U.S. patent application number 12/898298 was filed with the patent office on 2011-03-24 for total knee arthroplasty systems and processes.
Invention is credited to Christopher P. Carson.
Application Number | 20110071530 12/898298 |
Document ID | / |
Family ID | 26955127 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110071530 |
Kind Code |
A1 |
Carson; Christopher P. |
March 24, 2011 |
Total knee arthroplasty systems and processes
Abstract
Systems and processes for tracking anatomy, instrumentation,
trial implants, implants, and references, and rendering images and
data related to them in connection with surgical operations, for
example total knee arthroplasties ("TKA"). These systems and
processes are accomplished by using a computer to intraoperatively
obtain images of body parts and to register, navigate, and track
surgical instruments.
Inventors: |
Carson; Christopher P.;
(Seymour, CT) |
Family ID: |
26955127 |
Appl. No.: |
12/898298 |
Filed: |
October 5, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11098209 |
Apr 4, 2005 |
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12898298 |
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10084012 |
Feb 27, 2002 |
6923817 |
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11098209 |
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60271818 |
Feb 27, 2001 |
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60355899 |
Feb 11, 2002 |
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Current U.S.
Class: |
606/88 ; 606/86R;
606/87 |
Current CPC
Class: |
A61B 2034/107 20160201;
A61B 2034/2055 20160201; A61B 2034/256 20160201; A61F 2/4684
20130101; A61F 2002/30892 20130101; A61F 2/4657 20130101; A61B
2090/3916 20160201; A61B 90/10 20160201; A61B 2034/2068 20160201;
A61B 2090/3983 20160201; A61B 34/10 20160201; A61F 2/38 20130101;
A61F 2/3859 20130101; A61F 2002/4632 20130101; A61F 2002/30616
20130101; A61B 2034/252 20160201; A61F 2/389 20130101; A61B 34/20
20160201; A61B 2034/105 20160201; A61B 2034/2072 20160201; A61B
2034/102 20160201; A61B 17/70 20130101; A61B 2090/376 20160201;
A61B 34/25 20160201; A61B 2034/254 20160201; A61B 90/36
20160201 |
Class at
Publication: |
606/88 ;
606/86.R; 606/87 |
International
Class: |
A61F 2/46 20060101
A61F002/46 |
Claims
1-20. (canceled)
21. A computer system for facilitating a joint arthroplasty
procedure on a patient's joint, the patient's joint including at
least one bone, the computer system comprising: (a) an input that
receives image data about a structure of the at least one bone; (b)
a memory that at least temporarily stores: (i) the image data about
the structure of the at least one bone; (ii) reference data about
at least one reference related to the structure of the at least one
bone; (iii) device data about a first surgical device, wherein the
first surgical device is an orthopaedic implant; and (iv) device
data about a second surgical device, wherein the second surgical
device is a surgical instrument; (c) a processor that accesses the
image, reference and device data about the first and second
surgical devices at least temporarily stored in the memory and
identifies a desired position and orientation of the surgical
instrument relative to the at least one bone of the patient based
at least in part on the image, reference and device data about the
first and second surgical devices; and (d) an output that outputs
information about the desired position and orientation of the
surgical instrument relative to the at least one bone.
22. The computer system of claim 21, wherein the processor
identifies the desired position and orientation of the surgical
instrument relative to the at least one bone of the patient's joint
based at least in part on the image, reference and device data as
well as a surgeon's input.
23. The computer system of claim 21, wherein the input also
receives the reference data.
24. The computer system of claim 23, wherein the reference data is
at least one reference point on the structure of the at least one
bone.
25. The computer system of claim 24, wherein the at least one
reference point is at least one point on a femoral condyle or a
trochlear groove.
26. The computer system of claim 21, wherein the reference data is
a center of rotation of the at least one bone.
27. The computer system of claim 26, wherein the processor
determines an axis of the at least one bone using the reference
data.
28. The computer system of claim 27, wherein the axis is a
mechanical axis, an anterior/posterior axis, or a medial/lateral
axis of the at least one bone.
29. The computer system of claim 21, further comprising a position
sensor for tracking the position of the at least one bone and the
first and second surgical devices.
30. The computer system of claim 21, wherein the joint arthroplasty
procedure is a knee arthroplasty procedure, wherein the at least
one bone is a femur of the patient and a tibia of the patient, and
wherein the image data is about the patient's femur and tibia,
including at least portions of an upper and a lower extremity of
the femur and an upper and lower extremity of the tibia.
31. The computer system of claim 21, wherein the device data about
the surgical instrument is data about a surgical cutting block.
32. The computer system of claim 31, wherein the data about the
surgical cutting block is wire frame data.
33. The computer system of claim 21, wherein the desired position
and orientation of the surgical instrument determines an actual
position and orientation of the surgical device.
34. The computer system of claim 21, wherein the desired position
and orientation of the surgical instrument determines an actual
position and orientation of the orthopaedic implant.
35. The computer system of claim 21, further comprising a display
that displays a representation of the structure of the at least one
bone.
36. The computer system of claim 35, wherein the display displays a
representation of the at least one reference relative to the
representation of the structure of the at least one bone.
37. The computer system of claim 21, wherein the desired position
and orientation of the surgical instrument relative to the at least
one bone includes at least one of a desired varus/valgus
orientation of the surgical instrument relative to the at least one
bone, a desired internal/external rotation of the surgical device
relative to the at least one bone, and a desired flexion/extension
of the surgical device relative to the at least one bone.
38. The computer system of claim 21, wherein the image data is
X-ray image data, CT image data, MRI image data, or fluoroscopic
image data.
39. The computer system of claim 21, wherein the computer system is
a networked computer system.
40. The computer system of claim 21, wherein the joint arthroplasty
procedure is a total joint arthroplasty procedure or a partial
joint arthroplasty procedure.
41. The computer system of claim 21, wherein the joint arthroplasty
procedure is a knee arthroplasty, a hip arthroplasty, a shoulder
arthroplasty, an elbow arthroplasty or an ankle arthroplasty.
42. The computer system of claim 21, wherein the surgical
instrument is a knee arthroplasty cutting guide that includes an
interior surface for contacting the at least one bone.
43. The computer system of claim 42, wherein at least a portion of
the interior surface of the knee arthroplasty cutting guide is
concave.
44. A computer system for facilitating a joint arthroplasty
procedure on a patient's joint, the patient's joint including at
least one bone, the computer system comprising: (a) an input that
receives image data about a structure of the at least one bone; (b)
a memory that at least temporarily stores: (i) the image data about
the structure of the at least one bone; (ii) reference data about
at least one reference related to the structure of the at least one
bone; (iii) device data about a first surgical device, wherein the
first surgical device is an orthopaedic implant; and (iv) device
data about a second surgical device, wherein the second surgical
device is a surgical instrument; (c) a processor that: (1) accesses
the image, reference and device data about the first and second
surgical devices at least temporarily stored in the memory and
identifies a desired position and orientation of the surgical
instrument relative to the at least one bone of the patient based
at least in part on the image, reference and device data about the
first and second surgical devices, and (2) determines a mechanical
axis or an anatomic axis of the at least one bone using the
reference data; and (d) an output that outputs information about
the desired position and orientation of the surgical instrument
relative to the at least one bone.
45. The computer system of claim 44, wherein the processor
identifies the desired position and orientation of the surgical
instrument relative to the at least one bone of the patient based
at least in part on the image, reference and device data as well as
a surgeon's input.
46. The computer system of claim 44, wherein the desired position
and orientation of the surgical instrument determines an actual
position and orientation of the surgical instrument.
47. The computer system of claim 44, wherein the desired position
and orientation of the surgical instrument determines an actual
position and orientation of the orthopaedic implant.
48. The computer system of claim 44, further comprising a display
that displays a representation of the structure of the at least one
bone.
49. The computer system of claim 44, wherein the anatomic axis is
an anterior/posterior axis or a medial/lateral axis of the at least
one bone.
Description
RELATED APPLICATION DATA
[0001] This application is a continuation of U.S. Ser. No.
10/084,012, filed Feb. 27, 2002 and entitled "Total Knee
Arthroplasty Systems and Processes," which claims the benefit of
U.S. Ser. No. 60/271,818, filed Feb. 27, 2001 and entitled "Image
Guided System for Arthroplasty" and U.S. Ser. No. 60/355,899, filed
Feb. 11, 2002 and entitled "Surgical Navigation Systems and
Processes," all of which are incorporated herein by this
reference.
FIELD OF INVENTION
[0002] Systems and processes for tracking anatomy, implements,
instrumentation, trial implants, implant components and virtual
constructs or references, and rendering images and data related to
them in connection with orthopedic, surgical and other operations,
for example Total Knee Arthroplasty ("TKA"). Anatomical structures
and such items may be attached to or otherwise associated with
fiducial functionality, and constructs may be registered in
position using fiducial functionality whose position and
orientation can be sensed and tracked by systems and according to
processes of the present invention in three dimensions in order to
perform TKA. Such structures, items and constructs can be rendered
onscreen properly positioned and oriented relative to each other
using associated image files, data files, image input, other
sensory input, based on the tracking. Such systems and processes,
among other things, allow surgeons to navigate and perform TKA
using images that reveal interior portions of the body combined
with computer generated or transmitted images that show surgical
implements, instruments, trials, implants, and/or other devices
located and oriented properly relative to the body part. Such
systems and processes allow, among other things, more accurate and
effective resection of bone, placement and assessment of trial
implants and joint performance, and placement and assessment of
performance of actual implants and joint performance.
BACKGROUND AND SUMMARY
[0003] A leading cause of wear and revision in prosthetics such as
knee implants, hip implants and shoulder implants is less than
optimum implant alignment. In a Total Knee Arthroplasty, for
example, current instrument design for resection of bone limits the
alignment of the femoral and tibial resections to average values
for varus/valgus, flexion/extension, and external/internal
rotation. Additionally, surgeons often use visual landmarks or
"rules of thumb" for alignment which can be misleading due to
anatomical variability. Intramedullary referencing instruments also
violate the femoral and tibial canal. This intrusion increases the
risk of fat embolism and unnecessary blood loss in the patient.
Surgeons also rely on instrumentation to predict the appropriate
implant size for the femur and tibia instead of the ability to
intraoperatively template the appropriate size of the implants for
optimal performance. Another challenge for surgeons is soft tissue
or ligament balancing after the bone resections have been made.
Releasing some of the soft tissue points can change the balance of
the knee; however, the multiple options can be confusing for many
surgeons. In revision TKA, for example, many of the visual
landmarks are no longer present, making alignment and restoration
of the joint line difficult. The present invention is applicable
not only for knee repair, reconstruction or replacement surgery,
but also repair, reconstruction or replacement surgery in
connection with any other joint of the body as well as any other
surgical or other operation where it is useful to track position
and orientation of body parts, non-body components and/or virtual
references such as rotational axes, and to display and output data
regarding positioning and orientation of them relative to each
other for use in navigation and performance of the operation.
[0004] Several providers have developed and marketed various forms
of imaging systems for use in surgery. Many are based on CT scans
and/or MRI data or on digitized points on the anatomy. Other
systems align preoperative CT scans, MRIs or other images with
intraoperative patient positions. A preoperative planning system
allows the surgeon to select reference points and to determine the
final implant position. Intraoperatively, the system calibrates the
patient position to that preoperative plan, such as using a "point
cloud" technique, and can use a robot to make femoral and tibial
preparations.
[0005] Systems and processes according to one embodiment of the
present invention use position and/or orientation tracking sensors
such as infrared sensors acting stereoscopically or otherwise to
track positions of body parts, surgery-related items such as
implements, instrumentation, trial prosthetics, prosthetic
components, and virtual constructs or references such as rotational
axes which have been calculated and, stored based on designation of
bone landmarks. Processing capability such as any desired form of
computer functionality, whether standalone, networked, or
otherwise, takes into account the position and orientation
information as to various items in the position sensing field
(which may correspond generally or specifically to all or portions
or more than all of the surgical field) based on sensed position
and orientation of their associated fiducials or based on stored
position and/or orientation information. The processing
functionality correlates this position and orientation information
for each object with stored information regarding the items, such
as a computerized fluoroscopic imaged file of a femur or tibia, a
wire frame data file for rendering a representation of an
instrumentation component, trial prosthesis or actual prosthesis,
or a computer generated file relating to a rotational axis or other
virtual construct or reference. The processing functionality then
displays position and orientation of these objects on a screen or
monitor, or otherwise. Thus, systems and processes according to one
embodiment of the invention can display and otherwise output useful
data relating to predicted or actual position and orientation of
body parts, surgically related items, implants, and virtual
constructs for use in navigation, assessment, and otherwise
performing surgery or other operations.
[0006] As one example, images such as fluoroscopy images showing
internal aspects of the femur and tibia can be displayed on the
monitor in combination with actual or predicted shape, position and
orientation of surgical implements, instrumentation components,
trial implants, actual prosthetic components, and rotational axes
in order to allow the surgeon to properly position and assess
performance of various aspects of the joint being repaired,
reconstructed or replaced. The surgeon may navigate tools,
instrumentation, trial prostheses, actual prostheses and other
items relative to bones and other body parts in order to perform
TKA's more accurately, efficiently, and with better alignment and
stability. Systems and processes according to the present invention
can also use the position tracking information and, if desired,
data relating to shape and configuration of surgical related items
and virtual constructs or references in order to produce numerical
data which may be used with or without graphic imaging to perform
tasks such as assessing performance of trial prosthetics statically
and throughout a range of motion, appropriately modifying tissue
such as ligaments to improve such performance and similarly
assessing performance of actual prosthetic components which have
been placed in the patient for alignment and stability. Systems and
processes according to the present invention can also generate data
based on position tracking and, if desired, other information to
provide cues on screen, aurally or as otherwise desired to assist
in the surgery such as suggesting certain bone modification steps
or measures which may be taken to release certain ligaments or
portions of them based on performance of components as sensed by
systems and processes according to the present invention.
[0007] According to a preferred embodiment of systems and processes
according to the present invention, at least the following steps
are involved:
[0008] 1. Obtain appropriate images such as fluoroscopy images of
appropriate body parts such as femur and tibia, the imager being
tracked in position via an associated fiducial whose position and
orientation is tracked by position/orientation sensors such as
stereoscopic infrared (active or passive) sensors according to the
present invention.
[0009] 2. Register tools, instrumentation, trial components,
prosthetic components, and other items to be used in surgery, each
of which corresponds to a fiducial whose position and orientation
can be tracked by the position/orientation sensors.
[0010] 3. Locating and registering body structure such as
designating points on the femur and tibia using a probe associated
with a fiducial in order to provide the processing functionality
information relating to the body part such as rotational axes.
[0011] 4. Navigating and positioning instrumentation such as
cutting instrumentation in order to modify bone, at least partially
using images generated by the processing functionality
corresponding to what is being tracked and/or has been tracked,
and/or is predicted, by the system, and thereby resecting bone
effectively, efficiently and accurately.
[0012] 5. Navigating and positioning trial components such as
femoral components and tibial components, some or all of which may
be installed using impactors with a fiducial and, if desired, at
the appropriate time discontinuing tracking the position and
orientation of the trial component using the impactor fiducial and
starting to track that position and orientation using the body part
fiducial on which the component is installed.
[0013] 6. Assessing alignment and stability of the trial components
and joint, both statically and dynamically as desired, using images
of the body parts in combination with images of the trial
components while conducting appropriate rotation,
anterior-posterior drawer and flexion/extension tests and
automatically storing and calculating results to present data or
information which allows the surgeon to assess alignment and
stability.
[0014] 7. Releasing tissue such as ligaments if necessary and
adjusting trial components as desired for acceptable alignment and
stability.
[0015] 8. Installing implant components whose positions may be
tracked at first via fiducials associated with impactors for the
components and then tracked via fiducials on the body parts in
which the components are installed.
[0016] 9. Assessing alignment and stability of the implant
components and joint by use of some or all tests mentioned above
and/or other tests as desired, releasing tissue if desired,
adjusting if desired, and otherwise verifying acceptable alignment,
stability and performance of the prosthesis, both statically and
dynamically.
[0017] This process, or processes including it or some of it may be
used in any total or partial joint repair, reconstruction or
replacement, including knees, hips, shoulders, elbows, ankles and
any other desired joint in the body.
[0018] Such processes are disclosed in U.S. Ser. No. 60/271,818
filed Feb. 27, 2001, entitled Image Guided System for Arthroplasty,
which is incorporated herein by reference as are all documents
incorporated by reference therein.
[0019] Systems and processes according to the present invention
represent significant improvement over other, previous systems and
processes. For instance, systems which use CT and MRI data
generally require the placement of reference frames pre-operatively
which can lead to infection at the pin site. The resulting 3D
images must then be registered, or calibrated, to the patient
anatomy intraoperatively. Current registration methods are less
accurate than the fluoroscopic system. These imaging modalities are
also more expensive. Some "imageless" systems, or non-imaging
systems, require digitizing a large number of points to define the
complex anatomical geometries of the knee at each desired site.
This can be very time intensive resulting in longer operating room
time. Other imageless systems determine the mechanical axis of the
knee by performing an intraoperative kinematic motion to determine
the center of rotation at the hip, knee, and ankle. This requires
placement of reference frames at the iliac crest of the pelvis and
in or on the ankle. This calculation is also time consuming as the
system must find multiple points in different planes in order to
find the center of rotation. This is also problematic in patients
with a pathologic condition. Ligaments and soft tissues in the
arthritic patient are not normal and thus will give a center of
rotation that is not desirable for normal knees. Robotic systems
require expensive CT or MRI scans and also require pre-operative
placement of reference frames, usually the day before surgery.
These systems are also much slower, almost doubling operating room
time and expense.
[0020] None of these systems can effectively track femoral and/or
tibial trials during a range of motion and calculate the relative
positions of the articular surfaces, among other things. Also, none
of them currently make suggestions on ligament balancing, display
ligament balancing techniques, or, surgical techniques.
Additionally, none of these systems currently track the
patella.
[0021] An object of certain aspects of the present invention is to
use computer processing functionality in combination with imaging
and position and/or orientation tracking sensors to present to the
surgeon during surgical operations visual and data information
useful to navigate, track and/or position implements,
instrumentation, trial components, prosthetic components and other
items and virtual constructs relative to the human body in order to
improve performance of a repaired, replaced or reconstructed knee
joint.
[0022] Another object of certain aspects of the present invention
is to use computer processing functionality in combination with
imaging and position and/or orientation tracking sensors to present
to the surgeon during surgical operations visual and data
information useful to assess performance of a knee and certain
items positioned therein, including components such as trial
components and prosthetic components, for stability, alignment and
other factors, and to adjust tissue and body and non-body structure
in order to improve such performance of a repaired, reconstructed
or replaced knee joint.
[0023] Another object of certain aspects of the present invention
is to use computer processing functionality in combination with
imaging and position and/or orientation tracking sensors to present
to the surgeon during surgical operations visual and data
information useful to show predicted position and movement of
implements, instrumentation, trial components, prosthetic
components and other items and virtual constructs relative to the
human body in order to select appropriate components, resect bone
accurately, effectively and efficiently, and thereby improve
performance of a repaired, replaced or reconstructed knee
joint.
[0024] Other objects, features and advantages of the present
invention are apparent with respect to the remainder of this
document.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a schematic view of a particular embodiment of
systems and processes according to the present invention.
[0026] FIG. 2 is a view of a knee prepared for surgery, including a
femur and a tibia, to which fiducials according to one embodiment
of the present invention have been attached.
[0027] FIG. 3 is a view of a portion of a leg prepared for surgery
according to the present invention with a C-arm for obtaining
fluoroscopic images associated with a fiducial according to one
embodiment of the present invention.
[0028] FIG. 4 is a fluoroscopic image of free space rendered on a
monitor according to one embodiment of the present invention.
[0029] FIG. 5 is a fluoroscopic image of femoral head obtained and
rendered according one embodiment of the present invention.
[0030] FIG. 6 is a fluoroscopic image of a knee obtained and
rendered according to one embodiment of the present invention.
[0031] FIG. 7 is a fluoroscopic image of a tibia distal end
obtained and rendered according to one embodiment of the present
invention.
[0032] FIG. 8 is a fluoroscopic image of a lateral view of a knee
obtained and rendered according to one embodiment of the present
invention.
[0033] FIG. 9 is a fluoroscopic image of a lateral view of a knee
obtained and rendered according to one embodiment of the present
invention.
[0034] FIG. 10 is a fluoroscopic image of a lateral view of a tibia
distal end obtained and rendered according to one embodiment of the
present invention.
[0035] FIG. 11 shows a probe according to one embodiment of the
present invention being used to register a surgically related
component for tracking according to one embodiment of the present
invention.
[0036] FIG. 12 shows a probe according to one embodiment of the
present invention being used to register a cutting block for
tracking according to one embodiment of the present invention.
[0037] FIG. 13 shows a probe according to one embodiment of the
present invention being used to register a tibial cutting block for
tracking according to one embodiment of the present invention.
[0038] FIG. 14 shows a probe according to one embodiment of the
present invention being used to register an alignment guide for
tracking according to one embodiment of the present invention.
[0039] FIG. 15 shows a probe according to one embodiment of the
present invention being used to designate landmarks on bone
structure for tracking according one embodiment of the present
invention.
[0040] FIG. 16 is another view of a probe according to one
embodiment of the present invention being used to designate
landmarks on bone structure for tracking according one embodiment
of the present invention.
[0041] FIG. 17 is another view of a probe according to one
embodiment of the present invention being used to designate
landmarks on bone structure for tracking according one embodiment
of the present invention.
[0042] FIG. 18 is a screen face produced according to one
embodiment of the present invention during designation of landmarks
to determine a femoral mechanical axis.
[0043] FIG. 19 is a view produced according to one embodiment of
the present invention during designation of landmarks to determine
a tibial mechanical axis.
[0044] FIG. 20 is a screen face produced according to one
embodiment of the present invention during designation of landmarks
to determine an epicondylar axis.
[0045] FIG. 21 is a screen face produced according to one
embodiment of the present invention during designation of landmarks
to determine an anterior-posterior axis.
[0046] FIG. 22 is a screen face produced according to one
embodiment of the present invention during designation of landmarks
to determine a posterior condylar axis.
[0047] FIG. 23 is a screen face according to one embodiment of the
present invention which presents graphic indicia which may be
employed to help determine reference locations within bone
structure.
[0048] FIG. 24 is a screen face according to one embodiment of the
present invention showing mechanical and other axes which have been
established according to one embodiment of the present
invention.
[0049] FIG. 25 is another screen face according to one embodiment
of the present invention showing mechanical and other axes which
have been established according to one embodiment of the present
invention.
[0050] FIG. 26 is another screen face according to one embodiment
of the present invention showing mechanical and other axes which
have been established according to one embodiment of the present
invention.
[0051] FIG. 27 shows navigation and placement of an extramedullary
rod according to one embodiment of the present invention.
[0052] FIG. 28 is another view showing navigation and placement of
an extramedullary rod according to one embodiment of the present
invention.
[0053] FIG. 29 is a screen face produced according to one
embodiment of the present invention which assists in navigation
and/or placement of an extramedullary rod.
[0054] FIG. 30 is another view of a screen face produced according
to one embodiment of the present invention which assists in
navigation and/or placement of an extramedullary rod.
[0055] FIG. 31 is a view which shows navigation and placement of an
alignment guide according to one embodiment of the present
invention.
[0056] FIG. 32 is another view which shows navigation and placement
of an alignment guide according to one embodiment of the present
invention.
[0057] FIG. 33 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0058] FIG. 34 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0059] FIG. 35 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0060] FIG. 36 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0061] FIG. 37 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0062] FIG. 38 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0063] FIG. 39 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0064] FIG. 40 is a screen face which shows a fluoroscopic image of
bone in combination with computer generated images of axes and
components in accordance with one embodiment of the present
invention.
[0065] FIG. 41 is a view showing placement of a cutting block
according to one embodiment of the present invention.
[0066] FIG. 42 is a screen face according to one embodiment of the
present invention which may be used to assist in navigation and
placement of instrumentation.
[0067] FIG. 43 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and/or placement of instrumentation.
[0068] FIG. 44 is a view showing placement of an alignment guide
according to one embodiment of the present invention.
[0069] FIG. 45 is another view showing placement of a cutting block
according to one embodiment of the present invention.
[0070] FIG. 46 is a view showing navigation and placement of the
cutting block of FIG. 45.
[0071] FIG. 47 is another view showing navigation and placement of
a cutting block according to one embodiment of the present
invention.
[0072] FIG. 48 is a view showing navigation and placement of a
tibial cutting block according to one embodiment of the present
invention.
[0073] FIG. 49 is a screen face according to one embodiment of the
present invention which may be used to assist in navigation and
placement of instrumentation.
[0074] FIG. 50 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0075] FIG. 51 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0076] FIG. 52 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0077] FIG. 53 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0078] FIG. 54 is a view showing navigation and placement of a
femoral component using an impactor to which a fiducial according
to one embodiment of the present invention is attached.
[0079] FIG. 55 is a view showing navigation and placement of a
tibial trial component according to one embodiment of the present
invention.
[0080] FIG. 56 is a view showing articulation of trial components
during trial reduction according to one embodiment of the present
invention.
[0081] FIG. 57 is a screen face according to one embodiment of the
present invention which may be used to assist in assessing joint
function.
[0082] FIG. 58 is a screen face according to one embodiment of the
present invention which may be used to assist in assessing joint
function.
[0083] FIG. 59 is a screen face according to one embodiment of the
present invention which may be used to assist in assessing joint
function.
[0084] FIG. 60 is a screen face according to one embodiment of the
present invention which contains images and textural suggestions
for assisting in assessing performance and making adjustments to
improve performance of a joint in accordance with one aspect of the
invention.
[0085] FIG. 61 is a screen face according to one embodiment of the
present invention which contains images and textural suggestions
for assisting in assessing performance and making adjustments to
improve performance of a joint in accordance with one aspect of the
invention.
[0086] FIG. 62 is a screen face according to one embodiment of the
present invention which contains images and textural suggestions
for assisting in assessing performance and making adjustments to
improve performance of a joint in accordance with one aspect of the
invention.
[0087] FIG. 63 is a screen face according to one embodiment of the
present invention which contains images and textural suggestions
for assisting in assessing performance and making adjustments to
improve performance of a joint in accordance with one aspect of the
invention.
[0088] FIG. 64 is a computer generated graphic according to one
embodiment of the present invention which allows visualization of
trial or actual components installed in the bone structure
according to one embodiment of the invention.
DETAILED DESCRIPTION
[0089] Systems and processes according to a preferred embodiment of
the present invention use computer capacity, including standalone
and/or networked, to store data regarding spatial aspects of
surgically related items and virtual constructs or references
including body parts, implements, instrumentation, trial
components, prosthetic components and rotational axes of body
parts. Any or all of these may be physically or virtually connected
to or incorporate any desired form of mark, structure, component,
or other fiducial or reference device or technique which allows
position and/or orientation of the item to which it is attached to
be sensed and tracked, preferably in three dimensions of
translation and three degrees of rotation as well as in time if
desired. In the preferred embodiment, such "fidicuals" are
reference frames each containing at least three, preferably four,
sometimes more, reflective elements such as spheres reflective of
lightwave or infrared energy, or active elements such as LEDs.
[0090] In a preferred embodiment, orientation of the elements on a
particular fiducial varies from one fiducial to the next so that
sensors according to the present invention may distinguish between
various components to which the fiducials are attached in order to
correlate for display and other purposes data files or images of
the components. In a preferred embodiment of the present invention,
some fiducials use reflective elements and some use active
elements, both of which may be tracked by preferably two, sometimes
more infrared sensors whose output may be processed in concert to
geometrically calculate position and orientation of the item to
which the fiducial is attached.
[0091] Position/orientation tracking sensors and fiducials need not
be confined to the infrared spectrum. Any electromagnetic,
electrostatic, light, sound, radiofrequency or other desired
technique may be used. Alternatively, each item such as a surgical
implement, instrumentation component, trial component, implant
component or other device may contain its own "active" fiducial
such as a microchip with appropriate field sensing or
position/orientation sensing functionality and communications link
such as spread spectrum RF link, in order to report position and
orientation of the item. Such active fiducials, or hybrid
active/passive fiducials such as transponders can be implanted in
the body parts or in any of the surgically related devices
mentioned above, or conveniently located at their surface or
otherwise as desired. Fiducials may also take the form of
conventional structures such as a screw driven into a bone, or any
other three dimensional item attached to another item, position and
orientation of such three dimensional item able to be tracked in
order to track position and orientation of body parts and
surgically related items. Hybrid fiducials may be partly passive,
partly active such as inductive components or transponders which
respond with a certain signal or data set when queried by sensors
according to the present invention.
[0092] Systems and processes according to a preferred embodiment of
the present invention employ a computer to calculate and store
reference axes of body components such as in a TKA, for example,
the mechanical axis of the femur and tibia. From these axes such
systems track the position of the instrumentation and osteotomy
guides so that bone resections will locate the implant position
optimally, usually aligned with the mechanical axis. Furthermore,
during trial reduction of the knee, the systems provide feedback on
the balancing of the ligaments in a range of motion and under
varus/valgus, anterior/posterior and rotary stresses and can
suggest or at least provide more accurate information than in the
past about which ligaments the surgeon should release in order to
obtain correct balancing, alignment and stability. Systems and
processes according to the present invention can also suggest
modifications to implant size, positioning, and other techniques to
achieve optimal kinematics. Systems and processes according to the
present invention can also include databases of information
regarding tasks such as ligament balancing, in order to provide
suggestions to the surgeon based on performance of test results as
automatically calculated by such systems and processes.
[0093] FIG. 1 is a schematic view showing one embodiment of a
system according to the present invention and one version of a
setting according to the present invention in which surgery on a
knee, in this case a Total Knee Arthroplasty, may be performed.
Systems and processes according to the present invention can track
various body parts such as tibia 10 and femur 12 to which fiducials
of the sort described above or any other sort may be implanted,
attached, or otherwise associated physically, virtually, or
otherwise. In the embodiment shown in FIG. 1, fiducials 14 are
structural frames some of which contain reflective elements, some
of which contain LED active elements, some of which can contain
both, for tracking using stereoscopic infrared sensors suitable, at
least operating in concert, for sensing, storing, processing and/or
outputting data relating to ("tracking") position and orientation
of fiducials 14 and thus components such as 10 and 12 to which they
are attached or otherwise associated. Position sensor 16, as
mentioned above, may be any sort of sensor functionality for
sensing position and orientation of fiducials 14 and therefore
items with which they are associated, according to whatever desired
electrical, magnetic, electromagnetic, sound, physical, radio
frequency, or other active or passive technique. In the preferred
embodiment, position sensor 16 is a pair of infrared sensors
disposed on the order of a meter, sometimes more, sometimes less,
apart and whose output can be processed in concert to provide
position and orientation information regarding fiducials 14.
[0094] In the embodiment shown in FIG. 1, computing functionality
18 can include processing functionality, memory functionality,
input/output functionality whether on a standalone or distributed
basis, via any desired standard, architecture, interface and/or
network topology. In this embodiment, computing functionality 18 is
connected to a monitor on which graphics and data may be presented
to the surgeon during surgery. The screen preferably has a tactile
interface so that the surgeon may point and click on screen for
tactile screen input in addition to or instead of, if desired,
keyboard and mouse conventional interfaces. Additionally, a foot
pedal 20 or other convenient interface may be coupled to
functionality 18 as can any other wireless or wired interface to
allow the surgeon, nurse or other desired user to control or direct
functionality 18 in order to, among other things, capture
position/orientation information when certain components are
oriented or aligned properly. Items 22 such as trial components,
instrumentation components may be tracked in position and
orientation relative to body parts 10 and 12 using fiducials
14.
[0095] Computing functionality 18 can process, store and output on
monitor 24 and otherwise various forms of data which correspond in
whole or part to body parts 10 and 12 and other components for item
22. For example, in the embodiment shown in FIG. 1, body parts 10
and 12 are shown in cross-section or at least various internal
aspects of them such as bone canals and surface structure are shown
using fluoroscopic images. These images are obtained using a C-arm
attached to a fiducial 14. The body parts, for example, tibia 10
and femur 12, also have fiducials attached. When the fluoroscopy
images are obtained using the C-arm with fiducial 14, a
position/orientation sensor 16 "sees" and tracks the position of
the fluoroscopy head as well as the positions and orientations of
the tibia 10 and femur 12. The computer stores the fluoroscopic
images with this position/orientation information, thus correlating
position and orientation of the fluoroscopic image relative to the
relevant body part or parts. Thus, when the tibia 10 and
corresponding fiducial 14 move, the computer automatically and
correspondingly senses the new position of tibia 10 in space and
can correspondingly move implements, instruments, references,
trials and/or implants on the monitor 24 relative to the image of
tibia 10. Similarly, the image of the body part can be moved, both
the body part and such items may be moved, or the on screen image
otherwise presented to suit the preferences of the surgeon or
others and carry out the imaging that is desired. Similarly, when
an item 22 such as an extramedullary rod, intramedullary rod, or
other type of rod, that is being tracked moves, its image moves on
monitor 24 so that the monitor shows the item 22 in proper position
and orientation on monitor 24 relative to the femur 12. The rod 22
can thus appear on the monitor 24 in proper or improper alignment
with respect to the mechanical axis and other features of the femur
12, as if the surgeon were able to see into the body in order to
navigate and position rod 22 properly
[0096] The computer functionality 18 can also store data relating
to configuration, size and other properties of items 22 such as
implements, instrumentation, trial components, implant components
and other items used in surgery. When those are introduced into the
field of position/orientation sensor 16, computer functionality 18
can generate and display overlaid or in combination with the
fluoroscopic images of the body parts 10 and 12, computer generated
images of implements, instrumentation components, trial components,
implant components and other items 22 for navigation, positioning,
assessment and other uses.
[0097] Additionally, computer functionality 18 can track any point
in the position/orientation sensor 16 field such as by using a
designator or a probe 26. The probe also can contain or be attached
to a fiducial 14. The surgeon, nurse, or other user touches the tip
of probe 26 to a point such as a landmark on bone structure and
actuates the foot pedal 20 or otherwise instructs the computer 18
to note the landmark position. The position/orientation sensor 16
"sees" the position and orientation of fiducial 14 "knows" where
the tip of probe 26 is relative to that fiducial 14 and thus
calculates and stores, and can display on monitor 24 whenever
desired and in whatever form or fashion or color, the point or
other position designated by probe 26 when the foot pedal 20 is hit
or other command is given. Thus, probe 26 can be used to designate
landmarks on bone structure in order to allow the computer 18 to
store and track, relative to movement of the bone fiducial 14,
virtual or logical information such as mechanical axis 28, medial
lateral axis 30 and anterior/posterior axis 32 of femur 12, tibia
10 and other body parts in addition to any other virtual or actual
construct or reference.
[0098] Systems and processes according to an embodiment of the
present invention such as the subject of FIGS. 2-64, can use the
so-called FluoroNAV system and software provided by Medtronic
Sofamor Danek Technologies. Such systems or aspects of them are
disclosed in U.S. Pat. Nos. 5,383,454; 5,871,445; 6,146,390;
6,165,81; 6,235,038 and 6,236,875, and related (under 35 U.S.C.
Section 119 and/or 120) patents, which are all incorporated herein
by this reference. Any other desired systems can be used as
mentioned above for imaging, storage of data, tracking of body
parts and items and for other purposes. The FluoroNav system
requires the use of reference frame type fiducials 14 which have
four and in some cases five elements tracked by infrared sensors
for position/orientation of the fiducials and thus of the body
part, implement, instrumentation, trial component, implant
component, or other device or structure being tracked. Such systems
also use at least one probe 26 which the surgeon can use to select,
designate, register, or otherwise make known to the system a point
or points on the anatomy or other locations by placing the probe as
appropriate and signaling or commanding the computer to note the
location of, for instance, the tip of the probe. The FluoroNav
system also tracks position and orientation of a C-arm used to
obtain fluoroscopic images of body parts to which fiducials have
been attached for capturing and storage of fluoroscopic images
keyed to position/orientation information as tracked by the sensors
16. Thus, the monitor 24 can render fluoroscopic images of bones in
combination with computer generated images of virtual constructs
and references together with implements, instrumentation
components, trial components, implant components and other items
used in connection with surgery for navigation, resection of bone,
assessment and other purposes.
[0099] FIGS. 2-64 are various views associated with Total Knee
Arthroplasty surgery processes according to one particular
embodiment and version of the present invention being carried out
with the FluoroNav system referred to above. FIG. 2 shows a human
knee in the surgical field, as well as the corresponding femur and
tibia, to which fiducials 14 have been rigidly attached in
accordance with this embodiment of the invention. Attachment of
fiducials 14 preferably is accomplished using structure that
withstands vibration of surgical saws and other phenomenon which
occur during surgery without allowing any substantial movement of
fiducial 14 relative to body part being tracked by the system. FIG.
3 shows fluoroscopy images being obtained of the body parts with
fiducials 14 attached. The fiducial 14 on the fluoroscopy head in
this embodiment is a cylindrically shaped cage which contains LEDs
or "active" emitters for tracking by the sensors 16. Fiducials 14
attached to tibia 10 and femur 12 can also be seen. The fiducial 14
attached to the femur 12 uses LEDs instead of reflective spheres
and is thus active, fed power by the wire seen extending into the
bottom of the image.
[0100] FIGS. 4-10 are fluoroscopic images shown on monitor 24
obtained with position and/or orientation information received by,
noted and stored within computer 18. FIG. 4 is an open field with
no body part image, but which shows the optical indicia which may
be used to normalize the image obtained using a spherical
fluoroscopy wave front with the substantially flat surface of the
monitor 24. FIG. 5 shows an image of the femur 12 head. This image
is taken in order to allow the surgeon to designate the center of
rotation of the femoral head for purposes of establishing the
mechanical axis and other relevant constructs relating to of the
femur according to which the prosthetic components will ultimately
be positioned. Such center of rotation can be established by
articulating the femur within the acetabulum or a prosthesis to
capture a number of samples of position and orientation information
and thus in turn to allow the computer to calculate the average
center of rotation. The center of rotation can be established by
using the probe and designating a number of points on the femoral
head and thus allowing the computer to calculate the geometrical
center or a center which corresponds to the geometry of points
collected. Additionally, graphical representations such as
controllably sized circles displayed on the monitor can be fitted
by the surgeon to the shape of the femoral head on planar images
using tactile input on screen to designate the centers according to
that graphic, such as are represented by the computer as
intersection of axes of the circles. Other techniques for
determining, calculating or establishing points or constructs in
space, whether or not corresponding to bone structure, can be used
in accordance with the present invention.
[0101] FIG. 5 shows a fluoroscopic image of the femoral head while
FIG. 6 shows an anterior/posterior view of the knee which can be
used to designate landmarks and establish axes or constructs such
as the mechanical axis or other rotational axes. FIG. 7 shows the
distal end of the tibia and FIG. 8 shows a lateral view of the
knee. FIG. 9 shows another lateral view of the knee while FIG. 10
shows a lateral view of the distal end of the tibia.
Registration of Surgically Related Items
[0102] FIGS. 11-14 show designation or registration of items 22
which will be used in surgery. Registration simply means, however
it is accomplished, ensuring that the computer knows which body
part, item or construct corresponds to which fiducial or fiducials,
and how the position and orientation of the body part, item or
construct is related to the position and orientation of its
corresponding fiducial or a fiducial attached to an impactor or
other component which is in turn attached to an item. Such
registration or designation can be done before or after registering
bone or body parts as discussed with respect to FIGS. 4-10. FIG. 11
shows a technician designating with probe 26 an item 22 such as an
instrument component to which fiducial 14 is attached. The sensor
16 "sees" the position and orientation of the fiducial 14 attached
to the item 22 and also the position and orientation of the
fiducial 14 attached to the probe 26 whose tip is touching a
landmark on the item 22. The technician designates onscreen or
otherwise the identification of the item and then activates the
foot pedal or otherwise instructs the computer to correlate the
data corresponding to such identification, such as data needed to
represent a particular cutting block component for a particular
knee implant product, with the particularly shaped fiducial 14
attached to the component 22. The computer has then stored
identification, position and orientation information relating to
the fiducial for component 22 correlated with the data such as
configuration and shape data for the item 22 so that upon
registration, when sensor 16 tracks the item 22 fiducial 14 in the
infrared field, monitor 24 can show the cutting block component 22
moving and turning, and properly positioned and oriented relative
to the body part which is also being tracked. FIGS. 12-14 show
similar registration for other instrumentation components 22.
Registration of Anatomy and Constructs
[0103] Similarly, the mechanical axis and other axes or constructs
of body parts 10 and 12 can also be "registered" for tracking by
the system. Again, the system has employed a fluoroscope to obtain
images of the femoral head, knee and ankle of the sort shown in
FIGS. 4-10. The system correlates such images with the position and
orientation of the C-arm and the patient anatomy in real time as
discussed above with the use of fiducials 14 placed on the body
parts before image acquisition and which remain in position during
the surgical procedure. Using these images and/or the probe, the
surgeon can select and register in the computer 18 the center of
the femoral head and ankle in orthogonal views, usually
anterior/posterior and lateral, on a touch screen. The surgeon uses
the probe to select any desired anatomical landmarks or references
at the operative site of the knee or on the skin or surgical
draping over the skin, as on the ankle. These points are registered
in three dimensional space by the system and are tracked relative
to the fiducials on the patient anatomy which are preferably placed
intraoperatively. FIG. 15 shows the surgeon using probe 26 to
designate or register landmarks on the condylar portion of femur 12
using probe 26 in order to feed to the computer 18 the position of
one point needed to determine, store, and display the epicondylar
axis. (See FIG. 20 which shows the epicondylar axis and the
anterior-posterior plane and for lateral plane.) Although
registering points using actual bone structure such as in FIG. 15
is one preferred way to establish the axis, a cloud of points
approach by which the probe 26 is used to designate multiple points
on the surface of the bone structure can be employed, as can moving
the body part and tracking movement to establish a center of
rotation as discussed above. Once the center of rotation for the
femoral head and the condylar component have been registered, the
computer is able to calculate, store, and render, and otherwise use
data for, the mechanical axis of the femur 12. FIG. 17 once again
shows the probe 26 being used to designate points on the condylar
component of the femur 12.
[0104] FIG. 18 shows the onscreen images being obtained when the
surgeon registers certain points on the bone surface using the
probe 26 in order to establish the femoral mechanical axis. The
tibial mechanical axis is then established by designating points to
determine the centers of the proximal and distal ends of the tibia
so that the mechanical axis can be calculated, stored, and
subsequently used by the computer 18. FIG. 20 shows designated
points for determining the epicondylar axis, both in the
anterior/posterior and lateral planes while FIG. 21 shows such
determination of the anterior-posterior axis as rendered onscreen.
The posterior condylar axis is also determined by designating
points or as otherwise desired, as rendered on the computer
generated geometric images overlain or displayed in combination
with the fluoroscopic images, all of which are keyed to fiducials
14 being tracked by sensors 16.
[0105] FIG. 23 shows an adjustable circle graphic which can be
generated and presented in combination with orthogonal fluoroscopic
images of the femoral head, and tracked by the computer 18 when the
surgeon moves it on screen in order to establish the centers of the
femoral head in both the anterior-posterior and lateral planes.
[0106] FIG. 24 is an onscreen image showing the anterior-posterior
axis, epicondylar axis and posterior condylar axis from points
which have been designated as described above. These constructs are
generated by the computer 18 and presented on monitor 24 in
combination with the fluoroscopic images of the femur 12, correctly
positioned and oriented relative thereto as tracked by the system.
In the fluoroscopic/computer generated image combination shown at
left bottom of FIG. 24, a "sawbones" knee as shown in certain
drawings above which contains radio opaque materials is represented
fluoroscopically and tracked using sensor 16 while the computer
generates and displays the mechanical axis of the femur 12 which
runs generally horizontally. The epicondylar axis runs generally
vertically, and the anterior/posterior axis runs generally
diagonally. The image at bottom right shows similar information in
a lateral view. Here, the anterior-posterior axis runs generally
horizontally while the epicondylar axis runs generally diagonally,
and the mechanical axis generally vertically.
[0107] FIG. 24, as is the case with a number of screen
presentations generated and presented by the system of FIGS. 4-64,
also shows at center a list of landmarks to be registered in order
to generate relevant axes and constructs useful in navigation,
positioning and assessment during surgery. Textural cues may also
be presented which suggest to the surgeon next steps in the process
of registering landmarks and establishing relevant axes. Such
instructions may be generated as the computer 18 tracks, from one
step to the next, registration of items 22 and bone locations as
well as other measures being taken by the surgeon during the
surgical operation.
[0108] FIG. 25 shows mechanical, lateral, anterior-posterior axes
for the tibia according to points are registered by the
surgeon.
[0109] FIG. 26 is another onscreen image showing the axes for the
femur 12.
Modifying Bone
[0110] After the mechanical axis and other rotation axes and
constructs relating to the femur and tibia are established,
instrumentation can be properly oriented to resect or modify bone
in order to fit trial components and implant components properly
according to the embodiment of the invention shown in FIGS. 4-64.
Instrumentation such as, for instance, cutting blocks, to which
fiducials 14 are mounted, can be employed. The system can then
track instrumentation as the surgeon manipulates it for optimum
positioning. In other words, the surgeon can "navigate" the
instrumentation for optimum positioning using the system and the
monitor. In this manner, instrumentation may be positioned
according to the system of this embodiment in order to align the
ostetomies to the mechanical and rotational axes or reference axes
on an extramedullary rod that does not violate the canal, on an
intramedullary rod, or on any other type of rod. The touchscreen 24
can then also display the instrument such as the cutting block
and/or the implant relative to the instrument and the rod during
this process, in order, among other things, properly to select size
of implant and perhaps implant type. As the instrument moves, the
varus/valgus, flexion/extension and internal/external rotation of
the relative component position can be calculated and shown with
respect to the referenced axes; in the preferred embodiment, this
can be done at a rate of six cycles per second or faster. The
instrument position is then fixed in the computer and physically
and the bone resections are made.
[0111] FIG. 27 shows orientation of an extramedullary rod to which
a fiducial 14 is attached via impactor 22. The surgeon views the
screen 24 which has an image as shown in FIG. 29 of the rod
overlain on or in combination with the femur 12 fluoroscopic image
as the two are actually positioned and oriented relative to one
another in space. The surgeon then navigates the rod into place
preferably along the mechanical axis of the femur and drives it
home with appropriate mallet or other device. The present invention
thus avoids the need to bore a hole in the metaphysis of the femur
and place a reamer or other rod into the medullary canal which can
cause fat embolism, hemorrhaging, infection and other untoward and
undesired effects.
[0112] FIG. 28 also shows the extramedullary rod being located.
FIG. 29 shows fluoroscopic images, both anterior-posterior and
lateral, with axes, and with a computer generated and tracked image
of the rod superposed or in combination with the fluoroscopic
images of the femur and tibia. FIG. 30 shows the rod superposed on
the femoral fluoroscopic image similar to what is shown in FIG.
29.
[0113] FIG. 29 also shows other information relevant to the surgeon
such as the name of the component being overlain on the femur image
(new EM nail), suggestions or instructions at the lower left, and
angle of the rod in varus/valgus and extension relative to the
axes. Any or all of this information can be used to navigate and
position the rod relative to the femur. At a point in time during
or after placement of the rod, its tracking may be "handed off"
from the impactor fiducial 14 to the femur fiducial 14 as discussed
below.
[0114] Once the extramedullary rod, intramedullary rod, other type
of rod has been placed, instrumentation can be positioned as
tracked in position and orientation by sensor 16 and displayed on
screen face 24. Thus, a cutting block of the sort used to establish
the condylar anterior cut, with its fiducial 14 attached, is
introduced into the field and positioned on the rod. Because the
cutting block corresponds to a particular implant product and can
be adjusted and designated on screen to correspond to a particular
implant size of that product, the computer 18 can generate and
display a graphic of the cutting block and the femoral component
overlain on the fluoroscopic image as shown in FIGS. 33-36. The
surgeon can thus navigate and position the cutting block on screen
using not only images of the cutting block on the bone, but also
images of the corresponding femoral component which will be
ultimately installed. The surgeon can thus adjust the positioning
of the physical cutting block component, and secure it to the rod
in order to resect the anterior of the condylar portion of the
femur in order to optimally fit and position the ultimate femoral
component being shown on the screen. FIG. 32 is another view of the
cutting block of FIG. 31 being positioned. Other cutting blocks and
other resections may be positioned and made similarly on the
condylar component.
[0115] In a similar fashion, instrumentation may be navigated and
positioned on the proximal portion of the tibia 10 as shown in FIG.
41 and as tracked by sensor 16 and on screen by images of the
cutting block and the implant component as shown in FIGS. 37-40.
FIGS. 42 and 43 show other onscreen images generated during this
bone modification process for purposes of navigation and
positioning cutting blocks and other instrumentation for proper
resection and other modification of femur and tibia in order to
prepare for trial components and implant components according to
systems and processes of the embodiment of the present invention
shown in FIGS. 4-64.
[0116] FIGS. 44-48 also show instrumentation being positioned
relative to femur 12 as tracked by the system for resection of the
condylar component in order to receive a particular size of implant
component. Various cutting blocks and their attached fiducials can
be seen in these views.
[0117] FIG. 49 shows a femoral component overlaid on the femur as
instrumentation is being tracked and positioned in order for
resection of bone properly and accurately to be accomplished. FIG.
50 is another navigational screen face showing a femoral component
overlay as instrumentation is being positioned for resection of
bone.
[0118] FIG. 51 is tibial component overlay information on a
navigation screen as the cutting block for the tibial plateau is
being positioned for bone resection.
[0119] FIGS. 52 and 53 show femoral component and tibial component
overlays, respectively, according to certain position and
orientation of cutting blocks/instrumentation as bone resections
are made. The surgeon can thus visualize where the implant
components will be and can assess fit, and other things if desired,
before resections are made.
Navigation, Placement and Assessment of Trials and Implants
[0120] Once resection and modification of bone has been
accomplished, implant trials can then be installed and tracked by
the system in a manner similar to navigating and positioning the
instrumentation, as displayed on the screen 24. Thus, a femoral
component trial, a tibial plateau trial, and a bearing plate trial
may be placed as navigated on screen using computer generated
overlays corresponding to the trials.
[0121] During the trial installation process, and also during the
implant component installation process, instrument positioning
process or at any other desired point in surgical or other
operations according to the present invention, the system can
transition or segue from tracking a component according to a first
fiducial to tracking the component according to a second fiducial.
Thus, as shown as FIG. 33, the trial femoral component is mounted
on an impactor to which is attached a fiducial 14. The trial
component is installed and positioned using the impactor. The
computer 18 "knows" the position and orientation of the trial
relative to the fiducial on the impactor (such as by prior
registration of the component attached to the impactor) so that it
can generate and display the image of the femoral component trial
on screen 24 overlaid on the fluoroscopic image of the condylar
component. At any desired point in time, before, during or after
the trial component is properly placed on the condylar component of
the femur to align with mechanical axis and according to proper
orientation relative to other axes, the system can be instructed,
by foot pedal or otherwise to begin tracking the position of the
trial component using the fiducial attached to the femur rather
than the one attached to the impactor. According to the preferred
embodiment, the sensor 16 "sees" at this point in time both the
fiducials on the impactor and the femur 12 so that it already
"knows" the position and orientation of the trial component
relative to the fiducial on the impactor and is thus able to
calculate and store for later use the position and orientation of
the trial component relative to the femur 12 fiducial. Once this
"handoff" happens, the impactor can be removed and the trial
component tracked with the femur fiducial 14 as part of or moving
in concert with the femur 12. Similar handoff procedures may be
used in any other instance as desired in accordance with the
present invention.
[0122] FIG. 55 shows the tibial plateau trial being tracked and
installed in a manner similar to femoral component trial as
discussed above. Alternatively, the tibial trial can be placed on
the proximal tibia and then registered using the probe 26. Probe 26
is used to designate preferably at least three features on the
tibial trial of known coordinates, such as bone spike holes. As the
probe is placed onto each feature, the system is prompted to save
that coordinate position so that the system can match the tibial
trial's feature's coordinates to the saved coordinates. The system
then tracks the tibial trial relative to the tibial anatomical
reference frame.
[0123] Once the trial components are installed, the surgeon can
assess alignment and stability of the components and the joint.
During such assessment, in trial reduction, the computer can
display on monitor 24 the relative motion between the trial
components to allow the surgeon to make soft tissue releases and
changes in order to improve the kinematics of the knee. The system
can also apply rules and/or intelligence to make suggestions based
on the information such as what soft tissue releases to make if the
surgeon desires. The system can also display how the soft tissue
releases are to be made.
[0124] FIG. 56 shows the surgeon articulating the knee as he
monitors the screen which is presenting images such as those shown
in FIGS. 57-59 which not only show movement of the trial components
relative to each other, but also orientation, flexion, and
varus/valgus data. During this assessment, the surgeon may conduct
certain assessment processes such as external/internal rotation or
rotational laxity testing, varus/valgus tests, and
anterior-posterior drawer at 0 and 90 degrees and mid range. Thus,
in the AP drawer test, the surgeon can position the tibia at the
first location and press the foot pedal. He then positions the
tibia at the second location and once again presses the foot pedal
so that the computer has registered and stored two locations in
order to calculate and display the drawer and whether it is
acceptable for the patient and the product involved. If not, the
computer can apply rules in order to generate and display
suggestions for releasing ligaments or other tissue, or using other
component sizes or types, such as shown, for example, in FIGS.
60-63. Once the proper tissue releases have been made, if
necessary, and alignment and stability are acceptable as noted
quantitatively on screen about all axes, the trial components may
be removed and actual components navigated, installed, and assessed
in performance in a manner similar to that in which the trial
components were navigated, installed, and assessed.
[0125] FIG. 64 is another computer generated 3-dimensional image of
the trial components as tracked by the system during trialing.
[0126] At the end of the case, all alignment information can be
saved for the patient file. This is of great assistance to the
surgeon due to the fact that the outcome of implant positioning can
be seen before any resections have been made to the bone. The
system is also capable of tracking the patella and resulting
placement of cutting guides and the patellar trial position. The
system then tracks alignment of the patella with the patellar
femoral groove and will give feedback on issues, such as, patellar
tilt.
[0127] The tracking and image information provided by systems and
processes according to the present invention facilitate telemedical
techniques, because they provide useful images for distribution to
distant geographic locations where expert surgical or medical
specialists may collaborate during surgery. Thus, systems and
processes according to the present invention can be used in
connection with computing functionality 18 which is networked or
otherwise in communication with computing functionality in other
locations, whether by PSTN, information exchange infrastructures
such as packet switched networks including the Internet, or as
otherwise desire. Such remote imaging may occur on computers,
wireless devices, videoconferencing devices or in any other mode or
on any other platform which is now or may in the future be capable
of rending images or parts of them produced in accordance with the
present invention. Parallel communication links such as switched or
unswitched telephone call connections may also accompany or form
part of such telemedical techniques. Distant databases such as
online catalogs of implant suppliers or prosthetics buyers or
distributors may form part of or be networked with functionality 18
to give the surgeon in real time access to additional options for
implants which could be procured and used during the surgical
operation.
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