U.S. patent application number 15/430711 was filed with the patent office on 2017-06-01 for fixation implant and method of insertion.
The applicant listed for this patent is K2M, Inc.. Invention is credited to Michael Barrus, John Kostuik, Nick Missos, Richard W. Woods.
Application Number | 20170150977 15/430711 |
Document ID | / |
Family ID | 50343588 |
Filed Date | 2017-06-01 |
United States Patent
Application |
20170150977 |
Kind Code |
A1 |
Kostuik; John ; et
al. |
June 1, 2017 |
FIXATION IMPLANT AND METHOD OF INSERTION
Abstract
An implant includes an implantable portion and a housing. The
implantable portion has a head and a shank extending from the head.
The shank has a solid outer surface and defines a radius of
curvature. The housing is pivotally and rotatably coupled to the
head and is configured to secure a rod to the implantable portion.
The housing is fixed relative to the implantable portion when a rod
is secured within the housing.
Inventors: |
Kostuik; John; (Baltimore,
MD) ; Woods; Richard W.; (Catonsville, MD) ;
Missos; Nick; (Leesburg, VA) ; Barrus; Michael;
(Ashburn, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
K2M, Inc. |
Leesburg |
VA |
US |
|
|
Family ID: |
50343588 |
Appl. No.: |
15/430711 |
Filed: |
February 13, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14207740 |
Mar 13, 2014 |
9579127 |
|
|
15430711 |
|
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|
61778588 |
Mar 13, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 17/1671 20130101;
A61B 17/7037 20130101; A61B 17/7034 20130101; A61B 17/7011
20130101; A61B 17/70 20130101; A61B 17/7055 20130101; A61B 17/1757
20130101; A61B 17/1642 20130101; A61B 17/7035 20130101 |
International
Class: |
A61B 17/16 20060101
A61B017/16; A61B 17/70 20060101 A61B017/70; A61B 17/17 20060101
A61B017/17 |
Claims
1. A method of fixing two bony elements relative to one another,
the method comprising: inserting an implantable portion of an
implant into a curved drilled hole defined in two bony elements of
a patient, the implant including: the implantable portion including
a head and a shank extending from the head, the shank defining a
radius of curvature, the shank having a solid outer surface; and a
housing pivotally and rotatably coupled to the head; and permitting
bone growth of the bony elements to secure the implantable portion
within the curved drilled hole and to fuse the two bony elements to
one another.
2. The method of claim 1, further comprising fixing the housing
relative to the implant.
3. The method of claim 2, further comprising securing a rod in the
housing of the implant.
4. The method of claim 1, further comprising: drilling the curved
drilled hole in a first bony element and into a second bony element
with a drilling apparatus, the drilling apparatus including: a
drill guide assembly including a guide shaft, side guides, and a
curved guide, the guide shaft defining a drill channel and the side
guides defining a guide slot in communication with the drill
channel, the curved guide slidably disposed within the guide slot;
and a drill shaft assembly including a proximal portion and a
flexible distal portion, the drill shaft assembly slidably and
rotatably disposed within the drill channel, the curved guide
deflecting the flexible distal portion as the drill shaft assembly
advances through the drill guide assembly such that the flexible
distal portion defines a curved path.
5. The method of claim 4, wherein drilling the curved drilled hole
includes coupling the curved guide to the flexible distal
portion.
6. The method of claim 5, wherein drilling the curved drilled hole
includes advancing the drill shaft assembly through the drill
channel of the drill guide assembly such that the flexible distal
portion defines a curved path.
7. The method of claim 6, wherein advancing the drill shaft
assembly includes steering the flexible distal portion along the
curved path with the curved guide.
8. The method of claim 7, further comprising selecting a curved
guide with a radius of curvature substantially equal to a radius of
curvature of the shank of the implant, wherein the radius of
curvature of the curved guide defines the curved path of the
drilled hole.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S.
patent application Ser. No. 14/207,740, filed Mar. 13, 2014, which
claims the benefit of, and priority to, U.S. Provisional Patent
Application Ser. No. 61/778,588, filed on Mar. 13, 2013. The entire
contents of each of these applications are incorporated herein by
reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to methods, systems, and
apparatuses for bony fixation and, more specifically, to methods,
systems, and apparatuses adapted for fixing the bones of the
spine.
[0004] 2. Discussion of Related Art
[0005] Fixation or fusion of vertebral columns with bone or
material, rods or plates is a common, long practiced surgical
method for treating a variety of conditions. Many of the existing
procedures involve the use of components that protrude outwardly,
which may contact and damage a body part, such as the aorta, the
vena cava, the sympathetic nerves, the lungs, the esophagus, the
intestine, and the ureter. In addition, many constructions involve
components that may loosen and cause undesirable problems, often
necessitating further surgical intervention. Additionally, limiting
the success of these procedures are the biomechanical features of
the spine itself, whose structure must simultaneously provide
support to regions of the body, protect the vertebral nervous
system, and permit motion in multiple planes.
[0006] As indicated above, spinal surgery for spine fusion
generally involves using implants and instrumentation to provide
support to the affected area of the spine while allowing the bones
thereof to fuse. The technology initially evolved using bone chips
around and on top of an area of the spine that had been roughened
to simulate a fracture in its consistency. The area, having
encountered the bone chips, would then proceed to heal like a
fracture, incorporating the bone chips.
[0007] Surgical procedures dealing with the spine present notable
challenges. For example, bioengineers have been required to
identify the various elements of the complex motions that the spine
performs, and the components of the complex forces it bears. This
complexity has made it difficult to achieve adequate stability and
effective healing in surgical procedures directed to the spine. One
surgical technique, involves cutting a dowel type hole with a saw
across or through the moveable intervertebral disc and replacing it
with a bone graft that was harvested from the hip bone. This
procedure limits motion and mobility and results in a fusion of the
adjacent vertebral bodies. However, as a result of the complex
motions of the spine, it is often difficult to secure the dowel
from displacing. Further, it has become apparent over time that
this particular technique does not always yield a secure
fusion.
[0008] Other techniques have been developed that involve the
placement of various hardware elements, including rods and hooks,
rods and screws and plates and screws. The dowel technique also has
advanced over the past five years or so, with dowels being
fabricated from cadaver bone or metals such as titanium or
stainless steel. These techniques, whether using hardware, dowels
or some combination thereof, have a common goal to enhance
stability by diminishing movement, thereby resulting in or
enhancing the potential of a fusion of adjacent vertebral bones.
For example, in one of these other techniques, the disc is removed
and adjacent vertebrae are positioned in a stable position by
placing a plate against and traversing them, which plate is secured
or anchored to each by means of screws.
[0009] Thus, it would be desirable to provide a new apparatus,
system, and methods for spinal fixation that enhances healing of
the bone while providing structural support to the spine. It would
be particularly desirable to provide such an apparatus, system, and
method that would involve the use of open surgical or minimally
invasive surgical techniques. In addition, it would be desirable
for an implant placeable adjacent the sacrum at the end of a long
construct with numerous screws and/or hooks securing one or more
rods to the spine where fixation at the sacrum can experience
considerable stress, which can in some instances break traditional
screws, pull rods free from screws or fatigue the bone-screws
interface, in all cases compromising the security of the fixation
to the sacrum.
SUMMARY
[0010] In an aspect of the present disclosure, an implant includes
an implantable portion and a housing. The implantable portion
includes a head and a shank extending from the head. The shank
defines a radius of curvature and has a solid outer surface. The
housing is pivotally and rotatably coupled to the head. The housing
is configured to secure a rod to the implantable portion. The
housing is fixed relative to the implantable portion when a rod is
secured to the implantable portion.
[0011] The housing may be a taper lock housing or a set screw
housing. The shank may define a plurality of recesses in the outer
surface thereof. The shank may be generally cylindrical. The head
and the shank may be integrally formed with one another. The shank
may be a solid shaft. The outer surface of the shank may be
uninterrupted.
[0012] In embodiments, the implant portion is for insertion through
a sacrum of a patient and into an L5 vertebra of the patient to
create a fusion of the sacrum and the L5 vertebra.
[0013] In some aspects of the present disclosure, a system for
inserting an implant in bony anatomy of a patient includes an
implant and a drilling apparatus. The implant may be any of the
implants disclosed herein. The drilling apparatus includes a drill
guide assembly and a drill shaft assembly. The drill guide assembly
includes a guide shaft and a distal section. The guide shaft
defines a drill channel and the distal section defines a guide slot
in communication with the drill channel. The drill shaft assembly
includes a proximal portion, a flexible distal portion, and a
curved guide. The proximal and distal portions of the drill shaft
assembly are slidably and rotatably disposed within the drill
channel. The curved guide is coupled to the flexible distal portion
and is slidably disposed within the guide slot. The curved guide
deflects the flexible distal portion as the drill shaft assembly
advances through the drill guide assembly such that the flexible
distal portion defines a curved path.
[0014] The drill shaft assembly may include a drill tip coupled to
a distal end of the flexible distal portion and configured to
forward cut and side cut bone in contact therewith. The curved
guide may include a coupling mechanism that is adjacent a first end
thereof. The coupling mechanism may capture the flexible distal
portion while permitting the flexible distal portion to rotate
relative to the curved guide. The coupling mechanism may prevent
the first end of the curved guide from sliding through the guide
slot. The curved guide may include a stop adjacent a second end
thereof that prevents the second end of the curved guide from
sliding through the guide slot.
[0015] In certain aspects of the present disclosure, a method of
fixing two bony elements relative to one another includes inserting
an implant portion into a curved drilled hole defined in two bony
elements of a patient and permitting bone growth of the bony
elements to secure an implantable portion of the implant within the
curved drilled hole to fuse the two bony elements to one another.
The method may include fixing a housing relative to the implant.
The method may also include securing a rod in the housing of the
implant.
[0016] In embodiments, the method includes drilling the curved
drilled hole in a first bony element and into a second bony element
with a drilling apparatus. The drilling apparatus may be any of the
drilling apparatuses disclosed herein. Drilling the curved drilled
hole may include coupling a curved guide to a flexible distal
portion. Drilling the curved drilled hole may include advancing the
drill shaft assembly through the drill channel such that the
flexible distal portion defines a curved path. Advancing the drill
shaft assembly may include steering the flexible distal portion
along the curved path with the curved guide. The method may further
include selecting a curved guide with a radius of curvature
substantially equal to a radius of curvature of the shank of the
implant. The radius of curvature of the curved guide may define the
curved path of the drilled hole.
[0017] The implant may burrow in the vertebral body, traverse
across the disk space, and end in an adjacent or neighboring
vertebrae or vertebras, to provide limited or no protrusions. The
implant may be retained within the bone without requiring
contour-varying external vertebral wall fixation as compared to
conventional devices, as such the implant may avoid blood vessel
injury or erosion into organs and may be placeable near nerves. In
addition, the implant may be utilized in the sacral region of the
spine to attach spinal rods typically used in a spinal constructs
that run longitudinally down either side of the spinous process
providing further support to the construct. Further, the implant
may be placeable at the end of a long construct with numerous
screws and/or hooks securing one or more rods to the spine where
fixation at the sacrum can experience considerable stress.
[0018] Further, to the extent consistent, any of the aspects
described herein may be used in conjunction with any or all of the
other aspects described herein.
[0019] Certain embodiments of the present disclosure may include
some, all, or none of the above advantages. One or more other
technical advantages may be readily apparent to those skilled in
the art for the figures, descriptions, and claims included herein.
Moreover, while specific advantages have been enumerated above,
various embodiments may include all, some, or none of the
enumerated advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Various aspects of the present disclosure are described
hereinbelow with reference to the drawings, wherein:
[0021] FIG. 1 is a perspective view of an implant in accordance
with the present disclosure receiving a spinal rod;
[0022] FIG. 2 is an exploded view of the implant of FIG. 1;
[0023] FIG. 3 is a side view of the implant portion of the implant
of FIG. 1;
[0024] FIG. 4 is a side perspective view of a drilling apparatus in
accordance with the present disclosure;
[0025] FIG. 5 is an exploded view of a drill guide assembly of the
drilling apparatus of FIG. 4;
[0026] FIG. 6 is an exploded view of a drive shaft assembly of the
drilling apparatus of FIG. 4 illustrating a flexible distal portion
in a non-curved configuration;
[0027] FIG. 7 is a view of the drive shaft assembly of FIG. 6
illustrating the flexible distal portion in a curved
configuration;
[0028] FIGS. 8-10 show a progression of side perspective views of
the drilling apparatus of FIG. 4 and cutaway views of bony elements
of an anatomy illustrating the drilling apparatus creating a
drilled hole through the bony elements; and
[0029] FIGS. 11-13 show a progression of cutaway views of the bony
elements of the anatomy of FIG. 10 illustrating the insertion of
the implant into the drilled hole and the securing of a spinal rod
to the implant.
DETAILED DESCRIPTION
[0030] Embodiments of the present disclosure are now described in
detail with reference to the drawings in which like reference
numerals designate identical or corresponding elements in each of
the several views. As used herein, the term "clinician" refers to a
doctor, a nurse, or any other care provider and may include support
personnel. Throughout this description, the term "proximal" will
refer to the portion of the device or component thereof that is
closest to the clinician and the term "distal" will refer to the
portion of the device or component thereof that is farthest from
the clinician. In addition, the term "cephalad" 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, for the purposes of this
application, 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. Additionally, in the drawings and in
the description that follows, terms such as front, rear, upper,
lower, top, bottom, and similar directional terms are used simply
for convenience of description and are not intended to limit the
disclosure.
[0031] Referring now to FIGS. 1-3, an implant 10 is provided in
accordance with the present disclosure including an implantable
portion 12 and a housing 20. The implant portion 12 provides a
mounting or anchoring point for a spinal rod 100. In addition, the
implant portion 12 may secure two or more bony elements (e.g., a
sacrum and a vertebra) together to facilitate fusion of the two or
more bony elements. Portions of the implant portion 12 and the
housing 20 may be made of any suitable biocompatible material
including but not limited to titanium, titanium alloys, stainless
steel, cobalt chrome, nickel titanium, or polymer compositions.
[0032] The implant portion 12 includes a head 14 and a shank 16
extending from the head 14. The head 14 and the shank 16 may be
integrally formed with one another that may increase the strength
of the overall construct or that may simplify the use of the
implant portion 12 as detailed below. The shank 16 is rigid along
its length. The shank 16 may have a solid outer surface that is
uninterrupted along its length. In embodiments, the shank is a
solid shaft. In some embodiments, the shank 16 is a solid shaft
with a hollow core or channel (not shown) to reduce the weight
and/or material used to manufacture the shank 16. The outer surface
of the shank 16 may be non-porous. Additionally or alternatively,
the outer surface of the shank 16 may include surface features to
promote bone growth including, but not limited to, ridges,
indentations, or textures.
[0033] The shank 16 defines a radius of curvature C. The radius of
curvature C may be constant along the entire length of the shank
16. However, it is also within the scope of this disclosure that
the radius of curvature of the implant portion may vary along the
length of the shank 16 (e.g., the radius of curvature may increase
or decrease along the length of the shank 16). The shank 16 has a
substantially constant diameter along the entire length thereof.
The diameter of the shank 16 may be from about 4 mm to about 12 mm
(e.g., about 8 mm). It is also within the scope of this disclosure
that the shank 16 is less than 4 mm or greater than 12 mm.
[0034] The shank 16 defines a plurality of recesses 17 in an outer
surface thereof and defines an arcuate axis S-S. Each recess 17 may
be a ring about the outer surface of the shank and substantially
orthogonal to the axis S-S defined by the shank 16. It is also
within the scope of this disclosure that each recess 17 is a groove
helically disposed in the outer surface of the shank 16 along the
axis S-S. The recesses may increase the surface area of the outer
surface of the shank 16. The increased surface area of the outer
surface of the shank 16 may promote bone ingrowth to the shank
and/or increase the retention of the shank within a bony element of
the anatomy as detailed below.
[0035] The housing 20 is pivotally mounted over the head 14 of the
implant portion 12. The head 14 of the implant portion 12 is
substantially spherical to permit the housing 20 to pivot or rotate
about the head 14. The housing 20 is configured to secure a rod
(e.g., spinal rod 100) to the implant 10. When a rod is secured
within the housing 20, the housing may be pivotally or rotatably
fixed relative to the implant portion 12. The housing 20 includes
an outer housing or coupling 22, and an inner housing or collet 32.
The coupling 22 includes an annular body portion 24 having an
opening 25 extending axially therethrough. Additionally, the
coupling 22 includes a plurality of fingers 26 that are located in
opposing regions of the coupling 22 and define a saddle 28 having a
generally U-shaped configuration. The U-shaped saddle 28 is
configured and dimensioned for receiving a rod. The collet 32 has a
generally cylindrical body portion 34 with an opening 35 extending
axially therethrough. A pair of upstanding wings 36 defines a
saddle 38 having a generally U-shaped configuration. The saddle 38
is configured and dimensioned for receiving a rod. The wings 36
compress towards each other to engage an outer surface of a rod
located in the saddle 38, thereby frictionally securing the rod in
a desired position relative to the implant portion 12. As detailed
above, the housing 20 is configured as a taper lock housing;
however, it is also within the scope of this disclosure that the
housing 20 is configured as a set screw housing. An exemplary
embodiment of a taper lock housing is disclosed in commonly owned
U.S. patent application Ser. No. 12/739,461 filed Apr. 23, 2010,
and published as U.S. Patent Pub. No. 2010/0262196, and an
exemplary embodiment of a set screw housing is disclosed in
commonly owned U.S. Pat. No. 7,947,066, the contents of each is
incorporated herein in its entirety.
[0036] Referring now to FIGS. 4-6, a drilling apparatus 40 may be
used in accordance with the present disclosure to create the
drilled hole 110 (FIG. 11) in bony elements. The drilling apparatus
40 includes a drill guide assembly 41 and a drill shaft assembly
50. The drill guide assembly 41 includes a handle 42, a guide shaft
44, and a distal section 45 formed from a pair of side guides 46.
The handle 42 defines a first passage 42a about a longitudinal axis
thereof. The handle 42 receives a proximal end of the guide shaft
44 within a distal end of the first passage 42a. The distal end of
the handle 42 may be coupled to the proximal end of the guide shaft
44 by a variety of known techniques including, but not limited to,
threaded engagement, a friction fit, a snap ring, an adhesive,
welding, etc.
[0037] The guide shaft 44 defines a second passage 44a in
communication with the first passage 42a. The side guides 46 couple
together over the distal end of the guide shaft 44 to form the
distal section 45. The distal section 45 defines a third passage
46a therethrough in communication with the second passage 44a. The
first, second, and third passages 42a, 44a, 46a form a drill
channel 43 (FIG. 4) through the drill guide assembly 41. The side
guides 46 may be coupled together by a variety of known techniques
including but not limited to a friction fit, screwing, gluing,
welding, etc. The distal section 45 defines a guide slot 47
adjacent the proximal end thereof, adjacent the distal end of the
guide shaft 44, and in communication with the third passage 46a.
The guide slot 47 is configured to slidably receive the curved
guide 58.
[0038] Referring to FIGS. 6 and 7, the drill shaft assembly 50
includes a proximal portion 52, a flexible distal portion 54, a
drill tip 56, and a curved guide 58. The proximal portion 52 may be
rigid such that during use the proximal portion 52 remains in a
substantially linear configuration. A proximal end of the flexible
distal portion 54 is coupled to the distal end of the proximal
portion 52. In some embodiments, the proximal and distal portions
52, 54 are integrally formed with one another to form a unitary
construct. When non-stressed, the flexible distal portion 54 is in
the non-curved or linear configuration as shown in FIG. 6. When a
stress or force is applied to the flexible distal portion 54, the
flexible distal portion 54 deflects to a curved configuration as
shown in FIG. 7. In use, the flexible distal portion 54 rotates
about its longitudinal axis in cooperation with rotation of the
proximal portion 52 in either of the non-curved or curved
configurations.
[0039] The drill tip 56 is coupled to the distal end of the
flexible distal portion 54. The drill tip 56 may be coupled to the
distal end of the flexible distal portion 54 by a variety of known
techniques including, but not limited to, threaded engagement,
friction fit, snap ring, welding, etc. The drill tip 56 is
configured to create a hole through bone in contact therewith as
the drill tip 56 is rotated. The drill tip 56 is configured for
forward cutting and/or side cutting. In embodiments, the drill tip
56 is integrally formed on the distal end of the flexible distal
portion 54. The drill tip 56 may be sized and configured to be
partially or fully retracted into the third passage 46a of the
drill guide assembly 40. In some embodiments, the drill tip 56 is
sized to prevent the drill tip 56 from retracting into the second
passage 44a.
[0040] With particular reference to FIG. 7, the curved guide 58
defines a radius of curvature D. The radius of curvature D may be
constant along the entire length of the curved guide 58. However,
it is also within the scope of this disclosure that the radius of
curvature of the curved guide 58 varies along the length of the
curved guide 58 (e.g., the radius of curvature of the curved guide
58 may increase or decrease along the length of the curved guide
58). In addition, the radius of curvature of the curved guide 58
may be similar to or the same as the radius of curvature C of the
shank 16 (FIG. 3) to create a drilled hole (e.g., drilled hole 110
(FIG. 11)) for the implant 10 as detailed below.
[0041] Referring to FIG. 6, a first end 58a of the curved guide 58
includes a coupling mechanism 59 configured to capture a portion of
the flexible distal portion 54 and steer the flexible distal
portion 54 as the flexible distal portion 54 advances. The coupling
mechanism 59 permits the flexible distal portion 54 to rotate
relative to the curved guide 58. The curved guide 58 may be
substantially half-cylindrical in shape to substantially conform to
the outer surface of the flexible distal portion 54. The curved
guide 58 may be curved such that the outer wall has a smaller
radius of curvature than the inner wall of the half-cylindrical
shape as shown in FIGS. 6 and 7. The curved guide 58 is rigid such
that the curved guide 58 maintains the radius of curvature D. A
second end 58b of the curved guide 58 may include a stop that
prevents the second end 58b from passing through the guide slot 47.
It is also within the scope of this disclosure that the coupling
mechanism 59 may prevent the first end 58a from passing through the
guide slot 47. An example of a suitable drill shaft assembly is
disclosed in U.S. Pat. Nos. 6,447,518 and 6,053,922 the contents of
each is incorporated herein in its entirety
[0042] Referring to FIGS. 3 and 8-11, the drilling apparatus 40
creates a drilled hole 110 in a bony element of an anatomy in
accordance with the present disclosure. A curved guide (e.g.,
curved guide 58) with a predefined radius of curvature
corresponding to the radius of curvature of a shank 16 of an
implant 10 to be inserted into the bony element is selected. The
first end 58a of the curved guide 58 is positioned within the guide
slot 47 defined by the side guides 46 of the drill guide assembly
41. The side guides 46 are joined together to form the distal
section 45 and to capture the curved guide 58 within the guide slot
47. The proximal and distal portions 52, 54 of the drill shaft
assembly 50 are inserted through the drill channel 43 of the drill
guide assembly 41 such that the distal end of the flexible distal
portion 54 extends from the distal end of the distal section 45 and
the proximal end of the proximal portion 52 extends from the
proximal end of the handle 42 as shown in FIG. 3. The drill tip 56
may be removably coupled to the distal end of the flexible distal
portion 54 and coupled to the flexible distal portion 54 through
the coupling mechanism 59 to couple the flexible distal portion 54
to the curved guide 58.
[0043] With particular reference to FIG. 8, the drill shaft
assembly 50 is positioned such that the drill tip 56 abuts the bony
element at a desired mounting point for a spinal rod (e.g., spinal
rod 100 (FIG. 1)) with the flexible distal portion 54 in the
unstressed configuration. The drill tip 56 may be partially or
wholly disposed within the third passage 46a of the drill guide
assembly 41 and the distal end of the side guides 46 of the drill
guide assembly 41 may be positioned against a bony element (e.g.,
sacrum S) in which the implant 10 is to be inserted. The distal end
of the side guides 46 may be pinned or screwed in place against the
bony element.
[0044] A drill 120 is coupled to the proximal end of the proximal
portion 52 to rotate the proximal portion 52 about a longitudinal
axis thereof as shown in FIG. 9. The drill 120 may be a powered
instrument as shown or a manual handle. It will be appreciated that
the flexible distal portion 54 and the distal tip 56 cooperate with
the rotation of the proximal portion 52. As the proximal portion 52
is rotated, the flexible distal portion 54 is advanced through the
side guides 46 and the drill tip 56 creates a hole through the bony
element as shown in FIG. 9. As the flexible distal portion 54
advances, the curved guide 58 is advanced through the guide slot 47
and applies a force to the flexible distal portion 54 to steer the
drill tip 56 along a predefined arcuate path defined by the radius
of curvature D of the curved guide 58. As the curved guide 58
stresses the flexible distal portion 54, the flexible distal
portion 54 deflects away from the longitudinal axis of the proximal
portion 52 to follow the radius of curvature D of the curved guide
58. The drill tip 56 uses a side-cutting action to cooperate with
the deflection of the flexible distal portion 54. The flexible
distal portion 54 may be advanced until the stop adjacent the
second end 58b of the curved guide 58 engages the guide slot 47 to
prevent excessive advancement of the flexible distal portion 54 as
shown in FIG. 10.
[0045] When the drill tip 56 reaches a desired depth, the drill tip
56 is withdrawn from the drilled hole 110 as shown in FIG. 11. When
the drill tip 56 is withdrawn, the drilling apparatus 40 is removed
from the bony element leaving a drilled hole 110 having a radius of
curvature similar to the radius of curvature of the curved guide 58
and a depth substantially equal to the length between the first and
second ends 58a, 58b (FIG. 6) of the curved guide 58. The drilled
hole 110 may be defined within a single bony element (e.g., sacrum
S). It is also within the scope of this disclosure that the drilled
hole 110 may pass through more than one bony element; for example,
the drilled hole 110 may pass through a first bony element (e.g.,
sacrum S), through a bone interface BI, and into a second bony
element (e.g., vertebra L5).
[0046] Referring now to FIGS. 11-13, the implant 10 is seated
within the drilled hole 110 to fix the bony elements (e.g., sacrum
S and vertebra L5) relative to one another and to provide a
fixation point for a spinal rod (e.g., spinal rod 100). When the
drilled hole 110 passes through more than one bony element, the
implant 10 may fix the bony elements relative to one another such
that the bony elements fuse to one another; continuing the example
above, the sacrum S is fused to the vertebra L5.
[0047] To seat the implant 10 into the drilled hole 110, the shank
16 of the implant 10 is inserted into the drilled hole 110 until
the shank 16 is fully seated within the drilled hole 110 as shown
in FIG. 12 (i.e., the distal end of the shank 16 is adjacent a
bottom 110a of the drilled hole 110). The diameter or shape of the
shank 16 may partially interfere with the diameter or shape of the
drilled hole 110 requiring an additional force to be applied to the
implant 10 to insert the shank 16 into the drilled hole 110. A
mallet (not shown) may be used to apply an additional force to the
implant 10 to insert the implant 10 within the drilled hole 110. It
will be appreciated that the partial interference of the diameter
or shape of the shank 16 may secure the shank 16 within the drilled
hole 110 and/or the first and second bony elements relative to one
another. It will also be appreciated that the shank 16 is rigid to
substantially maintain its shape as additional force is applied to
seat the shank 16 into the drilled hole 110.
[0048] When the shank 16 is fully seated within the drilled hole
110, the housing 20 is oriented to receive the spinal rod 100 as
shown in FIG. 13 (i.e., the housing 20 is orientated such that the
saddles 28, 38 align with the spinal rod 100). The spinal rod 100
is then secured within the housing as detailed above. The spinal
rod 100 may be secured to a plurality of implants 110.
[0049] It will be appreciated that the outer surface of the shank
16 may be textured or patterned to prevent the shank 16 from
backing out of the drilled hole 110 or to enhance bone growth to
secure the shank 16 within the drilled hole 110. The recesses 17
may also engage the sides of the drilled hole 110 to prevent the
shank 16 from backing out of the drilled hole 110 or to enhance
bone growth to the shank 16.
[0050] 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.
Any combination of the above embodiments is also envisioned and is
within the scope of the appended claims. 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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