U.S. patent application number 11/199418 was filed with the patent office on 2006-01-12 for percutaneous registration apparatus and method for use in computer-assisted surgical navigation.
Invention is credited to John B. Clayton, Kevin T. Foley, Anthony Melkent, Michael C. Sherman.
Application Number | 20060009780 11/199418 |
Document ID | / |
Family ID | 26739359 |
Filed Date | 2006-01-12 |
United States Patent
Application |
20060009780 |
Kind Code |
A1 |
Foley; Kevin T. ; et
al. |
January 12, 2006 |
Percutaneous registration apparatus and method for use in
computer-assisted surgical navigation
Abstract
An apparatus and procedures for percutaneous placement of
surgical implants and instruments such as, for example, screws,
rods, wires and plates into various body parts using image guided
surgery. An apparatus for use with a surgical navigation system, an
attaching device rigidly connected to a body part, such as the
spinous process of a vertebrae, with an identification
superstructure rigidly but removably connected to the attaching
device. This identification superstructure, for example, is a
reference arc and fiducial array which accomplishes the function of
identifying the location of the superstructure, and, therefore, the
body part to which it is fixed, during imaging by CAT scan or MRI,
and later during medical procedures.
Inventors: |
Foley; Kevin T.;
(Germantown, TN) ; Clayton; John B.; (Superior,
CO) ; Melkent; Anthony; (Memphis, TN) ;
Sherman; Michael C.; (Memphis, TN) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
26739359 |
Appl. No.: |
11/199418 |
Filed: |
August 8, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10423332 |
Apr 24, 2003 |
|
|
|
11199418 |
Aug 8, 2005 |
|
|
|
09148498 |
Sep 4, 1998 |
6226548 |
|
|
10423332 |
Apr 24, 2003 |
|
|
|
60059915 |
Sep 24, 1997 |
|
|
|
Current U.S.
Class: |
606/99 |
Current CPC
Class: |
A61B 17/7032 20130101;
A61B 2090/3983 20160201; A61B 34/10 20160201; A61B 90/11 20160201;
A61B 2034/2055 20160201; A61B 2090/3945 20160201; A61B 17/7083
20130101; A61B 2017/00477 20130101; A61B 2090/363 20160201; A61B
2034/2072 20160201; A61B 34/20 20160201; A61B 17/70 20130101 |
Class at
Publication: |
606/099 |
International
Class: |
A61B 17/58 20060101
A61B017/58 |
Claims
1. A method of positioning an implant in an anatomy, including a
first implant portion and a second implant portion with a surgical
navigation system, comprising: positioning the first implant
portion through an opening in a soft tissue of the anatomy;
tracking a position of the first implant portion; interconnecting
an implant inserter with the second implant portion; determining a
location of the second implant portion; and moving the second
implant portion relative to the first implant portion via
determining a location of the second implant portion.
2. The method of claim 1, wherein positioning a first implant
portion through an opening in a soft tissue, moving the second
implant portion relative to the first implant portion, or
combinations thereof includes positioning the first implant
portion, the second implant portion, or combinations thereof
percutaneously.
3. The method of claim 2, wherein tracking a position of the first
implant portion includes; interconnecting a tracking apparatus with
the first implant portion; and tracking the tracking apparatus
interconnected to the first implant portion.
4. The method of claim 3, further comprising: determining a
position of the portion of the first implant portion; wherein
moving the second implant portion relative to the first implant
portion includes determining a location of a second implant portion
relative to the first implant portion.
5. The method of claim 4, further comprising: displaying the
determined position of the first implant portion and the position
of the second implant portion.
6. The method of claim 1, further comprising: configuring the
second implant portion based upon a tracked position of the first
implant portion, a determined location of the second implant
portion, or combinations thereof.
7. The method of claim 1, further comprising: interconnecting a
reference frame with the anatomy.
8. The method of claim 7, further comprising: displaying a
determined position of the second implant portion on a display
relative to a registered image of the anatomy.
9. The method of claim 1, further comprising: interconnecting a
tracking apparatus with the implant inserter; and tracking the
tracking apparatus.
10. The method of claim 1, wherein determining a location of the
second implant further includes tracking the tracking
apparatus.
11. The method of claim 9, wherein the tracking apparatus includes
a sensor.
12. The method of claim 11, further comprising: selecting a sensor
to include at least one of a light emitter, an infrared light
emitter, an electromagnet, a magnet, a radiation emitter, or
combinations thereof.
13. The method of claim 1, further comprising: imaging the anatomy
while at least one of tracking the position of the first implant,
tracking the tracking apparatus, determining a location of a
portion of the second implant portion, or combinations thereof.
14. The method of claim 13, wherein imaging the anatomy includes
imaging the anatomy with an ultrasound system.
15. The method of claim 1, further comprising: positioning a third
implant portion through an opening in a soft tissue; and
interconnecting the first implant portion and the third implant
portion with the second implant portion by moving the second
implant portion relative to the first implant portion and the third
implant portion.
16. The method of claim 1, wherein said first implant portion is a
slot in a screw head; wherein said second implant portion is a rod;
wherein moving the second implant portion includes aligning the rod
with the slot.
17. The method of claim 16, further comprising: fixing the first
implant portion to a vertebrae.
18. The method of claim 1, wherein tracking a position includes
tracking with an acoustic tracking system, optical tracking system,
electromagnetic tracking system, micropulsed radar, or combinations
thereof.
19. A method of performing a spinal procedure in an anatomy with a
surgical navigation system, comprising: positioning a first screw
implant in a vertebrae percutaneously through an opening in a soft
tissue of the anatomy; tracking a position of the first screw
implant; orientating the first screw implant in a selected
orientation at least in part via tracking the position of the first
screw implant; interconnecting an implant inserter with a rod;
determining a position of a portion of the rod; and moving the rod
relative to the first screw implant via determining a location of
the rod to interconnect the screw with rod.
20. The method of claim 19, further comprising: interconnecting a
second tracking apparatus with the implant inserter.
21. The method of claim 19, wherein orientating said first screw
implant includes orientating a slot defined by the screw.
22. The method of claim 21, wherein tracking a position of the
first screw implant includes interconnecting a screw tracking
apparatus with the first screw implant.
23. The method of claim 22, wherein interconnecting the screw
tracking apparatus includes selecting a sensor.
24. The method of claim 23, wherein selecting the sensor includes
selecting a light emitting diode, a light reflector, an infrared
emitter, a magnet, an electromagnet, an acoustic emitter, an
infrared reflector, or combinations thereof.
25. The method of claim 22, wherein interconnecting the screw
tracking apparatus with the first screw implant includes
positioning the screw tracking apparatus percutaneously.
26. The method of claim 22, wherein tracking the tracking apparatus
includes at least triangulating a position of the tracking
apparatus with the surgical navigational system.
27. The method of claim 26, wherein the surgical navigation system
includes an acoustic tracking system, or electromagnetic tracking
system, an optical tracking system, a micropulsed radar, or
combinations thereof.
28. The method of claim 19, wherein orientating the first screw
implant includes selecting an orientation of a head of the screw
relative to a portion of the anatomy.
29. The method of claim 21, wherein orientating the first screw
implant includes orientating the slot relative to the anatomy.
30. The method of claim 29, further comprising: positioning a
second screw implant in a vertebrae percutaneously; and orientating
the second screw implant; wherein orientating the second screw
implant includes orientating second screw implant relative to the
first screw implant.
31. The method of claim 30, wherein moving the rod relative to the
first screw implant includes moving the rod relative to both the
first screw implant and the second screw implant.
32. The method of claim 31, further comprising: manipulating the
rod to achieve an interconnection of the first screw implant and
the second screw implant.
33. The method of claim 19, wherein interconnecting the implant
inserter with the rod includes interconnecting the implant inserter
near a first end of the rod, a second end of the rod, a portion
intermediate between the first end and the second end, or
combinations thereof.
34. The method of claim 19, wherein interconnecting an implant
inserter with a rod includes rigidly interconnecting an implant
inserter with the rod.
35. The method of claim 34, further comprising: interconnecting a
tracking apparatus with the implant inserter that includes rigidly
interconnecting the tracking apparatus with the implant
inserter.
36. The method of claim 19, wherein interconnecting an implant
inserter with a rod includes releasably interconnecting the implant
inserter with the rod.
37. The method of claim 19, further comprising: interconnecting a
tracking apparatus with the implant inserter that includes
positioning an emitter on the tracking apparatus.
38. The method of claim 37, wherein interconnecting a sensor with
the tracking apparatus includes selecting at least one of a light
emitting a diode, a light reflecting portion, an infrared light
emitting portion, an infrared light reflecting portion, an acoustic
emitter, an electromagnet, a magnet, or combinations thereof.
39. The method of claim 19, further comprising: imaging a portion
of the anatomy.
40. The method of claim 39, wherein imaging a portion of the
anatomy includes obtaining an MRI scan, a CT scan, an x-ray image,
an ultrasound image, or combinations thereof.
41. The method of claim 19, further comprising: displaying an image
of the anatomy; and displaying a position of the portion of the
screw on the display relative to the image of the anatomy, and
displaying a determined position of the rod relative to the image
of the anatomy.
42. The method of claim 41, wherein moving the rod relative to the
screw includes displaying on the display the portion of the rod
relative to the position of the head of the screw.
43. The method of claim 42, further comprising: manipulating the
rod to achieve a selected interconnection of the rod and the screw
implant.
44. The method of claim 43, wherein manipulating the rod includes
bending the rod.
45. The method of claim 44, further comprising: positioning a
second screw implant in a vertebrae percutaneously; and moving the
rod relative to the screw implant and the second screw implant.
46. The method of claim 19, wherein moving the rod relative to the
screw includes moving the rod substantially percutaneously.
47. The method of claim 46, wherein moving the rod substantially
percutaneously includes inserting the rod through a substantially
single opening in a soft tissue of the anatomy and moving the rod
based upon a tracked position of the rod.
48. The method of claim 47, wherein tracking a position of the
portion of the screw and determining a position of a portion of the
rod is substantially percutaneous.
49. The method of claim 19, wherein tracking the position of the
first screw implant includes tracking a position of a slot defined
by the screw.
50. The method of claim 49, wherein moving the rod relative to the
first screw implant includes moving the rod percutaneously through
the slot.
51. The method of claim 50, further comprising: positioning a
second screw implant in a vertebrae percutaneously through an
opening in a soft tissue of the anatomy; tracking a position of the
second screw implant; and orientating the second screw implant in a
selected orientation at least in part via tracking the position of
the second screw implant.
52. The method of claim 51, wherein orientating the second screw
implant includes aligning a second slot defined by the second screw
implant with a first slot defined by the first screw implant at
least in part by tracking the position of the first screw implant,
tracking the position of the first screw implant, or combinations
thereof; wherein moving the rod includes moving the rod through the
first slot and the second slot;
53. The method of claim 52, further comprising: fixing the rod to
the first screw implant and the second screw implant.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/423,332 filed on Apr. 24, 2003; which is a
reissue of 09/148,498 filed Sep. 4, 1998 which is now U.S. Pat. No.
6,226,548 issued on May 1, 2001; which claims rights under 35
U.S.C. .sctn.119 on provisional application No. 60/059,915, filed
on Sep. 24, 1997. The disclosures of the above applications are
incorporated herein by reference.
FIELD
[0002] The present teachings relate generally to guiding,
directing, or navigating instruments or implants in a body
percutaneously, in conjunction with systems that use and generate
images during medical and surgical procedures, which images assist
in executing the procedures and indicate the relative position of
various body parts, surgical implants, and instruments. In
particular the teachings relate to apparatus and minimally invasive
procedures for navigating instruments and providing surgical
implants percutaneously in the spine, for example, to stabilize the
spine, correct deformity, or enhance fusion in conjunction with a
surgical navigation system for generating images during medical and
surgical procedures.
BACKGROUND
[0003] Typically, spinal surgical procedures used, for example, to
provide stabilization, fusion, or to correct deformities, require
large incisions and substantial exposure of the spinal areas to
permit the placement of surgical implants such as, for example,
various forms of screws or hooks linked by rods, wires, or plates
into portions of the spine. This standard procedure is invasive and
can result in trauma, blood loss, and post operative pain.
Alternatively, fluoroscopes have been used to assist in placing
screws beneath the skin. In this alternative procedure at least
four incisions must be made in the patient's back for inserting
rods or wires through previously inserted screws. However, this
technique can be difficult in that fluoroscopes only provide
two-dimensional images and require the surgeon to rotate the
fluoroscope frequently in order to get a mental image of the
anatomy in three dimensions. Fluoroscopes also generate radiation
to which the patient and surgical staff may become over exposed
over time. Additionally, the subcutaneous implants required for
this procedure may irritate the patient. A lever arm effect can
also occur with the screws that are not connected by the rods or
wires at the spine. Fluoroscopic screw placement techniques have
traditionally used rods or plates that are subcutaneous to connect
screws from vertebra to vertebra. This is due in part to the fact
that there is no fluoroscopic technique that has been designed
which can always adequately place rods or plates at the submuscular
region (or adjacent to the vertebrae). These subcutaneous rods or
plates may not be well tolerated by the patient. They also may not
provide the optimal mechanical support to the spine because the
moment arm of the construct can be increased, thereby translating
higher loads and stresses through the construct.
[0004] A number of different types of surgical navigation systems
have been described that include indications of the positions of
medical instruments and patient anatomy used in medical or surgical
procedures. For example, U.S. Pat. No. 5,383,454 to Bucholz; PCT
Application No. PCT/US94/04530 (Publication No. WO 94/24933) to
Bucholz; and PCT Application No. PCT/US95/12894 (Publication No. WO
96/11624) to Bucholz et al., the entire disclosures of which are
incorporated herein by reference, disclose systems for use during a
medical or surgical procedure using scans generated by a scanner
prior to the procedure. Surgical navigation systems typically
include tracking means such as, for example, an LED array on the
body part, LED emitters on the medical instruments, a digitizer to
track the positions of the body part and the instruments, and a
display for the position of an instrument used in a medical
procedure relative to an image of a body part.
[0005] Bucholz et al. WO 96/11624 is of particular interest, in
that it identifies special issues associated with surgical
navigation in the spine, where there are multiple vertebral bodies
that can move with respect to each other. Bucholz et al. describes
a procedure for operating on the spine during an open process
where, after imaging, the spinous process reference points may move
with respect to each other. It also discloses a procedure for
modifying and repositioning the image data set to match the actual
position of the anatomical elements. When there is an opportunity
for anatomical movement, such movement degrades the fidelity of the
pre-procedural images in depicting the intra-procedural anatomy.
Therefore, additional innovations are desirable to bring image
guidance to the parts of the body experiencing anatomical
movement.
[0006] Furthermore, spinal surgical procedures are typically highly
invasive. There is, thus, a need for more minimally invasive
techniques for performing these spinal procedures, such as biopsy,
spinal fixation, endoscopy, spinal implant insertion, fusion, and
insertion of drug delivery systems, by reducing incision size and
amount. One such way is to use surgical navigation equipment to
perform procedures percutaneously, that is beneath the skin. To do
so by means of surgical navigation also requires apparatus that can
indicate the position of the spinal elements, such as, for example
the vertebrae, involved in the procedure relative to the
instruments and implants being inserted beneath the patient's skin
and into the patient's spine. Additionally, because the spinal
elements naturally move relative to each other, the user requires
the ability to reorient these spinal elements to align with earlier
scanned images stored in the surgical navigation system computer,
to assure the correct location of those elements relative to the
instruments and implants being applied or inserted
percutaneously.
[0007] In light of the foregoing, there is a need in the art for
apparatus and minimally invasive procedures for percutaneous
placement of surgical implants and instruments in the spine,
reducing the size and amount of incisions and utilizing surgical
navigation techniques.
SUMMARY
[0008] Accordingly, the present teachings are directed to apparatus
and procedures for percutaneous placement of surgical implants and
instruments such as, for example, screws, rods, wires and plates
into various body parts using image guided surgery. Various
embodiments are directed to apparatus and procedures for the
percutaneous placement of surgical implants and instruments into
various elements of the spine using image guided surgery.
[0009] To achieve these objects and other advantages and in
accordance with the purpose of the invention, as embodied and
broadly described herein, an apparatus for use with a surgical
navigation system and comprises an attaching device rigidly
connected to a body part, such as the spinous process of a
vertebrae, with an identification superstructure rigidly but
removably connected to the attaching device. This identification
superstructure is a reference arc and fiducial array, which
accomplishes the function of identifying the location of the
superstructure, and, therefore, the body part to which it is fixed,
during imaging by CAT scan or MRI, and later during medical
procedures.
[0010] According to various embodiments, the attaching device is a
clamp with jaws and sharp teeth for biting into the spinous
process.
[0011] According to various embodiments, the fixture is a screw,
having a head, wherein the screw is implanted into the spinous
process and a relatively rigid wire is attached to the head of the
screw and also implanted into the spinous process at an angle to
the axis of the screw to prevent the screw from rotating in either
direction.
[0012] According to various embodiments, the superstructure
includes a central post, and a fiducial array and a reference arc
rigidly but removably attached to the central post. The fiducial
array is composed of image-compatible materials, and includes
fiducials for providing a reference point, indicating the position
of the array, which are rigidly attached to the fiducial array,
composed of, for example titanium or aluminum spheres. The
reference arc includes emitters, such as, for example Light
Emitting Diodes ("LEDs"), passive reflective spheres, or other
tracking means such as acoustic, magnetic, electromagnetic,
radiologic, or micropulsed radar, for indicating the location of
the reference arc and, thus, the body part it is attached to,
during medical procedures.
[0013] According to various embodiments, a method for monitoring
the location of an instrument, surgical implants and the various
portions of the body, for example, vertebrae, to be operated on in
a surgical navigation system comprising the steps of: attaching a
fixture to the spinous process; attaching a superstructure
including a fiducial array with fiducials and a reference arc to
the fixture; scanning the patient using CT, MRI or some other
three-dimensional method, with fiducial array rigidly fixed to
patient to identify it on the scanned image; and thereafter, in an
operating room, using image-guided technology, touching an
image-guided surgical pointer or other instrument to one or more of
the fiducials on the fiducial array to register the location of the
spinal element fixed to the array and emitting an audio, visual,
radiologic, magnetic or other detectable signal from the reference
arc to an instrument such as, for example, a digitizer or other
position-sensing unit, to indicate changes in position of the
spinal element during a surgical procedure, and performing a
surgical or medical procedure percutaneously on the patient using
instruments and implants locatable relative to spinal elements in a
known position in the surgical navigation system.
[0014] In another aspect, the method includes inserting screws or
rigid wires in spinal elements in the area involved in the
anticipated surgical procedure before scanning the patient, and
after scanning the patient and bringing the patient to the
operating area, touching an image-guided or tracked surgical
pointer to these screws and wires attached to the vertebrae to
positively register their location in the surgical navigation
computer, and manipulating either the patient's spine or the image
to align the actual position of the spinal elements with the
scanned image.
[0015] In another aspect, the method includes percutaneously
implanting screws into spinal elements, which screws are located
using image guided surgical navigation techniques, and further
manipulating the orientation of the screw heads percutaneously
using a head-positioning probe containing an emitter, that can
communicate to the surgical navigation computer the orientation of
the screw heads and position them, by use of a specially designed
head-positioning tool with an end portion that mates with the heads
of the screws and can rotate those screw heads to receive a rod,
wire, plate, or other connecting implant. If a rod is being
inserted into the screw heads for example, the method further
includes tracking the location and position of the rod,
percutaneously using a rod inserter having one or more emitters
communicating the location and orientation of the rod to the
surgical navigation computer.
[0016] According to various embodiments, a system and method is
provided to a user, such as a surgeon, to track an instrument and
surgical implants used in conjunction with a surgical navigation
system in such a manner to operate percutaneously on a patient's
body parts, such as spinal vertebrae which can move relative to
each other.
[0017] According to various embodiments, is provided a system and
method to simply and yet positively indicate to the user a change
in position of body parts, such as spinal vertebrae segments, from
that identified in a stored image scan, such as from an MRI or CAT
scan, and provide a method to realign those body parts to
correspond with a previously stored image or the image to
correspond with the actual current position of the body parts.
[0018] According to various embodiments, is provided a system or
method for allowing a fiducial array or reference arc that is
removable from a location rigidly fixed to a body part and
replaceable back in that precise location.
[0019] According to various embodiments, is provided a system and
method for positively generating a display of instruments and
surgical implants, such as, for example screws and rods, placed
percutaneously in a patient using image-guided surgical methods and
techniques.
[0020] According to various embodiments, is provided a percutaneous
reference array and fiducial array, as described herein, to be used
to register and track the position of the vertebrae for the
purposes of targeting a radiation dose to a diseased portion of
said vertebrae using a traditional radiosurgical technique.
[0021] Additional application of the teachings will be set forth in
part in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
teaching. The applications of the teachings will be realized and
attained by means of the elements and combinations particularly
pointed out in this description.
[0022] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive.
[0023] Further areas of applicability of the present teachings will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and various
examples, while indicating various embodiments, are intended for
purposes of illustration only and are not intended to limit the
scope of the teachings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate various
embodiments of the teachings and together with the description,
serve to explain the principles of the invention.
[0025] FIG. 1 is a schematic diagram of various embodiments of a
superstructure for use with the current teachings, including a
reference arc, center post and fiducial array and rigid Kirschner
wires ("K wires") and screws placed in the spine for use with a
surgical navigation system for percutaneous spinal surgical
procedures.
[0026] FIG. 1A is an enlarged view of the superstructure depicted
in FIG. 1 engaging a vertebra by a clamp and also K wires implanted
in adjacent vertebrae in the superior and inferior positions of the
spinous process.
[0027] FIG. 2 is a diagram of various embodiments of a clamp
fixture for rigid connection to the spinous process of a single
vertebrae with an H-shaped fiducial array attached to a center post
rigidly attached to the clamp and a mating connector at the tip of
the post for mating with a reference array, and a reference array
for use in the current invention.
[0028] FIG. 2A is a side view of FIG. 2.
[0029] FIG. 2B is another side view of FIG. 2.
[0030] FIG. 2C is a top view of FIG. 2.
[0031] FIG. 2D is an exploded view of FIG. 2 without the reference
arc.
[0032] FIG. 2E is an exploded view of the interface of the center
post and clamp of FIG. 2.
[0033] FIG. 3 is a diagram of a W-Shaped fiducial array mounted to
a central post with generally spherical fiducials attached to the
array, for mounting to a single vertebrae.
[0034] FIG. 3A is a side view of FIG. 3.
[0035] FIG. 3B is another side view of FIG. 3.
[0036] FIG. 3C is a top view of FIG. 3.
[0037] FIG. 4 is a diagram of a reference arc and fiducial attached
to a center post for use in the current invention in mounting to a
single vertebrae.
[0038] FIG. 4A is a side view of FIG. 4.
[0039] FIG. 4B is a back view of FIG. 4.
[0040] FIG. 4C is a top view of FIG. 4.
[0041] FIG. 4D is an expanded view of FIG. 4.
[0042] FIG. 4E is an expanded side view of FIG. 4.
[0043] FIG. 4F is an expanded view of the array foot and shoe of
FIG. 4E.
[0044] FIG. 5 is a diagram according to various embodiments of a
fixture using a cannulated screw for insertion into a vertebrae,
with Kirschner wire mounted on a central post and including a
fiduciary array and reference arc combined on a single
structure.
[0045] FIG. 6 is a side view of the screw and Kirschner wire
fixture of FIG. 5 implanted in a spinous process of a
vertebrae.
[0046] FIG. 7 is a diagram of a screw-head positioning probe and
multiaxial screw for insertion into a single vertebrae.
[0047] FIG. 7A is a diagram of the screw of FIG. 7.
[0048] FIG. 8 is a diagram of a head positioning probe, multiaxial
screw and spinal segment.
[0049] FIG. 9 is a diagram of a rod inserter with an LED.
[0050] FIG. 10 is a diagram of various embodiments of the teachings
including a cannulated tube and attachment for holding a reference
arc.
[0051] FIG. 11 is a diagram of the cannulated tube of FIG. 10 with
a reference arc and screw for attachment to a spinal process.
[0052] FIG. 12 is a posterior view of spinal segment and implanted
screws before alignment.
[0053] FIG. 13 is a posterior view of spinal segment and implanted
screws after alignment.
DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS
[0054] Reference will now be made in detail to various embodiments,
an example of which is illustrated in the accompanying drawings.
Wherever possible, the same reference numbers will be used
throughout the drawings to refer to the same or like parts. The
following example is intended to be purely exemplary.
[0055] As generally described in PCT/US95/12894, the entire
disclosure of which is incorporated herein by reference, a typical
surgical navigation system is shown in FIG. 1. A computer assisted
image-guided surgery system, indicated generally at 10, generates
an image for display on a monitor 106 representing the position of
one or more body elements, such as spinal elements fixedly held in
a stabilizing frame or device such as a spinal surgery frame 125
commonly used for spinal surgery. A reference arc 120 bearing
tracking means or emitters, such as for example LED emitters 122,
is mounted to the spinous process by a central post 150. The
structures 20 and K wires 260 of FIG. 1 are depicted in more detail
in FIG. 1A. The image 105 is generated from an image data set,
usually generated preoperatively by a CAT scanner or by MRI for
example, which image 105 has reference points for at least one body
element, such as a spinal element or vertebrae. The reference
points of the particular body element have a fixed spatial relation
to the particular body element.
[0056] The system includes an apparatus such as a digitizer or
other Position Sensing Unit (PSU), such as for example sensor array
110 on support 112 for identifying, during the procedure, the
relative position of each of the reference points to be displayed
by tracking the position of emitters 122 on arc 120. The system
also includes a processor 114 such as a PC or other suitable
workstation processor associated with controller 108 for modifying
the image data set according to the identified relative position of
each of the reference points during the procedure, as identified by
digitizer 110. The processor 114 can then, for example, generate an
image data set representing the position of the body elements
during the procedure for display on monitor 106. A surgical
instrument 130, such as a probe or drill or other tool, may be
included in the system, which is positioned relative to a body part
and similarly tracked by sensor array 110.
[0057] In summary, the general operation of a surgical navigating
system is well known in the art and need not further be described
here.
[0058] With further reference to FIGS. 1 through 6, a registration
device 20 is rigidly fixed to a spinal element by, for example, a
device such as a bone clamp 30 depicted in FIG. 2. Alternatively, a
screw retention device 40, such as the cannulated screw 42 depicted
in FIG. 5, and described in more detail below, can be used.
[0059] With reference now to FIG. 2, bone clamp 30 is fixedly
attached to the spinous process. The clamp 30 includes at least two
blades (or jaws) 32 with tips or teeth 34, which are preferably
sharp, for driving together and penetrating soft tissue or more
dense bone for rigid fixation to the spinous process. The teeth 34
are also preferably sized to accommodate the bulb shape of the
spinous process. The driving mechanism 40 is, for example, a screw
driven into a sleeve 41 and is also preferably located such that it
will be accessible in a percutaneous manner. Attached to the clamp
30 is a superstructure 20. The superstructure 20 includes a central
post 150 which is relocatable, that is, it fixes to the clamp 30 in
a rigid fashion, for example, as depicted in FIGS. 2D and 2E, by
being inserted into a V-shaped wedge 44 orienting the post 150
front to back and providing a mating hole 48 along the wedge 44 for
insertion of post 150 in a single orientation and also providing
fasteners such as screw 43 for tightening to lock the post 150 in
place. The post 150 can be removed and reapplied by loosening and
tightening screw 43, such that the original geometry and
orientation is maintained. The central post 150 has at its apex a
connector 60 with unique geometrical configuration, such as, for
example, a starburst, onto which a spinal reference arc 120 of the
superstructure 20 attaches. Any such standard reference arc 120 can
be used, such as depicted in FIGS. 1A, 4, and 11, preferably
including emitters 122, such as for example LEDs or reflective
spheres for providing a positive indication of movement to the
surgical navigation system during a procedure.
[0060] Also rigidly attached to the central post 150, as part of
the superstructure 20 preferably at a location closer to the skin,
or possibly collocated with or also performing the function of the
reference arc 120, is a fiducial array 170, which can be of various
different shapes, such as, for example the H-shaped frame 170
depicted in FIG. 2, the W-shaped frame 170' as depicted in FIG. 3,
the U-shaped frame 170'' as depicted in FIG. 4 or the X-shaped
frame 120', 170''' depicted in FIG. 5 (depicting a structure that
is both a fiducial array and a reference arc). As depicted in FIGS.
2 and 3, this array can include fiducial points 29 or spheres 17,
rigidly attached to fiducial array 170, 170' and is, for example,
as depicted in FIG. 3, substantially in the shape of spheres 17 and
of a material detectable by the CAT scan or MRI, preferably
titanium or aluminum. This fiducial array such as 170 indicates to
the surgical navigation system the location of the bone structure
to which the clamp 30 and central post 150 are attached by touching
a pointed surgical tracker to fiducial points 29 or a cup-shaped
probe to fiducial spheres 17, thereby indicating the center of the
fiducial to the surgical navigation controller 114. The array 170
and central post 150 are also attached to the clamp 30, as
described above, in such a way that they can be removed and
replaced in the same geometric orientation and location, for
example, by means of a uniquely shaped interface, for example, a
triangle, or a single unique shape or a combination of unique
angles or pins with the clamp 30 such that the post 150 can only be
reinserted the same way it was removed.
[0061] Additionally, the fiducial array 170, can be located at
various heights on the post 150 to accommodate variations in
patient tissue depth and size, preferably as close to the patient's
body as possible, and then fixed at that specific height by the use
of pins or indents matched to holes 19 (shown in FIG. 2) in the
central post 150 or by placing the rods 39 of H-shaped array 170 in
different holes 31. The fiducial array 170 also has, for example,
divots 29 (shown in FIG. 2) shaped to interface with an instrument
such as a surgical pointer 130 which can touch that divot 29 to
register the location of the divot 29 and, thus, the location of
the fiducial array 170 and likewise the spinal element in the
surgical navigation system. Multiple divots can be registered to
further increase accuracy of the registration system. In one
preferred embodiment of the array, the fiducials 17 or 29 can be
mounted in a manner such that they can be adjusted, for example by
mounting them on a rotatable or collapsible arm 66 (as depicted in
FIG. 3) that pivots and folds together, to get the maximum distance
between fiducials while not dramatically increasing the field of
view required at the time of scanning.
[0062] Alternatively, rather than using clamp 30, a screw 42 and
rigid wire 45 attachment, as depicted in FIGS. 5 and 6, may be used
to rigidly attach the central post of the superstructure 20 to a
body element, such as, for example, a vertebrae. As depicted in
FIG. 6, screw 42 is screwed into the spinal process of spinal
element 100. A rigid wire 45, post, or other sufficiently rigid
fastener such as for example a Kirschner wire (K-wire), is inserted
through the cannulation in the center of post 150 and the screw 42
or is otherwise fixed to the screw 42, and exits the tip of the
screw 42 at some angle, and is also implanted into the spinal
element 100 to prevent the screw 42 from rotating in either
direction.
[0063] Another embodiment for preventing the superstructure 20 from
rotating as depicted in FIGS. 10 and 11 includes the insertion of a
screw 85 through a cannulated tube 86 which has teeth 89 in the end
(or V-shaped end) that would bite into the tip of the spinous
process, preventing rotation.
[0064] Having described various embodiments of this apparatus of
the present system, a method of using this apparatus for
registering a single vertebrae will now be discussed. The operation
of a surgical navigating system is generally well known and is
described in PCT/US95/12894. According to various embodiments
method of operation, clamp 30 of FIG. 2 or screw 42 and K-Wire 45
of FIG. 5 are implanted percutaneously through a small incision in
the skin and rigidly attached to the spinal process. This
attachment occurs with the clamp 30, by driving the blades 32 of
the clamp 30 together to hold the spinous process rigidly. The
central post 150 is then rigidly fixed to the clamp 30 or screw 42
and the fiducial array 170 is rigidly fixed to the central post
150. The patient is then scanned and imaged with a CAT scan or MRI
with a field of view sufficiently large to display the spinal
anatomy and the clamp 30 or screw 42 and the fiducial array 170.
This scan is loaded into the surgical navigation system processor
104.
[0065] After scanning the patient, the array 120 and post 150 can
be removed from the patient, while leaving in place the rigidly
connected clamp 30 or screw 42. For example, as depicted in FIGS.
4D and 4E, a foot 55 located below array 170'' engages with shoe 56
and rigidly connected by screws 57 and 58. Before the surgical
procedure, the post 150, array 120 and other remaining portions of
the superstructure 20, once removed, may be sterilized. The patient
is then moved to the operating room or similar facility from, for
example, the scanning room.
[0066] Once in the operating room, the patient may be positioned in
an apparatus, such as, for example, a spinal surgery frame 125 to
help keep the spinal elements in a particular position and
relatively motionless. The superstructure 20 is then replaced on
the clamp 30 or screw 42 in a precise manner to the same relative
position to the spinal elements as it was in the earlier CAT scan
or MRI imaging. The reference arc 120 is fixed to the starburst or
other interface connector 60 on the central post 150 which is fixed
to the clamp 30 or screw 42. The operator, for example a surgeon,
then touches an instrument with a tracking emitter such as a
surgical pointer 130 with emitters 195 to the divots 29 on the
fiducial array 170 to register the location of the array 170 and,
thus, because the spinal process is fixed to the fiducial array
170, the location of the spinal element is also registered in the
surgical navigation system.
[0067] Once the superstructure 20 is placed back on the patient,
any instrument 130 fitted with tracking emitters thereon such as,
for example, a drill or screw driver, can be tracked in space
relative to the spine in the surgical navigation system without
further surgical exposure of the spine. The position of the
instrument 130 is determined by the user stepping on a foot pedal
116 to begin tracking the emitter array 190. The emitters 195
generate infrared signals to be picked up by camera digitizer array
110 and triangulated to determine the position of the instrument
130. Additionally, other methods may be employed to track reference
arcs, pointer probes, and other tracked instruments, such as with
reflective spheres, or sound or magnetic emitters, instead of
LED's. For example, reflective spheres can reflect infrared light
that is emitted from the camera array 110 back to the camera array
110. The relative position of the body part, such as the spinal
process is determined in a similar manner, through the use of
similar emitters 122 mounted on the reference frame 120 in
mechanical communication with the spinal segment. As is well known
in this art and described generally in PCT/US95/12894, based upon
the relative position of the spinal segment and the instrument 130
(such as by touching a known reference point) the computer would
illustrate a preoperative scan--such as the proper CAT scan
slice--on the screen of monitor 106 which would indicate the
position of the tool 130 and the spinal segment for the area of the
spine involved in the medical procedure.
[0068] For better access by the operator of various areas near the
central post 150, the fiducial array 170 can be removed from the
central post 150, by, for example, loosening screw 42 and sliding
the array 170 off post 150, leaving the reference arc 120 in place
or replacing it after removal of array 170. By leaving the
reference arc 120 in place, the registration of the location of the
spinal process is maintained. Additionally, the central post 150,
reference arc 120, and fiducial array 170 can be removed after the
spinal element has been registered leaving only the clamp 30 or
screw 42 in place. The entire surgical field can then be sterilized
and a sterile post 150 and reference arc 170 fixed to the clamp 30
or screw 42 with the registration maintained.
[0069] This surgical navigation system, with spinal element
registration maintained, can then be used, for example, to place
necessary and desired screws, rods, hooks, plates, wires, and other
surgical instruments and implants percutaneously, using
image-guided technology. Once the location of the spinal element
100 involved in the procedure is registered, by the process
described above, in relation to the image data set and image 105
projected on monitor 106, other instruments 130 and surgical
implants can be placed under the patient's skin at locations
indicated by the instrument 130 relative to the spinal element
100.
[0070] Additionally, the location of other spinal elements,
relative to the spinal element 100 containing the fiducial array
170, can be registered in the surgical navigation system by, for
example, inserting additional screws 250, rigid wires 260, or other
rigid implants or imageable devices into the spinal segment.
[0071] For example, as depicted in FIG. 1, and in more detail FIG.
1A, additional screws 250 or rigid and pointed wires 260 are placed
in the vertebrae adjacent to the vertebrae containing the clamp 30
and post 150 prior to scanning. On the image 105 provided by
monitor 106, the surgeon can see the clamp 30 or screw 42 and
fiducial array 170 and also the additional screws 250, wires 260 or
other imageable devices. When screws 250 or other devices are used,
these screws 250 (as depicted in FIG. 7) may contain a divot 256 or
other specially shaped interface on the head 255 so that a pointer
probe 130 can be used to point to the head 255 of the screw 250 (or
wire) and indicate the orientation of the screw 250 or wire 260 to
the surgical navigation system by communicating to the controller
114 or by emission from LEDs 195 on probe 130 to digitizer 110. The
image of these additional screws 250 also appear in the scan. Once
the patient is then moved to the operating facility, rather than
the scanning area, the image of the screw 250 can be compared to
the actual position of the screw 250 as indicated by the pointer
probe 130 that is touched to the head 255 of the screw 250 or wire
260. If necessary, the operator can manipulate the position of the
patient to move the spinal element and thus the location of the
screw 250 or wire 260 to realign the spinal elements with the
earlier image of the spine. Alternatively, the operator can
manipulate the image to correspond to the current position of the
spinal segments.
[0072] For additional positioning information, the operator can
place additional rigid wires 260 or screws 250 into the vertebrae,
for example, located at the superior (toward the patient's head)
and inferior (towards the patient's feet) ends of the spinal
process to more accurately position those vertebrae relative to the
other vertebrae and the image data. Additionally, the wires 260 and
screws 250 implanted to provide positioning information can also be
equipped with emitters, such as, for example, LEDs, to provide
additional information to the surgical navigation system on the
location of the wire 260 or screw 250, and thus the vertebra to
which they are affixed.
[0073] Alternatively, the patient can be placed in a position
stabilizing device, such as a spinal surgery frame 125 or board,
before a scan is taken, and then moved to the operating facility
for the procedure, maintaining the spine segments in the same
position from the time of scanning until the time of surgery.
Alternatively, a fluoroscope can be used to reposition the spinal
segments relative to the earlier image from the scan. An ultrasound
probe can be used to take real-time images of the spinal segment
which can be portrayed by monitor 106 overlayed or superimposed on
image 105. Then the operator can manually manipulate the spinal
elements and take additional images of these elements with the
fluoroscope to, in an iterative fashion, align the spinal elements
with the previously scanned image 105.
[0074] Alternatively, a clamp 30 or screw 42 and superstructure 20
can be rigidly fixed to each vertebra involved in the surgical or
medical procedure to register the position of each vertebra as
explained previously for a single vertebra.
[0075] After the spinal elements are registered in the spine,
various medical and surgical procedures can be performed on that
patient. For example, spinal implants, endoscopes, or biopsy probes
can be passed into the spine and procedures such as, for example,
spinal fusion, manipulation, or disc removal can be performed
percutaneously and facilitated by the surgical navigation
image-guiding system. Additionally, a radiation dose can be
targeted to a specific region of the vertebrae.
[0076] One such procedure facilitated by the apparatus and methods
described above is the percutaneous insertion of screws and rods,
fixed to different vertebra in a spine to stabilize them. Once
screws, for example multiaxial screws 250, (as depicted in FIG. 12,
before manipulation) are implanted through small incisions they can
be manipulated by a head-positioning probe 280. The final position
of screws 250 and heads 255 are depicted in FIG. 13. This probe
280, as depicted in FIG. 7, includes a head 285 that mates in a
geometrically unique fashion with the head 255 of the screw 250. An
emitter, such as, for example, an LED array 380 on the probe 280,
indicates the location and orientation of the screw head 255 to the
computer 114 of the surgical navigation system by providing an
optical signal received by digitizer 110. The screw head 255 can
then be rotatably manipulated under the patient's skin by the head
positioning probe 280 to be properly oriented for the receipt of a
rod 360 inserted through the rotating head 255. The operator can
then plan a path from the head 255 of each screw 250 to the other
screws 250 to be connected. Then, with reference now to FIG. 9, an
optically tracked rod inserter 245 also equipped with emitters,
such as, for example LEDs 247, can be placed through another small
incision to mate with and guide a rod 360 through the holes or
slots in the screw heads 245, through and beneath various tissues
of the patient, with the rod inserter 245, and, therefore, the rod
360, fixed to the inserter 245, being tracked in the surgical
navigation system. The operator can also use the computer 114 to
determine the required bending angles of the rod 360. For greater
visualization, the geometry of the screws 250 could be loaded into
the computer 114 and when the position and orientation of the head
255 is given to the computer 114 via the probe 280, the computer
114 could place this geometry onto the image data and
three-dimensional model. The rod 360 geometry could also be loaded
into the computer 114 and could be visible and shown in real time
on monitor 106 as the operator is placing it in the screw heads
255.
[0077] In an alternative procedure, one or more plates and/or one
or more wires may be inserted instead of one or more rods 360.
[0078] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present teachings
and in construction of this surgical navigation system without
departing from the scope or spirit of the teachings. Other
embodiments of the teachings will be apparent to those skilled in
the art from consideration of the specification and practice of the
teachings disclosed herein. It is intended that the specification
and examples be considered as exemplary only.
* * * * *