U.S. patent application number 11/697957 was filed with the patent office on 2007-10-04 for computer assisted knee arthroplasty instrumentation, systems, and processes.
Invention is credited to Christopher Patrick Carson, Christopher M. Lyons, Crista Smothers.
Application Number | 20070233121 11/697957 |
Document ID | / |
Family ID | 31976205 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070233121 |
Kind Code |
A1 |
Carson; Christopher Patrick ;
et al. |
October 4, 2007 |
Computer Assisted Knee Arthroplasty Instrumentation, Systems, and
Processes
Abstract
Instrumentation, 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 instrumentation, systems, and processes are accomplished by
using a computer to intraoperatively obtain images of body parts
and to register, navigate, and track surgical instruments.
Disclosed in this document are also alignment modules and other
structures and processes which allow for coarse and fine alignment
of instrumentation and other devices relative to bone for use in
connection with the tracking systems of the present invention.
Inventors: |
Carson; Christopher Patrick;
(Collierville, TN) ; Smothers; Crista; (Cordova,
TN) ; Lyons; Christopher M.; (Hernando, MS) |
Correspondence
Address: |
CHIEF PATENT COUNSEL;SMITH & NEPHEW, INC.
1450 BROOKS ROAD
MEMPHIS
TN
38116
US
|
Family ID: |
31976205 |
Appl. No.: |
11/697957 |
Filed: |
April 9, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10229372 |
Aug 27, 2002 |
|
|
|
11697957 |
Apr 9, 2007 |
|
|
|
10084012 |
Feb 27, 2002 |
6923817 |
|
|
10229372 |
Aug 27, 2002 |
|
|
|
60271818 |
Feb 27, 2001 |
|
|
|
60355899 |
Feb 11, 2002 |
|
|
|
Current U.S.
Class: |
378/205 ;
606/88 |
Current CPC
Class: |
A61B 2090/3983 20160201;
A61B 2090/3916 20160201; A61B 2034/256 20160201; A61F 2/389
20130101; A61B 2034/2055 20160201; A61B 2034/102 20160201; A61B
34/10 20160201; A61B 2034/252 20160201; A61F 2/4657 20130101; A61B
2034/105 20160201; A61F 2/3859 20130101; A61B 2034/2068 20160201;
A61B 2034/2072 20160201; A61B 2090/376 20160201; A61F 2/4684
20130101; A61F 2002/4632 20130101; A61B 17/154 20130101; A61B 90/10
20160201; A61F 2002/30892 20130101; A61F 2002/30616 20130101; A61B
34/20 20160201; A61B 17/70 20130101; A61B 34/25 20160201; A61F 2/38
20130101; A61B 90/36 20160201; A61B 2034/254 20160201; A61B
2034/108 20160201 |
Class at
Publication: |
606/072 ;
606/088 |
International
Class: |
A61B 17/58 20060101
A61B017/58 |
Claims
1. A process for conducting knee surgery, comprising: a. exposing
bones in the vicinity of knee joint; b. fastening a rod to bone in
the vicinity of the knee joint in a manner intended at least
coarsely to align the rod to a desired axis relative to the bone;
c. attaching a rod retention component of an alignment module to
the rod, the alignment module comprising: i. a rod retention
component adapted to connect to the rod; ii. a surgical
instrumentation retention component adapted to connect to surgical
instrumentation; iii. an intermediate component adapted to connect
to the rod retention component in a fashion that allows the rod
retention component and intermediate component to rotate relative
to each other about at least one axis, and adapted to connect to
the surgical instrumentation retention component in a fashion that
allows the surgical instrumentation retention component and the
intermediate component to rotate relative to each other about at
least one axis; iv. an adjustment mechanism connecting the
intermediate component and the rod retention component, the
adjustment mechanism adapted to control and fix orientation of the
intermediate component relative to the rod retention component; and
v. an adjustment mechanism connecting the intermediate component
and the surgical instrumentation retention component, the
adjustment mechanism adapted to control and fix orientation of the
intermediate component and the surgical instrumentation retention
component; d. attaching instrumentation to the alignment module; e.
adjusting at least one of the adjustment mechanisms in order to
finely align the instrumentation relative to the bone; f. resecting
bone using the instrumentation; g. attaching a surgical implant to
the resected bone; h. reassembling the knee; and i. closing the
exposed knee.
2. The process according to claim 1, further comprising attaching a
fiducial at least indirectly to the instrumentation and tracking
the instrumentation position using the fiducial and a surgical
navigation system.
3. The process according to claim 1, in which fastening the rod to
the bone does not include penetrating the medullary canal with the
rod.
4. The process according to claim 1, in which the instrumentation
is adjusted by adjusting both adjustment mechanisms.
5. A process for conducting knee surgery, comprising: a. exposing
bones in the vicinity of knee joint; b. fastening a structural
member to bone in the vicinity of the knee joint in a manner
intended at least coarsely to align the structural member to a
desired axis relative to the bone; c. attaching a second member of
an alignment module to the structural member, the alignment module
comprising: i. a first member adapted to be connected to
instrumentation; ii. a second member connected to the first member
in a fashion that allows the second member and the first member to
be varied in orientation relative to each other about at least two
substantially orthogonal axes; iii. adjustment structure for
controlling motion of the second member relative to the first
member and for fixing the position of the second member relative to
the first member; iv. attaching instrumentation to the first
member; and v. attaching at least one fiducial to the
instrumentation, at least indirectly; d. tracking orientation of
the instrumentation relative to bone using the fiducial and a
surgical navigation system; e. adjusting the adjustment structure
in order to finely align the instrumentation relative to the bone;
f. resecting bone using the instrumentation; g. attaching a
surgical implant to the resected bone; h. reassembling the knee;
and i. closing the exposed knee.
6. A process according to claim 5, in which tracking orientation of
the instrumentation relative to the bone involves storing,
processing and displaying radiograms of the bone taken before the
process begins.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 10/229,372 filed on Aug. 27, 2002, which is
continuation-in-part of U.S. patent application Ser. No. 10/084,012
filed on Feb. 27, 2002, which claims the benefit of U.S.
Provisional Application No. 60/355,899 filed on Feb. 11, 2002 and
Provisional Application No. 60/271,818 filed on Feb. 27, 2001. The
disclosure of each prior application is incorporated by reference
in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The field of the invention includes instrumentation,
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 processes 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 instrumentation, 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 instrumentation, 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] Instrumentation, 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, instrumentation, 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. Instrumentation, 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. Instrumentation, 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
instrumentation, systems, and processes according to the present
invention.
[0007] According to a preferred embodiment of instrumentation,
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] Instrumentation, systems, and processes according to the
present invention represent significant improvement over other
previous instrumentation, systems, and processes. For instance,
systems which use CT and MRI data generally require the placement
of reference frames preoperatively 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 at 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] Some systems provide variable alignment modules, but none of
these systems allow gross placement of cutting instruments followed
by fine adjustment of cutting instruments through computer assisted
navigation technology. Further, these systems can only be used with
tibial instrumentation and cannot be used for femoral alignment and
cutting.
[0021] 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.
[0022] An aspect 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.
[0023] Another aspect 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.
[0024] Another aspect 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. Further areas of
applicability of the present invention will become apparent from
the detailed description provided hereinafter. It should be
understood that the detailed description and specific examples,
while indicating the preferred embodiment of the invention, are
intended for purposes of illustration only and are not intended to
limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, which are incorporated in and
form a part of the specification, illustrate the embodiments of the
present invention and together with the written description serve
to explain the principles, characteristics, and features of the
invention. In the drawings:
[0026] FIG. 1 is a schematic view of a particular embodiment of
instrumentation, systems, and processes according to the present
invention.
[0027] 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.
[0028] 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.
[0029] FIG. 4 is a fluoroscopic image of free space rendered on a
monitor according to one embodiment of the present invention.
[0030] FIG. 5 is a fluoroscopic image of femoral head obtained and
rendered according one embodiment of the present invention.
[0031] FIG. 6 is a fluoroscopic image of a knee obtained and
rendered according to one embodiment of the present invention.
[0032] FIG. 7 is a fluoroscopic image of a tibia distal end
obtained and rendered according to one embodiment of the present
invention.
[0033] FIG. 8 is a fluoroscopic image of a lateral view of a knee
obtained and rendered according to one embodiment of the present
invention.
[0034] FIG. 9 is a fluoroscopic image of a lateral view of a knee
obtained and rendered according to one embodiment of the present
invention.
[0035] 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.
[0036] 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.
[0037] 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.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] FIG. 19 is a view produced according to one embodiment of
the present invention during designation of landmarks to determine
a tibial mechanical axis.
[0045] FIG. 20 is a screen face produced according to one
embodiment of the present invention during designation of landmarks
to determine an epicondylar axis.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] FIG. 27 shows navigation and placement of an extramedullary
rod according to one embodiment of the present invention.
[0053] FIG. 28 is a view of an extramedullary rod according to one
embodiment of the present invention.
[0054] FIG. 29 is another view showing navigation and placement of
an extramedullary rod according to one embodiment of the present
invention.
[0055] FIG. 30 is a screen face produced according to one
embodiment of the present invention which assists in navigation
and/or placement of an extramedullary rod.
[0056] FIG. 31 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.
[0057] FIG. 32 is a view which shows navigation and placement of an
alignment guide according to one embodiment of the present
invention.
[0058] FIG. 33 is another view which shows navigation and placement
of an alignment guide according to one embodiment of the present
invention.
[0059] 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.
[0060] 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.
[0061] 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.
[0062] 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.
[0063] FIGS. 38A-C are views showing certain aspects of a gimbal
alignment module according to one embodiment of the present
invention.
[0064] FIGS. 39A-C are views showing other aspects of the module
shown in FIGS. 38A-C.
[0065] FIGS. 40A-C show other aspects of the module shown in FIGS.
38A-C.
[0066] FIG. 41 shows additional aspects of the module shown in
FIGS. 38A-C.
[0067] FIGS. 42A and B are an exploded perspective view showing
certain aspects of a tibial gimbal alignment module according to
one embodiment of the present invention.
[0068] FIG. 43 shows other aspects of the module shown in FIGS. 42A
and 42B.
[0069] FIG. 44 shows additional aspects of the module shown in
FIGS. 42A and 42B.
[0070] FIG. 45 additional aspects of the module shown in FIGS. 42A
and 42B.
[0071] FIGS. 46A and 46B show another structure for alignment
modules according to alternative embodiments of the present
invention.
[0072] FIG. 47 shows another structure for alignment modules
according to alternative embodiments of the present invention.
[0073] FIG. 48 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.
[0074] FIG. 49 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.
[0075] FIG. 50 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.
[0076] FIG. 51 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.
[0077] FIG. 52 is a view showing placement of a cutting block
according to one embodiment of the present invention.
[0078] FIG. 53 is a screen face according to one embodiment of the
present invention which may be used to assist in navigation and
placement of instrumentation.
[0079] FIG. 54 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.
[0080] FIG. 55 is a view showing placement of an alignment guide
according to one embodiment of the present invention.
[0081] FIG. 56 is another view showing placement of a cutting block
according to one embodiment of the present invention.
[0082] FIG. 57 is a view showing navigation and placement of the
cutting block of FIG. 45.
[0083] FIG. 58 is another view showing navigation and placement of
a cutting block according to one embodiment of the present
invention.
[0084] FIG. 59 is a view showing navigation and placement of a
tibial cutting block according to one embodiment of the present
invention.
[0085] FIG. 60 is a screen face according to one embodiment of the
present invention which may be used to assist in navigation and
placement of instrumentation.
[0086] FIG. 61 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0087] FIG. 62 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0088] FIG. 63 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0089] FIG. 64 is another screen face according to one embodiment
of the present invention which may be used to assist in navigation
and placement of instrumentation.
[0090] FIG. 65 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.
[0091] FIG. 66 is a view showing navigation and placement of a
tibial trial component according to one embodiment of the present
invention.
[0092] FIG. 67 is a view showing articulation of trial components
during trial reduction according to one embodiment of the present
invention.
[0093] FIG. 68 is a screen face according to one embodiment of the
present invention which may be used to assist in assessing joint
function.
[0094] FIG. 69 is a screen face according to one embodiment of the
present invention which may be used to assist in assessing joint
function.
[0095] FIG. 70 is a screen face according to one embodiment of the
present invention which may be used to assist in assessing joint
function.
[0096] FIG. 71 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.
[0097] FIG. 72 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.
[0098] FIG. 73 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.
[0099] FIG. 74 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.
[0100] FIG. 75 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 OF THE EMBODIMENTS
[0101] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0102] Instrumentation, 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.
[0103] 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.
[0104] 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.
[0105] Instrumentation, 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. Instrumentation, systems and processes according to the
present invention allow the attachment of a variable alignment
module so that a surgeon can grossly place a cutting block based on
visual landmarks or navigation and then finely adjust the cutting
block based on navigation and feedback from the system.
[0106] Instrumentation, systems, and processes according to the
present invention can also suggest modifications to implant size,
positioning, and other techniques to achieve optimal kinematics.
Instrumentation, 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 instrumentation, systems, and processes.
[0107] 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.
Instrumentation, 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.
[0108] 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 wireline 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 and
instrumentation components may be tracked in position and
orientation relative to body parts 10 and 12 using fiducials
14.
[0109] 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 36 (See, e.g., FIG. 28),
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 36 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 36
properly
[0110] 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 overlain 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.
[0111] 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
laterial 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.
[0112] Instrumentation, systems, and processes according to an
embodiment of the present invention such as the subject of FIGS.
2-75, 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.
[0113] FIGS. 2-75 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.
[0114] 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.
[0115] 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
[0116] 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 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
[0117] 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.
[0118] 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.
[0119] 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.
[0120] 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.
[0121] FIG. 24, as is the case with a number of screen
presentations generated and presented by the system of FIGS. 4-75,
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. Textual 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.
[0122] FIG. 25 shows mechanical, lateral, anterior-posterior axes
for the tibia according to points are registered by the
surgeon.
[0123] FIG. 26 is another onscreen image showing the axes for the
femur 12.
Modifying Bone
[0124] 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. 4-75.
Instrumentation such as, for instance, cutting blocks 34, to which
fiducials 14 are mounted, can be employed. The system can then
track cutting block 34 as the surgeon manipulates it for optimum
positioning. In other words, the surgeon can "navigate" the cutting
block 34 for optimum positioning using the system, the monitor,
visual landmarks, and other devices, such as variable alignment
modules 54. 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 36 or any other structure that allows the
instrumentation to be positioned without invading the medullary
canal. The touchscreen 24 can then also display the instrument,
such as the cutting block 34 and/or the implant and/or the variable
alignment module 54 relative to the instruments and the rod 36
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.
[0125] FIG. 27 shows orientation of an extramedullary rod 36 to
which a fiducial 14 is attached via impactor 22. The surgeon views
the screen 24 which has an image as shown in FIG. 32 of the rod 36
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 36 into place
preferably along the mechanical axis of the femur and drives it
home with appropriate mallet or other device.
[0126] FIG. 28 shows an extramedullary rod 36, according to one
embodiment of the invention, which includes a first end that is
adapted to fasten to bone and a second end that is adapted for
attachment or connection to a cutting block 34 or other
instrumentation. In a preferred embodiment of this invention, the
first end of the extramedullary rod 36 has a pointed, splined tip
38 that is capable being being driven or otherwise introduced into
and fastened to bone with a mallet, wrench or other suitable tool
or device. The tip can feature threads, curved spines, or any
structure that is suitable for efficient and effective introduction
into and purchase of or fastening bone sufficient to support
cutting block 34 or other instrumentation while being used to alter
bone. Devices according to aspects of the present invention thus
avoid the need to bore a hole in the metaphysis of the femur and
place a reamer or other rod 36 into the medullary canal which can
cause fat embolism, hemorrhaging, infection and other untoward and
undesired effects.
[0127] As shown in FIG. 28, the second end of the extramedullary
rod 36 may be attached to a base member 40 (permanently or in
releasable fashion) and that is capable of permanent or releasable
attachment to a cylindrical connector 42. The cylindrical connector
42 is capable of permanent or releasable attachment to a
cylindrical knob 44 that has an integrated, circumferential groove
46. The circumferential groove 46 is adapted to secure an impactor
or any other desired structure to the second end of the
extramedullary rod 36. The base member 40, connector 42, and knob
44 may form a unitary structure that is capable of permanent or
releasable attachment to an extramedullary rod 36. Any desired
connection structure can be employed.
[0128] FIG. 29 also shows the extramedullary rod 36 being located
through computer assisted navigation. FIG. 30 shows fluoroscopic
images, both anterior-posterior and lateral, with axes, and with a
computer generated and tracked image of the rod 36 superposed or in
combination with the fluoroscopic images of the femur and tibia.
FIG. 31 shows the rod 36 superposed on the femoral fluoroscopic
image similar to what is shown in FIG. 30.
[0129] FIG. 30 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 36 in varus/valgus and extension relative to the
axes. Any or all of this information can be used to navigate and
position the rod 36 relative to the femur. At a point in time
during or after placement of the rod 36, its tracking may be
"handed off" from the impactor fiducial 14 to the femur fiducal 14
as discussed below.
[0130] Once the extramedullary rod 36, intramedullary rod, other
type of rod or any other type of structural member 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 34 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 36. Because the cutting block 34
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 34 and the femoral component overlain on the
fluoroscopic image as shown in FIGS. 34-37. The surgeon can thus
navigate and position the cutting block 34 on screen using not only
images of the cutting block 34 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 34 component, and secure it to the rod 36 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. 35 is another view of the cutting block
34 of FIG. 32 being positioned.
[0131] Cutting blocks 34 and other instrumentation may be
positioned relative to femoral, tibial or other bone using
instruments and devices such as variable alignment or orientation
modules, versions of which according to particular aspects of the
invention are shown in FIGS. 38-47. FIGS. 38-41 show a first
version of a variable alignment module 54. It includes a post 58
which may be connected to an extramedullary rod 36 as shown in FIG.
28, an intramedullary rod or as otherwise desired. Post 58 connects
to a cutting block or other instrument 34 via two gimbal members,
first or outer gimbal 60 and a second or inner gimbal 62. First or
outer gimbal 60, which may be mechanically connected to cutting
block 34 as shown in FIGS. 40A-C and 41, is connected in pivoting
fashion to second gimbal 62 using, for example, openings 64 and
pins 70. First gimbal 60 receives a worm gear 66 which cooperates
with a first follower (located on the second gimbal 62) whose teeth
follow action of the worm gear 66 in order to vary the angle of the
first and second gimbals 60, 62 relative to each other. In the
embodiment shown in FIGS. 38-41, worm gear 66 in this fashion
adjusts varus/valgus angulation of cutting block or instrument 34
relative to bone.
[0132] FIGS. 39A-C shows more clearly the post 58 (which can
receive and be secured to extramedullary rod 36 or other devices
using, for example, a bore and pin 70) and second gimbal 62
connected in pivoting relationship in a fashion conceptually
similar to the manner in which first and second gimbals 60 and 62
are connected. As shown in FIG. 39C, post 58 penetrates gimbal 62
in pivoting fashion using openings 64 and pins 70. Second gimbal 62
receives a worm gear 68 which cooperates with a second follower on
post 58 to vary the angle of post 58 relative to second gimbal
62.
[0133] As shown in FIGS. 40A-C and 41, the angulation of cutting
block 34 relative to rod 36 may be varied in varus and valgus using
worm gear 66 and flexion/extension using worm gear 68.
[0134] FIGS. 42-45 show a variable alignment module which may used
for instrumentation employed in connection with the tibia. The
operation and structure are conceptually similar to the femoral
module shown in FIGS. 38-41. Here, a first gimbal 76 may be rigidly
or otherwise mounted to a member 74 which in turn receives
instrumentation such as a cutting block 75. First gimbal 76
connects to second gimbal 78 using pin 82 extending through holes
80 in first gimbal 76 to capture second gimbal 78 so that it may
pivot relative to first gimbal 76. A worm gear 84 connects to first
gimbal 76 and drives a follower on second gimbal 78 to adjust
angulation of second gimbal 78 relative to first gimbal 76. Worm
gear 84 can thus adjust flexion/extension orientation of the
cutting block 75 relative to the tibia.
[0135] A post 86 which receives extramedullary rod 36 or other rod
or bone-connecting structure, and which may be formed of a
cylindrical member in combination with other structure for
retaining rod 36 in desired relationship, is received relative to
second gimbal 78 in adjustable fashion. In the embodiment shown in
FIGS. 42-45, an adjustment screw 88 cooperates with a slot in the
second gimbal 78 in order to allow the post 86 to rotate within
gimbal 78 and be secured at desired angulation. Adjustment screw 88
and slot 90 are but one variation of any adjustment mechanism, such
as worm and follower, rack and pinion, vernier, or other angulation
control devices or structures which could be used in this
embodiment, the embodiment shown in FIGS. 38-41 other embodiments.
Accordingly, this structure may be used to adjust varus/valgus
alignment of cutting block 75.
[0136] With respect to the femoral structure shown in FIGS. 38-41
and the tibial structure shown in FIGS. 42-45, other structures
which allow adjustment of angulation or orientation not only of the
two axis, but any desired angulation of cutting block 75 relative
to rod 36 (and thus bone) can be used. Gimbals can be reversed in
structure and function, different calibration and adjustment
mechanisms can be used including with indicia in order to introduce
repeatability, and other structures may be employed as well.
Fiducials 14 can be attached to any desired portion of these
structures, directly or indirectly, for tracking in accordance with
aspects of the invention.
[0137] FIGS. 46 and 47 show two structures among many which can be
used to adjust positioning of cutting block 34 or other
instrumentation relative to rod 36. In the version shown in FIG.
46, rod 36 which may be extramedullary, intramedullary, or
otherwise, features a spherical or otherwise curved
three-dimensional head with a generally concentric threaded bore.
An adjustment bolt 90 features threads which cooperate with the
threads in head 36. The bolt 90 penetrates cutting block 34 in
desired fashion so that the cutting block 34, which features a
recess 92 on its bottom surface that corresponds to the shape of
the head of 36, however closely, can be angulated as desired in any
dimension and then set via tightening of bolt 90 at any desired
angulation in multiple planes.
[0138] FIG. 47 shows a variation in which the cutting block 34 may
be connected to external fixation systems 92, such as those
described U.S. Pat. No. 5,728,095, which is incorporated herein by
this reference, in order to adjustably position the cutting block
34 relative to femoral or tibial bone. As described in that patent
and others on the subject, calibrations may be employed on the
struts connecting the cutting block 34 and the fixator element 92
in order for repeatability and controllability of angulation of
cutting block 34 relative to fixation element or device 92.
[0139] FIGS. 48-52 show instrumentation that has been navigated and
positioned on the proximal portion of the tibia 10 as shown in FIG.
52 and as tracked by sensor 16 and on screen by images of the
cutting block and the implant component as shown in FIGS.
48-51.
[0140] FIGS. 53 and 54 show other onscreen images generated during
this bone modification process for purposes of navigation and
positioning cutting blocks 34 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
instrumentation, systems, and processes of the embodiment of the
present invention shown in FIGS. 4-75.
[0141] FIGS. 55-59 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 34 and their attached fiducials
can be seen in these views.
[0142] FIG. 60 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.
61 is another navigational screen face showing a femoral component
overlay as instrumentation is being positioned for resection of
bone.
[0143] FIG. 62 is tibial component overlay information on a
navigation screen as the cutting block 34 for the tibial plateau is
being positioned for bone resection.
[0144] FIGS. 63 and 64 show femoral component and tibial component
overlays, respectively, according to certain position and
orientation of cutting blocks/instrumentation as resecting is being
done. 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
[0145] 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.
[0146] 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. 36, 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.
[0147] FIG. 66 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.
[0148] 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.
[0149] FIG. 67 shows the surgeon articulating the knee as he
monitors the screen which is presenting images such as those shown
in FIGS. 68-70 which not only show movement of the trial components
relative to each other, but also orientation, flexion, and
varus/valgus. During this assessment, the surgeon may conduct
certain assessment processes such as external/internal rotation or
rotary 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. 71-74. 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.
[0150] FIG. 75 is another computer generated 3-dimensional image of
the trial components as tracked by the system during trialing.
[0151] 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 resectioning has been done on 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.
[0152] The tracking and image information provided by
instrumentation, 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, instrumentation, 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.
[0153] As various modifications could be made to the exemplary
embodiments, as described above with reference to the corresponding
illustrations, without departing from the scope of the invention,
it is intended that all matter contained in the foregoing
description and shown in the accompanying drawings shall be
interpreted as illustrative rather than limiting. Thus, the breadth
and scope of the present invention should not be limited by any of
the above-described exemplary embodiments, but should be defined
only in accordance with the following claims appended hereto and
their equivalents.
* * * * *