .Iadd.to .Iaddend.claim 7, wherein
manipulating the first and second elongate members with the force
applying device includes positioning the first and second elongate
members between the first and second hook members of the force
applying device to compress the first and second elongate members
towards one another.
9. The method according .[.of.]. .Iadd.to .Iaddend.claim 7, wherein
manipulating the first and second elongate members with the force
applying device includes positioning the first and second hook
members of the force applying device between the first and second
elongate members to distract the first and second elongate members
away from one another.
10. The method according .[.of.]. .Iadd.to .Iaddend.claim 7,
further comprising positioning a fulcrum over a .[.distal.].
.Iadd.proximal .Iaddend.end of each of the first and second
elongate members before manipulating the first and second elongate
members with the force applying device.
11. The method according to claim 10, wherein manipulating the
elongate members with the force applying device includes engaging
the first elongate member with the first hook member between the
fulcrum and the pedicle screw and engaging the second elongate
member with the second hook member between the fulcrum and the
pedicle screw.
12. The method according .[.of.]. .Iadd.to .Iaddend.claim 7,
further comprising: reducing a spinal rod into a head of the first
pedicle screw with the first elongate member; and reducing the
spinal rod into a head of the second pedicle screw with the second
elongate member.
13. A method for manipulating vertebrae comprising: securing a
first elongate member to a first pedicle screw that is secured in a
first vertebra; securing a second elongate member to a second
pedicle screw that is secured in a second vertebra; and
manipulating the first and second elongate members with a force
applying device until the first and second pedicle screws are in a
desired position, the force applying device having a compressing
configuration, a distracting configuration, and a neutral
configuration and including two hook members, at least one of the
two hook members including switch assembly for selecting a
respective one of the compressing, distracting, and neutral
configurations, the switch assembly defining detents which each
correspond to a respective one of the compressing, distracting, and
neutral configurations of the force applying device.
.Iadd.14. The method according to claim 10, wherein positioning the
fulcrum over the proximal end of each of the first and second
elongate members comprises positioning each of the first and second
elongate members in a respective through hole of a plurality of
through holes extending through the fulcrum..Iaddend.
.Iadd.15. The method according to claim 14, wherein the plurality
of through holes extending through the fulcrum includes multiple
through holes for each of the first and second elongate members,
the through holes being spaced apart from one another such that
each of the first and second elongate members can be selectively
received within different ones of the multiple through holes, so as
to thereby define a variable spacing between the first and second
elongate members at a location where the fulcrum receives the first
and second elongate members..Iaddend.
.Iadd.16. The method according to claim 15, wherein the plurality
of first and second through holes are aligned along an axis of the
fulcrum, the through holes being spaced apart along the
axis..Iaddend.
.Iadd.17. The method according to claim 14, wherein each of the
plurality of through holes includes a bearing ring received within
the respective through hole..Iaddend.
.Iadd.18. The method of claim 1, wherein the fulcrum includes a
plurality of through holes configured to receive each of the outer
members therein..Iaddend.
.Iadd.19. The method of claim 18, wherein the plurality of through
holes in the fulcrum includes multiple through holes for each of
the outer members, the through holes being spaced apart from one
another such that each outer member can be selectively received
within different ones of the multiple through holes, so as to
thereby define a variable spacing between the outer members at a
location where the fulcrum receives the outer members..Iaddend.
.Iadd.20. The method of claim 19, wherein the plurality of through
holes are aligned along an axis of the fulcrum, the through holes
being spaced apart along the axis..Iaddend.
.Iadd.21. The method of claim 18, wherein each of the plurality of
through holes includes a bearing ring received within the
respective through hole..Iaddend.
.Iadd.22. The method of claim 13, further comprising engaging the
first and second elongate members with a fulcrum by positioning
each of the first and second elongate members in a respective
through hole of a plurality of through holes extending through the
fulcrum..Iaddend.
.Iadd.23. The method of claim 22, wherein the plurality of through
holes extending through the fulcrum includes multiple through holes
for each of the first and second elongate members, the through
holes being spaced apart from one another such that each of the
first and second elongate members can be selectively received
within different ones of the multiple through holes, so as to
thereby define a variable spacing between the first and second
elongate members at a location where the fulcrum receives the first
and second elongate members..Iaddend.
.Iadd.24. The method of claim 23, wherein the plurality of first
and second through holes are aligned along an axis of the fulcrum,
the through holes being spaced apart along the axis..Iaddend.
.Iadd.25. The method of claim 22, wherein each of the plurality of
through holes includes a bearing ring received within the
respective through hole..Iaddend.
.Iadd.26. A method for manipulating vertebrae comprising: securing
a first elongate member to a first pedicle screw that is secured in
a first vertebra; securing a second elongate member to a second
pedicle screw that is secured in a second vertebra; selecting a
selected spacing from a plurality of different possible spacings
provided by a fulcrum having a plurality of receptacles configured
to receive the first and second elongate members therein, the
spacings each being characterized by a length dimension defined
between any first one of the receptacles and any second one of the
receptacles, such that the selected spacing is defined by the
length dimension between a selected first one of the receptacles
and a selected second one of the receptacles; engaging the first
and second elongate members with the fulcrum by receiving the first
elongate member within the selected first one of the receptacles
and receiving the second elongate member within the selected second
one of the receptacles so as to fix a distance between the first
and second elongate members at a fulcrum location along the first
and second elongate members, the distance being the length
dimension defined between the selected first one of the receptacles
and the selected second one of the receptacles; and applying
compression and/or distraction forces to the first and second
elongate members while the fulcrum fixes the distance between the
first and second elongate members at the fulcrum
location..Iaddend.
.Iadd.27. The method of claim 26, wherein the first and second
receptacles are through holes extending through the
fulcrum..Iaddend.
.Iadd.28. The method of claim 26, wherein the plurality of first
and second receptacles are aligned along an axis of the fulcrum,
the receptacles being spaced apart along the axis..Iaddend.
.Iadd.29. The method of claim 26, wherein each of the plurality of
first and second receptacles includes a bearing ring received
therein..Iaddend.
.Iadd.30. The method of claim 26, wherein each of the first and
second elongate members is a rod reducer..Iaddend.
.Iadd.31. The method of claim 26, wherein each of the plurality of
different possible spacings provided by the fulcrum corresponds to
a different respective angle defined between the first and second
elongate members when the first and second elongate members are
secured to the respective first and second pedicle screws and when
the first and second members are engaged with the fulcrum at the
fulcrum location..Iaddend.
.Iadd.32. The method of claim 26, wherein the step of applying
compression and/or distraction forces to the first and second
elongate members comprises engaging a force applying device to the
first and second elongate members, the force applying device being
engageable to a plurality of force applying locations on each of
the first and second elongate members..Iaddend.
.Iadd.33. The method of claim 32, wherein the step of engaging the
force applying device to the first and second elongate members
comprises engaging the force applying device to the first and
second elongate members at a selected one of the force applying
locations, the selected force applying location being between the
fulcrum and the first and second pedicle screws..Iaddend.
.Iadd.34. The method of claim 26, wherein the fulcrum is engageable
with the first and second elongate members by receiving the first
and second elongate members at a variety of different fulcrum
locations along a respective portion of each of the first and
second elongate members..Iaddend.
Description
BACKGROUND
Technical Field
The present disclosure relates to a system and method for operating
on the spine. More particularly, the present disclosure relates to
a minimally invasive rod reducer, compressor/distractor system, and
a method for using the compressor/distractor system to deliver a
spinal rod to the head of a pedicle screw.
Background of Related Art
The spinal column is a complex system of bones and connective
tissues that provide support for the human body and protection for
the spinal cord and nerves. The adult spine is comprised of an
upper and lower portion. The upper portion contains 24 discrete
bones, which are subdivided into three areas including 7 cervical
vertebrae, 12 thoracic vertebrae and 5 lumbar vertebrae. The lower
portion is comprised of the sacral and coccygeal bones. The
cylindrical shaped bones, called vertebral bodies, progressively
increase in size from the upper portion downwards to the lower
portion.
An intervertebral disc along with two posterior facet joints
cushion and dampen the various translational and rotational forces
exerted upon the spinal column. The intervertebral disc is a spacer
located between two vertebral bodies. The facets provide stability
to the posterior portion of adjacent vertebrae. The spinal cord is
housed in the canal of the vertebral bodies. It is protected
posteriorly by the lamina. The lamina is a curved surface with
three main protrusions. Two transverse processes extend laterally
from the lamina, while the spinous process extends caudally and
posteriorly. The vertebral bodies and lamina are connected by a
bone bridge called the pedicle.
The spine is a flexible structure capable of a large range of
motion. There are various disorders, diseases, and types of injury
which restrict the range of motion of the spine or interfere with
important elements of the nervous system. The problems include, but
are not limited to scoliosis, kyphosis, excessive lordosis,
spondylolisthesis, slipped or ruptured discs, degenerative disc
disease, vertebral body fracture, and tumors. Persons suffering
from any of the above conditions typically experience extreme or
debilitating pain and often times diminished nerve function. These
conditions and their treatments can be further complicated if the
patient is suffering from osteoporosis, or bone tissue thinning and
loss of bone density.
Spinal fixation apparatuses are widely employed in surgical
processes for correcting spinal injuries and diseases. When the
disc has degenerated to the point of requiring removal, there are a
variety of interbody implants that are utilized to take the place
of the disc. These include polyetheretherketone ("PEEK") interbody
spacers, metal cages, and cadaver and human bone implants. In order
to facilitate stabilizing the spine and keeping the interbody in
position, other implants are commonly employed, including
longitudinally linked rods secured to coupling elements, which in
turn are secured to the bone by spinal bone fixation fasteners such
as pedicle screws, hooks, and others. The opposing pair of
longitudinally linked rods is commonly disposed along the long axis
of the spine via a posterior approach. Pedicle screws are utilized
to capture these rods and can be manufactured from any
biocompatible material, including cobalt chrome, stainless steel,
titanium, and PEEK. It is desired to perform these procedures in a
minimally invasive manner to minimize pain and reduce recovery time
for the patient. Therefore, a need exists for a minimally invasive
rod reducer, compressor, distractor system that can deliver the rod
into the head of the pedicle screw or bone anchor while maintaining
the proper screw and rod construct alignment.
A rod reducer that is small enough in diameter to work with a
minimally invasive retractor, such as the rod reducer disclosed in
U.S. Patent Publication No. 2013/0046345, the contents of which are
hereby incorporated by reference in their entirety and a minimally
invasive retractor, such as the minimally invasive retractor
disclosed in U.S. Pat. No. 7,846,093, the contents of which are
hereby incorporated by reference in their entirety, are also
disclosed.
SUMMARY
The present disclosure is directed towards a system for operating
on the spine. The system includes pedicle screws, rod reducers, and
a force applying device.
According to one aspect, the rod reducers include a proximal end
and a distal end and define a longitudinal axis between the
proximal and distal ends. The rod reducer includes an outer member
and an inner member. The inner member is selectively attachable to
the housing of the pedicle screw. The outer member is axially
movable relative to the inner member when the inner member is
secured to the housing of the pedicle screw to secure the spinal
rod within the saddle of the housing of the pedicle screw. The
outer member includes a proximal segment and a distal segment. The
proximal segment is rotatable for axially translating the distal
segment. The distal segment is engageable with the spinal rod to
secure the spinal rod within the saddle upon the axial translation
of the distal segment. The proximal segment independently rotates
relative to the distal segment. The rod reducer includes a pair of
gripping members configured to engage the housing of the pedicle
screw. The pair of gripping members is positioned between the inner
and outer members of the rod reducer.
The handle assembly is selectively engageable with the rod reducer
to move the outer member of the rod reducer axially relative to the
inner member of the rod reducer. The handle assembly is configured
to rotate the outer member so that the rotational movement of the
outer member axially moves the outer member relative to the inner
member. The handle assembly includes a turning handle and an
anti-torque handle. The anti-torque handle is selectively
engageable with the proximal end of the rod reducer and the turning
handle is selectively engageable with a proximal end of the
anti-torque handle.
In another aspect, an embodiment of the system includes two rod
reducers, a force applying device, and a fulcrum. The force
applying device is configured for selectively engaging each rod
reducer. The system may also include at least one minimally
invasive retraction device.
In yet another aspect, the force applying device is a
compressor/distractor device including a first hook member, a
second hook member, and a body portion. The body portion has a
first end and a track extending from the first end. The first end
includes the first hook member in a fixed position. The first end
may slidably receive the first hook member in a fixed position. The
track includes a set of teeth and is configured for slidably
receiving the second hook member.
The second hook member includes a switch assembly and a gear
assembly. The second hook member traverses the track when the gear
assembly is rotated. The gear assembly may also retain the second
hook member within the track. The switch assembly permits the
second hook member to traverse the track in a desired direction,
towards the first hook member or away from the first hook member.
The switch assembly may also restrain the second hook member from
traversing the track in an undesired direction.
The first and second hook members may be configured in a
compressing configuration to engage the two rod reducers such that
rod reducers are between the hook members. The first and second
hook members may also be configured in a distracting configuration
to engage the rod reducers such that the hook members are between
the rod reducers.
The fulcrum is configured to receive the proximal segment of the
outer member of each rod reducer and remain in a fixed position on
the longitudinal axis of each rod reducer.
According to still another aspect, a method for compressing or
distracting vertebrae including two minimally invasive rod
reducers, a compressor/distractor system, a spinal rod, and two
pedicle screws. The method includes the steps of accessing the
spinal area of a patient having at least two pedicle screws secured
to respective vertebrae, engaging each pedicle screw with a rod
reducer, advancing the spinal rod into the head of each pedicle
screw, attaching a compressor/distractor device to each rod
reducer, inserting a set screw through each rod reducer,
manipulating the compressor/distractor device, and securing the
spinal rod to each pedicle screw.
The method may also include the step of attaching a fulcrum to the
proximal segment of each outer member before rotating the gear
assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute
a part of this specification, illustrate embodiments of the
disclosure and, together with a general description of the
disclosure given above, and the detailed description of the
embodiments given below, serve to explain the principles of the
disclosure, wherein:
FIG. 1A is a perspective view of a minimally invasive rod reducer
in accordance with the principles of the present disclosure before
engagement with a rod and a pedicle screw;
FIG. 1B is a perspective view of the rod reducer of FIG. 1A after
initial engagement of the rod and pedicle screw;
FIG. 1C is a perspective view of the rod reducer of FIG. 1B after
the rod has been received by the shoulder portion of the pedicle
screw
FIG. 2 is a perspective view of the outer member of FIG. 1A;
FIG. 3 is a exploded view of the outer member of FIG. 2;
FIG. 4 is a bottom cross-sectional view of the outer member of FIG.
2 taken along the section line 4-4;
FIG. 5 is an exploded view of the rod reducer of FIG. 1A;
FIG. 6 is a side cross-sectional view of the of the rod reducer of
FIG. 1A;
FIG. 6A is an enlarged view of the detail area 6A of FIG. 6;
FIG. 7A is a perspective view of the outer member of FIG. 2 engaged
with a turning handle and an anti-torque handle;
FIG. 7B is an exploded view of FIG. 7A;
FIG. 8 is a perspective view of an embodiment of a
compressor/distractor system in accordance with the principles of
the present disclosure in a compressing configuration;
FIG. 9 is a perspective view of the compressor/distractor system of
FIG. 8 in a distracting configuration;
FIG. 10A is a perspective view of another embodiment of a
compressor/distractor system in accordance with the principles of
the present disclosure in a compressing configuration;
FIG. 10B is a perspective view of the compressor/distractor system
of FIG. 10A in a distracting configuration;
FIG. 11 is a perspective view of the fulcrum of FIG. 9;
FIG. 11A is an exploded view of the fulcrum of FIG. 11;
FIG. 11B is a top view of the fulcrum of FIG. 11;
FIG. 11C is a side cross-sectional view of the fulcrum taken along
the section line 11C-11C in FIG. 11B;
FIG. 12 is an enlarged view of the compressor/distractor device of
FIG. 9;
FIG. 13 is a top view of the compressor/distractor device of FIG.
12; and
FIG. 14 is an exploded view of the compressor/distractor device of
FIG. 12.
DETAILED DESCRIPTION OF THE DRAWINGS
Particular embodiments of the present disclosure will be described
herein with reference to the accompanying drawings. As shown in the
drawings and as described throughout the following description, and
as is traditional when referring to relative positioning on an
object, the terms "proximal" and "trailing" may be employed
interchangeably, and should be understood as referring to the
portion of a structure that is closer to a clinician during proper
use. The terms "distal" and "leading" may also be employed
interchangeably, and should be understood as referring to the
portion of a structure that is farther from the clinician during
proper use. In addition, the term "cephalad" or "cranial" is used
in this application to indicate a direction toward a patient's
head, whereas the term "caudad" indicates a direction toward the
patient's feet. Further still, the term "medial" indicates a
direction toward the middle of the body of the patient, whilst the
term "lateral" indicates a direction toward a side of the body of
the patient (i.e., away from the middle of the body of the
patient). The term "posterior" indicates a direction toward the
patient's back, and the term "anterior" indicates a direction
toward the patient's front. In the following description,
well-known functions or constructions are not described in detail
to avoid obscuring the present disclosure in unnecessary
detail.
Turning now to FIGS. 2-6A, a rod reducer 10 includes an outer
member 20, an inner member 30, and a pair of gripping members 40,
such as the rod reducer disclosed in U.S. patent application Ser.
No. 13/595,533 which is incorporated by reference. Outer member 20
includes a proximal segment 21, a distal segment 22, and a ring
member 27 that is disposed between proximal and distal segments 21,
22. Proximal segment 21 includes an engaging portion 21a at a
distal end of proximal segment 21 and a gripping portion 21b at a
proximal end of proximal segment 21. An inner surface 28 of
proximal segment 21 is threaded. Distal segment 22 defines a slot
26 therethrough and includes a reducing portion 22a at a distal end
of distal segment 22 and a receiving portion 22b at a proximal end
of distal segment 22. Receiving portion 22b includes a plurality of
gripping features 22c on an outer surface of receiving portion 22b.
A pair of rod engaging slots 25 and a pair of gripping member
receiving slots 24 are defined through reducing portion 22a.
Receiving portion 22b of distal segment 22 is configured to receive
engaging portion 21a of proximal segment 21 so that ring member 27
is disposed between proximal and distal segments 21, 22. The
components of outer member 20 may be integrally formed or
assembled.
Inner member 30 includes an elongate body member 39 that defines an
annular recess 33 configured to receive the pair of gripping
members 40 so that the gripping members 40 are disposed in
opposition on the elongate body member 39. Inner member 30 includes
a pair of arms 32 supported on a distal end of elongate body member
39. A proximal end of elongate body member 39 has a threaded
arrangement 38 that mates with threaded inner surface 28 of
proximal segment 21 of outer member 20 to axially advance outer
member 20 relative to inner member 30 as will be described in
greater detail below.
Each gripping member 40 includes a body 47 having a supporting
member 43, a proximal finger 46, and a distal finger 45. Supporting
member 43 is configured to engage annular recess 33 of inner member
30 to support body 47 of each gripping member 40 on inner member
30. Proximal finger 46 extends proximally from supporting member 43
and is slidably positionable within slot 26 of outer member 20.
Distal finger 45 extends distally from supporting member 43 and is
positionable between an arm 32 of inner member 30 and reducing
portion 22a of outer member 20 so that distal finger 45 is
substantially aligned with a gripping member receiving slot 24 of
reducing portion 22a.
As illustrated in FIGS. 1A-1C, outer member 20 of rod reducer 10 is
disposed in a proximal position relative to inner member 30 of rod
reducer 10, distal fingers 45 of gripping member 40 of rod reducer
10 are secured to an outer surface of pedicle screw head 910.
Proximal segment 21 of outer member 20 may then be rotated by
virtue of the threaded arrangement between outer member 20 and
inner member 30 for axially advancing distal segment 22 of outer
member 20 relative to inner member 30 and proximal segment 21.
Proximal segment 21 remains axially fixed when rotated. Notably, as
proximal segment 21 rotates, distal segment 22 remains radially
fixed as distal segment 22 axially translates relative to inner
member 30 and proximal segment 21. Outer member 20 approximates a
spinal rod 800 positioned between rod reducer 10 and pedicle screw
900 as outer member 20 is advanced toward pedicle screw 900 to
secure spinal rod 800 within a saddle 912 of pedicle screw 900. As
outer member 20 advances distally, a proximal end of slot 26 of
outer member 20 approximates a proximal end of proximal fingers 46
of gripping member 40.
Turning now to FIGS. 7A and 7B, a rod reducer and handle assembly
650 includes the rod reducer 10 and a handle assembly 652. Handle
assembly 652 includes a turning handle 600 and an anti-torque
handle 700 that are selectively connectable to gripping portion 21b
and gripping features 22c respectively on rod reducer 10. Turning
handle 600 includes a shaft 610, a handle 620, and a socket 630
that defines an opening 632. Opening 632 is configured to receive a
proximal end of gripping portion 21b of rod reducer 10. Handle 620
is secured to a proximal end of shaft 610 and a socket 630 that may
be integrally formed is secured to a distal end of shaft 610.
Anti-torque handle 700 includes a shaft 720 and a handle 710 that
may be integrally formed. Shaft 720 includes a socket 722 that
defines an opening 722a at a distal end of socket 722. Opening 722a
is disposed in communication with a lumen 725 defined within shaft
720 and another opening 724 disposed at a proximal end of shaft 720
so that anti-torque handle 700 may slide over gripping portion 21b
of rod reducer 10 and engage with gripping feature 22c of rod
reducer 10 to prevent rotational movement of distal segment 22 of
outer member 20 of rod reducer 10.
Thus, if needed, either or both the turning handle 600 and the
anti-torque handle 700 may be used to facilitate the rotational
movement of outer member 20 relative to inner member 30. In
particular, rotation of turning handle 600 imparts rotational
movement to proximal segment 21 of outer member 20 and anti-torque
handle 700 imparts counter rotational movement to distal segment 22
of outer member 20 so that proximal segment 21 rotates and distal
segment 22 axially translates without rotating. As appreciated,
anti-torque handle 700 is configured to limit the amount of torque
imparted from the rotational movement imparted by turning handle
600 to prevent undesirable torquing of the outer member 20. More
particularly, anti-torque handle 700 slides down over the outer
surface of outer member 20 of rod reducer 10 so that a distal end
of anti-torque handle 700 engages distal segment 22 of outer member
20 and a proximal end of proximal segment 21 of outer member 20 is
exposed for engagement with turning handle 600. Meanwhile, since
gripping member 40 is secured within annular recess 33 of inner
member 30 such that proximal finger 46 of gripping member 40 is
supported in slot 26 of distal segment 22 of outer member 20, the
engagement of anti-torque handle 700 with gripping feature 22c of
distal segment 22 of outer member 20 prevents rotation of both
distal segment 22 of outer member 20 and inner member 30 as
proximal segment 21 of outer member 20 is rotated with turning
handle 600. After spinal rod 800 is fully reduced into the saddle
910 of pedicle screw 900, turning handle 600 and anti-torque handle
700 may be removed and a set screw (not shown) may be inserted down
an inner diameter of rod reducer 10 to lock spinal rod 800 into
place. Alternatively, anti-torque handle 700 may also be used to
prevent rotation when tightening the set screw after spinal rod 800
has been fully reduced. Rod reducer 10 may then be removed.
Referring now to FIGS. 8 and 9, a compressor/distractor system 200
includes rod reducers 10, a compressor/distractor device 210, and a
fulcrum 300. System 200 may further include one or more minimally
invasive retraction devices 950, such as the retractor disclosed in
U.S. Pat. No. 7,846,093, the entire contents of which is
incorporated by reference. Each of the two rod reducers 10 engages
a respective pedicle screw 900. Each pedicle screw 900 is inserted
into a respective vertebra and is configured to receive spinal rod
800 in saddle portion 912 as shown in FIG. 1C.
Compressor/distractor device 210 is configured for selective
engagement with each rod reducer 10 when each rod reducer 10 is
attached to pedicle screw 900.
FIGS. 10A and 10B illustrate other embodiments of
compressor/distractor system 200a using compressor 400 and
distractor 500 respectively as the force applying device. As shown
in FIG. 10A, the compressor 400 has a handle assembly 410 with
handles 402, 404 that are pivotably coupled together by pivot pin
406. Distal portions of handles 402, 404 have respective grippers
402a, 404a for engaging rod reducers 10. Each gripper 402a, 404a
includes an arcuate recess configured for engaging an outer surface
of rod reducer 10. Compressor 400 also includes an arm 420 having
teeth 422 disposed thereon. Teeth 422 releasably engage a distal
portion of handle 404 for maintaining a predetermined distance or
spacing between handles 402, 404 during a compression stroke that
moves rod reducers 10 towards each other. The arm 420 is pivotably
coupled to a distal end of arm 402 such that it can be repositioned
and allow handles 402, 404 to be moved away from each other once
the desired amount of compression is achieved. Similarly, as shown
in FIG. 10B, the distractor 500 has a handle assembly 510 with
handles 502, 504 that are pivotably coupled together by pivot pin
506. Distal portions of handles 502, 504 have respective grippers
502a, 504a for engaging rod reducers 10. Each gripper 502a, 504a
includes an arcuate recess configured for engaging an outer surface
of rod reducer 10. Distractor 500 also includes an arm 520 having
teeth 522 disposed thereon. Teeth 522 releasably engage a distal
portion of handle 502 for maintaining a predetermined distance or
spacing between handles 502, 504 during a distraction stroke that
moves rod reducers 10 away from each other. The arm 520 is
pivotably coupled to a distal end of arm 504 such that it can be
repositioned and allow handles 502, 504 to be moved away from each
other once the desired amount of distraction is achieved.
Now referring to FIGS. 11-11C illustrating fulcrum 300 including
through holes 315 which receive inner bearing rings 320 which house
retaining rings 330 that are prevented from falling out of fulcrum
300 by caps 340. Fulcrum 300 is an elongate structure and each
through hole 315 includes an annular groove for retaining inner
bearing rings 320 and their respective retaining rings 330.
Referring now to FIGS. 12-14, compressor/distractor device 210 has
a first hook member 220, a second hook member 230, and a body
portion 260. Body portion 260 includes first end 261 and track 262
extending from first end 261 along a length of body portion 260.
Track 262 includes a set of teeth 263 and sidewall 264. First end
261 is insertable into a recess of the first hook member 220 and is
fixed in position at first end 261 of body portion 260 by the
cooperation of retaining pin 221 and first end retaining ring
222.
First and second hook members 220, 230 may each include hook
portions 224, 234 for engaging rod reducers 10. Hook portions 224,
234 have respective distracting hooks 225, 235 and compressing
hooks 226, 236. When rod reducers 10 are between first and second
hook members 220, 230, each compressing hook 226, 236 engages a rod
reducer 10 in a compressing configuration of compressor/distractor
device 210 (FIG. 8). When first and second hook members 220, 230
are between rod reducers 10, each distracting hook 225, 235 engages
a rod reducer 10 in a distracting configuration of
compressor/distractor device 210 (FIG. 9). Compressor/distractor
device 210 may also have a neutral configuration. Each hook member
220, 230 may engage gripping features 22c of each rod reducer
10.
Second hook member 230 may include a switch assembly 250 and a gear
assembly 240. Switch assembly 250 may include a pawl 251, a pawl
switch pin 252, a switch cap 253, a spring 254, a ball 255, ball
detents 258, a switch 256, and a switch shaft 257. Switch assembly
250 is selectable amongst a first condition, a second condition,
and a third condition. Each condition may correspond to a
configuration of the compressor/distractor device 210. In the first
condition, switch assembly 250 restrains second hook member 230
from traversing track 262 towards the first hook member 220, while
permitting second hook member 230 to traverse track 262 away from
the first hook member 220 (i.e., a distracting configuration). In
the second condition, switch assembly 250 restrains second hook
member 230 from traversing track 262 away from the first hook
member 220, while permitting second hook member 230 to traverse
track 262 towards the first hook member 220 (i.e., a compressing
configuration). In the third condition, switch assembly 250 allows
the second hook member 230 to freely move along track 262 in either
direction (i.e., a neutral configuration), which allows for quick
adjustment of compressor/distractor device 210.
Switch 256 rotates about switch shaft 257 causing pawl pivot pin
252 to rotate pawl 251 about switch shaft 257. Pawl pivot pin 252
acts on pawl 251 causing pawl 251 to engage set of teeth 263 which
restrains second hook member from traversing in the undesired
direction.
Second hook member 230 may include ball detents 258. Each ball
detent 258 corresponds to a position of switch 256. Switch 256 may
be retained in each position by spring 254 pressing ball 255 into a
corresponding ball detent 258. Ball 255 selectively engages each
ball detent 258 when the switch is in one of the positions
corresponding to the compressing, distracting, and neutral
configurations of the compressor/distractor device 210.
Gear assembly 240 engages set of teeth 263 causing second hook
member 230 to traverse track 262. Rotation of traversing screw 244
rotates pinion 242. The cooperation of pinion 242 with set of teeth
263 induces the second hook member 230 to traverse track 262. A
drive tool (not shown) may engage and rotate traversing screw
244.
A method for using system 200 to manipulate a vertebra into a
desired position with respect to a second vertebra is discussed
below. First, a surgeon accesses the spinal area of a patient
having at least two pedicle screws 900 secured to adjacent
vertebrae (not shown). Each pedicle screw 900 may be engaged by a
minimally invasive retraction device 950. The surgeon then engages
each pedicle screw 900 with a rod reducer 10 by attaching inner
member 30 to pedicle screw head 910 as shown in FIG. 1B. Each inner
member 30 receives a respective pedicle screw head 910 between arms
32. Next, the surgeon advances an outer member 20 along each inner
member 30 by rotating the distal segment 21 of the outer member 20.
The surgeon may use handle assembly 650 to rotate distal segment
21.
Rod engaging slots 25 of proximal segment 22 of each outer member
20 receives a portion of rod 800 and advances rod 800 into saddle
portion 912 of each pedicle screw 900 as shown in FIGS. 1B and 1C.
Once each outer member 20 is fully advanced with respect to each
inner member 30 as shown in FIG. 1C, the surgeon engages each outer
member 20 with a force applying device 210, 400, 500 as shown in
FIGS. 8-10B. The force applying device may include gear assembly
240. Then the surgeon inserts a set screw (not shown) through each
rod reducer 10 for securing the rod 800 to each pedicle screw 900.
The surgeon may rotate at least one of the set screws to either
partially or fully secure rod 800 to at least one of the pedicle
screws 900.
Then the surgeon manipulates gear assembly 240 until each pedicle
screw 900 is in a desired position on rod 800. Manipulation of gear
assembly 240 may include rotating traversing screw 244. The surgeon
may use a drive tool to manipulate gear assembly 240.
Then the surgeon rotates each set screw to fully secure rod 800 to
each pedicle screw 900 in the desired position. Then the surgeon
may remove compressor/distractor device 210 and each rod reducer
10.
The surgeon may also attach fulcrum 300 to gripping portion 21b of
proximal segment 21 of each outer member 20 before manipulating
gear assembly 240. Fulcrum 300 may then be removed with the
compressor/distractor device 210 and each of the rod reducers
10.
While several embodiments of the disclosure have been shown in the
drawings, it is not intended that the disclosure be limited
thereto, as it is intended that the disclosure be as broad in scope
as the art will allow and that the specification be read likewise.
Therefore, the above description should not be construed as
limiting, but merely as exemplifications of particular embodiments.
Those skilled in the art will envision other modifications within
the scope and spirit of the claims appended hereto.
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