U.S. patent application number 12/142142 was filed with the patent office on 2008-12-25 for patient-matched surgical component and methods of use.
Invention is credited to Ryan Schoenefeld.
Application Number | 20080319491 12/142142 |
Document ID | / |
Family ID | 40137311 |
Filed Date | 2008-12-25 |
United States Patent
Application |
20080319491 |
Kind Code |
A1 |
Schoenefeld; Ryan |
December 25, 2008 |
PATIENT-MATCHED SURGICAL COMPONENT AND METHODS OF USE
Abstract
A method of automatically registering a surgical navigation
system to a patient's anatomy is provided. The method comprises
programming a surgical navigation system with a first spatial
relationship between a surgical component and a reference array
connected to the surgical component, programming the surgical
navigation system with a second spatial relationship between an
anatomical feature of a patient and the surgical component,
installing the surgical component on the patient such that the
surgical component engages the anatomical feature in the second
spatial relationship, and locating the reference array with the
surgical navigation system. The navigation system automatically
recognizes the position of the reference array relative to the
patient's anatomy.
Inventors: |
Schoenefeld; Ryan; (Fort
Wayne, IN) |
Correspondence
Address: |
BOSE MCKINNEY & EVANS LLP
111 MONUMENT CIRCLE, SUITE 2700
INDIANAPOLIS
IN
46204
US
|
Family ID: |
40137311 |
Appl. No.: |
12/142142 |
Filed: |
June 19, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60944817 |
Jun 19, 2007 |
|
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Current U.S.
Class: |
606/86R ;
382/128; 606/130 |
Current CPC
Class: |
A61B 90/37 20160201;
A61B 34/20 20160201; A61B 17/15 20130101; A61B 17/1703 20130101;
A61B 2034/2074 20160201; A61B 2034/102 20160201; A61B 2090/3983
20160201; A61B 34/10 20160201; A61B 2034/2055 20160201; A61B 34/25
20160201; A61B 90/36 20160201; A61B 2034/108 20160201; A61B
2034/105 20160201; A61B 2034/107 20160201; A61B 2034/254
20160201 |
Class at
Publication: |
606/86.R ;
382/128; 606/130 |
International
Class: |
A61B 17/56 20060101
A61B017/56 |
Claims
1. A method of automatically registering a surgical navigation
system to a patient's anatomy, comprising: programming the surgical
navigation system with a first spatial relationship between a
surgical component and a reference array connected to the surgical
component; programming the surgical navigation system with a second
spatial relationship between an anatomical feature of a patient and
the surgical component; installing the surgical component on the
patient such that the surgical component engages the anatomical
feature in the second spatial relationship; and locating the
reference array with the surgical navigation system, wherein the
navigation system automatically recognizes the position of the
reference array relative to the patient's anatomy.
2. The method of claim 1, wherein installing the surgical component
onto the patient comprises mating a surface of the surgical
component with a corresponding surface on the anatomical feature,
the corresponding surface on the anatomical feature being shaped to
substantially correspond to the shape of the surgical component's
surface.
3. The method of claim 2, wherein installing the surgical component
on the patient comprises adjusting the position of the surgical
component relative to the anatomical feature until a tactile
sensation of correct placement is achieved.
4. The method of claim 2, wherein mating the surface of the
surgical component with the corresponding surface on the anatomical
feature comprises attaching the surgical component to the
anatomical feature with at least one of pins and screws.
5. The method of claim 1, further comprising identifying a finite
number of predefined points on a representative model of the
anatomical feature, the model being generated from a preoperative
image of the patient's anatomy.
6. The method of claim 5, wherein at least one of the predefined
points is a bony anatomical landmark selected from at least one of
a femoral head landmark, a central knee landmark, a medial femoral
condyle landmark, a lateral femoral condyle landmark, a medial
epicondyle landmark, a lateral epicondyle landmark, a medial
posterior condyle landmark, a lateral posterior condyle landmark
and an anterior cortex point landmark.
7. The method of claim 5, further comprising using the surgical
navigation system to calculate a bone cut by analyzing the
predefined points on the model.
8. The method of claim 1, further comprising removing a portion of
the anatomical feature and a portion of the installed surgical
component.
9. The method of claim 8, further comprising tracking a remaining
portion of the anatomical feature with the surgical navigation
system, the remaining portion of the anatomical feature including a
portion of the installed surgical component, the remaining portion
of the installed surgical component including the reference
array.
10. A method of performing a surgical procedure aided by a surgical
navigation system, comprising: generating a representative model of
an anatomical feature from an image of a patient's anatomy; using
the model to make a surgical component, the surgical component
having a surface that is shaped to substantially mate with the
anatomical feature in a predefined spatial relationship; installing
the surgical component on the anatomical feature by mating the
surface of the component with the anatomical feature in the
predefined spatial relationship; and tracking movement of the
anatomical feature with a tracking system when the installed
surgical component is moved within a measurement field of the
tracking system.
11. The method of claim 10, wherein installing the surgical
component on the anatomical feature comprises adjusting the
position of the surgical component relative to the anatomical
feature until a tactile sensation of correct placement is
achieved.
12. The method of claim 10, wherein tracking movement of the
anatomical feature with the tracking system comprises tracking
movement of a reference array attached to the surgical
component.
13. The method of claim 10, further comprising identifying a finite
number of predefined points on the anatomical feature, the
predefined points being shown on the model to assist in making the
surgical component.
14. The method of claim 13, wherein at least one of the predefined
points is a bony anatomical landmark selected from at least one of
a femoral head landmark, a central knee landmark, a medial femoral
condyle landmark, a lateral femoral condyle landmark, a medial
epicondyle landmark, a lateral epicondyle landmark, a medial
posterior condyle landmark, a lateral posterior condyle landmark
and an anterior cortex point landmark.
15. The method of claim 10, further comprising removing a portion
of the anatomical feature and a portion of the installed surgical
component.
16. The method of claim 15, further comprising tracking a remaining
portion of the anatomical feature with the surgical navigation
system, the remaining portion of the anatomical feature including a
portion of the installed surgical component, the remaining portion
of the installed surgical component including the reference
array.
17. A patient matched surgical component, comprising: a body having
a surface that is shaped to substantially mate with the shape of an
anatomical feature of a patient in a predefined spatial
relationship; and a reference array connected to the body, the
reference array being trackable by a tracking system when exposed
to a measurement field of the tracking system.
18. The patient matched surgical component of claim 17, wherein the
surface of the body and a surface of the anatomical feature have
interfitting shapes, the interfitting shapes being configured to
allow a surgeon to achieve a tactile sensation when correctly
placing the surgical component relative to the anatomical feature
during a surgical procedure.
19. The patient matched surgical component of claim 17, wherein a
first portion of the surgical component is adapted to be removed
during a surgical procedure and a second portion is adapted to
remain attached to the anatomical feature, the remaining portion
being trackable by the tracking system during a remainder of the
surgical procedure.
20. The patient matched surgical component of claim 17, wherein the
reference array comprises a frame and at least one marker attached
to the frame and detectable by the tracking system during a
surgical procedure.
21. The patient matched surgical component of claim 17, wherein the
surgical component further comprises a coupler adapted to
releasably attach the reference array thereto.
22. The patient matched surgical component of claim 21, further
comprising an attachment means for attaching the reference array to
the surgical component, the attachment means being selected from at
least one of welding, fusing, molding, gluing, threading,
snap-connecting and quick disconnecting.
23. A method of performing a surgical procedure aided by a surgical
navigation system, comprising: generating a representative model of
an anatomical feature from an image of a patient's anatomy; using
the model to make a surgical component, the surgical component
having a reference array associated therewith and a surface that is
shaped to substantially mate with an anatomical feature in a
predefined spatial relationship; installing the surgical component
on the anatomical feature by mating the surface of the component
with the anatomical feature in the predefined spatial relationship;
tracking movement of the anatomical feature with the tracking
system when the installed surgical component is moved within a
measurement field of the tracking system; removing a portion of the
anatomical feature, the removed portion also including a portion of
the installed surgical component; and tracking a remaining portion
of the anatomical feature with the tracking system, the remaining
portion of the anatomical feature including a portion of the
installed surgical component, the remaining portion of the
installed surgical component including the reference array.
24. The method of claim 23, wherein installing the surgical
component on the anatomical feature comprises adjusting the
position of the surgical component relative to the anatomical
feature until a tactile sensation of correct placement is
achieved.
25. The method of claim 23, further comprising identifying a finite
number of predefined points on the anatomical feature, the
predefined points being shown on the model to assist in making the
surgical component.
26. The method of claim 25, wherein at least one of the predefined
points is a bony anatomical landmark selected from at least one of
a femoral head landmark, a central knee landmark, a medial femoral
condyle landmark, a lateral femoral condyle landmark, a medial
epicondyle landmark, a lateral epicondyle landmark, a medial
posterior condyle landmark, a lateral posterior condyle landmark
and an anterior cortex point landmark.
27. The method of claim 23, wherein removing a portion of the
anatomical feature comprises resecting bone with a saw blade
through a cut slot of the surgical component.
28. The method of claim 23, wherein mating the surface of the
component with the anatomical feature in the predefined spatial
relationship comprises attaching the surgical component to the
anatomical feature with at least one of pins and screws.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 60/944,817, filed Jun. 19, 2007, the
complete disclosure of which is expressly incorporated herein by
this reference.
FIELD OF THE INVENTION
[0002] The present teachings relate generally to surgical
navigation, and more particularly to patient-matched surgical
components that are adapted to conform to a patient's anatomy, as
well as to methods for using such surgical components during a
surgical navigation procedure.
BACKGROUND
[0003] Surgical navigation systems, also known as computer assisted
surgery systems and image guided surgery systems, aid surgeons in
locating patient anatomical structures, guiding surgical
instruments, and implanting medical devices with a high degree of
accuracy. Surgical navigation has been compared to a global
positioning system that aids vehicle operators to navigate the
earth. A surgical navigation system typically includes a computer,
a tracking system, and patient anatomical information. The patient
anatomical information can be obtained by using an imaging mode
such as fluoroscopy, magnetic resonance imaging (MRI), computer
tomography (CT) or by simply defining the location of patient
anatomy with the surgical navigation system. Surgical navigation
systems can be used for a wide variety of surgeries to improve
patient outcomes.
[0004] To successfully implant a medical device, surgical
navigation systems often employ various forms of computing
technology, as well as utilize intelligent instruments, digital
touch devices, and advanced 3-D visualization software programs.
All of these components enable surgeons to perform a wide variety
of standard and minimally invasive surgical procedures and
techniques. Moreover, these systems allow surgeons to more
accurately plan, track and navigate the placement of instruments
and implants relative to a patient's body, as well as conduct
preoperative and intra-operative body imaging.
[0005] To accomplish the accurate planning, tracking and navigation
of surgical instruments, tools and/or medical devices during a
surgical procedure utilizing surgical navigation, surgeons often
couple "tracking arrays" to the surgical components. These tracking
arrays allow the surgeons to track the physical location of these
surgical components, as well as the patient's bones during the
surgery. By knowing the physical location of the tracking array,
software associated with the tracking system can accurately
calculate the position of the tracked component relative to a
surgical plan image.
[0006] It is known to use surgical navigation instruments to
measure the size and general contour of a bone before selecting
and/or manufacturing a prosthetic implant. This process allows the
surgeon to choose a prosthetic component that generally resembles
the shape and size of the patient's anatomy, thereby achieving a
more customized fit during the implantation process. Despite such
customization efforts, most orthopaedic procedures still require
the use of adjustable components or guides during the surgical
procedure, particularly as such instruments are needed to fit the
prosthetic components to the patient's anatomy. However, this
process is time consuming, as well as subject to error during the
placement and registration of the surgical components. As such, it
would be desirable to improve this process to reduce surgery time
and improve prosthetic fit and/or function.
SUMMARY OF THE INVENTION
[0007] The present teachings provide a patient matched surgical
component that is custom manufactured to fit a patient's anatomy in
a precise manner. To achieve such customization, the patient's
anatomy is preoperatively scanned and uploaded to a software
program, which then recreates a three-dimensional model of the
patient's anatomy from the scanned image. The three-dimensional
model is then used by the software program to identify and locate
on the image specific known anatomical landmarks of the patient's
anatomy. Planning software then analyzes the identified anatomical
landmarks together with any specific surgical instructions needed
to develop and plan a surgical protocol for the patient. Once the
surgical protocol has been approved by the surgeon, the protocol is
presented to a software program, which then uses the protocol, as
well as the preoperative scan images, to create a virtual patient
matched surgical component. The virtual component is then sent to a
rapid prototyping machine or a standard machining process, which in
turn manufactures the surgical component for use during the
surgical procedure. Because the surgical component is custom
manufactured to fit the patient's anatomy relative to specific
anatomical landmarks, it can be manufactured with a reference array
positioned on its surface in a predefined spatial relationship with
respect to the patient's anatomy. By having a predefined spatial
relationship between the reference array and the patient's anatomy,
the need for intra-operative registration during the surgical
procedure is minimized or even eliminated altogether. Furthermore,
since the patient matched component is fixable to the patient's
anatomy with pins, the reference array can act as an automatically
registered rigid bone reference marker that can be used throughout
the surgical navigation procedure.
[0008] According to one aspect of the present teachings, a method
of automatically registering a surgical navigation system to a
patient's anatomy is provided. The method comprises programming a
surgical navigation system with a first spatial relationship
between a surgical component and a reference array connected to the
surgical component, programming the surgical navigation system with
a second spatial relationship between an anatomical feature of a
patient and the surgical component, installing the surgical
component on the patient such that the surgical component engages
the anatomical feature in the second spatial relationship, and
locating the reference array with the surgical navigation system.
The navigation system automatically recognizes the position of the
reference array relative to the patient's anatomy.
[0009] According to another exemplary embodiment herein, a method
of performing a surgical procedure aided by a surgical navigation
system is provided. The method comprises generating a
representative model of an anatomical feature from an image of a
patient's anatomy, using the model to make a surgical component,
installing the surgical component on the anatomical feature by
mating the surface of the component with the anatomical feature in
the predefined spatial relationship, and tracking movement of the
anatomical feature with a tracking system when the installed
surgical component is moved within a measurement field of the
tracking system. According to this embodiment, the surgical
component has a surface that is shaped to substantially mate with
the anatomical feature in a predefined spatial relationship.
[0010] According to yet another exemplary embodiment herein, a
patient matched surgical component is provided. The surgical
component comprises a body having a surface that is shaped to
substantially mate with the shape of an anatomical feature of a
patient in a predefined spatial relationship, and a reference array
connected to the body, the reference array being trackable by a
tracking system when exposed to a measurement field of the tracking
system.
[0011] In still another exemplary embodiment, a method of
performing a surgical procedure aided by a surgical navigation
system is provided. According to this exemplary embodiment, the
method comprises generating a representative model of an anatomical
feature from an image of a patient's anatomy, using the model to
make a surgical component, the surgical component having a
reference array associated therewith and a surface that is shaped
to substantially mate with an anatomical feature in a predefined
spatial relationship, installing the surgical component on the
anatomical feature by mating the surface of the component with the
anatomical feature in the predefined spatial relationship, tracking
movement of the anatomical feature with the tracking system when
the installed surgical component is moved within a measurement
field of the tracking system, removing a portion of the anatomical
feature, the removed portion also including a portion of the
installed surgical component, and tracking a remaining portion of
the anatomical feature with the tracking system, the remaining
portion of the anatomical feature including a portion of the
installed surgical component, the remaining portion of the
installed surgical component including the reference array.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The above-mentioned aspects of the present teachings and the
manner of obtaining them will become more apparent and the
invention itself will be better understood by reference to the
following description of the embodiments of the invention taken in
conjunction with the accompanying drawings, wherein:
[0013] FIG. 1 is a perspective view of an exemplary operating room
setup in a surgical navigation embodiment in accordance with the
present teachings;
[0014] FIG. 2 is a patient-matched surgical component created from
a preoperative scan image of the patient's bone;
[0015] FIG. 3A is a fragmentary perspective view of a surgeon
aligning the patient-matched surgical component of FIG. 2 with a
bone;
[0016] FIG. 3B is a fragmentary perspective view of the backside of
the surgical component of FIG. 3A, the component being shown
aligned with a bone;
[0017] FIG. 4 is a fragmentary perspective view of the
patient-matched surgical component of FIG. 2 being attached to the
bone by the surgeon;
[0018] FIG. 5 is a fragmentary perspective view of the
patient-matched surgical component of FIG. 4 attached to the bone
and its corresponding reference array, which is connectable
thereto;
[0019] FIGS. 6 and 7 are fragmentary perspective views illustrating
the bone of FIG. 5 undergoing an exemplary resection process in
accordance with the present teachings;
[0020] FIG. 8 is a fragmentary perspective view of a surgeon
aligning a patient-matched surgical component with a patient's
pelvis in accordance with the present teachings;
[0021] FIG. 9 is a fragmentary perspective view of the
patient-matched surgical component of FIG. 8 being attached to the
pelvis by the surgeon; and
[0022] FIG. 10 is a fragmentary perspective view of the
patient-matched surgical component of FIG. 8 and its corresponding
reference array connected thereto.
[0023] Corresponding reference characters indicate corresponding
parts throughout the several views.
DETAILED DESCRIPTION
[0024] The embodiments of the present teachings described below are
not intended to be exhaustive or to limit the invention to the
precise forms disclosed in the following detailed description.
Rather, the embodiments are chosen and described so that others
skilled in the art may appreciate and understand the principles and
practices of the present teachings.
[0025] FIG. 1 shows a perspective view of an operating room with
surgical navigation system 20. Surgeon 21 is aided by surgical
navigation system 20 in performing knee arthroplasty, also known as
knee replacement surgery, on patient 22 shown lying on operating
table 24. Surgical navigation system 20 has a tracking system that
locates arrays and tracks them in real-time. To accomplish this,
the surgical navigation system includes optical locator 23, which
has two CCD (charge couple device) cameras 25 that detect the
positions of the arrays in space by using triangulation methods.
The relative location of the tracked arrays, including the
patient's anatomy, can then be shown on a computer display (such as
computer display 27 for instance) to assist the surgeon during the
surgical procedure. The arrays that are typically used include
probe arrays, instrument arrays, reference arrays, and calibrator
arrays. The tracking system also detects the location of reference
array 36, which is attached to patient matched surgical component
34. The relative location of patient matched surgical component 34
with respect to the patient's anatomy can then be shown on computer
display image 38 of computer monitor 42. The operating room also
includes instrument cart 45 having tray 44 for holding a variety of
surgical instruments and arrays 46. Instrument cart 45 is also
draped in sterile cover 48 to eliminate contamination risks within
the sterile field.
[0026] The surgery is performed within a sterile field, adhering to
the principles of asepsis by all scrubbed persons in the operating
room. Patient 22, surgeon 21 and assisting clinician 50 are
prepared for the sterile field through appropriate scrubbing and
clothing. The sterile field will typically extend from operating
table 24 upward in the operating room. Typically, the computer
display is located outside of the sterile field.
[0027] A representation of the patient's anatomy 52 can be acquired
with an imaging system, a virtual image, a morphed image, or a
combination of imaging techniques. The imaging system can be any
system capable of producing images that represent the patient's
anatomy such as a fluoroscope producing x-ray two-dimensional
images, computer tomography (CT) producing a three-dimensional
image, magnetic resonance imaging (MRI) producing a
three-dimensional image, ultrasound imaging producing a
two-dimensional image, and the like. A virtual image of the
patient's anatomy can be created by defining anatomical points with
the surgical navigation system 20 or by applying a statistical
anatomical model. A morphed image of the patient's anatomy can be
created by combining an image of the patient's anatomy with a data
set, such as a virtual image of the patient's anatomy.
[0028] The tracking system of the present invention can be any
system that can determine the three-dimensional location of devices
carrying or incorporating markers that serve as tracking indicia.
More particularly, the tracking system may be an active tracking
system that has a collection of infrared light emitting diode
(ILEDs) illuminators surrounding the position sensor lenses to
flood a measurement field of view with infrared light.
Alternatively, the system may be a passive tracking system, which
incorporates retro-reflective markers that reflect infrared light
back to the position sensor, and the system triangulates the
real-time position (x, y, and z location) and orientation (rotation
around x, y, and z axes). In yet other embodiments, the tracking
system may be a hybrid tracking system that detects active and
active wireless markers in addition to passive markers. Active
marker based instruments enable automatic tool identification,
program control of visible LEDs, and input via tool buttons.
Finally, in yet other exemplary embodiments, the tracking system
may utilize electromagnetic tracking techniques. These systems
locate and track devices and produce a real-time, three-dimensional
video display of the surgical procedure by using electromagnetic
field transmitters that generate a local magnetic field around the
patient's anatomy.
[0029] The present teachings enhance surgical navigation system 20
by incorporating into the system a process for custom manufacturing
patient-matched surgical component 34 so that it fits the anatomy
of patient 22 in a precise manner. Particularly, in addition to
tracking surgical components, the navigation system can also
generate preoperative images of the patient's anatomy and then use
such images to manufacture a surgical component that is custom
matched to the patient's anatomy. More specifically, the patient's
anatomy is preoperatively scanned and uploaded to a software
program, which then recreates a three-dimensional virtual model of
the patient's anatomy from the scanned image. The virtual model is
then used by the software program to identify and locate known bony
anatomical landmarks or predefined points of the patient's anatomy.
For a further description about the acquisition and registration of
bony landmarks, see U.S. patent application Ser. No. 11/689,711,
entitled "Modeling Method and Apparatus for use in Surgical
Navigation," filed Mar. 22, 2007, which is incorporated by
reference herein in its entirety.
[0030] As is appreciated by those of skill within the art, bony
anatomical landmarks are visible points or locations on a patient's
anatomy, which are identifiable by referencing known locations on
the surface of the bone. For instance, known bony landmarks on the
femur include, but are not limited to, a femoral head landmark, a
central knee landmark, a medial femoral condyle landmark, a lateral
femoral condyle landmark, a medial epicondyle landmark, a lateral
epicondyle landmark, a medial posterior condyle landmark, a lateral
posterior condyle landmark and an anterior cortex point landmark.
Similar bony landmarks are also found on other bones (such as the
tibia, fibula, patella and pelvis, for instance), however, for
simplicity purposes, the exemplary illustrations provided here are
specifically directed to the femur. As the present teachings are
not intended to be limiting, it should be understood and
appreciated that these teachings are also applicable to bony
landmark structures other than the femur.
[0031] Planning software analyzes the identified anatomical
landmarks together with any specific surgical instructions received
from the surgeon and develops a surgical procedure or protocol for
the patient. After its approval, the protocol is then entered into
a software program, which uses the protocol together with the
preoperative scan images to create a virtual representation of a
patient matched surgical component. The virtual representation of
the surgical component is then sent to a rapid prototyping machine
or a standard machining process, which in turn manufactures a
physical prototype of the surgical component. Because the surgical
component is custom manufactured to fit the patient's anatomy
relative to known anatomical landmarks, it can be manufactured to
include a reference array that extends from its surface in a
predefined manner. By having the reference array positioned in a
predefined spatial orientation with respect to the patient's
anatomy, the need to further register the component
intraoperatively is unnecessary; particularly as the registration
of the reference array is completed preoperatively during the
surgical planning stages. Furthermore, since the patient matched
component can be secured to the patient's anatomy, the reference
array can also function as an automatically registered and
trackable bone reference array during the surgical procedure.
[0032] The principles upon which exemplary embodiments of the
present invention rely can be understood with reference to FIG. 2,
which illustrates three-dimensional bone model 301 on surgical
display image or user interface screen 303 of monitor 305. Model
301 is based on an image of the patient's anatomy, which was
obtained from a preoperative diagnostic imaging procedure, such as
by magnetic resonance imaging (MRI), computer assisted tomography
(CT), fluoroscopy, ultrasound or positron emission tomography
(PET). It should be understood that model 301 is intended to
illustrate general principles of the present teachings and is not
representative of any particular screen shot that a surgeon may
observe during a surgical navigation procedure. Moreover, it should
be understood and appreciated herein that processes for generating
three-dimensional models from preoperative images of anatomical
features are well known by those within the surgical navigation
field and therefore not discussed in detail herein.
[0033] Once three-dimensional model 301 has been created, it is
then used by the software program to identify and locate specific
known anatomical landmarks characteristic of the anatomical
feature. The number of anatomical landmarks identified on the model
will depend on the bony anatomy that is being characterized, as
well as what type of surgical procedure is being performed on the
patient undergoing the operation. In some exemplary embodiments,
however, less than about ten anatomical landmarks are identified by
the software program and represented on the three-dimensional
model. In other exemplary embodiments, less than about seven
anatomical landmarks are identified, while in still other exemplary
embodiments, less than about three landmarks are identified.
[0034] In FIG. 2, model 301 depicts five bony anatomical landmarks
common to a typical femur. These bony landmarks include the distal
most point of the medial femoral condyle 307, the distal most point
of the lateral femoral condyle 309, the medial epicondyle 311, the
lateral epicondyle 313 and the anterior cortex point of the femur
315. By acquiring such bony landmarks, the surgeon can use such
information to assist in planning the surgical protocol to be
performed on the patient. For instance, by acquiring the
epicondyles (311, 313), the transepicondylar axis of the femur can
be determined to assist with the rotation and positioning of a
femoral implant component. Moreover, by acquiring the anterior
cortex point of the femur 315, proper implant sizing techniques can
be utilized.
[0035] Once model 301 has been created and the bony anatomical
landmarks identified, the surgeon can use the model as a visual aid
and manipulate it to gather important surgical information, such as
gap analysis data, resection plane details and bone alignment
angles. Furthermore, if the surgeon desires, he can rotate or
manipulate model 301 so that he can visually appreciate the general
shape and characteristics of the patient's femur, particularly as
the acquired bony anatomical landmark points shown on the model
remain accurate as it is manipulated by the surgeon. In addition to
displaying the acquired femoral landmark points (i.e. points 307,
309, 311, 313 and 315), model 301 can also depict a representation
of the implant component that will be implanted onto the patient
during the surgical procedure. By displaying a representation of
the implant on the bone model, the system can gather additional
information useful for finalizing the surgical protocol,
particularly implant sizing and rotation information. The
representation of the implant can also be rotated and aligned
preoperatively, particularly so that the navigation system can
calculate the location of necessary bone cuts and/or resection
planes to be used during the surgical procedure. Some resection
planes that can be determined preoperatively include, but are not
limited to, the tibial proximal cut, the femoral distal cut, the
femoral anterior cut, as well as the chamfer cuts made by a 4-in-1
resection block.
[0036] After the surgical protocol has been planned and is
approved, the software then creates a virtual surgical component
that is custom-shaped to effect implementation of the surgical
specifications (e.g., bone cuts, resection planes, drill holes,
etc.) that were determined by the planning software. In some
exemplary embodiments, the surgical component may function as a
patient-matched reference array and not include any cut slots in
its body design. More particularly, in certain embodiments, the
surgical component may replace one or more rigid bone reference
arrays or markers typically attached to the patient's anatomy
during a surgical procedure. By eliminating the use of such rigid
bone reference arrays, the surgical procedure can be performed in a
minimally invasive manner, particularly as fewer incisions would be
required of the patient's anatomy. Reducing the number of required
incisions during a surgical procedure is advantageous, particularly
in terms of reducing associated scarring and/or complications
typically caused from such incisions.
[0037] Once the component has been virtually designed, the virtual
representation is then sent to a rapid prototyping machine or a
standard machining process, which in turn manufactures a physical
component that corresponds to the dimensional parameters of the
virtual component. For instance, as shown in FIGS. 2, 3A and 3B,
surgical component 320 has been created having an interior surface
322, which matches the topography of model 301. Surgical component
320 also includes one or more cutting slots or guides 324, which
are specifically designed to accommodate cutting devices (e.g., saw
blades) during a bone resection process. It should be understood
and appreciated herein that the position, shape and directional
orientation of the cutting slot(s) on the surgical component will
depend particularly on the surgical procedure that is to be
performed on the given patient. For instance, if the surgeon will
be performing a total knee arthroplasty, a cutting slot to
accommodate the distal femur cut, such as slot 324 shown in FIG. 2,
may be included. Surgical component 320 may also include one or
more holes 328 to accommodate drilling into the patient's bone
and/or attaching the component to the patient's bone during a
surgical procedure.
[0038] FIGS. 3A and 3B show surgeon 402 positioning surgical
component 320 relative to bone 404 during a surgical procedure. As
the interior surface of the surgical component is shaped to
substantially match the general topographic landscape and contour
of bone 404, the surgeon is able to align the component with the
bone in such a manner that the component mates with the bone in a
position predefined by the software. In other words, surgeon 402 is
able to press inner surface 322 of surgical component 320 against
outer surface 406 of bone 404 until a tactile sensation is felt by
the surgeon indicating that the component has mated with or
"matched" its corresponding surface of the bone. Because surgical
component 320 is patient-matched to the shape of bone 404, surgeon
402 can position surgical component 320 by feel with a high degree
of precision. More particularly, the body of the surgical component
is shaped in such a manner that it interfits or interlocks to the
shape of the anatomical feature during installation. This
interfitting or interlocking relationship allows the surgeon to
achieve the tactile sensation when the surgical component is
correctly installed onto the anatomical feature. When the surgical
component 320 is properly or correctly installed, it sits
substantially flush against the surface of bone 404, i.e., there
will not be significant gaps around the edge of the component as it
sits against the patient's anatomical feature or bone.
[0039] As explained above, surgical component 320 further includes
one or more holes 328 for drilling into the bone and/or for
attaching the component to the bone's surface during a surgical
procedure, as well as one or more cutting slots 324 to accommodate
cutting devices during a bone resection process. According to one
exemplary embodiment, holes 328 are configured to function as
anchoring holes, which can be used for inserting temporary pins or
screws into the bone to hold the surgical component into place
during a surgical procedure. Holes 328 may also be configured into
various dimensional patterns and arrangements to accommodate the
surgical plan and/or to accommodate the anatomical shape of the
bony structure or anatomical feature to which the component is to
be affixed. Moreover, in certain exemplary embodiments, the same
surgical component may be used in multiple resection procedures,
whereby the holes are arranged such that the remaining portion of
surgical component 320 remains securely fastened to the bone after
the initial resection is completed. Holes 328 may also be
configured to use previously placed reference markers or anchors
already attached to the surface of the bone. More particularly,
according to this embodiment, the arrangement of the holes can be
positioned such that the surgeon places the surgical component over
one or more reference markers or anchor devices previously placed
into the bone. Such reference markers or anchor devices may have
been placed during prior diagnostic or therapeutic surgeries, or
may have been placed preoperatively for use in future diagnostic or
therapeutic procedures.
[0040] FIG. 4 shows surgical component 320 aligned with and
positioned substantially flush against bone 404. Once positioned,
surgical component 320 can be affixed to bone 404 by inserting one
or more pins 502 into the bone through holes 328. Affixing surgical
component 320 to bone 404 with pins, screws, or other attachment
means insures that the surgical component is securely held in place
during the surgical procedure. In FIG. 4, surgeon 402 is shown
using a pin insertion device 504 to insert pin 502 into bone 404
through one of holes 328. Such surgical pin insertion techniques
and instrumentation are known by those of skill within the art and
therefore not discussed in detail herein.
[0041] FIG. 5 shows surgical component 320 positioned against bone
404 and secured into place with attachment pins 502. Surgical
component 320 also includes a quick connect receptacle 602, which
is configured to connect to a tracking device, such as a reference
array. According to this embodiment, tracking or reference array
604 is provided with a quick connect base 606 that dimensionally
corresponds with receptacle 602 such that a removable snap-fit
connection can be achieved between the two components. While FIG. 5
illustrates a snap-fit attachment means between the reference array
and the component, it should be understood that in other
embodiments, reference array 604 may be "pre-installed" onto
surgical component 320, whereby no additional attachment means is
required after the component is attached to the bone. It should
also be understood and appreciated that any attachment means known
within the art may be used to secure reference array 604 to
surgical component 320. Such attachment means include, but are not
limited to, welding, fusing, molding, gluing, threading,
snap-connections, quick disconnect connections and the like.
[0042] Once reference array 604 is attached to surgical component
320, navigation system 20 is able to locate and track its position
in real-time and display its tracked position on a surgical plan
image. In other words, once the navigation system locates the
array, the system automatically knows its position with respect to
the landmarks identified on the model image, as well as where it
has been pre-registered with respect to the image. To accomplish
this, and with reference to FIG. 6, cameras 702 of optical locator
704 detect in space the position of markers 706, which extend from
the surface of reference array 604. It should be understood and
appreciated herein that while this embodiment shows four markers
706 attached to the frame of reference array 604, in other
embodiments less than four markers may be used, while in yet other
embodiments, more than four markers may be used. For instance, in
some embodiments using electromagnetic tracking technology, only
one marker is needed to track the position of the surgical
component in space. In yet other embodiments, three markers may be
used to triangulate the position of the surgical component in
space. As such, it should be fully appreciated that the present
teachings are not intended to be limited herein.
[0043] To detect the position of the markers in space, known
triangulation methods are used. These triangulation methods allow
the navigation system to determine the relative location of the
reference array and its markers with respect to the patient's
anatomy, and then display the same on a surgical plan image. As
reference array 604 is trackable in real-time, the position of bone
404 can also be tracked in real-time, particularly since reference
array 604 is fixably attached to its surface by way of surgical
component 320. As explained above, by having reference array 604
positioned relative to the surgical component 320 in a predefined
spatial manner, the need for intra-operative registration during
the surgical procedure is substantially minimized.
[0044] As used herein, "predefined" refers to a preoperatively
planned spatial relationship between the surgical component and the
anatomical feature of the patient to which the component is to be
attached. In other words, once the component is installed onto the
anatomical feature in its predefined spatial orientation, it is
automatically registered with the system and can be tracked by the
navigation system for the remainder of the procedure without
further registration techniques. Moreover, since the patient
matched component is fixably secured to the patient's anatomy
throughout the surgical procedure, reference array 604 is able to
function as a rigid reference bone marker to track bone 404 during
the surgical procedure. Such rigid bone reference arrays are
commonly used in orthopaedic surgical procedures and are able to
track a patient's bones with respect to various surgical
instruments during a surgical navigation procedure. Because the
presently disclosed reference arrays are preoperatively registered
with the navigation system in a predefined manner with respect to
the patient's anatomy, these components can be used to track the
patient's anatomy without the need to insert additional rigid array
markers into the patient during the procedure. Moreover, because
such surgical components are registered with the navigation system
during the preoperative planning steps of the surgical procedure,
timely intraoperative registration processes are also
unnecessary.
[0045] An exemplary illustration of a bone undergoing a resection
process in accordance with the present teachings is depicted in
FIGS. 6-7. Surgical instrument 714 may optionally include a marker
array 715, which can be further identified and tracked by cameras
702 of optical locator 704. However, since surgical component 320
was custom designed to match and mate with the specific shape of
bone 404, the surgeon does not need to track the position of the
surgical instrument relative to the bone during the surgical
procedure. More particularly, the position of cutting slot 324 on
surgical component 320 was previously registered with the tracking
system during the preoperative planning stages of the surgical
procedure. As such, once the surgeon attaches the component to the
bone in its predetermined position, he can proceed directly to
resecting the bone with the surgical instrument without further
tracking or registering of the surgical instrument. As such, it
should be understood that the depiction of marker array 715 on
surgical instrument 714 is optional and is not intended to limit
the scope of the present teachings.
[0046] Referring still to FIGS. 6 and 7, as surgeon 716 moves
instrument 714 relative to bone 404, the tracking system locates
and tracks marker array 715 in real-time. The relative location of
marker array 715 is then shown on surgical plan image 708 of
computer display 710. The tracking system detects the location of
surgical instrument 714 relative to bone 404 by referencing the
position of marker array 715 as it moves with respect to reference
array 604, which is fixably attached to bone 404 by way of surgical
component 320. The position of saw blade 712 of surgical instrument
714 is displayed on surgical plan image 708 as cut plane 713. By
viewing cut plane 713 on surgical plan image 708, surgeon 716 can
confirm that the surgical component is positioned properly,
although as just noted, this step is optional since the component
can be properly positioned by the surgeon by feel alone.
[0047] FIG. 7 shows a portion of bone 404 removed after surgeon 716
has inserted saw blade 712 into cut slot 324 of surgical component
320. A portion of the surgical component 321 remains affixed to the
removed bone by attachment pin 329. Because reference array 604 is
still attached to bone 404 by way of surgical component 320, the
surgical navigation system continues to recognize and track the
position of bone 404 and the remaining portion of the attached
surgical component 320 in real-time throughout the remainder of the
surgical procedure. As such, the remaining portion of surgical
component 320, and its reference array 604, can be used for
additional steps in the surgical procedure, such as the removal or
modification of a second predefined part of the bone after the
initial resection, or the placement and use of additional surgical
components. The tracked remaining portion of surgical component 320
can also be used to perform other surgical procedures that require
tracking, such as ligament balancing, range of motion and
impingement analyses.
[0048] It should be understood and appreciated herein that while
FIG. 7 depicts portion 321 of surgical component 320 being removed
with saw blade 712, in other exemplary embodiments, portion 321 may
be removed by being snapped, broken or cleaved away from surgical
component 320. For instance, cut slot 324 could be replaced by a
groove or cleave that is designed to be physically broken or torn
away from the surgical component after it has been attached to the
patient's anatomy. As such, the attachment means useful for the
present teachings are not intended to be limited herein.
[0049] While the above-described embodiments illustrate the
presently disclosed surgical components as being useful for knee
related applications, it should be appreciated and understood
herein that the exemplary components disclosed herein may also be
used together with any other anatomical features without straying
from the present teachings. For instance, in certain exemplary
embodiments, the surgical components may also be used together with
hip-related navigation applications. More particularly, as is known
within the surgical navigation field, registration processes for
the hip can be quite challenging, particularly as the surgeon must
register both sides of the patient's pelvis, including rolling the
patient onto their side to collect data points and then re-draping
and re-scrubbing the patient between such registration steps. By
using the presently disclosed surgical components, navigating the
hip during a surgical procedure is significantly simplified,
particularly as the need to register the hip intraoperatively is
eliminated.
[0050] Further principles upon which exemplary embodiments of the
present invention rely can be understood with reference to FIG. 8.
FIG. 8 depicts surgical component 802, which has been created by a
rapid prototyping machine or a standard machining process to match
the dimensional parameters of a virtual representation of a
patient's pelvis according to the process described above. More
particularly, surgical component 802 has an interior surface that
matches the topographic landscape of pelvis 803. According to this
embodiment, surgeon 806 positions surgical component 802 relative
to pelvis 803 during a hip procedure. As the interior surface of
the surgical component is shaped to substantially match the general
topographic landscape and contour of pelvis 803, the surgeon is
able to align the component with the pelvis in such a manner that
the component mates with the pelvis in a position predefined by the
software. In other words, surgeon 806 is able to press the inner
surface of surgical component 802 against outer surface 804 of
pelvis 803 until a tactile sensation is felt by the surgeon
indicating that the component has mated with or "matched" its
corresponding surface of the pelvis. Because surgical component 802
is patient-matched to the shape of pelvis 803, surgeon 806 can
position surgical component 802 by feel with a high degree of
precision. When properly positioned, surgical component 802 will
sit substantially flush against the surface of pelvis 803, i.e.,
there will not be significant gaps around the edge of the component
as it sits against the patient's pelvic bone.
[0051] Surgical component 802 also includes one or more holes 808
for drilling into the pelvis and/or for attaching the component to
the pelvis's surface during a hip procedure. According to one
exemplary embodiment, holes 808 are configured to function as
anchoring holes, which can be used for inserting temporary pins or
screws into the pelvis, thereby holding the surgical component into
place during a surgical procedure. For instance, FIG. 9 shows
surgical component 802 aligned with and positioned substantially
flush against pelvis 803. Once positioned, surgical component 802
can be affixed to pelvis 803 by inserting one or more pins 810 into
the pelvis through holes 808. Affixing surgical component 802 to
pelvis 803 with pins, screws, or other attachment means insures
that the surgical component is securely held in place during the
surgical procedure. In FIG. 9, surgeon 806 is shown using a pin
insertion device 812 to insert pin 810 into pelvis 803 through one
of holes 808.
[0052] FIG. 10 shows surgical component 802 positioned against
pelvis 803 and secured into place with attachment pins 810.
Surgical component 802 also includes a quick connect receptacle
814, which is configured to connect to a tracking device, such as
reference array 816. Once reference array 816 is attached to
surgical component 802, navigation system 20 is able to locate and
track its position in real-time and display its tracked position on
a surgical plan image. In other words, once the navigation system
locates the array, the system automatically knows its position with
respect to the landmarks identified on the model image, as well as
where it has been pre-registered with respect to the image. To
accomplish this, cameras 818 of optical locator 820 detect in space
the position of markers 817, which extend from the surface of
reference array 816. To detect the position of the markers in
space, known triangulation methods are used. These triangulation
methods allow the navigation system to determine the relative
location of the reference array and its markers with respect to the
patient's anatomy, and then display the same on a surgical plan
image. As reference array 816 is trackable in real-time, the
position of pelvis 803 can also be tracked in real-time,
particularly since reference array 816 is fixably attached to its
surface by way of surgical component 802. As explained above, by
having reference array 816 positioned relative to the surgical
component 802 in a predefined spatial manner, the need for
intra-operative registration during the surgical procedure is
substantially minimized.
[0053] In additional to navigating knees and hips, the present
teachings can also be used with surgical procedures involving the
shoulder, spine, ankle, elbow, skull or any other type of bony
structure found within the human anatomy. As such, the present
teachings are not intended to be limited herein.
[0054] While an exemplary embodiment incorporating the principles
of the present invention has been disclosed hereinabove, the
present invention is not limited to the disclosed embodiments.
Instead, this application is intended to cover any variations,
uses, or adaptations of the invention using its general principles.
Further, this application is intended to cover such departures from
the present disclosure as come within known or customary practice
in the art to which this invention pertains and which fall within
the limits of the appended claims.
* * * * *