U.S. patent application number 14/938482 was filed with the patent office on 2016-03-03 for devices and methods for hip replacement.
The applicant listed for this patent is Benjamin A. Gillman, Michael Gillman. Invention is credited to Benjamin A. Gillman, Michael Gillman.
Application Number | 20160058577 14/938482 |
Document ID | / |
Family ID | 53008858 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160058577 |
Kind Code |
A1 |
Gillman; Michael ; et
al. |
March 3, 2016 |
DEVICES AND METHODS FOR HIP REPLACEMENT
Abstract
Devices and methods for use in hip replacement surgery can
incorporate computer models of a patient's acetabulum and
surrounding bone structure, a first patient-specific jig designed
from the computer model and configured to correspond to a final
installation position and orientation of a prosthetic hip implant,
a second patient-specific jig, also designed from the computer
model, configured to refine the procedure, if necessary, following
use of the first patient-specific jig, and/or a third patient
specific jig, designed from the computer model, configured to
refine the procedure, if necessary, following use of the first and
second patient-specific jigs, allowing the surgeon to properly
position and orient the hip prosthesis. Also shown and described
are novel devices for implanting an acetabular cup.
Inventors: |
Gillman; Michael; (Laguna
Beach, CA) ; Gillman; Benjamin A.; (Laguna Beach,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gillman; Michael
Gillman; Benjamin A. |
Laguna Beach
Laguna Beach |
CA
CA |
US
US |
|
|
Family ID: |
53008858 |
Appl. No.: |
14/938482 |
Filed: |
November 11, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14255761 |
Apr 17, 2014 |
9211128 |
|
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14938482 |
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Current U.S.
Class: |
606/87 |
Current CPC
Class: |
A61B 17/1703 20130101;
A61F 2002/4681 20130101; A61F 2/4609 20130101; A61B 17/1666
20130101; A61B 2017/568 20130101; A61B 17/1746 20130101; A61B
2034/108 20160201; A61F 2002/4677 20130101; A61F 2002/30772
20130101; A61F 2/34 20130101 |
International
Class: |
A61F 2/46 20060101
A61F002/46; A61F 2/34 20060101 A61F002/34; A61B 17/17 20060101
A61B017/17 |
Claims
1. A method, comprising: positioning a first component of a
patient-specific jig in an acetabulum of a patient, the
patient-specific jig formed according to a predetermined
installation position of a prosthesis implant to be secured to the
patient, the first component of the patient-specific jig having a
first aperture, a first alignment member attached at a respective
position to the first component of the patient-specific jig
corresponding to the installation position of the prosthesis
implant, and a first alignment structure; engaging the first
alignment member to a predefined selected area of a coxal bone
adjacent the acetabulum of the patient; positioning a second
component of the patient-specific jig in the first aperture of the
first component of the patient-specific jig and in an acetabulum of
a patient, the second component of the patient-specific jig formed
according to a predetermined installation position of a prosthesis
implant to be secured to the patient, the second component of the
component of the patient-specific jig having a second aperture and
a second alignment structure, the second alignment structure to
engage with the first alignment structure at a respective position
corresponding to the installation position of the prosthesis
implant; positioning a guide post through the aperture of the
second component of the patient-specific jig and securing the guide
post to the patient, the guide post positioned corresponding to the
installation position of the prosthesis implant; removing the
second component of the patient-specific jig from the acetabulum in
a direction substantially parallel to a central axis of the guide
post; removing the first component of the patient-specific jig from
the acetabulum.
2. The method of claim 1, further comprising: determining whether
the acetabulum has been reamed to receive a prosthetic acetabular
cup; if the acetabulum has not been reamed to receive a prosthetic
acetabular cup, reaming the acetabulum; and if the acetabulum has
been reamed to receive a prosthetic acetabular cup, securing the
prosthesis implant to the acetabulum.
3. The method of claim 2 wherein the step of determining whether
the acetabulum has been reamed to receive a prosthetic acetabular
cup, further comprises: determining whether the first alignment
member of the first component of the patient-specific jig is
engaged to the selected area proximate the acetabulum of the
patient and determining whether the second alignment structure is
engaged with the first alignment structure at a respective position
corresponding to the installation position of the prosthesis
implant; if the first alignment member of the first component of
the patient-specific jig is not engaged to said selected area or
the second alignment structure is not engaged with the first
alignment structure, reaming the acetabulum until the alignment
member is engaged to said selected area and the second alignment
structure is engaged with the first alignment structure; and if the
first alignment member is engaged to said selected area and the
second alignment structure is engaged with the first alignment
structure, thereby indicating information that an installation
reference point has been reached, securing the prosthesis implant
to the reamed acetabulum over the guide post, with or without the
guide post in place.
4. A system for use in joint replacement surgery, the system
comprising: an imaging machine configured to generate imaging data
corresponding to an anatomic structure of a patient; a
patient-specific device generator configured to generate a model of
a reamed surface of the anatomic structure of the patient and a
first patient-specific jig image, the first patient-specific jig
image including an outer component image and an inner component
image; and a patient-specific device converter configured to
generate design control data to control operation of a machine for
making a first patient-specific jig that corresponds to the
generated first patient-specific jig image, the first
patient-specific jig positionable against the anatomic structure of
the patient at a position corresponding to an instillation position
of a prosthesis implant.
5. The system of claim 4 wherein the outer component image includes
a first alignment structure image configured to align with a second
alignment structure image of the inner component image, the first
and second alignment structure images configured such that
alignment of the first alignment structure image with the second
alignment structure image corresponds to a final installation
position of a prostheses to be secured to the anatomic structure of
the patient according to the imaging data.
6. The system of claim 5 wherein the outer component image includes
a first alignment member image at a position on the outer component
image corresponding to a selected area of the anatomic structure of
the patient determined from the imaging data.
7. The system of claim 4 wherein the inner component image includes
an aperture image, the aperture image extending from a distal end
of the inner component image to a proximal end of the inner
component image.
8. The system of claim 7 wherein: the distal end of the inner
component image is a reference end that matches the model of the
reamed surface of the anatomic structure of the patient; and
wherein the aperture image aligns with an orientation of a guide
post according to a final installation position of a
prostheses.
9. The system of claim 8 wherein: the patient-specific device
generator is configured to generate a guide post image; the distal
end of the inner component image is a reference end that matches
the model of the reamed surface of the anatomic structure of the
patient; and the aperture image aligns with an orientation of the
guide post image.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to devices and methods for
the replacement of joints, and more particularly, to
patient-specific hip replacement devices, including methods of
manufacturing and using such devices for achieving accurate hip
replacement based on computer generated imaging of a patient.
[0003] 2. Background of the Invention
[0004] One known method of treating hip and other joints with
arthritis and other medical conditions is to replace surfaces of
articulating joints with prosthetic devices through surgical
procedures. It is critical that such prosthetic devices are
accurately designed and manufactured, and are installed correctly
in order to relieve pain and provide an effective treatment method
for such ailments. An orthopedic surgeon performing such joint
replacement on a patient seeks to ensure, through surgery, adequate
placement of the prosthetic and proper reconstruction of the joint
being replaced. Prosthetic components used to replace a joint may
be placed optimally by templates and jigs according to the unique
anatomy of a patient before surgery occurs. A particular patient's
bone structure symmetry is one important consideration that a
surgeon must consider when performing joint replacement surgery.
Additionally, malposition of joint replacement prosthetics can
result in premature wear of the bearing surfaces, which may require
additional surgeries to correct.
[0005] In the case of a hip, the condition of the patient's joint
may require a partial or total replacement. A partial hip
replacement involves replacing the femoral head (the ball) of the
damaged hip joint; however, the acetabulum (the socket) is not
replaced in a partial hip replacement surgery. A total hip
replacement includes replacing both the femoral head and the
acetabulum with prosthetic devices. The femoral head is replaced
with a femoral prosthetic that typically includes a head portion
and a stem. The stem extends into the femur of the patient and is
utilized to secure the femoral device to the femur, with the head
portion protruding out from the femur. The acetabulum is then
resurfaced and replaced with a cup-shaped acetabular device. The
cup-shaped acetabular device provides a bearing surface for the
head portion of the femoral prosthetic to allow a desirable amount
of range of motion via the joint upon total hip replacement.
[0006] To replace the acetabulum effectively, a surgeon will
typically enlarge the acetabulum with a reamer machine and reamer
head to create a resurfaced cavity to receive a prosthetic
acetabular cup, which may or may not be secured by cement or bone
screws. One particular issue of concern during the reaming portion
of the surgery is that the cutting portion of the reamer is
hemispherical while the prosthetic acetabular cup is typically
sub-hemispherical. If the acetabulum is reamed too deeply, the
prosthetic acetabular cup will be positioned too deep within the
reamed cavity. If the acetabulum is reamed too shallowly, the
prosthetic acetabular cup will not be positioned deep enough. If
the acetabulum is reamed at an improper angle, the prosthetic
acetabular cup will not be installed properly. These imperfections
can cause malalignment of the prosthetic hip joint. Moreover even
if the acetabular bone is properly reamed, it is quite difficult
with standard techniques to place the acetabular prosthetic cup.
Recent studies, reflect a 50% rate of error in placement of the
acetabular cup from an acceptably optimal range of positions when
standard techniques are utilized. Thus, accurate reaming of the
acetabulum and accurate positioning of the prosthetic acetabular
cup are critical.
[0007] With the assistance of computer generated data derived from
CT, MRI, or other scans, such as X-rays, surgeons can more
effectively determine proper alignment and positioning of the
prosthetic acetabular cup in a patient through 3D modeling and
rendering. While some surgeons use lasers or peripheral guide pins
during surgery in an attempt to properly place the prosthetic
acetabular cup; however, accuracy and simplicity of existing
devices and methods remain limited due to a variety of factors.
BRIEF SUMMARY
[0008] The present disclosure pertains to patient-specific hip
replacement devices and methods of designing and manufacturing such
devices for achieving accurate acetabular component placement
during hip replacement surgery based on computer generated imaging
of a particular patient. When an orthopedic surgeon recommends
total hip replacement surgery for a particular patient, a variety
of images may be obtained utilizing CT, MRI, and other scans, such
as x-rays, to generate 3D modeling of the patient's bone structure,
particularly the femur, the pelvic bone, and the coxal (hip) bone.
From such 3D models, the surgeon may determine the specific, final
location and orientation of an acetabular cup to be secured to the
patient's acetabulum during surgery. Once the final location and
orientation of the acetabular cup is determined, the surgeon
(utilizing 3D images) may create a first patient-specific jig and a
second--and in some cases a third--patient-specific jig to be
inserted into the patient's acetabulum during the surgery to
ultimately achieve accurate positioning of the prosthetics to be
installed in the patient.
[0009] The first patient-specific jig may be designed and
manufactured based on a first patient-specific acetabulum male
portion, while the second patient-specific jig may be designed and
manufactured based on a second patient-specific acetabulum male
portion. The first and second patient-specific acetabulum male
portions can be developed as either physical components via a
prototyping machine or visual representations in a 3D modeling
software program based upon the 3D images of the patient. The male
portion may or may not fully contact the patient's native
acetabulum.
[0010] The first patient-specific jig can be a hemispherical shaped
device or a sub-hemispherical shaped device, and can be comprised
of composite material or other materials. The first
patient-specific jig may include at least three alignment members
for attachment to specific portions of the jig based on the
specific bone structure of the patient's coxal bone. The at least
three alignment members may assist with proper alignment of the
first patient-specific jig in the patient's acetabulum during
surgery. The three alignment members may include first, second, and
third alignment members that are positioned at specific outer
portions of the first patient-specific jig.
[0011] In some embodiments, the first, second, and third alignment
members are designed and adapted to be hooked on or engaged with
(or otherwise positioned at) particular portions of the coxal bone
adjacent to the acetabulum to stabilize and properly orient the
first patient-specific jig into the acetabulum during surgery. The
first alignment member may be positioned on the first
patient-specific jig to engage a particular portion of the medial
rim of the acetabulum of the coxal bone. The second alignment
member may be positioned on the first patient-specific jig to
engage a particular portion of the greater sciatic notch of the
coxal bone. The third alignment member may be positioned on the
first patient-specific jig to engage a particular portion of the
obturator foramen of the coxal bone. These alignment members may
contact any three areas of bone peripheral to the acetabulum. Thus,
the first patient-specific jig includes three reference
points/members, specific to the patient's acetabulum of the coxal
bone, to properly align the first patient-specific jig in the
acetabulum during surgery and provide for proper orientation of the
reaming machine when resurfacing the acetabulum.
[0012] The three alignment members may each comprise a pair of
hooks or other devices that provide sufficient engagement with the
particular portions of the coxal bone, as determined by the surgeon
during preoperation. A person having ordinary skill in the art when
reviewing this disclosure will understand that the three alignment
members may be secured or removably attached or abutted to the
first patient-specific jig by any currently or later known suitable
means or attachment methods. The three alignment members may pivot,
swivel or otherwise move relative to the first patient-specific
jig, or they may be relatively immovable or inflexible to provide
sufficient force against respective portions of the coxal bone to
ensure proper orientation of the first patient-specific jig.
[0013] An aperture may be provided radially into or through the
first patient-specific jig. The aperture is adapted to receive a
guide pin or post extension through the aperture during surgery.
The guide pin or extension is placed into the aperture and is
removably secured to the coxal bone of the patient in a particular
orientation and at a particular depth, as determined by the surgeon
during preoperation. The first patient-specific jig is then removed
while the guide post remains positioned in the coxal bone at the
desired angle and position. The guide post may then serve as a
guide for the reaming machine to accurately ream (resurface) the
acetabulum to a predetermined depth and orientation for receiving
the acetabular cup. The guide post and the reamer may have the same
or similar central axes, as with conventional reaming machines and
processes. In some embodiments the guide post may be removed prior
to reaming and a surgeon at his discretion may use the guide post
sinus tract as a guide to reaming without the guide post at a
desired angle and to a desired depth.
[0014] As discussed above, it is critical to ream the acetabulum
accurately and as determined during preoperation. Accordingly, the
second patient-specific jig may be provided to assist in
determining accurate reaming and proper alignment of the acetabular
cup before the cup is implanted into the patient's acetabulum. As
indicated below, a third patient-specific jig may also be used to
progressively prepare the acetabulum to properly receive the
prosthetic acetabular cup.
[0015] The second patient-specific jig may be designed and
manufactured based on the second patient-specific male portion, but
it may also be based on the first patient-specific male portion.
The second patient-specific jig may include at least three
alignment members, which may be based on the same or similar
positions as the first, second, and third alignment members of the
first patient-specific jig, or the positions may be different
depending upon the patient's anatomy. The second patient-specific
jig may also include an aperture having the same or similar
position and orientation as the aperture in the first
patient-specific jig, or it may be different. The second
patient-specific jig may also have an axial length that is greater
than a corresponding axial length of the first patient-specific jig
due to the fact that the second patient-specific jig is utilized
after some or all of the reaming of the acetabulum has
occurred.
[0016] After the surgeon has removed the first patient-specific jig
and reamed the acetabulum to a predetermined depth and orientation,
the reamer device is removed from the acetabulum and the guide post
may remain attached to the coxal bone or, in some instances, may be
removed. The surgeon may then position the second patient-specific
jig into the reamed acetabulum without a pin or, alternatively,
onto the original guide pin or post extension, or alternatively
over a different pin or post extension used to align the second
patient-specific jig. Using the particular shape and size of the
second patient-specific jig and, where applicable, the alignment of
the aperture through the jig, the surgeon may then rotate and
position the second patient-specific jig in the reamed acetabulum
to determine whether additional reaming is required in one or more
quadrants, or whether the acetabulum has been reamed accurately to
receive the prosthetic acetabular cup. In furtherance of such
determination, the surgeon may also utilize the alignment members
attached to the second patient-specific jig, if they were designed
and manufactured for attachment to the jig; it may be that the
aperture and the shape of the second patient-specific jig is
sufficient for purposes of accurate alignment of the prosthetic
acetabular cup.
[0017] In some instances, if adequate remaining in any direction
has not been accomplished and confirmed with only one or two jigs,
there may be a need for additional reaming after which a third jig
may be used. The third patient specific jig may be similar or
different in regards to alignment members and guide post aperture
orientation as the first and/or second patient specific jigs.
[0018] Once accurate reaming is accomplished through utilizing some
or all of the above described devices and methods, the surgeon may
then implant or secure the acetabular prosthetic cup to the reamed
acetabulum in a traditional manner, such as with or without screws
and with or without cement and with or without use of a guide pin
or post extension.
[0019] The predetermined orientation of the apertures and the
alignment members of both the first and second (and, as applicable,
third) patient-specific jigs may provide the surgeon with a quick,
accurate means to properly resurface the acetabulum without the use
of additional devices and machines. This is possible because the
positions of the alignment members of the first, second and third
patient-specific jigs are based upon the patient's bone structure,
thereby providing three reference points to accurately utilize the
first jig, the guide post, the reamer, and the second and third
jigs, as planned during preoperation based upon the 3D modeling
images of the patient, a combination of two-dimensional
radiographic images of the patient, or a combination of
three-dimensional and two-dimensional images of a patient.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIGS. 1-4 are flow diagrams illustrating steps for
pre-operative imaging and planning for a joint replacement
procedure, according to an aspect of the present invention.
[0021] FIG. 4A schematically illustrates a system for carrying out
the steps of FIGS. 1-4.
[0022] FIGS. 5 and 6 are flow diagrams illustrating steps for
performing a joint replacement procedure, according to an aspect of
the present invention.
[0023] FIG. 7 is a front view of a pelvic bone.
[0024] FIG. 8 is a top view of a prosthetic implant seated in the
pelvic bone of FIG. 7.
[0025] FIG. 9A is a top view of a patient-specific jig mounted on
the pelvic bone of FIG. 7 according to one embodiment.
[0026] FIG. 9B is a partial cross-sectional view of the pelvic bone
of FIG. 7 and a side view of the patient-specific jig of FIG.
9A.
[0027] FIG. 10A is an isometric view of a first patient-specific
jig according to one embodiment.
[0028] FIG. 10B is an elevational view of the first
patient-specific jig of FIG. 10A.
[0029] FIG. 11A is an isometric view of a second patient-specific
jig according to one embodiment.
[0030] FIG. 11B is an elevational view of the second
patient-specific jig of FIG. 11A.
[0031] FIG. 12A is an isometric view of a third patient-specific
jig according to one embodiment.
[0032] FIG. 12B is an elevational view of the third
patient-specific jig of FIG. 8.
[0033] FIG. 13A is a side view of a first patient-specific jig
positioned in an acetabulum and a guide post positioned through
said jig and secured to the acetabulum.
[0034] FIG. 13B is a side view of the pelvic bone showing the first
patient-specific jig positioned in the acetabulum.
[0035] FIG. 14 is a cross-sectional view of a reaming tool
positioned in the acetabulum.
[0036] FIG. 15A is a side view of a second patient-specific jig
positioned in an acetabulum and a supplemental guide post
positioned through said jig and secured to the acetabulum.
[0037] FIG. 15B is a side view of the pelvic bone showing the
second patient-specific jig positioned in the acetabulum 15A.
[0038] FIG. 16 is a cross-sectional view of a reaming tool
positioned in the acetabulum.
[0039] FIG. 17A is a side view of a third patient-specific jig
positioned in the acetabulum and the supplemental guide post of
FIG. 15A.
[0040] FIG. 17B is a top view of the third patient-specific jig
positioned in the acetabulum as shown in FIG. 17A.
[0041] FIG. 18 is an isometric view of an impactor tool used to
install a prosthetic implant in a reamed acetabulum according to
one aspect of the present disclosure.
[0042] FIG. 19 is an isometric view of a cannulated acetabular
impactor according to an embodiment of the present invention.
[0043] FIG. 20 is an end view of the cannulated acetabular impactor
of FIG. 19.
[0044] FIG. 21 is a partial cross-sectional view of a prosthetic
implant in a reamed acetabulum that is being installed with the
impactor tool of FIG. 18 and the cannulated acetabular impactor of
FIG. 19, according to one aspect of the present disclosure.
[0045] FIG. 22 is a cross-sectional view of a portion of another
cannulated acetabular impactor according to an alternate embodiment
of the invention.
[0046] FIG. 23A is a perspective view of a patient specific
jig.
[0047] FIG. 23B is a cross-sectional view of the patient specific
jig of FIG. 23A.
[0048] FIG. 24A is a perspective view of a patient specific
jig.
[0049] FIG. 24B is a cross-sectional view of the patient specific
jig of FIG. 24A.
[0050] FIG. 25A is a perspective view of a patient specific
jig.
[0051] FIG. 25B is a cross-sectional view of the patient specific
jig of FIG. 25A.
[0052] FIG. 25C is a perspective view of an outer component of the
patient specific jig of FIG. 25A
[0053] FIG. 25D is a perspective view of an inner component of the
patient specific jig of FIG. 25A
[0054] FIG. 26A is a side elevation view of a cannulated
impactor.
[0055] FIG. 26B is a cross-sectional view of cannulated impactor of
FIG. 26A.
DETAILED DESCRIPTION
[0056] As mentioned above, the methods and systems of the present
invention are based at least in part on pre-operating
(pre-operative) imaging and at least in part on orthopedic surgical
procedures based upon the pre-operative methods and systems. As is
understood in the art, pre-operative imaging has a number of
different purposes and generally is performed in order to
subsequently guide the surgeon during the surgical procedure, allow
for patient-specific tools and/or implants to be formed, etc. The
present disclosure is part of a system for designing and
constructing one or more patient-specific jigs for use in an
orthopedic surgical procedure in which an acetabular component is
prepared, orientated and implanted. The referenced systems and
methods are now described more fully with reference to the
accompanying drawings, in which one or more illustrated embodiments
and/or arrangements of the systems and methods are shown. Aspects
of the present systems and methods can take the form of an entirely
hardware embodiment, an entirely software embodiment (including
firmware, resident software, micro-code, etc.), or an embodiment
combining software and hardware. One of skill in the art can
appreciate that a software process can be transformed into an
equivalent hardware structure, and a hardware structure can itself
be transformed into an equivalent software process. Thus, the
selection of a hardware implementation versus a software
implementation is one of design choice and left to the implementer.
Throughout this disclosure, the term "prosthetic implant" and
"acetabular component" refer to cup-shaped implants that are
installed into patients during hip replacement surgery.
[0057] FIGS. 1-4 are flow diagrams illustrating methods pertaining
to pre-operative imaging and planning according to aspects of the
present invention. FIG. 4A shows a system for carrying out the
methods of the present disclosure, such as those described with
reference to FIGS. 1-4. As a preliminary matter, FIG. 4A is a
simplified system 410 of devices that may be used to carry out the
methods of the present disclosure. The system 410 comprises a
computing system 412 coupled to an imaging system 414 that captures
and transmits patient image data to the computing system 412. The
computing system 412 processes such data and transmits the data to
the display device 416 for display of images and other data. An
input device 418 receives input from a computer or an operator
(such as a surgeon) and transmits inputted information to the
computing system 412 for processing. Such systems are well known in
the art and will not be described in greater detail. The imaging
system 412 may include a bone imaging machine for forming
three-dimensional image data from bone structure of a patient. The
computing system 412 may include a patient-specific device
generator for processing and generating images, and a
patient-specific device converter for generating design control
data. A manufacturing machine 420 receives the control data from
the computing system 412 for making patient-specific various
jigs.
[0058] In FIG. 1, a method 100 according to an embodiment starts at
101. At 102, a bone imaging machine generates a bone surface image
from three-dimensional image data from bone structure of a patient.
At 104, a patient-specific device generator generates a prosthesis
implant image superimposed in an acetabulum of the bone surface
image. The implant in the image is positioned in its final,
implanted position and orientation, regardless of the state of the
patient's bone. The jigs created from the present invention will be
designed to modify the bone such that the implant will be properly
positioned at the end of the procedure.
[0059] At 106, the patient-specific device generator generates a
first-patient specific jig image superimposed proximate the
acetabulum of the bone surface image according to the installation
position. At 108, a patient-specific device converter generates
control data from the first patient-specific jig image and ends or
moves to 110. At 110, the patient-specific device generator
generates a second patient-specific jig image superimposed in the
acetabulum of the bone surface image and ends or moves to 112. At
step 112, the patient-specific device generator generates a third
patient-specific jig image superimposed in the acetabulum of the
bone surface image and ends.
[0060] FIG. 2 shows a method 200 according to an aspect of the
present disclosure. At 202, a patient-specific device generator
generates a guide post image at least partially positioned through
an acetabulum of the bone surface image. At 204, the
patient-specific device generator generates a first
patient-specific jig image superimposed in the acetabulum of the
bone surface image according to the installation position. At 206,
the patient-specific device generator generates an aperture image
through the body image of the second patient-specific jig image and
ends.
[0061] FIG. 3 shows a method 300 according to an aspect of the
present disclosure. At 302, a patient-specific device generator
generates a guide post image at least partially positioned through
an acetabulum of the bone surface image. At 304, the
patient-specific device generator generates a second
patient-specific jig image superimposed in the acetabulum of the
bone surface image according to the installation position. At 306,
the patient-specific device generator generates an aperture image
through the body image of the first patient-specific jig image and
ends.
[0062] FIG. 4 shows a method 400 according to an aspect of the
present disclosure. At 402, a patient-specific device generator
generates a guide post image at least partially positioned through
an acetabulum of the bone surface image. At 404, the
patient-specific device generator generates a third
patient-specific jig image superimposed in the acetabulum of the
bone surface image according to the installation position. At 306,
the patient-specific device generator generates an aperture image
through the body image of the third patient-specific jig image and
ends.
[0063] As discussed above, FIG. 4A shows a system 410 for carrying
out the methods of FIGS. 1-4 according to some aspects of the
present disclosure. The computing system 412 may include
instructions in the form of computer software for automatically
generating images of prosthesis implants in final installation
positions on the bone structure images and for automatically
generating various guide post images and jig images designed for
use during surgery on the particular patient. In some aspects, it
may be necessary for the surgeon during preoperative planning to
input information into the input device 418 for creating or
altering guide post and jig images for a particular patient based
on the surgeon's understanding of the particular bone structure of
the patient as displayed on the display device 416.
[0064] FIGS. 5 and 6 are flow diagrams of methods pertaining to
operative surgery according to aspects of the present disclosure.
The methods of FIGS. 5 and 6 may be carried out by a surgeon or by
a machine, or by both. Moreover, the surgeon may utilize some or
all of the devices discussed with reference to FIGS. 1-4A during
surgery, such as viewing the preoperative images displayed on the
display device while operating on a patient.
[0065] In FIG. 5, a method 500 according to an aspect starts at
501. At 502, a first patient-specific jig is positioned in an
acetabulum of a patient. The first patient-specific jig is formed
according to a predetermined installation position of a prosthesis
implant to be secured to the patient. At 504, each of three
alignment members is engaged with a corresponding pre-selected area
on a coxal bone and adjacent the acetabulum of the patient. At 506,
a guide post is positioned through the aperture of the first
patient-specific jig and is secured into the coxal bone of the
patient. At 508, the first patient-specific jig is removed from the
guide post. At 510, bone material from the acetabulum is reamed
with aid of a reaming machine. At 512, it is determined whether the
reaming machine has reached an installation reference point of the
installation position; this may be determined by the surgeon or by
a measuring device or other device to determine the depth of bone
that was reamed. If the reaming machine has reached an installation
reference point, at 514 the guide post is removed and the
prosthesis implant is installed in the patient, then ends. If the
reaming machine has not reached an installation reference point, at
516 the guide post is removed and a second patient-specific jig is
positioned in the reamed acetabulum of the patient, then to step
602 in FIG. 6. As further discussed below, in some aspects the
guide post is not removed and remains secured to the patient until
the prosthesis implant is installed.
[0066] At step 602, three alignment members of the second
patient-specific jig are respectively engaged with predefined
selected areas proximate the acetabulum of the patient. At 604, a
supplemental guide post is positioned through the aperture of the
second patient-specific jig and is secured into the coxal bone of
the patient. At 606, the second patient-specific jig is removed
from the supplemental guide post and the acetabulum. At 608, the
acetabulum is reamed with aid of a reaming machine. In some
instances the guide post can be removed prior to reaming and the
sinus tract in the bone from the guide post is used as a visual
guide to ream at a desired orientation and to a desired depth. At
610, a third patient-specific jig is positioned in the reamed
acetabulum of the patient. At 612, it is determined whether all
three alignment members of the third patient-specific jig are
engaged to respective selected areas proximate the acetabulum of
the patient. If yes, at 616 the supplemental guide post may or may
not be removed and the prosthesis implant is secured to the reamed
acetabulum and then ends. If no, the method returns to 608 and the
operations are repeated until it is determined that all three
alignment members of the third patient-specific jig are engaged to
respective selected areas proximate the acetabulum of the patient
so that the prosthesis implant may be installed in the patient.
[0067] FIGS. 7 and 8 show an acetabular component 700 oriented an
in an acetabulum 702 of a coxal bone 704 of a pelvic bone 706. The
acetabular component 700 is positioned according to an installation
position 708, which is in part determined by a prescribed
anteversion angle and a prescribed inclination angle of the
acetabular component 700. FIG. 7 shows a front view of the pelvic
bone 706 and the acetabular component 700 positioned in the
acetabulum 702 of the patient's right coxal bone 704, and FIG. 8
shows a lateral view of the right coxal bone 704 with the
acetabular component 700 positioned in the acetabulum 702. These
figures illustrate the incorporation of steps discussed with
reference to FIGS. 1-4A where the acetabular component 700 is a
generated image that is superimposed over a generated image of bone
structure (e.g., the coxal bone 704) of a patient to determine an
installation position 708 of the acetabular component 700.
Determining the prescribed anteversion angle and the prescribed
inclination angle for a particular patient involves techniques and
calculations that are known in the art, and thus, will not be
described in detail. Although not necessarily part of the
preoperative planning, for purposes of illustration an installation
axis P is shown on FIG. 7
[0068] Once the installation position 708 is determined, a
reference point 710 is established that represents a particular
point in the coxal bone 704 of the patient for purposes of
determining the depth to which a reaming machine will ream bone
material, which will be further discussed below. The reference
point 710 may be considered a point on the tangential plane of a
hemispherical shaped surface, such as the outer surface shape of
the acetabular component 700.
[0069] With continued reference to FIG. 8, the coxal bone 704
includes (among many others) a medial rim 712, a sciatic notch 714,
and an obturator foramen 716, which all have various shapes and
surfaces that are specific to each patient.
[0070] FIGS. 9A and 9B show a patient-specific jig 720 oriented in
the acetabulum 702 of the coxal bone 704 according to the
installation position 708 of the acetabular component 702. These
figures show a technique that incorporates steps of FIGS. 1-4A in
that the patient-specific jig 720 is a generated image that is
superimposed over the generated image of the bone structure of a
patient. As a preliminary matter, the patient-specific jig 720 may
be any one of the first, second, and third patient-specific jigs
discussed with reference to FIGS. 10A-15B and elsewhere in this
disclosure. FIGS. 9A and 9B are mere illustrations of one possible
patient-specific jig 720.
[0071] The patient-specific jig 720 includes an aperture 722 and
three alignment members 724a, 724b, 724c. The aperture 722 is
formed through the patient-specific jig 720 at an angle that
corresponds to the installation position 708 of the acetabular
component 700. Depending upon the particular patient-specific jig
720 (i.e., the first, second, or third), the relative orientation
of the aperture 722 may vary depending upon the required amount of
bone to be removed and the particular required angle of a reaming
head during operation, which is ultimately determined by the
installation position 708 of the acetabular component 700. The
angles of the various apertures for the various jigs are discussed
further below.
[0072] The three alignment members 724a, 724b, 724c are attached to
the patient-specific jig 720 at positions around a circumference
end 726 (or distal end) of the patient-specific jig 720 depending
upon the particular bone structure of the particular patient. The
three alignment members 724a, 724b, 724c may be formed integral
with the jig or may be attached to the jig with any suitable
attachment means. The purpose of the three alignment members 724a,
724b, 724c help the surgeon: 1) determine the proper orientation of
a guide post to be installed in the patient (FIGS. 13A and 15A),
and/or 2) determine whether additional reaming of bone is necessary
before utilizing another jig or before final installation of an
acetabular component. In any event, depending on whether all of the
three alignment members 724a, 724b, 724c of a particular
patient-specific jig 720 are in contact with respective selected
areas of the patient's bone during surgery when the particular jig
is placed in the acetabulum 702, corresponding information is
conveyed to the surgeon. The surgeon will be able to determine the
next appropriate steps during surgery, as further described
below.
[0073] The positions of the three alignment members 724a, 724b,
724c will depend on which particular jig (i.e., first, second, or
third jigs) the three alignment members are attached to. However,
the positions the three alignment members 724a, 724b, 724c may be
the same on each jig depending on the preoperative requirements
determined by the surgeon and the computing systems. In one example
and as shown on FIG. 9B, the first alignment member 724a is
attached to the patient-specific jig 720 at an attachment portion
726a, and the second alignment member 724b is attached to the
patient-specific jig 720 at an attachment portion 726b, and the
third alignment member 724c is attached to the patient-specific jig
720 at an attachment portion 726c. The position of the respective
attachment portions 726a, 726b, 726c are determined during
pre-operative imaging and planning steps. Accordingly, the three
alignment members 724a, 724b, 724c extend from the circumference
end 726 of the patient-specific jig 720 and are designed to contact
certain selected areas of the coxal bone 704 depending on the bone
structure of the patient. The first alignment member 724a contacts
a selected area 728a of the medial rim 712. The second alignment
member 724b contacts a selected area 728b of the sciatic notch 714.
Finally, the third alignment member 724c contacts a selected area
728c inferiorally below the transverse acetabular ligament at the
superior portion of the obturator foramen 716. In some instances,
such as when using the second and third jigs, the contact between
the alignment members and the respective selected areas is
dependent upon whether the surgeon has reamed enough bone. If not,
at least one of the alignment members will not be in contact with
the respective selected area, indicating that more bone needs to be
removed, as further discussed below.
[0074] FIGS. 10A and 10B show a first patient-specific jig 730.
FIGS. 11A and 11B show a second patient-specific jig 744. FIGS. 12A
and 12B show a third patient-specific jig 754. These figures
represent that the patient-specific jigs are generated images based
on the installation position of the acetabulum component and based
on the bone structure of the patient. Some or all of the
patient-specific jigs are formed by a machine based on the
generated images, as further discussed elsewhere in this
disclosure. In some cases, only a first patient-specific jig is
generated and created in instances where very little bone reaming
is required, for example. In other instances, only a second or only
a third patient-specific jig is utilized to accurately guide
placement of an acetabular component without using the patient
specific jig(s) to assist with removal of acetabular bone.
[0075] FIG. 10A shows an isometric view of a first patient-specific
jig 730 and FIG. 10B shows a side elevational view of FIG. 10A. The
first patient-specific jig 730 includes three alignment members
732a, 732b, 732c that extend from a circumference end 734 of the
first patient-specific jig 730 at positions to contact certain
selected areas of the coxal bone (see FIG. 9A (generically) and
FIG. 13B (specifically)). The first alignment member 732a is
attached to the patient-specific jig 730 at an attachment portion
736a, and the second alignment member 732b is attached to the first
patient-specific jig 730 at an attachment portion 736b, and the
third alignment member 732c is attached to the patient-specific jig
730 at an attachment portion 736c. The angle and position of each
alignment member 732a, 732b, 732c relative to the circumference end
734 is determined according to the particular position and surface
of the selected areas of the coxal bone of the patient that the
alignment members 732a, 732b, 732c are designed to contact during
use of the first patient-specific jig 730 during operation. Each
alignment member 732a, 732b, 732c includes an engagement portion
738a, 738b, 738c, respectively, which is the portion of the
alignment member that contacts respective selected areas of the
coxal bone 704. See FIGS. 13A and 13B for illustrations of the
position of each alignment members 732a, 732b, 732c relative to the
first patient-specific jig 730 and the selected areas of the
patient's coxal bone 704.
[0076] The first patient-specific jig 730 includes an aperture 740
that extends from a reference end 742 to the circumference end 734
of the first patient-specific jig 730. The aperture 740 is sized
and configured to receive a guide post positioned in a patient
(FIG. 13A). As further described below, the guide post is
positioned according to the installation position 708 of the
acetabular component 700 (FIGS. 7 and 8). The first
patient-specific jig 730 includes a height H1, which is selected so
that the reference end 742 does not contact an unreamed acetabulum
at the beginning stages of surgery. This is discussed further
below.
[0077] FIG. 11A shows an isometric view of a second
patient-specific jig 744 and FIG. 11B shows a side elevational view
of FIG. 11A. The second patient-specific jig 744 includes three
alignment members 746a, 746b, 746c that extend from a circumference
end 748 of the second patient-specific jig 744 at positions to
contact certain selected areas of the coxal bone (see FIG. 9A
(generically) and FIG. 15B (specifically)). The alignment members
746a, 746b, 746c are attached to the second patient-specific jig
744 at respective attachment portions 750a, 750b, 750c, similar to
the first patient-specific jig 730. The angle and position of each
alignment member 746a, 746b, 746c relative to the circumference end
748 is determined according to the particular position and surface
of the selected areas of the coxal bone of the patient that the
alignment members 746a, 746b, 746c are designed to contact during
use of the second patient-specific jig 744 during operation. The
angle and position of each alignment member 746a, 746b, 746c may be
the same as or different than that of the alignment members of the
first patient-specific jig 730 of FIG. 10A. Each alignment member
746a, 746b, 746c includes an engagement portion 748a, 748b, 748c,
respectively, which is the portion of the alignment member that
contacts respective selected areas of the coxal bone 704. See FIGS.
15A and 15B for illustrations of the position of each alignment
member 746a, 746b, 746c relative to the second patient-specific jig
744 and the selected areas of the patient's coxal bone 704.
[0078] The second patient-specific jig 744 includes an aperture 750
that extends from a reference end 752 to the circumference end 748
of the second patient-specific jig 744. The aperture 750 is sized
and configured to receive a supplemental guide post positioned in a
patient (FIG. 15A). As further described below, the supplemental
guide post is positioned according to the installation position 708
of the acetabular component 700 (FIGS. 7 and 8). The second
patient-specific jig 744 includes a height H2, which is selected so
that, if the reference end 752 contacts a reamed acetabulum, and if
at least one of the alignment members 746a, 746b, 746c is not in
contact with a respective selected area of the coxal bone, the
surgeon will know that additional reaming is necessary before
installing the supplemental guide post and placing the final
acetabular prosthesis. This is discussed further below.
Understandably, height H2 can be greater than height H1, in part
because bone is reamed between usage of the first and second
jigs.
[0079] FIG. 12A shows an isometric view of a third patient-specific
jig 754 and FIG. 12B shows a side elevational view of FIG. 12A. The
third patient-specific jig 754 includes three alignment members
756a, 756b, 756c that extend from a circumference end 758 of the
third patient-specific jig 754 at positions to contact certain
selected areas of the coxal bone (see FIG. 9A (generically) and
FIG. 17B (specifically)). The alignment members 756a, 756b, 756c
are attached to the third patient-specific jig 754 at respective
attachment portions 760a, 760b, 760c, similar to the first
patient-specific jig 730. The angle and position of each alignment
member 756a, 756b, 756c relative to the circumference end 758 is
determined according to the particular position and surface of the
selected areas of the coxal bone of the patient that the alignment
members 756a, 756b, 756c are designed contact during use of the
third patient-specific jig 754 during operation. The angle and
position of each alignment member 756a, 756b, 756c may be the same
or different to that of the alignment members of the first and
second patient-specific jigs of FIGS. 10A and 11A. Each alignment
member 756a, 756b, 756c includes an engagement portion 762a, 762b,
762c, respectively, which is the portion of the alignment member
that contacts respective selected areas of the coxal bone 704. See
FIGS. 17A and 17B for illustrations of the position of each
alignment members 756a, 756b, 756c relative to the third
patient-specific jig 754 and the selected areas of the patient's
coxal bone 704.
[0080] The third patient-specific jig 754 includes an aperture 764
that extends from a reference end 766 to the circumference end 758
of the third patient-specific jig 754. The aperture 764 is sized
and configured to receive the supplemental guide post positioned in
a patient (FIG. 17A). As further described below, the supplemental
guide post is positioned according to the installation position 708
of the acetabular component 700 (FIGS. 7 and 8). The third
patient-specific jig 754 includes a height H3, which is selected so
that, if the reference end 766 contacts a reamed acetabulum,
thereby causing at least one of the alignment members 756a, 756b,
756c to not be in contact with a respective selected area of the
coxal bone, the surgeon will know that additional reaming is
necessary before installing the acetabular component 700 in the
patient. This is discussed further below. Understandably, height H3
can be greater than height H2 because bone is reamed between usage
of the second and third jigs, and because the second
patient-specific jig is used for purposes of positioning the
supplemental guide post while the third patient-specific jig is
used for purposes of determining whether additional reaming is
necessary before installing the acetabular component 700 in the
patient.
[0081] It will be appreciated that each or all of the alignment
members of any one of the patient-specific jigs may be formed in
various configuration and shapes. For example, an alignment member
may be an arc shaped or other non-linear shaped member, or it may
have two or more angles surfaces. The exact shape, position, and
alignment of each alignment member is determined by the surgeon and
the computing system during preoperative planning depending upon
the specific bone structure of the patient and the installation
position of the acetabulum component.
[0082] FIGS. 13A and 13B show the first patient-specific jig 730
positioned in an un-reamed acetabulum 703 of the patient, and FIG.
14 shows a reaming tool 768 positioned in the acetabulum 703 and
ready to ream bone material. These figures show a technique that
incorporates the preoperative steps of FIGS. 1-4A in that the first
patient-specific jig 730 and a guide post 770 are generated images
that are superimposed over the generated image of the bone
structure of a patient. These figures also show a technique that
incorporates the operative steps practiced by a surgeon on a
patient, such as described with reference to FIGS. 5 and 6.
[0083] During preoperative planning and with reference to FIGS. 9A
and 9B, a generated image of an acetabular component 700 is imposed
over the bone structure image, which ultimately shows the
installation position 708 of the acetabular component 700. Based on
such installation position 708, the computer system determines,
with input from the surgeon, the exact position of the guide post
770 to be installed in the patient during early stages of
operation. The guide post 770 will be the guide for the position of
the first patient-specific jig 730 and the reaming machine 768.
Preferably, the guide post 770 is positioned substantially
perpendicular to a central axis of the acetabular component 700 to
be later installed in the patient; however, the angle of the guide
post 770 relative to the acetabular component 700 may vary
depending upon the preoperative surgery analysis by the computer
system and the surgeon based on patient requirements. Once the
orientation of the guide post 770 is established and displayed as a
generated image, an image is generated of the first
patient-specific jig 730. As noted above, the purpose of the first
patient-specific jig 730 is to establish the exact position of the
guide post 770 to be installed in the patient during surgery.
Accordingly, the reference end 742 of the first patient-specific
jig 730 is designed to make contact with the un-reamed acetabulum
703. The three alignment members 732a, 732b, 732c are designed to
contact respective selected areas of the coxal bone 704 adjacent
the acetabulum 703.
[0084] With particular reference to FIG. 13B, during surgery the
surgeon inserts the first patient-specific jig 730 into the
acetabulum 703 and rotates or otherwise orients the first
patient-specific jig 730 in the patient until all three alignment
members 732a, 732b, 732c are in contact with respective selected
areas 772a, 772b, 772c of the coxal bone 704. Once the first
patient-specific jig 730 is properly oriented, the surgeon inserts
the guide post 770 through the aperture 740 and guide post 770,
which may be a threaded pin, and may be drilled into the bone
(typically 2 mm to 20 mm deep). Thus, the guide post 770 will be
installed at the exact position determined during preoperative
planning and according to the installation position of the
acetabular component 700. The first patient-specific jig 730 may
then be removed and a reaming machine 768 may be used to remove
bone material from the patient, either over the guide post or
without it in place.
[0085] FIG. 14 illustrates the reaming machine 768 used for such
purpose. The reaming machine 768 includes a reaming head 774, which
may be a detachable head of a selected size corresponding to the
size of the acetabular component 700 to be installed. The reaming
head 774 includes a guide aperture 776 that slidably receives the
guide post 770. The reaming head 774 reams bone with a consistent
axial motion in a direction depicted by Arrow A because the guide
aperture 776 includes a central axis coextensive with a central
axis of the guide post 770 and because the guide aperture 776
closely receives the guide post 770. In some embodiments, the
reaming may be cannulated while in other embodiments, the reaming
may not be cannulated. In some embodiments, The surgeon may remove
the guide post prior to reaming and use the visible pilot hole as a
visual guide to center the reamers that can be used by traditional
means without cannulated reaming. Such reaming heads with a guide
aperture and methods of using such reaming heads with a guide post
in a patient are well known in the art and will not be described in
greater detail.
[0086] FIGS. 15A and 15B show the second patient-specific jig 744
positioned in a reamed acetabulum 705 of the patient, and FIG. 16
shows a reaming tool 768 ready to ream additional bone material.
These figures show a technique that incorporates the preoperative
steps in that the second patient-specific jig 744 is a generated
image that is superimposed over the generated image of the bone
structure of a patient. These figures also show a technique that
incorporates the operative steps practiced by a surgeon on a
patient.
[0087] FIG. 15A shows the reamed acetabulum 705 as the result of
the surgeon reaming a portion of the acetabulum 703 to a desired
depth. In some instances, the surgeon will ream a couple
millimeters of bone and will have reached the reference point 710
(FIG. 7) such that bone reaming is completed and the acetabular
component 700 can be installed in the patient. In other instances,
additional bone reaming is necessary to a depth depending upon the
installation position 708 for a particular patient as determined
during preoperative planning. When it is determined that additional
bone reaming is necessary, in some instances the guide post 770 of
FIG. 13A remains installed in the patient and the second
patient-specific jig 744 is utilized to determine if additional
bone reaming is necessary; this is accomplished by inserting the
second patient-specific jig 744 into the reamed acetabulum 705. In
some embodiments, the second patient-specific jig 744 is inserted
over the guide post 770 while in other embodiments, the guide post
770 may be removed before inserting the second patient specific jig
774. With the second patient specific jig in the acetabulum 705,
the surgeon may determine whether the three alignment member 746a,
746b, 746c are all in contact with selected areas 772a, 772b, 772c
of the coxal bone 704. If not, in some embodiments, before further
reaming, the surgeon may reinsert the guide post 770 into the bone
and advance it or drill it further into the bone. The surgeon may
then remove the guide post 770 and may utilize the reaming machine
768 of FIG. 14 and ream additional bone material. The surgeon may
continue to check the depth of the reamed acetabulum 705 by
utilizing the second patient-specific jig 744 as noted above until
all three alignment members 746a, 746b, 746c are in contact with
the selected areas 772a, 772b, 772c of the coxal bone 704. Once
this is achieved, the surgeon will know with accurate precision
that the reference point 710 has been reached and at the desired
angle for accurate installation of the acetabular component 700 in
the patient. The surgeon may then install the acetabular component
700 in the patient utilizing known techniques in the art. In the
current method, a guide post may be utilized over which the
acetabular component 700 may be more accurately placed than with
standard techniques.
[0088] In other instances and where additional bone reaming is
necessary but at a different angle than with respect to FIG. 14
according to preoperative planning, the guide post 770 is removed
from the patient and a supplemental guide post 778 is installed in
the patient to guide the reaming machine 768 at a different angle
than the original guide post 770. In some instances the
supplemental guide post 778 may be removed prior to reaming and the
sinus tract in bone may guide the surgeon to ream at an appropriate
angle and to an appropriate depth. Such operative steps are
determined by the surgeon, with the use of the computing system,
during preoperative planning. For purposes of illustration and as
one example, FIGS. 15A and 15B show the supplemental guide post 778
installed in the patient at a different angle than the guide post
770 of FIGS. 13A and 14. Accordingly, once the bone is reamed as
described with reference to FIG. 14, the guide post 770 is removed
and the second patient-specific jig 744 is placed into the reamed
acetabulum 705. Similar to the first patient-specific jig 730, the
second patient-specific jig 744 is utilized to determine the
orientation of the supplemental guide post 778 to be installed in
the patient. Thus, the surgeon inserts the second patient-specific
jig 744 into the reamed acetabulum 705 and rotates or otherwise
orients the second patient-specific jig 744 in the patient until
all three alignment members 746a, 746b, 746c are in contact with
respective selected areas 772a, 772b, 772c of the coxal bone 704,
as depicted on FIGS. 15A and 15B. Once the second patient-specific
jig 744 is properly oriented, the surgeon inserts the supplemental
guide post 778 through the aperture 750 and the threads of the
supplemental guide post 778 engage the bone. Thus, the supplemental
guide post 778 will be installed at the exact position determined
during preoperative planning and according to the installation
position of the acetabular component 700. The second
patient-specific jig 774 may then be removed and a reaming machine
768 may be used to remove additional bone material from the
patient, with or without the guide post in place.
[0089] FIG. 16 illustrates the reaming machine 768 used for such
purpose. The reaming machine 768 includes a supplemental reaming
head 780, which may be a detachable head of a selected size
corresponding to the size of the acetabular component 700 to be
installed. The supplemental reaming head 780 may be smaller in size
than the reaming head 774 of FIG. 14, or it may be the same size.
The supplemental reaming head 780 may include a guide aperture 782
that slidably receives the supplemental guide post 778. The
supplemental reaming head 780 reams bone with a consistent axial
motion in a direction depicted by Arrow B because the guide
aperture 782 includes a central axis coextensive with a central
axis of the supplemental guide post 778 and because the guide
aperture 782 closely receives the supplemental guide post 778. Such
reaming heads having a guide aperture are well known in the art and
will not be described in greater detail.
[0090] FIGS. 17A and 17B show the third patient-specific jig 754
positioned in a reamed acetabulum 707 of the patient. These figures
show a technique that incorporates the preoperative steps of FIGS.
1-4A in that the third patient-specific jig 754 is a generated
image that is superimposed over the generated image of the bone
structure of a patient. These figures also show a technique that
incorporates the operative steps practiced by a surgeon on a
patient disclosed herein.
[0091] FIG. 17A shows a reamed acetabulum 707 as the result of the
surgeon reaming a portion of the acetabulum 705 to a desired depth,
as discussed with reference to FIG. 16. In some instances, the
surgeon will ream one or two millimeters of bone and utilize the
third patient-specific jig 754 to determine whether additional bone
reaming is necessary before final installation of the acetabular
component in the patient, as determined during preoperative
planning. Thus, the surgeon inserts the third patient-specific jig
754 into the reamed acetabulum 707. If all three alignment members
756a, 756b, 756c are in contact with respective selected areas
784a, 784b, 784c of the coxal bone 704, then the third
patient-specific jig 754 has indicated that the reference point 710
of the installation position 708 has been reached, and therefore,
bone reaming is completed.
[0092] The surgeon will then install the acetabular component 700
according to known techniques or over a supplemental guide post
using a cannulated acetabular impactor and mallet device as
described herein. For purposes of discussion, FIG. 17A shows that
alignment member 756b is not in contact with the selected area 784b
adjacent to the native acetabulum. As such, the illustrated third
patient-specific jig 754 indicates that the reference point 710 has
not been reached, and, therefore, additional bone reaming is
necessary. Accordingly, the surgeon reams bone with the reaming
head 780, utilizing the supplemental guide post 778 pilot hole or
sinus tract from the removed guide post as a guide member, and then
inserts the third patient-specific jig 754 to determine whether all
three alignment members 756a, 756b, 756c are in contact with the
coxal bone 704 and the reference point 710 (FIG. 7) has been
reached by the supplemental reaming head 780. These processes
continue until the acetabulum is reamed to the desired depth of the
reference point, at which point the surgeon installs the acetabular
component 700 in the patient, as shown on FIG. 8.
[0093] FIGS. 18-22 show aspects of the present disclosure in which
an impactor tool 800 is used to assist with installation of an
acetabular component 700 in a reamed acetabulum 705 or 707.
Typically, a reamed acetabulum is reamed to have a radius slightly
smaller than the radius of the acetabular component for a tight fit
configuration. As such, the surgeon typically utilizes a mallet or
other tool to impact the acetabular component into its final
position.
[0094] The impactor tool 800 includes a head 802 and a handle 804.
The head 802 includes a guide aperture 806 having a central axis X.
During surgery and once the acetabulum is reamed to a desired
depth, the acetabular component 700 is partially inserted into the
reamed acetabulum. An elongated guide post 808 is installed in the
coxal bone 704 and extends through a hole in the acetabular
component 700, as known in the art. A cannulated acetabular
impactor device 810 includes a cannulated channel 812 that receives
the elongated guide post 808; the cannulated acetabular impactor
device 810 may be threaded or slidably received over the elongated
guide post 808. The cannulated acetabular impactor device 810
includes a distal end 814 biased against the cup portion of the
acetabular component 700, and a proximal end 816 with a surface 818
to be impacted by the impactor tool 800. The distal end of the
cannulated impactor tool may be cylindrical, hemispherical, or any
other shape. The distal end may simply abut the acetabular
prosthesis or alternatively thread into the acetabular prosthesis.
The distal end of the impactor tool may be one piece or more than
one piece. The guide aperture 806 of the impactor tool 800 slidably
receives a portion of the guide post 808. The proximal portion of
an impactor tool may have a cannulated opening for the guide post
in some embodiments. In some embodiments, the proximal portion of
the impactor tool may not have a cannulated opening. The proximal
portion of an impactor tool may be one piece or more than one
piece.
[0095] During installation of the acetabular component 700, the
surgeon holds the handle 804 and slidably engages the guide
aperture 806 of the impactor tool 800 with the guide post 808. The
surgeon then repeatedly impacts the surface 818 of the proximal end
816 of the cannulated acetabular impactor device 810 with the
impactor tool 800, causing an impacting force against the
acetabular component 700, until the acetabular component 700 is in
its final position. Typically several impacts with the impactor
tool 800 will suffice, and typically the surgeon can hear when the
acetabular component 700 is seated flush against the acetabulum in
its final position. One advantage of the impactor tool 800 is that
impact against the elongated member 810 (and ultimately the
acetabular component 700) occurs at approximately the same impact
location upon each repeated impact with the tool 800. Typically,
the surgeon uses a mallet or hammer without the assistance of any
guidance, which can result in improper installation of the
acetabular component 700. The guide aperture 806 of the impactor
tool 800 ensures repeatable impact location and position of the
impactor tool 800, which reduces or eliminates the possibility for
human error during repeated impacts with a mallet or hammer.
[0096] According to an alternate embodiment, FIGS. 23A and 23B show
a first patient-specific jig 900; FIGS. 24A and 24B show a second
patient-specific jig 1000; and FIGS. 25A and 25B show a third
patient-specific jig assembly 1100. These figures show
computer-generated images that represent the patient-specific jigs.
They are created based on the installation position of the
acetabulum component and the bone structure of the patient. Some of
the information for generating the patient-specific jigs may be
derived from data gathered using two-dimensional and/or
three-dimensional imaging techniques.
[0097] The physical patient-specific jigs can be formed based on
the generated images, as further discussed elsewhere in this
disclosure. In some cases, only a first patient-specific jig is
generated and created; for example, in instances where very little
bone reaming is required. In some embodiments, physical jigs are
created using a machining process, such as, an additive
manufacturing process, a subtractive process, or a combination of
additive and subtractive manufacturing processes.
[0098] FIG. 23A shows an isometric view of a first patient-specific
jig 900; and FIG. 23B shows a cross-sectional view of a first
patient-specific jig 900. The first patient-specific jig 900 may
include three alignment members 905a, 905b, 905c that extend from a
circumference end 910 of the first patient-specific jig 900. The
alignment members are positioned to contact certain selected areas
of the coxal bone (see, for example, FIG. 9A (generically) and FIG.
13B (specifically) and their associated text). The first alignment
member 905a is attached to the patient-specific jig 900 at an
attachment portion 906a; the second alignment member 905b is
attached to the first patient-specific jig 900 at an attachment
portion 906b; and the third alignment member 905c is attached to
the patient-specific jig 900 at an attachment portion 906c. The
angle and position of each alignment member 905a, 905b, 905c
relative to the circumference end 910 is determined according to
the particular position and surface of the selected areas of the
coxal bone of the patient that the alignment members 905a, 905b,
905c contact during a procedure. Each alignment member 905a, 905b,
905c includes an engagement portion 904a, 904b, 904c, respectively,
that contacts the coxal bone.
[0099] The engagement portion 904a of the first alignment member
905a may be contoured or shaped to abut the surface of the medial
rim of the patient; the engagement portion 904b of the second
alignment member 905b may be contoured or shaped to abut the
surface of the sciatic notch of the patient; and the engagement
portion 904c of the third alignment member 905c may be contoured or
shaped to abut the surface of the acetabular notch of the patient.
The angle A between the first alignment member 905a and the second
alignment member 905b may be approximately 105 degrees; the angle B
between the second and third alignment members 905b, 905c may be
approximately 120 degrees; and the angle C between the third and
first alignment members 905c, 905a may be approximately 135
degrees. See FIGS. 13A and 13B for exemplary illustrations of the
position of alignment members relative to a first patient-specific
jig and the selected areas of a patient's coxal bone.
[0100] The first patient-specific jig 900 can include an aperture
925 that extends from a reference end 920, through a collar 926, to
a distal end of the first patient-specific jig 900. The illustrated
aperture 925 is sized and configured to receive a guide post
positioned in a patient (for example, as shown in FIG. 13A and
described in the associated text). The collar 926 may be supported
by one or more supports, such as support 927, which may extend from
the collar 926 to the circumference of the jig. As further
described below, the guide post is positioned according to an
installation position, for example, installation position 708 of
the acetabular component 700 (FIGS. 7 and 8). The first
patient-specific jig 900 includes a height h1, which may be
selected so that the reference end 920 may not contact an unreamed
acetabulum at the beginning stages of surgery. In some embodiments,
the reference end 920 may not contact the undreamed acetabulum.
This is discussed further below.
[0101] FIG. 24A shows an isometric view of a second
patient-specific jig 1000 and FIG. 24B shows a cross-sectional view
of the second patient-specific jig 1000. The second
patient-specific jig 1000 includes three alignment members 1005a,
1005b, 1005c that extend from a circumference end 1010 of the
second patient-specific jig 1000 at positions selected to contact
certain areas of the coxal bone (see, for example, FIG. 9A
(generically) and FIG. 15B (specifically) and accompanying text).
The alignment members 1005a, 1005b, 1005c are attached to the
second patient-specific jig 1000 at respective attachment portions
1006a, 1006b, 1006c, similar to the first patient-specific jig 900.
The angle and position of each alignment member 1005a, 1005b, 1005c
relative to the circumference end 1010 is determined according to
the particular position and surface of the selected areas of the
coxal bone or other anatomy or anatomic structure of the patient
that the alignment members 1005a, 1005b, 1005c are designed to
contact during use of the second patient-specific jig 900. The
angle and position of each alignment member 1005a, 1005b, 1005c may
be the same as or different than that of the alignment members of
the first patient-specific jig 900. Each alignment member 1005a,
1005b, 1005c includes an engagement portion 1004a, 1004b, 1004c,
respectively, that contacts selected areas of a coxal bone. For
example, see FIGS. 15A and 15B for illustrations of the position of
alignment members relative to a second patient-specific jig and
selected areas of a patient's coxal bone.
[0102] The second patient-specific jig 1000 can include an aperture
1025 that extends from a reference end 1020 through a collar 1026,
to a distal end of the collar 1026 of the first patient-specific
jig 1000. The illustrated aperture 1025 is sized and configured to
receive a supplemental guide post positioned in a patient (see, for
example, FIG. 15A). The collar 1026 may be supported by one or more
supports, such as support 1027, which may extend from the collar to
the circumference of the jig. The supplemental guide post may be
positioned according to the installation position of the acetabular
cup. The second patient-specific jig 1000 includes a height h2,
which is selected so that, if the reference end 1020 contacts a
reamed acetabulum, or if at least one of the alignment members
1005a, 1005b, 1005c is not in contact with a respective selected
area of the coxal bone, the surgeon will know that additional
reaming is necessary before installing the supplemental guide post
and placing the final acetabular prosthesis. This is discussed
further below. Understandably, height h2 can be greater than height
h1, in part because bone is reamed between usage of the first and
second jigs.
[0103] The reaming process may cause undercuts to develop in the
acetabulum. An undercut occurs when the reamer removes material
from the interior of the acetabulum and cuts underneath other areas
of the coxal, for example, beneath the acetabular margin. If a jig
is created to fit against the entire reamed surface of the
acetabulum, it would not fit. Therefore, the second
patient-specific jig 1000, and other jigs, in particular jigs for
use after reaming, may include a cutout 1030 that does not closely
match the surface of the reamed acetabulum, permitting easy
installation and removal of the jig from an acetabulum and, in
particular, a reamed acetabulum.
[0104] FIG. 25A shows an isometric view of a third patient-specific
jig assembly 1100 and FIG. 25B shows a cross-sectional view
thereof. The third patient-specific jig 1100 includes two
components: an outer component 1101 and an inner component 1102.
The outer component 1101 of the third patient-specific jig 1100
includes three alignment members 1105a, 1105b, 1105c that extend
from a circumference end 1110 of the third patient-specific jig
1100 at positions selected to contact certain areas of the coxal
bone (see, for example, FIG. 9A (generically) and FIG. 17B
(specifically)). As best shown in FIG. 25C, the alignment members
1105a, 1105b, 1105c are attached to the third patient-specific jig
1100 at respective attachment portions 1106a, 1106b, 1106c, similar
to the first patient-specific jig 900. The angle and position of
each alignment member 1105a, 1105b, 1105c relative to the
circumference end 1110 is determined according to the particular
position and surface of the selected areas of the coxal bone of the
patient that the alignment members 1105a, 1105b, 1105c are designed
to contact during the operation. The angle and position of each
alignment member 1105a, 1105b, 1105c may be the same or different
than that of the alignment members of the first and second
patient-specific jigs of FIGS. 23A and 24A. Each alignment member
1105a, 1105b, 1105c includes an engagement portion 1104a, 1104b,
1104c, respectively, that contacts respective selected areas of the
coxal bone. For example, see FIGS. 17A and 17B for illustrations of
the position of alignment members relative to a third
patient-specific jig and selected areas of a patient's coxal
bone.
[0105] FIG. 25C shown the outer component 1101 and FIG. 25D shows
the inner component 1102. The outer component 1101 of the third
patient-specific jig 1100 includes an aperture 1151 that accepts
the inner component 1102. The aperture 1151 includes at least one,
and preferably three, alignment structures or keyways 1155a, 1155b,
1155c. Each alignment keyway 1155a, 1155b, 1155c may be sized and
shaped to accept one of the alignment structures or keys 1156a,
1156b, 1156c of the interior component 1102 and can be configured
to only allow the interior component 1102 to fit within the
aperture 1151 in a single orientation. The depth of the keyways
1155a, 1155b, 1155c and length of the alignment keys 1156a, 1156b,
1156c can be sized such that when the inner component is properly
fit to the outer component, the bottom surface 1157a, 1157b,
(1157c, FIG. 25B) (see FIG. 25D) of each alignment key 1156a,
1156b, (1156c, not shown) contacts the shelf (1158a, 1158b, not
shown), 1158c (see FIG. 25C) of a respective keyway. The
illustrated keyways and alignment keys are also sized and shaped
such that when the inner component is properly fit to the outer
component, the inner component alignment surface 1161 is flush or
co-planar with the outer component alignment surface 1160. These
features provide the surgeon with an easy way to determine if the
reaming is complete and that the two jig components properly fit in
the joint and with each other.
[0106] In some embodiments, the alignment structures or keyways of
an outer component may be disposed along the circumference of an
aperture of the outer component, as shown in FIG. 25A. In some
embodiments the alignment structures may be at other locations on
the outer component, for example, displaced a distance from the
circumference of the aperture of the outer component.
[0107] In some embodiments, the alignment structures or keys of an
inner component may be disposed along the circumference of the
inner component, as shown in FIG. 25B. In some embodiments the
alignment structures may be at other locations on the inner
component, for example, displaced a distance from the circumference
of the inner component.
[0108] The third patient-specific jig 1100 includes an aperture
1125 that extends from a reference end 1121 to a distal end of the
of the first patient-specific jig 1100. The aperture 1125 is sized
and configured to receive the supplemental guide post positioned in
a patient (see, for example, FIG. 17A). The collar 1126 may be
supported by one or more supports 1127a, 1127b, 1127c which may
extend from the collar to an alignment surface 1161 of the jig. In
addition to supporting the collar 1126, the supports 1127a, 1127b,
1127c also provide a place for a surgeon to grip and handle the
interior component 1102. As further described below, the
supplemental guide post is positioned according to an installation
position of the acetabular component.
[0109] The two-component design of the third patient-specific jig
1100 provides for easy placement and removal of the jig in a reamed
acetabulum. In placing the jig, a surgeon may first align and place
the outer component 1101 of the third patient-specific jig 1100 in
the reamed acetabulum. The surgeon may then verify that the
reference end 1120 of the outer component does not contact the
reamed acetabulum. Then, the surgeon may place the inner component
1102 into the aperture 1151 of the outer component 1101 while
aligning the alignment keys 1156a, 1156b, 1156c with the keyways
1155a, 1155b, 1155c. The surgeon may then check that the inner
component alignment surface 1161 is co-planar with the outer
component alignment surface 1160. If they are co-planar, the
reaming is complete. If they are not co-planar, for example, when
the reference end 1121 of the inner component 1102 contacts a
portion of the acetabulum, the surgeon may need to conduct
additional reaming.
[0110] In addition, the third patient-specific jig 1100 includes a
height h3, which is selected so that the surgeon will know if
additional reaming is necessary before installing the acetabular
component in the patient. The surgeon may know more reaming is
necessary if the reference ends 1120, 1121 contact a reamed
acetabulum, and at least one of the alignment members 1105a, 1105b,
1105c is not in contact with a respective selected area of the
coxal bone, or if the alignment surfaces 1160 and 1161 are not
co-planar. Understandably, height h3 can be greater than height h2
because bone may be reamed between usage of the second and third
jigs, and because the second patient-specific jig may be used for
purposes of positioning the supplemental guide post, while the
third patient-specific jig may be used for purposes of determining
whether additional reaming is necessary before installing the
acetabular component in the patient.
[0111] Once the third patient-specific jig is in place and no more
reaming is required, the surgeon may install a supplemental guide
post through the aperture 1125 and into the patient.
[0112] With the guide post in place, the surgeon may remove the
third patient-specific jig 1100. If the third patient specific jig
1100 is a single component, the surgeon, in removing the jig, may
push against the guide post, knocking the jig out of position or
out of the patient altogether. With the two-component jig, the
surgeon may remove the inner component 1102 by sliding it along the
guide post and out of the acetabulum. The aperture 1151 of the
outer component may be aligned with and/or concentric with the
guide post. In some embodiments, the central axis of the aperture
1151 may coincide with or be parallel to the central axis of the
guide post. In still other embodiments, the aperture 1151 and inner
component 1102 may be configured such that inner component 1102 is
removed in a direction substantially parallel to the central axis
of the guide post. With the inner component 1102 removed, the
surgeon now has ample room to remove the outer component 1101 with
much less risk of altering the position of the guide post.
[0113] The physician may then place an implant or prosthesis over
the guide post and into the acetabulum, and then use a cannulated
impactor to place the prosthetic into the jip joint.
[0114] In some embodiments, a surgeon may only use a single jig
when replacing a joint. For example, a surgeon may use conventional
joint replacement techniques for the bone material removal or
reaming process and then use a single patient-specific jig to
confirm adequate removal of material. In some embodiments, a
surgeon may use a single jig to confirm adequate removal of bone
material and to guide the placement of the final prosthetic, for
example, by guiding the installation of a guide post. Bone or other
anatomic structures may be removed with reamers, burrs, rongeurs,
drills or any other instrument. 26A and 26B show an embodiment of a
cannulated impactor assembly. FIG. 26A shows a side view of the
cannulated impactor assembly 1200. FIG. 26B shows a cross-sectional
view of the cannulated impactor assembly 1200. The cannulated
impactor assembly 1200 includes a cannulated impactor 1210. The
cannulated impactor is comprised of a shaft 1211 that joins an
anvil 1213 at a first end of the shaft 1211 with a second end 1212
configured to accept a head 1220. The second end may be a tapered,
as shown in FIGS. 26A and 26B. The tapered end facilitates
alignment of the head 1220 with the cannulated impactor 1210.
[0115] As shown in FIG. 26B, the impactor 1210 includes a
cannulated channel or cavity 1214. The cannulated channel 1214
receives a guide post 1270 for guiding the placement of an
acetabular component. The cannulated channel 1214 may also receive
a sheath 1230. The sheath 1230 may fit within the cannulated
channel 1214 and around the guide post 1270. The sheath 1230, guide
post 1270, and cannulated channel 1214 may slidingly engage with
each other. In some embodiments the respective diameters of a
sheath, guide post, and cannulated channel allow for 0.1 mm
clearance between the inner diameter of an outer part and the outer
diameter of an inner part. In some embodiments, the cannulated
channel may be blind, for example, as illustrated in FIG. 26B.
[0116] The head 1220 may include an aperture 1222 configured to
slidably engage with the sheath 1230 and/or the guide post 1270.
The head 1220 may include an engagement surface, such as the
illustrated engagement surface 1221, which is configured to engage
with an end of a cannulated impactor. In the illustrated
embodiment, the head 1220 has a tapered engagement surface 1221
configured to engage with the tapered second end 1212 of the shaft
1211.
[0117] In some embodiments, the second end 1212 and engagement
surface 1221 may each include complementary threads. In such an
embodiment, the second end 1212 screws into the engagement surface
1221.
[0118] The guide post 1270 may include a bone engagement end 1271.
The bone engagement end my include threads for engaging the bone
and retaining the guide post 1270 in a patient's bone. In some
embodiments, for example, the embodiment shown in FIGS. 26A and
26B, the engagement end 1271 may have a tapered point to engage the
patient's bone.
[0119] It will be appreciated that each or all of the alignment
members of any one of the patient-specific jigs disclosed herein
may be formed in various configurations and shapes. For example, an
alignment member may be an arc shaped or other non-linear shaped
member, or it may have two or more angled surfaces. The alignment
members and engagement portions may be parts of a continuous rim or
lip that extends out from the entirety of the circumference end of
a jig. The exact shape, position, and alignment of each alignment
member may be determined by the surgeon and the computing system
during preoperative planning depending upon the specific bone
structure of the patient and the installation position of the
acetabulum component. Any three points adjacent to a joint, such as
an acetabulum, may be used as a reference location to determine and
place a jig, a joint replacement, or an acetabulum implant in a
desired position.
[0120] In some embodiments, a patient-specific jig may include one
or more alignment members. In some embodiments, one or more
alignment members may extend from the circumference of the jig and
be contoured or shaped such that each alignment member may include
one, two, three, or more engagement portions each contoured or
shaped to match up with a respective one, two, three, or more
selected areas near the joint, for example the coxal bone.
[0121] In some embodiments, a single alignment member may extend
around substantially the entire circumference of the
patient-specific jig. In doing so, the single alignment member may
include one, two, three, or more engagement portions that are
contoured or shaped to match up with an area near the joint.
[0122] In some embodiments, a single alignment member may extend
around more than 180 degrees of the circumference of the
patient-specific jig. In some embodiments, an alignment member may
extend around less than 180 degrees, 120-180 degrees, or 240-360
degrees of the circumference of the patient-specific jig.
[0123] In some embodiments, a single alignment member may extend
around the circumference of a patient specific jig such that two or
more engagement portions of the single alignment member are
contoured or shaped to match up with respective areas near the
joint.
[0124] In some embodiments, two alignment members may extend from
the circumference of a patient-specific jig. A first alignment
member may include two or more engagement portions that are
contoured or shaped to match up with a respective area near the
joint. A second alignment member may include one or more engagement
portions that are contoured or shaped to match up with a respective
area near the joint. In a preferred embodiment the first and second
alignment members may extend from opposing sides of the
circumference of a patient specific jig.
[0125] It will also be appreciated that although the jigs,
impactors, and methods have been descried in reference to a human
hip joint, they are not limited to those applications. The jigs,
impactors, and methods are also applicable to other joints, such as
a shoulder joint, and to animals other than humans, such as horses,
dogs, apes, etc.
[0126] The various embodiments described above can be combined to
provide further embodiments. Aspects of the embodiments can be
modified, if necessary to employ concepts of the various patents,
applications and publications to provide yet further
embodiments.
[0127] These and other changes can be made to the embodiments in
light of the above-detailed description. In general, in the
following claims, the terms used should not be construed to limit
the claims to the specific embodiments disclosed in the
specification and the claims, but should be construed to include
all possible embodiments along with the full scope of equivalents
to which such claims are entitled. Accordingly, the claims are not
limited by the disclosure.
* * * * *