U.S. patent application number 13/463075 was filed with the patent office on 2012-11-01 for system of preoperative planning and provision of patient-specific surgical aids.
This patent application is currently assigned to The Cleveland Clinic Foundation. Invention is credited to Wael K. Barsoum, Jason A. Bryan, Joseph P. Iannotti, Peter D. O'Neill.
Application Number | 20120276509 13/463075 |
Document ID | / |
Family ID | 49043046 |
Filed Date | 2012-11-01 |
United States Patent
Application |
20120276509 |
Kind Code |
A1 |
Iannotti; Joseph P. ; et
al. |
November 1, 2012 |
SYSTEM OF PREOPERATIVE PLANNING AND PROVISION OF PATIENT-SPECIFIC
SURGICAL AIDS
Abstract
A method for assisting a user with surgical implementation of a
preoperative plan includes generating a physical native tissue
model of a native patient tissue. The physical native tissue model
includes at least one primary patient tissue area including a
surface of interest, at least one secondary patient tissue area
including no surfaces of interest, and a base surface for engaging
a supporting structure. The physical native tissue model, as
generated, includes at least one information feature providing
clinically useful information to the user. The information feature
is substantially separated from the surface of interest. An
apparatus for assisting a user with surgical implementation of a
preoperative plan is also provided.
Inventors: |
Iannotti; Joseph P.;
(Strongsville, OH) ; Barsoum; Wael K.; (Bay
Village, OH) ; Bryan; Jason A.; (Avon Lake, OH)
; O'Neill; Peter D.; (Shaker Heights, OH) |
Assignee: |
The Cleveland Clinic
Foundation
|
Family ID: |
49043046 |
Appl. No.: |
13/463075 |
Filed: |
May 3, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13282550 |
Oct 27, 2011 |
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13463075 |
|
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61408392 |
Oct 29, 2010 |
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Current U.S.
Class: |
434/267 |
Current CPC
Class: |
A61F 2/4081 20130101;
A61B 17/1778 20161101; A61B 2034/105 20160201; G09B 23/34 20130101;
G09B 23/30 20130101; A61B 2017/568 20130101; A61B 17/1739 20130101;
A61B 34/25 20160201; G09B 23/28 20130101; G09B 23/32 20130101; A61B
34/10 20160201; A61B 2034/108 20160201; A61F 2002/4633
20130101 |
Class at
Publication: |
434/267 |
International
Class: |
G09B 23/28 20060101
G09B023/28 |
Claims
1. A method for assisting a user with surgical implementation of a
preoperative plan, the method comprising the steps of: generating a
physical native tissue model of a native patient tissue, the
physical native tissue model including at least one primary patient
tissue area including a surface of interest, at least one secondary
patient tissue area including no surfaces of interest, and a base
surface for engaging a supporting structure; and including in the
physical native tissue model, as generated, at least one
information feature providing clinically useful information to the
user; wherein the information feature is substantially separated
from the surface of interest.
2. The method of claim 1, wherein the step of providing a physical
native tissue model of a native patient tissue includes the steps
of: creating a virtual model of a native patient tissue; and
creating a physical native tissue model of the native patient
tissue as a tangible representation of the virtual model of the
native patient tissue.
3. The method of claim 1, wherein the information feature is a
predetermined orientation of the base surface which is operative to
position at least one surface of interest in a predetermined
orientation in space when the base surface is engaged with the
supporting structure.
4. The method of claim 3, wherein the predetermined orientation of
the base surface is chosen to dictate a clinically useful placement
of a landmark into engagement with the physical native tissue model
when the landmark is located orthogonally to the supporting
structure.
5. The method of claim 1, wherein the information feature indicates
a desired placement for a landmark, the landmark indicating at
least one of a marking location and a marking trajectory to which
reference is made during surgical modification of the native
patient tissue.
6. The method of claim 1, including the step of transferring the
clinically useful information embodied in the information feature
from the physical native tissue model to the native patient tissue
during a surgical procedure.
7. The method of claim 6, wherein the step of transferring the
clinically useful information embodied in the information feature
includes the step of adjusting a reusable surgical instrument to
transfer at least a portion of the clinically useful information
embodied in the information feature from the physical native tissue
model to the native patient tissue.
8. The method of claim 6, wherein the step of transferring the
clinically useful information embodied in the information feature
includes the step of generating at least one patient-specific
surgical aid via interaction with the physical native tissue model
and with the information feature.
9. The method of claim 1, including the steps of: providing a
prosthetic implant to be installed in the native patient tissue;
and including in the physical native tissue model, as generated, an
information feature structure replicating at least a portion of the
implant in a preoperatively planned installed position.
10. The method of claim 1, wherein the step of generating a
physical native tissue model of a native patient tissue includes
the step of generating a physical native tissue model of a partial
native patient tissue, the method including the steps of: providing
a holder base representing a portion of a native patient tissue;
mating the physical native tissue model of the partial native
patient tissue with the holder base; referencing the mated physical
native tissue model of the partial native patient tissue and holder
base; and exchanging the physical native tissue model of the
partial native patient tissue upon the holder base for another
physical native tissue model of the partial native patient
tissue.
11. An apparatus for assisting a user with surgical implementation
of a preoperative plan, the apparatus comprising: a physical native
tissue model of a native patient tissue, the physical native tissue
model including at least one primary patient tissue area including
a surface of interest, and at least one secondary patient tissue
area including no surfaces of interest; and at least one
information feature providing clinically useful information to the
user, the information feature being included in the physical native
tissue model as generated; wherein the information feature is
substantially separated from the surface of interest.
12. The apparatus of claim 11, wherein the physical native tissue
model includes a base surface for engaging a supporting structure
and the information feature is a predetermined orientation of the
base surface which is operative to position at least one surface of
interest in a predetermined orientation in space when the base
surface is engaged with the supporting structure.
13. The apparatus of claim 12, wherein the predetermined
orientation of the base surface is chosen to dictate a clinically
useful placement of a landmark into engagement with the physical
native tissue model when the landmark is located orthogonally to
the supporting structure.
14. The apparatus of claim 11, wherein the physical native tissue
model of the native patient tissue is a tangible representation of
a virtual model of the native patient tissue.
15. The apparatus of claim 11, wherein the information feature
indicates a desired placement for a landmark, the landmark
indicating at least one of a marking location and a marking
trajectory to which reference is made during surgical modification
of the native patient tissue.
16. The apparatus of claim 15, wherein the clinically useful
information embodied in the landmark is transferred from the
physical native tissue model to the native patient tissue during a
surgical procedure.
17. The apparatus of claim 16, wherein a reusable surgical
instrument is adjusted based upon the relationship of the landmark
to the physical native tissue model to transfer at least a portion
of the clinically useful information embodied in the landmark from
the physical native tissue model to the native patient tissue.
18. The apparatus of claim 16, wherein at least one
patient-specific surgical aid, containing at least a portion of the
clinically useful information embodied in the landmark, is
generated via interaction with the physical native tissue model and
with the landmark.
19. The apparatus of claim 11, including a prosthetic implant to be
installed in the native patient tissue, and wherein an information
feature structure replicating at least a portion of the implant in
a preoperatively planned installed position is included in the
physical native tissue model, as generated.
20. The apparatus of claim 11, including a holder base and wherein
the physical native tissue model of the native patient tissue is a
physical native tissue model of a partial native patient tissue,
the holder base selectively accepting the physical native tissue
model of the partial native patient tissue in a mating
relationship, the physical native tissue model of the partial
native patient tissue being selectively replaced with another
physical native tissue model of a partial native patient tissue
upon the holder base.
21. A method of preoperative planning for assisting a user with
surgical implementation of a preoperative plan, the method
comprising the steps of: generating a physical native tissue model
of a native patient tissue, the physical native tissue model
including at least one surface of interest and a base surface,
spaced apart from the surface of interest, for engaging a
supporting structure; and including in the physical native tissue
model, as generated, at least one information feature providing
clinically useful information to the user; wherein the information
feature includes at least one of: a landmark indicating at least
one of a marking location and a marking trajectory to which
reference is made during surgical modification of the native
patient tissue, the landmark being spaced apart from the surgical
modification location, a predetermined orientation of the base
surface which is operative to position at least one surface of
interest in a predetermined orientation in space when the base
surface is engaged with the supporting structure, and a replica of
at least a portion of a prosthetic implant in a preoperatively
planned installed position.
22. The method of claim 21, including the step of transferring the
clinically useful information embodied in the information feature
from the physical native tissue model to the native patient tissue
during a surgical procedure.
23. The method of claim 22, wherein the step of transferring the
clinically useful information embodied in the information feature
includes the step of adjusting a reusable surgical instrument to
transfer at least a portion of the clinically useful information
embodied in the information feature from the physical native tissue
model to the native patient tissue.
24. The method of claim 22, wherein the step of transferring the
clinically useful information embodied in the information feature
includes the step of generating at least one patient-specific
surgical aid via interaction with the physical native tissue model
and with the information feature.
25. The method of claim 21, wherein the step of providing a
physical native tissue model of a native patient tissue includes
the steps of: creating a virtual model of a native patient tissue;
and creating a physical native tissue model of the native patient
tissue as a tangible representation of the virtual model of the
native patient tissue.
26. A method of preoperative planning for assisting a user with
surgical implementation of a preoperative plan, the method
comprising the steps of: generating a physical native tissue model
of a native patient tissue, the physical native tissue model
including at least one surface of interest and a base surface,
spaced apart from the surface of interest, for engaging a
supporting structure; and including in the physical native tissue
model, as generated, at least one information feature providing
clinically useful information to the user; wherein the clinically
useful information is information other than a desired location for
material modification of the native patient tissue.
27. The method of claim 26, including the step of transferring the
clinically useful information embodied in the information feature
from the physical native tissue model to the native patient tissue
during a surgical procedure.
28. The method of claim 27, wherein the step of transferring the
clinically useful information embodied in the information feature
includes the step of adjusting a reusable surgical instrument to
transfer at least a portion of the clinically useful information
embodied in the information feature from the physical native tissue
model to the native patient tissue.
29. The method of claim 27, wherein the step of transferring the
clinically useful information embodied in the information feature
includes the step of generating at least one patient-specific
surgical aid via interaction with the physical native tissue model
and with the information feature.
30. The method of claim 26, wherein the step of providing a
physical native tissue model of a native patient tissue includes
the steps of: creating a virtual model of a native patient tissue;
and creating a physical native tissue model of the native patient
tissue as a tangible representation of the virtual model of the
native patient tissue.
Description
RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 13/282,550, filed 27 Oct. 2011 and claiming
priority to U.S. Provisional Application No. 61/408,392, filed 29
Oct. 2010, the subject matter of both of which is incorporated
herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a preoperative planning
system and, more particularly, to a system of preoperative planning
and provision of patient-specific surgical aids.
BACKGROUND OF THE INVENTION
[0003] The scapula, commonly known as the "shoulder blade", is a
flat, triangular bone that lies over the back of the upper ribs. A
right scapula 100 is depicted in posterior, anterior, and right
side views in FIGS. 1A, 1B, and 1C, respectively. The posterior
surface of the scapula 100 can be readily felt through a patient's
skin. The scapula 100 serves as an attachment point for some of the
muscles and tendons of the arm, neck, chest, and back, and aids in
the movements of the arm and shoulder. The scapula 100 is also well
padded with muscle, so that it may be difficult to palpate boney
landmarks. The rear surface of each scapula 100 is divided into
unequal portions by a spine 102. This spine 102 leads to a head
104, which ends in the acromion process 106. A coracoid process 108
forms a prominence of the shoulder that curves forward and down
below the clavicle (collarbone, not shown). The acromion process
106 joins the clavicle and provides attachments for muscles of the
arm and chest muscles. The acromion process 106 is a bony
prominence at the top of the scapula 100. On the head 104 of the
scapula 100, between the acromion and coracoid processes 106 and
108, is a depression or cavity called the glenoid vault 110, shown
partially in dashed line in the Figures. The glenoid vault 110
joins with the head of the upper arm bone (humerus, not shown) in a
ball-and-socket manner to enable articulation of the shoulder joint
thereby formed. Similarly, though not shown, an acetabulum of the
hip joins with a head of an upper leg bone (femur) to form an
analogous ball-and-socket manner for hip joint articulation.
[0004] For treatment of various problems with the shoulder, hip, or
other body joint or bone (such as degenerative arthritis and/or
traumatic injury), one method of providing relief to a patient is
to replace the articulating surfaces with an artificial or
prosthetic joint. In the case of a shoulder, the humerus and
glenoid vault 110 articulating surfaces are replaced or resurfaced.
In the case of a hip, the femur and acetabulum articulating
surfaces can be replaced or resurfaced. Both of these examples are
of ball-and-socket type joints. Hinge-type joints, such as the knee
or elbow, and static/fixed skeletal components, such as the long
bones of the arm or leg, as well as interfaces such as those
between spinal vertebrae and intervertebral discs, could also be
subject to replacement and/or repair by the implantation of
artificial or prosthetic components or other fixation devices
related to the treatment of fractures, the sequelae of trauma,
congenital pathology, or other issues causing a lack of ideal
function. For clarity of description, the subject application will
be hereafter described as the rehabilitation and/or replacement of
a patient's shoulder joint.
[0005] In such surgical procedures, pain relief, increased motion,
and/or anatomic reconstruction of the joint are goals of the
orthopedic surgeon. With multiple variations in human anatomy,
prosthetic systems must be carefully designed, chosen, and
implanted to accurately replicate the joints that they replace or
the bone structures that they aim to change (in any manner).
[0006] A shoulder replacement procedure may involve a partial
shoulder replacement (not shown) or the total shoulder replacement
shown in FIG. 2. In a total shoulder replacement procedure, a
humeral component 212 having a head portion is utilized to replace
the natural head portion of the upper arm bone, or humerus 214. The
humeral component 212 typically has an elongated stem which is
utilized to secure the humeral component to the patient's humerus
214, as depicted. In such a total shoulder replacement procedure,
the natural bearing surface of the glenoid vault 110 is resurfaced,
lined, or otherwise supplemented with a cup-shaped glenoid
component 216 that provides a bearing surface for the head portion
of the humeral component 212. The depicted total shoulder
replacement of FIG. 2 is an "anatomical" shoulder replacement. A
"reverse" shoulder replacement is also known in the art.
[0007] Standard prosthetic glenoid components 216 are available in
a number of different sizes and configurations. However, most are
designed for use in an scapula having minimal bone loss or
deformity. When the scapula has bone loss and/or significant
pathology due to disease or trauma, the standard glenoid component
216 may be difficult to implant and/or may not enable desired
shoulder function, if it cannot be implanted in a preferred manner.
The surgeon may thus need to substantially modify the patient's
glenoid vault 110 during surgery in an attempt to make the standard
glenoid component 216 fit into the glenoid vault. Presurgical
planning tools are available to help the surgeon anticipate the
changes which will be needed to reform the patient's pathological
anatomy. However, the surgeon cannot always readily determine
whether even a remodeled glenoid vault 110 will fit as desired with
a standard prosthesis because the surgeon does not know how a
"normal" glenoid vault 110 (for which the standard prosthesis is
designed) should be shaped for that patient.
[0008] It is known to use computer aided design ("CAD") software to
design custom prostheses based upon imported data obtained from a
computerized tomography ("CT") scan of a patient's body. For
example, mirror-imaged CT data of a patient's contralateral
"normal" joint could be used, if the contralateral joint does not
also display a pathological anatomy. However, using a unique
prosthesis design for each patient can result in future
biomechanical problems resulting from a non-proven design and takes
away the familiarity that the surgeon will likely have with
standardized prosthesis designs. Thus, prosthesis designs that are
entirely customized are considered sub-optimal solutions and may
also be extremely expensive to design and produce.
[0009] Further, detailed preoperative planning, using two- or
three-dimensional images of the shoulder joint, often assists the
surgeon in compensating for the patient's anatomical limitations.
During the surgery, for example, an elongated pin may be inserted
into the surface of the patient's bone, at a predetermined
trajectory and location, to act as a passive landmark or active
guiding structure in carrying out the preoperatively planned
implantation. This "guide pin" may remain as a portion of the
implanted prosthetic joint or may be removed before the surgery is
concluded. This type of pin-guided installation is common in any
joint replacement procedure--indeed, in any type of surgical
procedure in which a surgeon-placed fixed landmark is
desirable.
[0010] In addition, and again in any type of surgical procedure,
modern minimally invasive surgical techniques may dictate that only
a small portion of the bone or other tissue surface being operated
upon is visible to the surgeon. Depending upon the patient's
particular anatomy, the surgeon may not be able to precisely
determine the location of the exposed area relative to the
remaining, obscured portions of the bone through mere visual
observation. For example, in a shoulder surgery, the scapula 100 is
mobile along the posterior and lateral chest walls and it therefore
may be difficult to define the fixed relationship of the glenoid
vault 110 to the body of the scapula 100 (i.e., using the plane of
the scapula as a reference to the glenoid vault) and/or the body of
the scapula to an external coordinate system in the operating room.
These factors, particularly in a minimally invasive surgical
procedure, may make it difficult for the surgeon to orient the
glenoid vault during surgery. Again, a guide pin may be temporarily
or permanently placed into the exposed bone surface to help orient
the surgeon and thereby enhance the accuracy and efficiency of the
surgical procedure.
[0011] One goal of shoulder surgery may be to modify the pathologic
bone to correct pathologic position to be within the normal range
or the normal position of the patient's native anatomy before the
bone loss occurred. During surgery, and particularly minimally
invasive procedures, the plane of the scapula may be difficult or
impossible to determine by direct visual inspection, resulting in
the need for assistive devices or methods to define both the
pathologic version present at the time of surgery and the intended
correction angle.
[0012] It is generally believed that there is a preferred
orientation for the glenoid component 216 to provide a full range
of motion and to minimize the risk of dislocation. Some example
orientations of the glenoid component 216 relative to the glenoid
face are about 5.degree. of anteversion to about 15.degree. of
retroversion; average version is about 1-2.degree. of retroversion.
This broadly replicates the natural angle of the glenoid. However,
the specific angular orientation of the glenoid portion, as well as
the offset and inclination of the glenoid, varies from patient to
patient.
[0013] With a view to overcoming these and other disadvantages,
some arrangements have been recently suggested in which a
three-dimensional intraoperative surgical navigation system is used
to render a model of the patient's bone structure. This model is
displayed on a computer screen and the user is provided with
intraoperative three-dimensional information as to the desired
positioning of the instruments and the glenoid component 216 of the
prosthetic implant. However, surgical navigation arrangements of
this type are not wholly satisfactory since they generally use only
a low number of measured landmark points to register the patient's
anatomy and to specify the angle of the prosthetic implant
component (e.g., a glenoid component 216), which may not provide
the desired level of accuracy. Further, the information provided by
such systems may be difficult to interpret and may even provide the
user with a false sense of security. Moreover, these systems are
generally expensive to install and operate and also have high user
training costs.
[0014] Various proposals for trial prosthetic joint components have
been made in an attempt to overcome the problems associated with
accurately locating the glenoid component 216 of the prosthetic
implant. While these trial systems may help with checking whether
the selected position is correct, they are not well-suited to
specify the correct position initially, and thus there still is
user desire for a system which may assist a user in placement of
prosthetic implant component in a prepared native tissue site.
[0015] Finally, due to factors such as the high cost of operating
room time and the patient detriment sometimes posed by lengthy
surgeries, the surgeon or other user may wish to simulate a
surgical procedure during preoperative planning, in order to become
familiar with the tasks that will be required and possibly reduce
the time and/or actions needed to perform the surgery.
[0016] In summary, preoperative planning and/or simulation,
regardless of the planning tasks undertaken or the nature of the
changes to be made to the patient's native tissue, will generally
reduce the need for intraoperative imaging in most surgical
procedures and should result in decreased operative time and
increased positional accuracy, all of which are desirable in
striving toward a positive patient outcome.
SUMMARY OF THE INVENTION
[0017] In an embodiment of the present invention, a method for
assisting a user with surgical implementation of a preoperative
plan is disclosed. A physical native tissue model of a native
patient tissue is generated. The physical native tissue model
includes at least one primary patient tissue area including a
surface of interest, at least one secondary patient tissue area
including no surfaces of interest, and a base surface for engaging
a supporting structure. The physical native tissue model, as
generated, includes at least one information feature providing
clinically useful information to the user. The information feature
is substantially separated from the surface of interest.
[0018] In an embodiment of the present invention, an apparatus for
assisting a user with surgical implementation of a preoperative
plan is disclosed. A physical native tissue model of a native
patient tissue includes at least one primary patient tissue area
including a surface of interest, and at least one secondary patient
tissue area including no surfaces of interest. At least one
information feature provides clinically useful information to the
user. The information feature is included in the physical native
tissue model as generated. The information feature is substantially
separated from the surface of interest.
[0019] In an embodiment of the present invention, a method of
preoperative planning for assisting a user with surgical
implementation of a preoperative plan is disclosed. A physical
native tissue model of a native patient tissue is generated. The
physical native tissue model includes at least one surface of
interest and a base surface, spaced apart from the surface of
interest, for engaging a supporting structure. The physical native
tissue model, as generated, includes at least one information
feature providing clinically useful information to the user. The
information feature includes at least one of: a landmark indicating
at least one of a marking location and a marking trajectory to
which reference is made during surgical modification of the native
patient tissue, the landmark being spaced apart from the surgical
modification location; a predetermined orientation of the base
surface which is operative to position at least one surface of
interest in a predetermined orientation in space when the base
surface is engaged with the supporting structure; and a replica of
at least a portion of a prosthetic implant in a preoperatively
planned installed position.
[0020] In an embodiment of the present invention, a method of
preoperative planning for assisting a user with surgical
implementation of a preoperative plan is disclosed. A physical
native tissue model of a native patient tissue is generated. The
physical native tissue model includes at least one surface of
interest and a base surface, spaced apart from the surface of
interest, for engaging a supporting structure. The physical native
tissue model, as generated, includes at least one information
feature providing clinically useful information to the user. The
clinically useful information is information other than a desired
location for material modification of the native patient
tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For a better understanding of the invention, reference may
be made to the accompanying drawings, in which:
[0022] FIG. 1A is an anterior view of a right scapula;
[0023] FIG. 1B is a posterior view of the scapula of FIG. 1A;
[0024] FIG. 1C is a side view of the scapula of FIG. 1A;
[0025] FIG. 2 is a partial sectional anterior view of a prosthetic
shoulder joint in a patient;
[0026] FIG. 3 is a flowchart describing one embodiment of the
present invention;
[0027] FIGS. 4-10 are example user views of a program for
generating the embodiment of FIG. 3;
[0028] FIGS. 11A-11B are schematic views depicting a use
environment for the embodiment of FIG. 3;
[0029] FIGS. 12A-12C are schematic views depicting placement
options for one element of the embodiment of FIG. 3 in a first
configuration;
[0030] FIGS. 13A-13C are schematic views depicting placement
options for one element of the embodiment of FIG. 3 in a second
configuration;
[0031] FIGS. 14A-14B are schematic views depicting options for one
element of the embodiment of FIG. 3 in the first configuration;
[0032] FIG. 15 is a schematic view of a computer system that can be
employed to implement systems and methods described herein, such as
based on computer executable instructions running on the computer
system;
[0033] FIGS. 16A-16B are perspective views of a use environment of
the present invention;
[0034] FIGS. 17A-17C are perspective views of a physical native
tissue model in a first configuration;
[0035] FIGS. 18A-18C are perspective views of the model of FIGS.
17A-17B in a second configuration;
[0036] FIGS. 19A-19B are perspective views of the model of FIGS.
17A-17B in a third configuration;
[0037] FIGS. 20A-20B are perspective views of the model of FIGS.
17A-17B in a fourth configuration;
[0038] FIGS. 21A-21B are perspective views of the model of FIGS.
17A-17B in a fifth configuration;
[0039] FIGS. 22A-22B are perspective views of the model of FIGS.
17A-17B in a sixth configuration;
[0040] FIGS. 23A-23B are perspective views of a physical native
tissue model in a first configuration;
[0041] FIGS. 24A-24B are perspective views of the model of FIGS.
23A-23B in a second configuration;
[0042] FIGS. 25A-25B are perspective views of the model of FIGS.
23A-23B in a third configuration; and
[0043] FIGS. 26A-26D are perspective views of a physical native
tissue model.
DESCRIPTION OF EMBODIMENTS
[0044] The patient tissue is shown and described herein at least as
a scapula 100 and the prosthetic implant component is shown and
described herein at least as a glenoid component 216, but the
patient tissue and corresponding prosthetic implant component could
be any desired types such as, but not limited to, hip joints,
shoulder joints, knee joints, ankle joints, phalangeal joints,
metatarsal joints, spinal structures, long bones (e.g., fracture
sites), or any other suitable patient tissue use environment for
the present invention. For example, the prosthetic implant
component could be an internal fixation device (e.g., a bone
plate), a structure of a replacement/prosthetic joint, or any other
suitable artificial device to replace or augment a missing or
impaired part of the body.
[0045] The term "lateral" is used herein to refer to a direction
indicated by directional arrow 118 in FIG. 1C; the lateral
direction in FIG. 1C lies substantially within the plane of the
drawing and includes all of the superior, inferior, anterior, and
posterior directions. The term "longitudinal" is used herein to
refer to a direction defined perpendicular to the plane created by
directional arrow 118, with the longitudinal direction being
substantially into and out of the plane of the drawing in FIG. 1C
and representing the proximal (toward the medial line of the body)
and distal (out from the body) directions, respectively.
[0046] In accordance with the present invention, FIG. 3 is a
flowchart depicting one example series of steps of a method of
preoperative planning and provision of patient-specific surgical
aids. In first action block 320, a virtual three-dimensional model
of a native patient tissue is created. A "native" patient tissue
herein is used to reference the status of the actual, physical
patient tissue at the time that the surgery is being planned. For
example, the native patient tissue may have been in the "native"
state from birth, or may instead be subject to a congenital or
acquired deficiency and accordingly be in an altered state as
compared to the patient tissue originally present in the patient.
Regardless of the mechanism by which the patient tissue came into
the "native" condition, the "native" patient tissue is used herein
to reference the expected state of the patient tissue at the time
of the operation--when the user cuts into the patient's body, the
native patient tissue is what will be found at the surgical
site.
[0047] The virtual model of the native patient tissue may be based
upon, for example, scanned image data taken from an imaging scan of
the native patient tissue. The term "model" is used herein to
indicate a replica or copy of a physical item, at any relative
scale and represented in any medium, physical or virtual. The
patient tissue model may be a total or partial model of a subject
patient tissue, and may be created in any suitable manner. For
example, and as presumed in the below description, the patient
tissue model may be based upon computer tomography ("CT") data
imported into a computer aided drafting ("CAD") system.
Additionally or alternatively, the native patient tissue model may
be based upon digital or analog radiography, magnetic resonance
imaging, or any other suitable imaging means. The patient tissue
model will generally be displayed for the user to review and
manipulate preoperatively, such as through the use of a computer or
other graphical workstation interface. While this description
presumes a three-dimensional model, one of ordinary skill in the
art could use a two-dimensional model in a similar manner to that
shown and described herein, without harm to the present invention.
An example of a virtual model of the native patient tissue is the
native patient tissue model 422 shown in FIGS. 4-10.
[0048] FIGS. 4-10 pictorially depict the preoperative planning
procedure described in the FIG. 3 flowchart. FIGS. 4-10 are example
user views of a computer program and/or system for implementing a
method of using the present invention, with a perspective view on
the left side of each Figure and coronal, sagittal (looking
distally from underneath the perspective view, as shown), and
transverse views, respectively, from top to bottom on the right
side of each Figure.
[0049] During preoperative planning with a system such as that
described, the user can view the native patient tissue model 422
and, based upon knowledge of other patient characteristics (such
as, but not limited to, height, weight, age, and activity level),
choose a desired device, described hereafter as a stock device 424,
for use in the surgical procedure. This use may include placement
in engagement with a native patient tissue model 422, as shown in
second action block 326 of FIG. 3. Visually, such as in the user
view of FIG. 4, an image of the selected desired stock device 424
may be placed over the native patient tissue model image.
[0050] A desired device could be the depicted stock prosthetic
implant, a custom prosthetic implant, a stock or custom instrument
(not shown), or any other desired item. Because three-dimensional
image models are available of many instruments and prosthetic
implants, whether stock or custom, the user may be able to
"install" the instrument or prosthetic implant virtually in the
native patient tissue model 422 via the preoperative computer
simulation described herein. During such a simulation, the user can
automatically and/or manually adjust or reorient the position of
the virtual stock device 424 with respect to the virtual native
patient tissue model 422, even to the extent of simulating the
dynamic interaction between the two, as may be helpful to refine
the selection, placement, and orientation of the stock device for a
desired patient outcome. The stock device 422 may be chosen from a
library of available stock devices; with the choice based upon any
factor or characteristic desired.
[0051] The term "stock" is used herein to indicate that the
component indicated is not custom-manufactured or -configured for
the patient, but is instead provided as a standard inventory item
by a manufacturer. A particular stock component may be selected
automatically by the system and/or manually by the user from a
product line range (e.g., the aforementioned library) of available
components, optionally with the user specifying a desired
configuration, general or particular size (e.g., small, medium,
large, or a specific measurement), material, or any other
characteristic of the component. Indeed, the stock component could
be manufactured only after the user has selected the desired
options from the range of choices available. However, the stock
component is differentiated from a custom-manufactured or bespoke
component in that the stock component is agnostic and indifferent
regarding a particular patient anatomy during the design and
manufacturing processes for an instrument, prosthetic implant, or
other component intended for that patient, while the patient
anatomy is an input into at least one design and/or manufacturing
process for a custom-manufactured component. The following
description presumes the use of a stock prosthetic implant and
stock instrument, though one of ordinary skill in the art will be
able to provide for the use of the present invention with a
custom-manufactured prosthetic implant or instrument, instead.
[0052] At third action block 328 of FIG. 3, the stock device 424 is
placed, or reoriented, into a predetermined device orientation
relative to the native patient tissue model 422, to achieve the
position shown in FIG. 4. An orientation of a structure, as used
herein, includes both the absolute location of the structure upon
or with respect to another structure and the arrangement or
positioning in space of the structure (e.g., rotation, pitch, yaw,
camber, or any other placement-related variable of the
structure).
[0053] The system may place the stock device 424 into the
predetermined device orientation automatically by the system and/or
manually by the user, based upon any suitable criteria. For
example, the system may provide at least two optional device
orientations and compare the optional device orientations to each
other based upon any desired device property(ies), in a weighted or
unweighted manner. Device properties that could factor into the
comparison include at least one of device size, device shape,
device material, number of fasteners to be used, type of fasteners,
size of fasteners, shape of fasteners, amount of patient tissue
alteration, type of patient tissue alteration, orientation of the
stock device relative to an other stock device (e.g., orientation
of one part of a prosthetic joint relative to another part of the
prosthetic joint which has already been [virtually] placed with
respect to the native patient tissue model), and physical quality
of the native patient tissue. A plurality of optional device
orientations could be compared to one another based on these or any
other suitable factors, in any suitable manner (e.g., using a
decision algorithm or comparison scheme). It is contemplated that
certain device properties may be more important than others, and
that the comparisons will be made automatically by the system
and/or manually by the user to allow for compromises--if needed--on
certain device properties in order to strive for a better overall
outcome.
[0054] Once the comparison(s) is (are) made, the user and/or system
chooses an optional device orientation based upon the comparison
and designates the chosen optional device orientation as the
predetermined device orientation. The predetermined device
orientation of the stock device 424 with respect to the native
patient tissue model 422 is shown in the FIG. 4 view. As is
especially apparent in the coronal (top right) and transverse
(bottom right) portions of FIG. 4, there may be some overlap or
superposition between the stock device 424 and the native patient
tissue model 422. This superposition is permissible in the virtual
environment of the described system and may helps to indicate areas
of the native patient tissue model 422 which could be targeted for
alteration during placement of the stock device 424.
[0055] Once a chosen stock device 424 has been virtually placed in
a desired orientation with respect to the native patient tissue
model 422 (it will be understood that some mechanical modification
might need to be made to the actual native patient tissue to
accomplish this implant placement in situ), the placement of any
fasteners or other penetrating structures 430 (e.g., a drill, guide
pin, or other surgical tool), when present, may also be planned
through the use of the computer simulation. Consideration of the
location, amount, and pathology of the patient tissue, any of the
above device properties, or any other desired factors, may be taken
into account in this optional penetrating structure 430 planning.
The penetrating structure(s) 430 may be chosen from a library of
available penetrating structures.
[0056] Manually and/or with automatic computer assistance, the user
can experiment with various fastener sizes, placements, and
orientations for securing the stock prosthetic implant to the
patient tissue, and/or with various other types of penetrating
structure 430 insertions into the native patient tissue model 422
similarly to the previously described device placement, until
reaching at least one predetermined penetration orientation (such
as that shown in FIG. 4) for at least one penetrating structure(s)
430 to be used with the surgical procedure being planned, as
described in fourth action block 332 of the FIG. 3 flowchart. When
the penetrating structure 430 positioning has been finalized, with
the stock device 424 virtually positioned in a predetermined device
orientation with respect to the patient tissue, a location and
target trajectory 434 may be defined for each of the penetrating
structures 430 present (if any) to follow during installation. The
term "trajectory" is used herein to indicate an invisible line
along which an elongate body will travel to reach the predetermined
penetration orientation.
[0057] Once the predetermined device orientation and any desired
predetermined penetration orientation(s), when present, are known,
the displayed images of the selected stock device 424 and/or of any
included penetrating structures 430 may be removed from the
displayed image of the native patient tissue model 422, for greater
clarity in following portion(s) of the preoperative planning
system. The displayed images of the selected stock device 424
and/or of any included penetrating structures 430 may be reinstated
and re-removed, as desired, during any phase of the below
operations.
[0058] As shown in fifth action block 336 of FIG. 3, at least one
landmark 538 (shown in FIG. 5) may be placed in at least one
predetermined landmark orientation relative to the native patient
tissue model 422. The landmark(s) 538, when present, represent a
chosen point in space and/or indicate a chosen
direction/orientation relative to the native patient tissue model
422 and are used to convey positional information to the user
during a surgical procedure. For example, a guide pin is displayed
as a three-dimensional landmark 538a spaced apart from the stock
device 424 over the image of the native patient tissue model 422 in
FIG. 5, while an aperture or cavity formed in the native patient
tissue model is shown as a two-dimensional landmark 538b (i.e.,
represented by a cross mark when seen from above or below)
corresponding to a central portion of the stock device in FIG. 5.
In fact, the "negative" aperture-type landmark 538b of FIG. 5 is
configured to receive a device shaft 540 of the stock device 424,
which helps to locate and stabilize the stock device with respect
to the native patient tissue model 422. One of ordinary skill in
the art would readily be able to instead provide a "positive" pin-
or shaft-type landmark (not shown) protruding from the native
patient tissue model 422 and adapted to be received in a cavity
(not shown) of another type of device, in an axle-type manner.
[0059] Regardless of the number, location, type, or any other
characteristics of the provided landmark(s) 538, it is contemplated
that the user will want to transfer the landmarked information to
the actual patient tissue during the surgical procedure. To that
end, a patient-specific template may be created using the system
described herein. The landmark 538 could also or instead be placed
during the surgical procedure using a robotic surgical aid,
adjustable reusable (e.g., "dial-in") tools, intraoperative
imaging, or any other suitable placement aid.
[0060] As shown at sixth action block 342 of FIG. 3, a
patient-specific template is generated, which may be accomplished
by the system with steps represented in user views such as the
sequence of FIGS. 6-7. As shown in FIG. 6, a template blank 644 is
placed into a desired (final) predetermined template orientation
with respect to the native patient tissue model 422. The template
blank 644 may be selected, automatically and/or manually, from a
library of available template blanks and may be placed, again
automatically and/or manually, into the predetermined template
orientation based upon any of the above device properties or any
other desired factors.
[0061] As is particularly apparent in the coronal (top right) and
transverse (bottom right) portions of FIG. 6, at least a portion of
the native patient tissue model 422 and at least a portion of the
template blank 644 (virtually) overlap to create a superposed
volume 646 of space which is occupied by both the native patient
tissue model and the template blank. Since this superposed volume
646 is impracticable during the actual physical surgical procedure,
the superposed volume 646 is (again, virtually) removed from the
template blank 644 to create a mating surface 748 of the template
blank adjacent the native patient tissue model 422. In other words,
the system adjusts the dimensions of the bottom template surface
748 to mate with a surface of the native patient tissue model 422.
The term "mate" is used herein to indicate a relationship in which
the contours of two structures are at least partially matched or
coordinated in at least two dimensions.
[0062] The mating surface 748 may be seen in particularly the
coronal (top right) and transverse (bottom right) portions of FIG.
7. The patient-specific template 750 may be, for example, the type
disclosed in co-pending U.S. Provisional Patent Application No.
61/408,359, filed 29 Oct. 2010 and titled "System and Method for
Association of a Guiding Aid with a Patient Tissue", the entire
contents of which are incorporated herein by reference.
[0063] Regardless of its nature, the patient-specific template 750
virtually contains or embodies at least one predetermined landmark
orientation and has at least one landmark guiding feature 752
configured to place a landmark 538 in the predetermined landmark
orientation when the patient-specific template 750 is mated with
the native tissue model 422. As shown in FIG. 7, at least one
landmark guiding feature 752 is an aperture through the
patient-specific template 750 which is configured to guide a
penetrating structure, such as a guide pin or drill bit, into the
native patient tissue model 422 at a predetermined penetration
location and with a specified target trajectory 434.
[0064] When the landmark 538 is a two-dimensional landmark such as
a marking on the surface of the native patient tissue, the target
trajectory 434 of the landmark guiding feature 752 will likely be
of little to no import. In contrast, when the landmark 538 is a
three-dimensional landmark such as a drilled hole or an elongate
guide pin, the target trajectory 434 of the landmark may bear some
significance. In FIG. 7, the depicted target trajectory 434
corresponds to a desired drilling trajectory for an aperture which
receives a device shaft 540 at a later stage of the surgical
procedure. In this sense, therefore, at least one of the landmark
guiding features 752 shown in FIG. 7 may also serve as a
penetration-guiding feature.
[0065] Once the landmark(s) 538 have been virtually placed into the
predetermined landmark orientation(s) at fifth action block 336 of
FIG. 3 and the patient-specific template 750 created at sixth
action block 342, the stock device 424 may be (virtually) re-placed
upon the native patient tissue model 422 and at least one
patient-specific placement guide 958 may be generated at seventh
action block 356 of FIG. 3. The patient-specific placement guide
958 may be configured to interact simultaneously with at least one
previously placed landmark (here, at least guide pin-type landmark
538a) and with the stock device 424 when the stock device is in the
predetermined device orientation.
[0066] The patient-specific placement guide 958 may be, for
example, similar to any of those disclosed in co-pending U.S.
Provisional Patent Application No. 61/408,324, filed 29 Oct. 2010
and titled "System and Method for Assisting with Attachment of a
Stock Implant to a Patient Tissue", or in co-pending U.S.
Provisional Patent Application No. 61/408,376, filed 29 Oct. 2010
and titled "System and Method for Assisting with Attachment of a
Stock Instrument to a Patient Tissue", the entire contents of both
of which are incorporated herein by reference.
[0067] Regardless of the type of patient-specific placement guide
958 provided, the patient-specific placement guide may be generated
similarly to the patient-specific template 750. Namely, a placement
guide blank 854, shown in FIG. 8, may be automatically or manually
selected, optionally from a library of available placement guide
blanks. It is contemplated that the placement guide blank 356 may
be selected responsive to the selection of the stock device 424,
because in many applications of the present invention, the
patient-specific placement guide 958 will nest into or mate with
some physical feature of the stock device. For example, and as
shown in particularly the transverse view of FIG. 8, the placement
guide blank 356 may nest with a portion of the stock device 424
substantially collinear with the device shaft 540 to help
positively locate the patient-specific placement guide with respect
to the stock device.
[0068] The placement guide blank 854, once selected by any suitable
procedure, may then be (virtually) altered to register with at
least one landmark 538, as shown in FIG. 9 when the
patient-specific placement guide 958 is mated with the stock device
424 and the stock device is in the predetermined device
orientation. Registration of the patient-specific placement guide
958 with a chosen landmark 538 helps to indicate that the stock
device 424 has achieved the predetermined device orientation when
the patient-specific placement guide 958 is mated or nested with
the stock device and the stock device is in contact with the native
patient tissue model. The term "register" or "registration" is used
herein to indicate a predetermined condition of correct alignment
or proper relative position between a landmark 538 (of any type)
and some feature of the structure (here, the patient-specific
placement guide 958) being registered. For example, when the
landmark 538 is a two-dimensional marking on the native patient
tissue model 422, the registration might occur when an inscribed
mark on the patient-specific placement guide 958 aligns with the
two-dimensional landmark.
[0069] As another example, and as shown in FIG. 9, the landmark
538a might be a three-dimensional landmark such as a guide pin. In
this instance, the patient-specific placement guide 958 includes at
least one orienting feature 960 (having previously been provided to
the guide blank) which will register with the selected landmark
538a by contact with the guide pin embodying that landmark when the
patient-specific placement guide 958 is mated or nested with the
stock device 424 (as shown in FIG. 9) and the stock device is in
contact with the native patient tissue model in the predetermined
device orientation. In the view of FIG. 9, the stock device 424 is
not yet in the predetermined device orientation as indicated by the
separation of the orienting feature 960 and the landmark 538a,
though the patient-specific placement guide 958 is mated with the
stock device, as can be seen in particularly the coronal and
transverse views of FIG. 9.
[0070] In addition to the guiding/orienting function provided by
the patient-specific placement guide 958, at least one
penetration-guiding feature 962 (four shown in FIG. 9) may be
provided by the patient-specific placement guide. Here, the target
trajectory 434a indicates a target trajectory and associated
penetration location associated with a landmark 538b, whereas the
target trajectories marked 434b (shown in dashed line in the
coronal and transverse views since not strictly present in those
sections) and the associated penetration locations in FIG. 9 are
associated with one or more penetrating structures (not shown in
FIG. 9), such as fasteners, drill bits, other surgical tools, or
any other components used in the surgical procedure which the user
wishes to guide with the assistance of the patient-specific
placement guide 958.
[0071] FIG. 10 is similar to FIG. 9, though the stock device 424
has been reoriented into the predetermined device orientation, as
indicated by the registration of the orienting feature 960 and the
landmark 538a. As can also been seen in FIG. 10, the body of the
patient-specific placement guide 958 has been rotated sufficiently
to bring the penetration-guiding features 962 into a different
rotational orientation with respect to the native patient tissue
model 422 than that of FIG. 9. The target trajectories 434b of the
penetration-guiding features 962 should be in the desired
penetration locations with respect to the native patient tissue
model 422 when the stock device 424 has been brought into the
predetermined device orientation.
[0072] Once the patient-specific template 750 and/or the
patient-specific placement guide 958 have been generated as
desired, including any desired features as described above, a
physical version of the patient-specific template (when desired) is
created at eighth action block 364 of FIG. 3 and a physical version
of the patient-specific placement guide (when desired) is created
at ninth action block 366 of FIG. 3. These physical versions of the
patient-specific template 750 and/or the patient-specific placement
guide 958 are tangible (e.g., material and palpable)
representations of the virtual versions of the corresponding items
as manipulated, adjusted, and otherwise created using a system
similar to that shown via the user views of FIGS. 4-10.
[0073] Optionally, and as shown in tenth action block 368 of FIG.
3, a physical three-dimensional version of the native patient
tissue model 422 may be fabricated as a tangible (e.g., material
and palpable) representation of the virtual version of the native
patient tissue model. This physical native patient tissue model,
sometimes referred to as a "surrogate model" for its usefulness to
the surgeon as a manipulable surrogate of the actual patient
tissue, will be discussed in detail below, with reference to FIGS.
16A-26D.
[0074] The patient's name, identification number, surgeon's name,
and/or any other desired identifier may be molded into, printed on,
attached to, or otherwise associated with the physical version(s)
of the patient-specific template 750, the patient-specific
placement guide 958, and/or the native patient tissue model 422 in
a legible manner. The tangible representations of the
patient-specific template 750, the patient-specific placement guide
958, and/or the native patient tissue model 422 may be made by any
suitable method such as, but not limited to, selective laser
sintering ("SLS"), fused deposition modeling ("FDM"),
stereolithography ("SLA"), laminated object manufacturing ("LOM"),
electron beam melting ("EBM"), 3-dimensional printing ("3DP"),
contour milling from a suitable material, computer numeric control
("CNC"), other rapid prototyping methods, or any other desired
manufacturing process.
[0075] Once the physical versions of the patient-specific template
750, the patient-specific placement guide 958, and/or the native
patient tissue model 422 have been manufactured and prepared for
use (e.g., mechanically or chemically cleaned, cured, sterilized,
or the like) using any suitable process(es), they are available for
use during surgical procedures as described above and in the
incorporated references.
[0076] The preoperative planning system disclosed herein allows the
user to experiment with different placements and selections of
stock devices 424 and/or custom or patient-specific components in
an effort to produce positive patient outcomes. FIGS. 11A-14B
depict various examples of steps, alternate options, and
considerations that one of ordinary skill in the art may find
useful in preoperative planning, particularly with respect to
selection of the stock device 424 and of the predetermined device
orientation.
[0077] FIGS. 11A-11B depict a transverse view of a native patient
tissue model 422 of a typical clinical case of a patient with
osteoarthritis, having moderate bone loss. The scapular plane 1170
is perpendicular to reference plane 1172. The reference plane also
represents the 0.degree. reference from which glenoid version is
measured. The lower portion of FIGS. 11A-11B is posterior and the
top portion of these Figures is anterior, as shown by direction
arrow 118'. The diagonal dashed line labeled 1174 represents the
native glenoid plane of the patient. In this case, the native
glenoid plane 1174 exhibits a retroversion angle of approximately
26.degree. from the reference plane 1172. Glenoid version in the
normal population is reported to commonly be between 5.degree. of
anteversion and 15.degree. of retroversion. The average normal
glenoid version is approximately 1-2.degree. of retroversion.
[0078] The goal of arthroplasty surgery is to correct pathologic
anatomy and restore as best as possible normal anatomy and
function. Corrective options range between placing an implant
component at the standard ideal of perpendicular to the plane of
the scapula (0.degree.) up to the pathologic version (in this case,
26.degree. of retroversion). Common practice today is usually to
correct version with an attempt to place a stock device 424
approximately perpendicular to the scapular plane 1170 (i.e., lying
along the reference plane 1172 at about 0.degree. of version). For
clarity of description, the "angle" of the stock device 424 is
referenced hereafter as being the angle measured from a top face of
the stock device, the top face being foremost in the perspective
view of FIG. 4.
[0079] There normally will be a secondary surgical goals to
minimize removal of patient tissue needed to accommodate the stock
device 424, seat the entire stock device on the prepared patient
tissue surface, and minimize unwanted perforation of the outer
walls of the glenoid vault 110 or other patient tissue by the
device shaft 540 or another penetrating structure 430 used in the
surgical procedure or remaining in the patient tissue
postoperatively. When formulating a preoperative plan, typical
items of concern include the bone (or other patient tissue) loss in
the patient, the position and orientation of the normal joint line,
and where the stock device 424 or other component should be placed
to aim toward a positive patient outcome.
[0080] The present inventors have found that an average patient
tissue model 1176 (e.g., a "vault model") may be useful in
tailoring a surgical procedure to fit the needs of an individual
patient. A suitable average patient tissue model 1176 is described
in co-pending U.S. Patent Application Ser. No. 12/043,634, filed 6
Mar. 2008, and titled "Method and Apparatus for Preparing for a
Surgical Procedure", the contents of which are hereby incorporated
by reference in their entirety. In a similar manner, the shape of
an average acetabular vault may be used as a suitable average
patient tissue model and have some clinical relevance when defining
the normal anatomic relationships from the pathologic anatomy in a
hip use environment. The average patient tissue model 1176 of a
glenoid vault 110 is shown superimposed on the native patient
tissue model 422 in FIG. 11B. Although this is an "average" view,
the contours of the average patient tissue model 1176 can be seen
to substantially mirror the contours of the native glenoid vault
110 of even the depicted pathologic scapula 100.
[0081] FIG. 11B is similar to FIG. 11A, with the addition of an
average patient tissue model 1176. The average patient tissue model
1176 helps to define the location of the normal joint line and the
version of the normal glenoid fossa 1178 in a patient-specific
manner. The average patient tissue model 1176 may help define
reconstruction goals in pathologic cases, and may assist with
selection of position and type of a stock device 424 or a custom
device (not shown). Selection of version for the stock device 424
may be at least partially dependent upon the version of the average
patient tissue model 1176 which defines patient-specific normal
anatomy. In the patient of FIGS. 11A-14B, normal patient version,
based upon the average patient tissue model 1176, may be seen to be
approximately 12.degree. of retroversion, as shown by the angle of
the rightmost face (in the orientation of the Figures) of the
average patient tissue model 1176 with respect to reference plane
1172.
[0082] When planning a surgical procedure using preoperative
imaging, the user may specify at least one structural change to the
native patient tissue to facilitate placement of a stock device in
a predetermined device orientation. For example, native patient
tissue could be drilled, planed, reamed or otherwise removed, or
the native patient tissue could be built up using bone grafts or
other substances, with the latter being much more difficult to do
than the former during a standard surgical procedure. Using the
system described above, a (virtual) altered patient tissue model
(not shown) can be generated and viewed or otherwise used in the
preoperative planning. Optionally, a physical three-dimensional
version of the altered patient tissue model may be fabricated as a
tangible representation of the virtual version of the altered
patient tissue model. When provided, the physical altered patient
tissue model may also include at least one information feature
providing clinically useful information to the user. For example, a
landmark 538 (e.g., a cavity or aperture) may be present in the
physical altered patient tissue model and may therefore be made
palpable or otherwise apparent to the user during the surgical
procedure. The physical altered patient tissue model, when present,
may be used and referenced similarly to the aforementioned physical
native patient tissue model.
[0083] FIGS. 12A-14B are partial transverse cross-sectional
schematic views of a scapula which depict a comparison of the
likely surgical outcomes for various preoperative planning options.
FIGS. 12A-14B depict various ways in which the native patient
tissue model 422 can be compared to a reference patient tissue
model (regardless of whether any alterations are made to the native
patient tissue model), and the effect of that comparison on the
predetermined device orientation. The predetermined device
orientation can be adjusted, automatically by the system and/or
manually by the user, responsive to the comparison of the native
patient tissue model 422 to the reference patient tissue model. The
reference patient tissue may be at least one of a (mirrored) image
of a contralateral patient tissue of the same or a different
patient, a value taken from a standard reference patient tissue, a
value range taken from a standard reference patient tissue, and the
aforementioned average patient tissue model 1176. In FIGS. 12A-14B,
the reference patient tissue is shown and described as being the
average patient tissue model 1176. In FIG. 12A, a stock device 424
has been superimposed upon the native patient tissue model 422 of
FIGS. 11A-11B in a version of 0.degree. from the coronal plane
(shown in FIGS. 11A-13C as scapular plane 1170), with the bottom
portion (in the orientation of FIGS. 11A-13C) of the stock device
being located on an outer surface of the native patient tissue.
Since FIGS. 12A-13C show the scapula 100 having portions of the
native tissue removed to accommodate each stock device 424, the
patient tissue shown can be described as an altered patient tissue
model 1280. The excision of fairly large amounts of native patient
tissue is likely to adversely affect the dynamics within the
shoulder joint. Additionally, the glenoid vault 110 may be shaved
down enough that the device shaft 540 is in danger of breaching the
glenoid vault wall, which is generally undesirable and can cause
patient discomfort and possibly result in undesirable reoperation.
Accordingly, one goal of a presurgical planning process using the
average patient tissue model 1176 is to attempt to replicate the
total volume (or area, as depicted in the cross-sectional views of
FIGS. 12A-14B) of the average patient tissue model 1176 with a
combination of the total volume (or area) of the altered patient
tissue model 1280 and the stock device 424.
[0084] It is apparent from FIG. 12A that a substantial amount of
the native patient tissue will have to be removed from the native
patient tissue model 422 to allow the stock device 424 to seat
firmly and maintain the 0.degree. version with the stock device 424
substantially centered, posteriorly to anteriorly, upon the glenoid
fossa 1178. The device shaft 540 in FIG. 12A is in danger of
breaching the glenoid vault 110 wall, which should be avoided.
[0085] FIG. 12B also shows an altered patient tissue model 1280
with a relatively large volume of native patient tissue removed,
though less removed than in FIG. 12A. In FIG. 12B, the version is
still corrected to 0.degree. from the reference plane 1172, but the
stock device 424 has been moved upward (in the orientation of the
Figures) to distance the device shaft 540 from the glenoid vault
110 wall. This shifting of the stock device 424 can be seen to have
a different adverse effect, however--namely, the stock device now
substantially overhangs the anterior edge of the glenoid fossa
1178.
[0086] This problematic 0.degree. version correction is an example
of a value taken from a standard reference patient tissue--many
users will routinely correct version in all such cases to 0.degree.
as shown. As an example of a value range taken from a standard
reference patient tissue, the version may be corrected to a value
taken from the range of -5.degree. to +5.degree., with the user's
experience and intuition leading to the selection of one value from
that range. Another example, in a hip standard reference patient
tissue, might prescribe a range of 10-30.degree. of anteversion and
30-55.degree. of abduction for an acetabular prosthetic
implantation. However, a seemingly reasonable value based upon a
standard reference patient tissue--whether for a shoulder, hip, or
any other type of surgery--may markedly depart from a value which
leads to an acceptable result for a particular patient.
[0087] As a result, users will sometimes employ a mirror image of a
contralateral native patient tissue (from that patient or another
patient) to use as a reference patient tissue. However, even if
there is a contralateral native patient tissue to consult (e.g.,
the patient is not an amputee in that respect), the contralateral
native patient tissue may be pathologically or congenitally
asymmetrical from even the original state of the native patient
tissue which is being surgically corrected. Thus, there is a need
for another reference patient tissue for comparison to the native
patient tissue model 422.
[0088] In the aforementioned co-pending U.S. patent application
Ser. No. 12/043,634, filed 6 Mar. 2008, and titled "Method and
Apparatus for Preparing for a Surgical Procedure", the average
patient tissue model 1176 (i.e., the "vault model") is proposed as
providing an appropriate reference patient tissue for a wide range
of patients. The average patient tissue model 1176 is shown in
FIGS. 12A-13C superimposed over the altered patient tissue model
1280. Accordingly, one of ordinary skill in the art, with reference
to the average patient tissue model 1176, will be motivated to
preserve more of the native patient tissue by altering the native
tissue model 422, and placing the stock device 424 with reference
to the average patient tissue model 1176.
[0089] In the situation of FIG. 12C, the average patient tissue
model 1176 helps define the native patient joint line and the
native version for that particular patient. Accordingly, the
average patient tissue model 1176 helps direct the selection of the
stock device 424 to restore the native joint line and the patient's
native version, thereby reducing the risk of excessive bone removal
or perforation of the native patient tissue during or after the
stock device is installed. FIG. 12C depicts an altered patient
tissue model 1280 with the average patient tissue model 1176
superposed thereupon and the stock device 424 placed according to
the average patient tissue model (here, rotated clockwise, in the
orientation of the Figures.). It can be seen that placement of the
stock device 424 in a patient-specific version (informed by the
average patient tissue model 1176) will center the device shaft 420
(posteriorly to anteriorly) in the glenoid vault 110, provide more
thorough patient tissue contact for the stock device, and result in
less patient tissue removal and greater centering of the stock
device on the glenoid fossa 1178 as compared to the 0.degree.
versions of FIGS. 12A and 12B. Accordingly, the stock device 424
placement in FIG. 12C would seem to provide a preferred
predetermined device orientation compared to the orientations shown
in FIGS. 12A and 12B.
[0090] FIGS. 13A-13C depict a similar orientation comparison
sequence to that of FIGS. 12A-12C, but including a different stock
device 424a than that shown in FIGS. 12A-12C. The stock device 424a
includes a thickened leftmost section (in the orientation of the
Figures) which helps to compensate for the pathologic state of the
native patient tissue. This selection of this stock device 424a,
having a second configuration as compared to the first
configuration of the stock device 424 of FIGS. 12A-12C allows for
the combination of the native glenoid vault 110 plus the stock
device 424a to have a similar, and similarly arranged, volume of
material as that of the average patient tissue model 1176. The
arrangements of FIGS. 13A-13C are analogous to those of FIGS.
12A-12C, excepting the differences in the stock devices 424 and
424a, and therefore the description of FIGS. 12A-12C will not be
repeated with respect to 13A-13C.
[0091] The views of the combination of the altered glenoid vault
110 plus the stock device 424a of FIGS. 13A-13C may be favorably
contrasted with the analogous views of FIGS. 12A-12C, wherein the
combination of the altered glenoid vault 110 plus the stock device
424 has a substantially smaller volume in the latter when compared
to the average patient tissue model 1176, and thus the latter will
have less strength and ability to mechanically perform for the
patient as needed for a suitably long time after the surgical
procedure. Accordingly, the stock device 424a selection and
placement of FIG. 13C appears to meet the goal of preserving native
tissue the best of all of the options shown in FIGS. 12A-13C.
[0092] FIGS. 14A-14B show the effects of device orientation upon
the native patient tissue model 422. In FIG. 14A, the version has
been corrected to 0.degree.. That is, the target trajectory 534 of
the patient-specific template 750 is substantially parallel to the
scapular plane 1170. As is apparent in FIG. 14A, the device shaft
540 is cutting markedly into the coronal bone of the scapula 100 in
an undesirable manner, and a relatively large volume of native
patient tissue will need to be removed (near the top of FIG. 14A)
to accept the stock device 424. In FIG. 14B, the version has been
corrected to a value chosen by the user with consideration of the
native patient tissue model 422--the version in FIG. 14B is
approximately 12.degree.. As can be seen, by simply tilting the
stock device 424 in FIG. 14B as suggested by the average patient
tissue model 1176 or by a chosen value out of a value range taken
from a standard reference patient tissue, the stock device 424 is
seated more securely in the glenoid vault 110, with less removal of
native patient tissue required. It will be noted that the
patient-specific template 750 shown in FIG. 14A has a target
trajectory 534 that is different from the target trajectory
embodied in the patient-specific template of FIG. 14B.
[0093] FIG. 15 illustrates a computer system 1582 that can be
employed to implement systems and methods described herein, such as
based on computer executable instructions running on the computer
system. The user may be permitted to preoperatively simulate the
planned surgical procedure using the computer system 1582 as
desired. The computer system 1582 can be implemented on one or more
general purpose networked computer systems, embedded computer
systems, routers, switches, server devices, client devices, various
intermediate devices/nodes and/or stand alone computer systems.
Additionally, the computer system 1582 can be implemented as part
of the computer-aided engineering (CAE) tool running computer
executable instructions to perform a method as described
herein.
[0094] The computer system 1582 includes a processor 1584 and a
system memory 1586. Dual microprocessors and other multi-processor
architectures can also be utilized as the processor 1584. The
processor 1584 and system memory 1586 can be coupled by any of
several types of bus structures, including a memory bus or memory
controller, a peripheral bus, and a local bus using any of a
variety of bus architectures. The system memory 1586 includes read
only memory (ROM) 1588 and random access memory (RAM) 1590. A basic
input/output system (BIOS) can reside in the ROM 1588, generally
containing the basic routines that help to transfer information
between elements within the computer system 1582, such as a reset
or power-up.
[0095] The computer system 1582 can include one or more types of
long-term data storage 1592, including a hard disk drive, a
magnetic disk drive, (e.g., to read from or write to a removable
disk), and an optical disk drive, (e.g., for reading a CD-ROM or
DVD disk or to read from or write to other optical media). The
long-term data storage 1592 can be connected to the processor 1584
by a drive interface 15941594. The long-term data storage 1592
components provide nonvolatile storage of data, data structures,
and computer-executable instructions for the computer system 1582.
A number of program modules may also be stored in one or more of
the drives as well as in the RAM 1590, including an operating
system, one or more application programs, other program modules,
and program data.
[0096] A user may enter commands and information into the computer
system 1582 through one or more input devices 1596, such as a
keyboard or a pointing device (e.g., a mouse). These and other
input devices are often connected to the processor 1584 through a
device interface 1598. For example, the input devices can be
connected to the system bus by one or more a parallel port, a
serial port or a universal serial bus (USB). One or more output
device(s) 15100, such as a visual display device or printer, can
also be connected to the processor 1584 via the device interface
1598.
[0097] The computer system 1582 may operate in a networked
environment using logical connections (e.g., a local area network
(LAN) or wide area network (WAN) to one or more remote computers
15102. A given remote computer 15102 may be a workstation, a
computer system, a router, a peer device or other common network
node, and typically includes many or all of the elements described
relative to the computer system 1582. The computer system 1582 can
communicate with the remote computers 15102 via a network interface
15104, such as a wired or wireless network interface card or modem.
In a networked environment, application programs and program data
depicted relative to the computer system 1582, or portions thereof,
may be stored in memory associated with the remote computers
15102.
[0098] It is contemplated that multiple versions of the
patient-specific template 750 and/or the patient-specific placement
guide 958 could be created during preoperative planning and
fabricated as options for the user to select from during the
surgical procedure. For example, the user may not be able to clear
away surrounding (e.g., soft) tissue from the native patient tissue
as well as expected. In this situation, it may be useful to have a
patient-specific template 750 with a smaller footprint for easier
insertion into the surgical wound and manipulation at the surgical
site, even though the smaller footprint means that there is less
mating surface 748 to mate with the native patient tissue and
provide positive location assistance for the patient-specific
template 750.
[0099] As mentioned previously, a physical version of the native
patient tissue model 422 may be useful to the surgeon before,
during, and/or after a surgical procedure. Physical native patient
tissue models, or "surrogate models", will now be discussed at
length with reference to FIGS. 16A-26D.
[0100] FIGS. 16A and 16B depict different views of a virtual model
of a native patient tissue (here a scapula 100). In FIG. 16B, the
glenoid fossa 1178 surface is visible. The below description
presumes that the present invention is being used to assist with
the placement and installation of a glenoid component 216 upon the
glenoid fossa 1178. Therefore, the glenoid fossa 1178 can be
thought of, in the below description, as a "surface of interest".
The term "surface of interest" is used herein to indicate a surface
upon/into which a prosthetic device is to be placed or a surface
which is to be the main subject of substantially permanent physical
modification during a surgical procedure in an effort to provide
therapeutic benefit to the patient. "Substantially permanent
physical modification" is used here to indicate that the native
patient tissue is cut, reamed, drilled, burned, otherwise
mechanically or chemically altered, grafted (using natural or
synthetic materials), or in any other way physically altered in a
manner that remains in situ after completion of the surgery. While
another portion of patient tissue other than a surface of
interest--whether adjacent to or spaced apart from the surface of
interest--may be incidentally physically modified, in either a
transient or substantially permanent manner, during the surgical
procedure, this incidental modification alone does not transform
the other portion of patient tissue into a "surface of interest".
As one of a number of possible nonlimiting examples, a "footprint"
of bone surface underlying an installed prosthetic device will
normally be considered a surface of interest, while examples of
patient tissue which have incidental physical modification
(temporary or substantially permanent) but would not be considered
surfaces of interest in this situation include, but are not limited
to, soft tissue adjacent the bone surface which is retracted
temporarily for purposes of the procedure, bone surface which is
not machined to accept (and/or is not contacted by) the installed
prosthetic device, and bone surface which is lightly scored,
drilled, or marked for reference purposes during the surgical
procedure but which modification does not serve any therapeutic
purpose after the surgery is completed. As one of ordinary skill in
the art will be aware, a "surface of interest" in most cases will
not have clearly defined borders, but that person of ordinary skill
in the art will be able to readily differentiate between a surface
of interest and another patient tissue, which is not a surface of
interest, for a particular application of the present
invention.
[0101] One of ordinary skill in the art will often be provided with
a virtual model of a patient tissue, such as the scapula 100 shown
in FIGS. 16A-16B, for pre-operative planning use, such as in one of
the previously described planning functions. However, a user may
find it helpful to have a physical version of the native patient
tissue available for pre-operative, interoperative, or even
postoperative reference.
[0102] FIGS. 17A-17C depict a physical native tissue model 1706 as
a tangible representation of a portion of the virtual model of the
native patient tissue shown in FIGS. 16A-16B. (For reasons such as
savings of material and manufacturing time, the physical native
tissue model 1706 may be fabricated as a portion of a complete
virtual model, rather than the entirety of the virtual model.) The
physical native tissue model 1706 may be manufactured in any
suitable manner such as, for example, using a method (and
optionally including additional information) described above as
suitable methods for creating the aforementioned tangible
representations. When available, a physical native tissue model
1706 may be useful in many different contexts, such as preoperative
planning, patient education, visualization, practice, and
implementation of the surgical procedure by the user (e.g., for
assisting with performing the surgery using patient specific
templates and/or adjustable surgical instruments). To that end, the
physical native tissue model 1706 may include at least one
information feature providing clinically useful information to the
user. "Clinically useful" information is used herein to indicate
any information, other than the structure of the native patient
tissue itself, that assists one of ordinary skill in the art with,
for example, some pre- and/or intra-operative task. An "information
feature" is any physical feature or characteristic of the physical
native tissue model 1706 which signifies or communicates the
clinically useful information to the user, optionally in
combination with a preoperative plan. Optionally, the information
feature may be substantially separated from the surface of
interest.
[0103] For example, and as shown in FIGS. 17A-17C, a portion of the
scapula 100 may be fabricated as a physical native tissue model
1706, with planar faces 1708 bounding the omitted portions of the
scapula 100. Those planar faces 1708 may be chosen at predetermined
distances from, and/or with predetermined orientations with respect
to, a surface of interest (here, the glenoid fossa 1178) on the
physical native tissue model 1706. In other words, the physical
native tissue model 1706 includes at least one primary patient
tissue area including a surface of interest. In the embodiment
shown in FIGS. 17A-17C, the primary patient tissue area is the
glenoid fossa 1178 because at least a portion of the glenoid fossa
surface will be machined or otherwise subjected to substantially
permanent physical alteration (e.g., the implantation of a glenoid
component 216) during the surgical procedure.
[0104] The physical native tissue model 1706 also includes at least
one secondary patient tissue area including no surfaces of
interest. In the embodiment shown in FIGS. 17A-17C, the majority of
the physical native tissue model 1706 is a secondary patient tissue
area, because patient tissue surrounding the glenoid fossa 1178
(e.g., the acromion and coracoid processes 106 and 108) does not
include any surfaces of interest for the described surgical
procedure.
[0105] The physical native tissue model 1706 also includes a base
surface for engaging a supporting structure. Here, the base surface
is planar face 1708a, which simply sits upon a table or other
supporting structure (not shown) to present the glenoid fossa 1178
to the user for easy viewing, but any other base surface and
corresponding supporting structure (e.g., an interlocking,
magnetic, adhesive, or other arrangement) could be provided by one
of ordinary skill in the art.
[0106] The physical native tissue model 1706 includes in it, as
generated, at least one information feature providing clinically
useful information to the user. The term "as generated" is used
herein to mean "as brought into existence" or "as originated by a
vital, chemical, or physical process". In other words, the physical
native tissue model 1706 is not made, and then provided to the user
for inclusion of the information feature. Instead, during the
process of making the physical native tissue model 1706, the
information feature is integrally formed with the structure of the
physical native tissue model and/or is generated by the
manufacturing agent as part of the service of making the physical
native tissue model. For example, the virtual model of the patient
tissue could be manipulated in the computer system 1582
(optionally, under the direction of the user) to include the
information feature in an instruction file that is provided to a
rapid prototyping machine for manufacturing the physical native
tissue model 1706. Regardless of the way that the information
feature is associated with the physical native tissue model 1706,
it is contemplated that the information feature will be included
when the user initially receives the physical native tissue model
and the user does not place the information feature on/in the
physical native tissue model.
[0107] In many applications of the present invention, the
information feature will be substantially separated from the
surface of interest on the physical native tissue model 1706. For
example, the information feature may be a predetermined orientation
of the base surface which is operative to position at least one
surface of interest in a predetermined orientation in space when
the base surface is engaged with the supporting structure--this
concept will be discussed further below with reference to FIGS.
26A-26D. In the embodiment shown in FIGS. 17A-17C, a planar face
1708a bounding a lower portion of the physical native tissue model
1706 may be oriented to be substantially parallel to a sagittal
plane of the patient's body. Often the patient is oriented during
surgery (with the surface of interest minimally exposed) such that
the plane of the scapula 100 is not readily discernable with
reference to the orientation of the glenoid vault 110 or glenoid
fossa 1178 surface in the surgical field, although it is possible
for patients to be oriented during surgery with their scapular
plane substantially in a predetermined orientation in space.
Accordingly, by placing the physical native tissue model 1706 with
an information feature in a known position (e.g, by placing an
appropriately configured planar face 1708a of the physical native
tissue model flat on a table or other supporting structure), one of
ordinary skill in the art can position the glenoid fossa 1178 of
the physical native tissue model in a similar orientation to the
glenoid fossa of a pre-positioned patient or can, alternatively,
orient the patient such that the patient's glenoid fossa 1178
substantially matches the orientation of that of the physical
native tissue model placed upon a supporting surface for
intraoperative reference purposes.
[0108] Through use of a physical native tissue model 1706 which is
positioned in space (optionally with the aid of an information
feature such as the preconfigured planar face 1708a) analogously to
the actual patient tissue in the operating room, a user can readily
envision obscured portions of the patient's native tissue anatomy
through reference to the physical native tissue model 1706. The
physical native tissue model 1706 may be configured to provide the
user with a visualization of the native patient tissue in the same
orientation as in the patient's body but without the surrounding
tissue that prevents the user from directly seeing structures such
as, but not limited to, the acromion process 106, the coracoid
process 108, or any other structure of the scapula 100. This may be
particularly useful when the physical native tissue model 1706 is
fabricated at a 1:1 scale with the native patient anatomy, but also
will have utility when the model is scaled up or down from the
patient's actual tissue.
[0109] Optionally, the predetermined orientation of the base
surface (the planar face 1708a in FIGS. 17A-17C) may be chosen to
dictate a clinically useful placement of a landmark 538, such as a
guide pin, into engagement with the physical native tissue model
1706 when the landmark is located orthogonally to the supporting
structure. It may be relatively simple to orient a landmark
orthogonal to a table or other supporting structure, perhaps with
the aid of a leveling aid (e.g., a bubble level) or setting stand
(such as that disclosed in co-pending U.S. Provisional Patent
Application No. 61/534,142, filed 13 Sep. 2011 and titled
"Apparatus and Method for Transferring Predetermined Spatial
Positioning Information to an Adjustable Tool", the entire contents
of which are incorporated herein by reference), whereas achieving a
particular three-dimensional, non-orthogonal, trajectory of a
landmark relative to a surface of interest may be relatively
difficult to do accurately without a guiding aid.
[0110] For example, if the clinically useful placement of a guide
pin is at a predetermined trajectory with respect to the surface of
interest, the planar face 1708a could be configured at an angle to
the surface of interest such that orthogonal placement of the guide
pin (or other landmark 538) relative to the surface of interest
will achieve the desired predetermined trajectory of the guide pin
with respect to the surface of interest. Accordingly, the guide pin
could be placed with the assistance of the orthogonally-configured
planar face 1708a, and then the physical native tissue model 1706
could be manipulated as desired to reposition the surface of
interest (with the emplaced guide pin) into a similar orientation
to the native patient tissue exposed in the surgical procedure. In
such manner, the relatively easily orthogonally-positioned guide
pin or other landmark 538 and associated physical native tissue
model 1706 could be manipulated into a more clinically useful
orientation with respect to the exposed native patient tissue while
maintaining the predetermined trajectory of the guide pin. To aid
in this effort, the physical native tissue model 1706 could
optionally include a planar face 1708a including one type of
clinically useful information (e.g., the scapular plane information
previously referenced), and a separate, optionally
attachable/detachable positioning wedge (not shown) having another
type of clinically useful information (e.g., information related to
the orthogonal-positioning trajectory for the guide pin) could be
provided as an intermediate structure between the planar face 1708a
or other base surface and the supporting structure to facilitate
multi-faceted use of the physical native tissue model 1706 for a
variety of different interoperative assistance and visualization
tasks.
[0111] As another example embodiment of a physical native tissue
model 1706 giving spatial information, a pin-receiving aperture may
be provided in the physical native tissue model, to receive a guide
pin and thus demonstrate a certain direction or axis to the user
with respect to the native tissue. As a corollary to this example,
an axis-, direction-, or plane-indicating structure may extend from
the physical native tissue model to serve as a user visualization
aid or reference.
[0112] Some other examples of clinically useful information that
can be embodied in, and/or represented by, a physical native tissue
model 1706 include the location of an original joint line location
of a deformed patient tissue (to help the user define
reconstruction goals), an inference of the location and/or type of
deep tissue structures via an included trajectory and/or location
of a guide pin, the location of added materials such as tissue
(e.g., bone) grafts, the method of fixation, and the trajectory of
fixation devices to be added to patient tissue. Another example of
clinically useful information can include the location of a
"hidden" structure or pathology below the surface of the patient
tissue, which may assist the user with finding that structure in
three-dimensional space in the patient tissue--this could be
facilitated by depicting the "hidden" structure as being noticeably
distinct from neighbouring portions of the physical native tissue
model 1706. For example, the "hidden" structure could have a
particular color, visible through translucent
neighbouring/concealing structures and/or visible upon removal of a
"breakaway" or otherwise removable portion of a neighbouring
structure.
[0113] Turning to FIGS. 18A-18C, which illustrate a spatial type of
information feature, the physical native tissue model 1706 is shown
as having an information feature indicating a desired placement for
a landmark 538 (two shown). The landmark(s) 538 information
feature(s) indicates at least one of a marking location and a
marking trajectory to which reference is made during surgical
modification of the patient tissue. For example, the landmark 538
could be a two-dimensional marking on the surface of the physical
native tissue model 1706, or could be an aperture, protrusion, or
other three-dimensional structure embodying the desired clinically
useful information. As shown in FIG. 18A, a first landmark 538a is
located in the primary patient tissue area (i.e., an area including
at least one surface of interest, here the glenoid fossa 1178) and
a second landmark 538b is spaced apart from the surface of interest
and located in the secondary patient tissue area (i.e., an area
which includes no surfaces of interest). In other words, the second
landmark 538b is spaced apart from the surgical modification
location at which the glenoid component 216 will be placed in the
surgical procedure for which the depicted physical native tissue
models 1706 are being prepared, as will become apparent with
reference to succeeding Figures.
[0114] As can be seen in FIGS. 18A-18B, the second landmark 538b
may be an aperture extending through the body of the physical
native tissue model 1706. Optionally, this aperture may be sized to
accept a guide pin (not shown), such that the guide pin itself
extends from the physical native tissue model 1706 and acts as the
landmark 538b, to demonstrate both the marking location and the
marking trajectory at a glance to the user, in a readily
discernible format. Whether or not a guide pin or other readily
discerned aid is used, the clinically useful information embodied
in the information feature (whether a landmark 538 or some other
type) may be transferred from the physical native tissue model 1706
to the native patient tissue during a surgical procedure, in any
suitable manner.
[0115] The exact mechanism of transfer of the clinically useful
information may vary greatly depending upon such factors as the
nature of the clinically useful information, the nature of the
information feature, the structure of the physical native tissue
model 1706, the structure of the patient's actual native tissue,
the surgical procedure being performed, the nature of any assisting
devices, the preferences of the user, or the like. In its simplest
form, this clinically useful information could be transferred
mainly by the user's "eyeballing" or estimating the location of a
landmark 538 or some other clinically useful information and trying
to duplicate the landmark 538 location on the patient's tissue.
[0116] One example of a more sophisticated method of the transfer
of clinically useful information between a physical native tissue
model 1706 and a native patient tissue during a surgical procedure
includes adjusting a reusable surgical instrument to transfer at
least a portion of the clinically useful information embodied in
the information feature. Suitable reusable surgical instruments
include, but are not limited to, calipers, protractors, other
manually operated measuring tools, custom-made or stock adjustable
mechanical frames (e.g., pantographs), electronic location aids
(e.g., stereotactic surgical systems or other aided navigation
systems), patient-specific templates or aids such as those
disclosed in co-pending U.S. Provisional Patent Application Nos.
61/536,756, filed 20 Sep. 2011 and titled "Method and System for
Producing at least one Patient-Specific Surgical Aid" and
61/408,359, filed 29 Oct. 2010 and titled "System and Method for
Association of a Guiding Aid with a Patient Tissue" (the entire
contents of both of which are incorporated herein by reference),
the tool disclosed in co-pending U.S. patent application Ser. No.
12/854,362, filed 11 Aug. 2010 and titled "Method and Apparatus for
Insertion of an Elongate Pin Into a Surface" (the entire contents
of which are incorporated herein by reference), and the tools
disclosed in co-pending U.S. Provisional Patent Application No.
61/534,152, filed 13 Sep. 2011 and titled "Method and Apparatus for
Insertion of an Elongate Pin into a Surface" (the entire contents
of which are incorporated herein by reference).
[0117] As another option for transferring clinically useful
information between a physical native tissue model 1706 and a
native patient tissue during a surgical procedure, at least one
patient-specific surgical aid (not shown) could be generated via
interaction with the physical native tissue model and with the
information feature. For example, a system such as, but not limited
to, that disclosed in the aforementioned co-pending U.S.
Provisional Patent Application No. 61/536,756, filed 20 Sep. 2011
and titled "Method and System for Producing At Least One
Patient-Specific Surgical Aid" (previously incorporated by
reference) could be used to replicate at least a portion of the
surface of the physical native tissue model 1706 with the
landmark(s) 538 somehow memorialized therein. The user can then
transfer the clinically useful information by aligning some feature
of the patient-specific surgical aid with the patient's native
tissue in a way that substantially "registers" the patient-specific
surgical aid on the native tissue in the same orientation as the
patient-specific surgical aid was oriented on the physical native
tissue model 1706. The placement of the landmark(s) 538 or other
clinically useful information will then be readily transferred to,
and/or used with, the native tissue with a high degree of user
confidence in the replication.
[0118] The physical native tissue model 1706 could be used to
interact with an implant or instrument before or during the
surgical procedure, as well. For example, a user could rehearse
certain interactions of an implant or instrument with the physical
native tissue model 1706 to gain familiarity with the way that the
implant or instrument is likely to intraoperatively interact with
the patient's native tissue.
[0119] FIGS. 19A-19B depict a physical native tissue model 1706
which has undergone some initial tissue preparation (here, a
portion of the glenoid fossa 1178, toward the upper left in the
orientation of FIG. 19A, has been reamed away). Through use of a
physical native tissue model 1706 similar to that shown in FIGS.
19A-19B, a user can visualize an intermediate or initial step in
machining the patient tissue.
[0120] FIGS. 20A-22B depict different views of a series of physical
native tissue models 1706 which include, as generated, information
features which include, in addition to landmark 538b, clinically
useful information relating to the machining of the surface of
interest to accept a prosthetic implant (here, glenoid component
216) to be installed in the native patient tissue. In the physical
native tissue model 1706 of FIGS. 20A-20B, an initial reaming
process has been performed (a more extensive process than the
reaming shown in FIGS. 19A-19B) and the initial glenoid fossa 1178
has been machined away to reveal the material of the glenoid vault
110. Here, the reaming has been accomplished to accommodate a
variable-depth glenoid component 216 of a known variety. Landmark
538a remains and, since it is an aperture extending into the body
of the physical native tissue model 1706, it will continue to be
apparent as the machining away of the material progresses.
[0121] Proceeding to FIGS. 21A-21B, the physical native tissue
model 1706 is another version which includes, as generated,
information features relating both to the reaming process shown in
the FIGS. 20A-20B implant and to the drilling (location,
trajectory, and depth) of a plurality of apertures which may be
helpful in accommodating, for example, a device shaft 540 of a
known type of stock or custom prosthetic glenoid component 216.
[0122] The next physical native tissue model 1706 provided is shown
in FIGS. 22A-22B and includes, as generated, an information feature
structure replicating at least a portion of the prosthetic implant
(here, glenoid component 216) in a preoperatively planned installed
position.
[0123] By using the sequence of different physical native tissue
models 1706 shown successively in FIGS. 19A-19B, 20A-20B, 21A-21B,
and 22A-22B, the user can be provided with visual and tactile
depictions of clinically useful information regarding each major
step in the surgical procedure. Reference can be made to each of
these physical native tissue models 1706 at an appropriate time
during the surgery to remind the user of the preoperative plan, to
provide measurements for transference of the clinically useful
information to the patient's native tissue, to verify the
mechanical operations being done to the patient's native tissue, or
for any other reason. A user could hand-make a series of physical
native tissue models 1706 having the "stepwise" surgical phases
shown in the physical native tissue models of FIGS. 19A-19B,
20A-20B, 21A-21B, and 22A-22B during preoperative planning, and
even refer to these handmade models during the surgical procedure.
However, it should be understood that the present invention
contemplates that each of the sequence of physical native tissue
models 1706 shown successively in FIGS. 19A-19B, 20A-20B, 21A-21B,
and 22A-22B is generated with the clinically useful "stepwise"
information already contained therein, such that the physical
native tissue models each accurately replicate the dimensions,
placement, orientation, and other properties of the preoperatively
determined surgical plan for a major step of the surgery.
Similarly, while a user could create, from "blank" models of a
patient's tissue, physical native tissue models 1706 having simple
cutting plane or drilling location markings, the physical native
tissue models 1706 shown successively in FIGS. 19A-19B, 20A-20B,
21A-21B, and 22A-22B each include information features giving a
wealth of clinically useful information about the substantially
permanent physical modifications to be made during the surgical
procedure that would not be available if the user were simply given
a "resection line here" or other simple two-dimensional landmark.
For example, the depth, dimensions, and trajectory of the
preoperatively planned apertures 2110 in FIG. 21A would be
extremely difficult to communicate to a user through simple
markings, but are readily available to the user of the physical
patient tissue model 1706 shown in FIGS. 21A-21B without requiring
that user to reference a virtual patient tissue model during the
surgery.
[0124] Optionally, and as shown schematically in the Figures, the
sequence of physical native tissue models 1706 shown successively
in FIGS. 19A-19B, 20A-20B, 21A-21B, and 22A-22B may each be made in
a modular fashion to economize on space, fabrication costs,
sterilization requirements, or for any other reason. More
specifically a module line 2012 is shown on several of the depicted
physical native tissue models 1706 as delineating a lower portion
of the physical native tissue model as a "holder base", as
referenced herein. The holder base does not physically change
across the sequence of physical native tissue models 1706 shown
successively in FIGS. 19A-19B, 20A-20B, 21A-21B, and 22A-22B.
Accordingly, the upper portion (above the module line 2012) of the
physical native tissue model 2012, which includes the surface of
interest (here, the glenoid fossa 1178 and the machined features
which supplant the original glenoid fossa surface) can be a
separate piece which is selectively mated with the holder base for
reference by the user. When the physical native tissue models 1706
are made in this modular fashion, the bulk of the physical native
tissue model (the unchanged holder base portion, approximately
below the module line 2012) can remain the same and have a series
of partial native patient tissue models, each depicting the surface
of interest at a different step in the surgical procedure,
successively exchanged for one another as the surgical procedure
progresses. As long as each partial native patient tissue model
(including the surface of interest) mates appropriately with the
holder base, the manufacture of the series of physical native
tissue models 1706 shown successively in FIGS. 19A-19B, 20A-20B,
21A-21B, and 22A-22B can then be simplified while still including
all of the information shown in these Figures.
[0125] FIGS. 23A-25B depict a physical native tissue model 1706'
according to a second embodiment of the present invention. The
physical native tissue model 1706' of FIGS. 23A-25B is similar to
the physical native tissue model 1706 of FIGS. 17A-22B and
therefore, structures of FIGS. 23A-25B that are the same as or
similar to those described with reference to FIGS. 17A-22B have the
same reference numbers with the addition of a "prime" mark.
Description of common elements and operation similar to those in
the previously described first embodiment will not be repeated with
respect to the second embodiment.
[0126] The physical native tissue models 1706' shown successively
in FIGS. 23A-23B, 24A-24B, and 25A-25B depict a portion of a pelvis
and can be used in conjunction with a hip replacement surgery in
much the same way that the partial scapula physical native tissue
models 1706 shown in FIGS. 20A-20B, 21A-21B, and 22A-22B can be
used in conjunction with a shoulder replacement surgery. FIGS.
23A-23B depict an acetabulum 2314 of interest, including at least
one landmark 538' (shown in the bottom perspective view of FIG. 23B
but optionally extending as an aperture through a thickness of the
physical native patient tissue model 1706' to provide a landmark
function to the acetabulum).
[0127] In the version of the physical native patient tissue model
1706' shown in FIGS. 24A-24B, the acetabulum 2314 is depicted, as
generated, as having undergone initial reaming. In the version of
the physical native patient tissue model 1706' shown in FIGS.
25A-25B, an acetabular component 2316 of a prosthetic hip
replacement device is depicted, as generated, in the desired
preoperatively determined position with respect to the acetabulum
2314.
[0128] FIGS. 26A-26D depict a physical native tissue model 1706''
according to a third embodiment of the present invention. The
physical native tissue model 1706'' of FIGS. 26A-26D is similar to
the physical native tissue model 1706 of FIGS. 17A-22B and
therefore, structures of FIGS. 26A-26D that are the same as or
similar to those described with reference to FIGS. 17A-22B have the
same reference numbers with the addition of a double "prime" mark.
Description of common elements and operation similar to those in
the previously described first embodiment will not be repeated with
respect to the third embodiment.
[0129] The physical native tissue model 1706'' of FIGS. 26A-26D
includes an information feature which is shown as a
patient-specific base 2618 embodying multiple types of clinically
useful information, as alluded to above with reference to planar
face 1708a. That is, the patient-specific base 2618 of the third
embodiment of the physical native tissue model 1706'' is configured
to convey clinically useful information to the user by virtue of
interaction between the patient-specific base 2618 (or portions
thereof) and an underlying support surface on which the physical
native tissue model 1706'' is resting.
[0130] For example, the planar face 1708a'' shown in FIGS. 26B-26D
is a lower rim of the substantially cylindrical patient-specific
base 2618. When the physical native tissue model 1706'' is resting
atop a substantially planar (and parallel to the ground) first
supporting surface (not shown), the planar face 1708a'' holds the
depicted patient tissue with the glenoid fossa 1178'' surface
substantially perpendicular to the plane of the scapula. However,
the patient-specific base 2618 includes an auxiliary orienting
feature 2620 which is configured (e.g., via shape, size,
orientation, or any other physical characteristic) to rest atop a
suitable second supporting surface and convey different clinically
useful information than when the physical native tissue model
1706'' is supported by the first supporting surface.
[0131] As may be seen in FIGS. 26C and 26D, for example, the
auxiliary orienting feature 2620 is shaped to mate with, and be
supported by, a second supporting surface which interacts with the
auxiliary orienting feature 2620 to hold the physical native tissue
model 1706'' in a desired orientation in space. An example of a
suitable second supporting surface is the D-shaped lug shown in
certain embodiments of the previously incorporated co-pending U.S.
Provisional Patent Application No. 61/534,142, filed 13 Sep. 2011
and titled "Apparatus and Method for Transferring Predetermined
Spatial Positioning Information to an Adjustable Tool". When the
auxiliary orienting feature 2620 is dictating a spatial orientation
of the rest of the physical native tissue model 1706'' shown in
FIGS. 26A-26D, a guide pin inserted in at least one landmark 538a''
and 538b'' will be held substantially perpendicular to an
underlying ground surface, without regard to the spatial
orientation of the glenoid fossa 1178''. The "dual purpose"
physical native tissue model 1706'' shown in FIGS. 26A-26D
therefore has multiple information features embodied therein, each
of which may be useful to the user for different reasons and at
different times before, during, and/or after the surgical
procedure.
[0132] The physical native tissue model 1706 from any embodiment of
the present invention could be used for patient or professional
education before or after the surgical procedure, as well, to
explain the surgical procedure to the patient or an advocate; to
show an insurer, other third-party payer, follow-up medical
professional, or other party the extent and nature of the surgical
procedure; in a classroom setting to help train others in the
procedure done; as part of a scientific/research study or
presentation; or simply as a "souvenir" for the patient or user to
memorialize the surgical procedure.
[0133] Physical native tissue models 1706 with information features
or specific landmarks 538 related to the preoperatively developed
surgical plan are not currently provided or used as references
during surgical procedures. The availability of a physical native
tissue model 1706 to use as a reference in this manner may
supplement or even supplant the need for intraoperative imaging,
which is likely to reduce cost, operating room clutter, and time
required for the surgical procedure.
[0134] While aspects of the present invention have been
particularly shown and described with reference to the preferred
embodiment above, it will be understood by those of ordinary skill
in the art that various additional embodiments may be contemplated
without departing from the spirit and scope of the present
invention. For example, the specific methods described above for
using the described system are merely illustrative; one of ordinary
skill in the art could readily determine any number of tools,
sequences of steps, or other means/options for virtually or
actually placing the above-described apparatus, or components
thereof, into positions substantially similar to those shown and
described herein. Any of the described structures and components
could be integrally formed as a single piece or made up of separate
sub-components, with either of these formations involving any
suitable stock or bespoke components and/or any suitable material
or combinations of materials; however, the chosen material(s)
should be biocompatible for most applications of the present
invention. The mating relationships formed between the described
structures need not keep the entirety of each of the "mating"
surfaces in direct contact with each other but could include
spacers or holdaways for partial direct contact, a liner or other
intermediate member for indirect contact, or could even be
approximated with intervening space remaining therebetween and no
contact. Though certain components described herein are shown as
having specific geometric shapes, all structures of the present
invention may have any suitable shapes, sizes, configurations,
relative relationships, cross-sectional areas, or any other
physical characteristics as desirable for a particular application
of the present invention. An adhesive (such as, but not limited to,
bone cement) could be used in conjunction with the system and
method described herein. The patient-specific template 750 and/or
the patient-specific placement guide 958 may include a plurality of
structures cooperatively forming the base body and temporarily or
permanently attached together in such a manner as to permit
relative motion (e.g., pivoting, sliding, or any other motion)
therebetween. The patient-specific placement guide 958 may not
actually be, patient-specific but could instead be a stock item in
situations where the landmark(s) 538 are placed to "standardize" a
particular native patient tissue model with a standard frame of
reference. Any structures or features described with reference to
one embodiment or configuration of the present invention could be
provided, singly or in combination with other structures or
features, to any other embodiment or configuration, as it would be
impractical to describe each of the embodiments and configurations
discussed herein as having all of the options discussed with
respect to all of the other embodiments and configurations. Any of
the components described herein could have a surface treatment
(e.g., texturization, notching, etc.), material choice, and/or
other characteristic chosen to provide the component with a desired
interaction property (e.g., tissue ingrowth, eluting of a
therapeutic material, etc.) with the surrounding tissue. Clinically
useful information could include written or other legible
information, as well as spatial or other physically discernible
information. The system is described herein as being used to plan
and/or simulate a surgical procedure of implanting one or more
prosthetic structures into a patient's body, but also or instead
could be used to plan and/or simulate any surgical procedure,
regardless of whether a non-native component is left in the
patient's body after the procedure. A device or method
incorporating any of these features should be understood to fall
under the scope of the present invention as determined based upon
the claims below and any equivalents thereof.
[0135] Other aspects, objects, and advantages of the present
invention can be obtained from a study of the drawings, the
disclosure, and the appended claims.
* * * * *