U.S. patent application number 17/208425 was filed with the patent office on 2021-07-08 for method for preparing a patient's tibia to receive an implant.
The applicant listed for this patent is DEPUY IRELAND UNLIMITED COMPANY. Invention is credited to Jon M. Edwards, Corinna Johanna Klawon, Jeremy Oden, Erica Roche, Matthew S. Wallace, Megan Wallace, Thomas E. Wogoman.
Application Number | 20210205098 17/208425 |
Document ID | / |
Family ID | 1000005466544 |
Filed Date | 2021-07-08 |
United States Patent
Application |
20210205098 |
Kind Code |
A1 |
Wogoman; Thomas E. ; et
al. |
July 8, 2021 |
METHOD FOR PREPARING A PATIENT'S TIBIA TO RECEIVE AN IMPLANT
Abstract
An orthopaedic surgical instrument system that includes an
orthopaedic surgical instrument adapted to be positioned on a
proximal end of a patient's tibia, and a tibial bearing trial
assembly, and a tibial evaluation component, and a tibial base
trial component configured to be coupled to the orthopaedic
surgical instrument. A tibial evaluation component includes a base
plate and a generally Y-shaped posterior buttress extending
upwardly from a superior surface of the base plate, such that the
posterior buttress of the insert component is configured to be
received in the opening of the tibial bearing trial assembly to
prevent rotation of the tibial bearing trial component relative to
the tibial base trial component.
Inventors: |
Wogoman; Thomas E.; (Warsaw,
IN) ; Edwards; Jon M.; (Warsaw, IN) ; Wallace;
Matthew S.; (Warsaw, IN) ; Oden; Jeremy;
(Huntington, IN) ; Klawon; Corinna Johanna; (San
Rafael, CA) ; Wallace; Megan; (Warsaw, IN) ;
Roche; Erica; (Warsaw, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DEPUY IRELAND UNLIMITED COMPANY |
Ringaskiddy |
|
IE |
|
|
Family ID: |
1000005466544 |
Appl. No.: |
17/208425 |
Filed: |
March 22, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16241372 |
Jan 7, 2019 |
10952874 |
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17208425 |
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14886796 |
Oct 19, 2015 |
10195056 |
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16241372 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2002/30495
20130101; A61F 2/389 20130101; A61F 2002/30607 20130101; A61F
2002/30331 20130101; A61B 17/92 20130101; A61F 2002/30616 20130101;
A61F 2/3868 20130101; A61F 2002/30492 20130101; A61B 17/846
20130101; A61F 2/4684 20130101; A61B 17/1675 20130101; A61F 2/3859
20130101; A61B 17/1604 20130101 |
International
Class: |
A61F 2/46 20060101
A61F002/46; A61B 17/16 20060101 A61B017/16; A61B 17/84 20060101
A61B017/84; A61B 17/92 20060101 A61B017/92 |
Claims
1. An orthopaedic surgical instrument system for use during a
surgical procedure to implant an orthopaedic knee prosthesis,
comprising: a tibial trial component adapted to be positioned on a
surgically-prepared proximal end of a patient's tibia, the tibial
trial component having a base plate, and a generally Y-shaped
posterior buttress extending upwardly from a superior surface of
the base plate, and a bearing trial component having an inner
sidewall that defines an opening therein, wherein the posterior
buttress of the tibial trial component is configured to be received
in the opening of the bearing trial component to prevent rotation
of the bearing trial component relative to the tibial trial
component.
2. The orthopaedic surgical instrument system of claim 1, wherein
the posterior buttress includes a post positioned adjacent to a
posterior edge of the base plate and a pair of arms extending
posteriorly from the post and outwardly from the posterior edge of
the base plate.
3. The orthopaedic surgical instrument system of claim 2, wherein:
the pair of arms includes a first arm and a second arm, and a first
imaginary line extends along a lateral-most edge of the first arm
of the posterior buttress, a second imaginary line extends along a
medial-most edge of the second arm of the posterior buttress and
intersects the first imaginary line to define an angle of
intersection therebetween, the angle of intersection being between
45-145.degree..
4. The orthopaedic surgical instrument system of claim 1, wherein
the tibial trial component further comprises an anterior buttress
extending outwardly from an anterior edge of the base plate.
5. The orthopaedic surgical instrument system of claim 4, wherein
the anterior buttress includes (i) a pair of arms extending
anteriorly from the anterior edge of the base plate and (ii) a tab
extending superiorly from an anterior end of each arm.
6. An orthopaedic surgical instrument system for use during a
surgical procedure to implant an orthopaedic knee prosthesis,
comprising: a tibial trial component adapted to be positioned on a
surgically-prepared proximal end of a patient's tibia, the tibial
trial component having a base plate, and a generally Y-shaped
posterior buttress extending upwardly from a superior surface of
the base plate, and a bearing trial component having an inner
sidewall that defines an opening therein, wherein the posterior
buttress of the tibial trial component (i) is configured to be
received in the opening of the bearing trial component to prevent
rotation of the bearing trial component relative to the tibial
trial component, and (ii) includes a post positioned adjacent to a
posterior edge of the base plate and a pair of arms extending
posteriorly from the post and outwardly from the posterior edge of
the base plate.
7. The orthopaedic surgical instrument system of claim 6, wherein
the tibial trial component further comprises an anterior buttress
extending outwardly from an anterior edge of the base plate.
8. The orthopaedic surgical instrument system of claim 7, wherein
the anterior buttress includes (i) a pair of arms extending
anteriorly from the anterior edge of the base plate and (ii) a tab
extending superiorly from an anterior end of each arm.
9. The orthopaedic surgical instrument system of claim 7, wherein:
the pair of arms includes a first arm and a second arm, and a first
imaginary line extends along a lateral-most edge of the first arm
of the posterior buttress, a second imaginary line extends along a
medial-most edge of the second arm of the posterior buttress and
intersects the first imaginary line to define an angle of
intersection therebetween, the angle of intersection being between
45-145.degree..
Description
[0001] This continuation application claims priority to U.S. patent
application Ser. No. 16/241,372, now U.S. Pat. No. 10,952,874,
which claims priority to U.S. patent application Ser. No.
14/886,796, now U.S. Pat. No. 10,195,056, the entirety of each of
which is expressly incorporated herein by reference.
CROSS-REFERENCE
[0002] Cross-reference is made to co-pending U.S. patent
application Ser. No. 14/886,923 entitled "SURGICAL INSTRUMENTS FOR
PREPARING A PATIENT'S TIBIA TO RECEIVE AN IMPLANT" by Thomas E.
Wogoman et al. and filed on Oct. 19, 2015, U.S. patent application
Ser. No. 13/530,771, now U.S. Pat. No. 8,986,390, entitled "SYSTEM
AND METHOD FOR TRIALING A KNEE PROSTHESIS" by Thomas E. Wogoman et
al. and filed on Jun. 22, 2012, U.S. patent application Ser. No.
13/530,662, now U.S. Pat. No. 8,951,301, entitled "METHOD OF USING
A TRIALING SYSTEM FOR A KNEE PROSTHESIS" by Thomas E. Wogoman et
al. and filed on Jun. 22, 2012, U.S. patent application Ser. No.
13/530,649, now U.S. Pat. No. 8,968,412, entitled "TRIALING SYSTEM
FOR A KNEE PROSTHESIS AND METHOD OF USE" by Thomas E. Wogoman et
al. and filed on Jun. 22, 2012, and U.S. patent application Ser.
No. 14/265,960, now U.S. Pat. No. 9,861,491, entitled "TIBIAL TRIAL
SYSTEM FOR A KNEE PROSTHESIS" by David Waite et al. and filed on
Apr. 30, 2014, each of which is hereby incorporated by
reference.
TECHNICAL FIELD
[0003] The present disclosure relates generally to orthopaedic
surgical instruments and, more particularly, to surgical
instruments used with a patient's tibia.
BACKGROUND
[0004] Joint arthroplasty is a well-known surgical procedure by
which a diseased and/or damaged natural joint is replaced by a
prosthetic joint. A typical knee prosthesis includes a patella
prosthetic component, a tibial tray, a femoral component, and a
polymer insert or bearing positioned between the tibial tray and
the femoral component. Femoral components are designed to be
attached to a surgically-prepared distal end of a patient's femur.
Tibial trays are designed to be attached to a surgically-prepared
proximal end of a patient's tibia.
[0005] To facilitate the replacement of the natural joint with the
knee prosthesis, orthopaedic surgeons use a variety of orthopaedic
surgical instruments such as, for example, prosthetic trial
components, cutting blocks, drill guides, milling guides, and other
surgical instruments. Prosthetic trial components, such as, for
example, a femoral trial component and a tibial bearing trial
component, are used to size and select the components of the knee
prosthesis that will replace the patient's natural joint. A
procedure that utilizes the trial components to size and select the
components of the knee prosthesis is often referred to as a trial
reduction.
SUMMARY
[0006] According to one aspect of the disclosure, an orthopaedic
surgical instrument system for use during a surgical procedure to
implant an orthopaedic knee prosthesis is disclosed. The system
includes a tibial base trial component adapted to be positioned on
a surgically-prepared proximal end of a patient's tibia, an insert
component shaped to be received in an opening defined in the tibial
base trial component, and a tibial bearing trial component having
an inner sidewall that defines an opening therein. The insert
component comprises a base plate and a generally Y-shaped posterior
buttress extending upwardly from a superior surface of the base
plate. The posterior buttress of the insert component is configured
to be received in the opening of the tibial bearing trial component
to prevent rotation of the tibial bearing trial component relative
to the tibial base trial component.
[0007] In some embodiments, the posterior buttress may include a
post positioned adjacent to a posterior edge of the base plate and
a pair of arms extending posteriorly from the post and outwardly
from the posterior edge of the base plate.
[0008] In some embodiments, the pair of arms may include a first
arm and a second arm. A first imaginary line may extend along a
lateral-most edge of the first arm of the posterior buttress. A
second imaginary line may extend along a medial-most edge of the
second arm of the posterior buttress and intersect the first
imaginary line to define an angle of intersection therebetween. The
angle of intersection may be between 45-145.degree..
[0009] Additionally, in some embodiments, the insert component may
further comprise an anterior buttress extending outwardly from an
anterior edge of the base plate. The anterior buttress may include
a pair of arms extending anteriorly from the anterior edge of the
base plate and a tab extending superiorly from an anterior end of
each arm.
[0010] In some embodiments, the system may include a retention
mechanism to secure the insert component to the tibial base trial
component. The retention mechanism may comprise an annular rim
extending outwardly from the base plate of the insert component,
and a groove defined in the tibial base trial component sized to
receive the annular rim of the insert component.
[0011] In some embodiments, the insert component may include a
first prong extending medially from the base plate and a second
prong extending laterally from the base plate. Additionally, in
some embodiments, the insert component may include a keel
configured to extend inferiorly and outwardly from the opening in
the tibial base trial component when the insert component is
received in the opening defined in the tibial base trial
component.
[0012] In some embodiments, the tibial base trial component may
include an inferior surface positioned opposite the superior
surface. The opening in the tibial base trial component may be
defined by an inner wall extending inwardly from the superior
surface to a shelf surface positioned between the superior surface
and the inferior surface. A number of fixation pinholes may extend
through a posterior section of the shelf surface and the inferior
surface.
[0013] In some embodiments, the system may also comprise a fixation
pin including a head including an inferior surface configured to
engage the posterior section of the shelf surface and a superior
surface positioned opposite the inferior surface. The fixation pin
may also include a shaft extending from the inferior surface of the
head that is sized to extend inferiorly from at least one of the
fixation pinholes defined in the tibial base trial component. When
the inferior surface of the head of the fixation pin is engaged
with the posterior section of the shelf surface, the superior
surface of the head of the fixation pin may be configured to be
positioned at or below an imaginary plane defined by the superior
surface of the tibial base trial component.
[0014] In some embodiments, the system may comprise a pin
extraction tool comprising a stationary member, a pivoting member
pivotally coupled to the handle, and a receiving end including a
first jaw extending from the stationary member and a second jaw
extending from the pivoting member. The first jaw and the second
jaw may be configured to engage the head of the fixation pin. The
pivoting member is pivotable between a closed position in which the
first jaw and the second jaw define a pocket sized to retain the
head of the fixation pin, and an open position in which the first
jaw and the second jaw are spaced apart to permit the head of the
fixation pin to be disengaged from the first jaw and the second
jaw.
[0015] In some embodiments, the insert component may be a first
insert component. The system may further comprise a second insert
component configured to be separately received in the opening
defined in the tibial base trial component in place of the first
insert component. The second insert component may have a central
post, and a superior surface of the central post may have a ramp
surface defined therein. The ramp surface may incline superiorly in
an anterior-to-posterior direction.
[0016] According to another aspect, an orthopaedic surgical
instrument system for use during a surgical procedure to implant an
orthopaedic knee prosthesis comprises a tibial base trial component
including a superior surface, an inferior surface positioned
opposite the superior surface that is adapted to be positioned on a
surgically-prepared proximal end of a patient's tibia, an opening
being defined by an inner wall extending inwardly from the superior
surface to a shelf surface positioned between the superior surface
and the inferior surface, and a number of fixation pinholes
extending through a posterior section of the shelf surface and the
inferior surface of the tibial base trial component. The system
also comprises an insert component shaped to be received in the
opening defined in the tibial base trial component, and a tibial
bearing trial component having an inner sidewall that defines an
opening therein. The insert component comprises a base plate and a
posterior buttress extending upwardly from a superior surface of
the base plate. The posterior buttress of the insert component is
configured to be received in the opening of the tibial bearing
trial component to prevent rotation of the tibial bearing trial
component relative to the tibial base trial component.
[0017] In some embodiments, the insert component may further
comprise an anterior buttress extending outwardly from an anterior
edge of the base plate. Additionally, in some embodiments, the
anterior buttress of the insert component may include a pair of
arms extending anteriorly from the anterior edge of the base plate
and a tab extending superiorly from an anterior end of each
arm.
[0018] In some embodiments, the insert component may be a first
insert component of a plurality of insert components. Each insert
component may be shaped to be separately received in the opening
defined in the tibial base trial component. A number of the insert
components may include a base plate and a keel extending inferiorly
from the base plate. Additionally, in some embodiments, the keel
may include a pair of spikes extending inferiorly from the base
plate.
[0019] According to another aspect, an orthopaedic surgical
instrument system comprises a tibial base trial component including
a superior surface, an inferior surface positioned opposite the
superior surface that is adapted to be positioned on a
surgically-prepared proximal end of a patient's tibia, an opening
being defined by an inner wall extending inwardly from the superior
surface to a shelf surface positioned between the superior surface
and the inferior surface, and a fixation pinhole extending through
a posterior section of the shelf surface and the inferior surface
of the tibial base trial component. The system also comprises a
fixation pin including a head and a shaft extending inferiorly from
the head that is sized to be received in the fixation pinhole of
the tibial base trial component, an insert component shaped to be
received in the opening defined in the tibial base trial component,
and a tibial bearing trial component adapted to be positioned on
the insert component. The head of the fixation pin is sized to be
at or below the superior surface of the tibial base trial component
when the head is engaged with the shelf surface.
[0020] In some embodiments, the system may further comprise a
surgical instrument including a pair of jaws configured to
selectively engage the head of the fixation pin, the pair of jaws
comprising a first jaw including a semi-circular flange and a
second jaw including an arced flange extending less than 180
degrees.
[0021] According to another aspect of the disclosure, a method of
trialing prosthetic components of a knee prosthesis is disclosed.
The method comprises positioning a tibial base trial component on a
surgically-prepared proximal end of a patient's tibia, positioning
a femoral trial component on a surgically-prepared distal end of a
patient's femur, inserting an insert component into an opening
defined in the tibial base trial component, advancing a first
fixation pin into a posterior fixation pinhole defined in the
tibial base trial component, positioning a tibial bearing trial
component over the insert component, between the tibial base trial
component and the femoral trial component, and moving the patient's
tibia between extension and flexion with the femoral trial
component engaged with the tibial bearing trial component such that
the tibial base trial component rotates on the proximal end of the
patient's tibia about the first fixation pin. The method also
comprises advancing a second fixation pin into an anterior fixation
pinhole of the tibial base trial component to prevent rotation of
the tibial base trial component.
[0022] In some embodiments, positioning the tibial bearing trial
component over the insert component may include advancing the
tibial bearing trial component in a posterior direction into a gap
defined between the tibial base trial component and the femoral
trial component.
[0023] Additionally, in some embodiments, positioning the tibial
bearing trial component over the insert component may further
include securing the tibial bearing trial component to the insert
component to prevent relative movement between the tibial bearing
trial component and the tibial base trial component.
[0024] In some embodiments, securing the tibial bearing trial
component to the insert component may include engaging the tibial
bearing trial component with a posterior buttress of the insert
component. The posterior buttress may include a post sized be
received in an opening defined in the tibial bearing trial
component and a pair of arms extending posteriorly from the
post.
[0025] In some embodiments, securing the tibial bearing trial
component to the insert component may further include engaging the
tibial bearing trial component with an anterior buttress of the
insert component.
[0026] Additionally, in some embodiments, advancing the first
fixation pin into the posterior fixation pinhole may include
positioning a head of the first fixation pin at or below a superior
surface of the tibial bearing trial component, and positioning the
tibial bearing trial component over the insert component may
include engaging the tibial bearing trial component with the
superior surface of the tibial bearing trial component.
[0027] In some embodiments, the method may also comprise selecting
the insert component from a plurality of insert components. The
plurality of insert components may include a first insert component
configured to permit the tibial bearing trial component to rotate
relative to the insert component and a second insert component
configured to prevent the tibial bearing trial component from
rotating relative to the insert component.
[0028] Additionally, in some embodiments, the method may also
comprise inserting a keel punch into the patient's tibia after
advancing the second fixation pin into the anterior fixation
pinhole to define a surgically-prepared opening.
[0029] According to another aspect, a method of surgically
preparing a patient's bone to receive a knee prosthesis comprises
positioning a tibial base trial component on a surgically-prepared
proximal end of a patient's tibia, positioning a femoral trial
component on a surgically-prepared distal end of a patient's femur,
inserting an insert component into an opening defined in the tibial
base trial component, advancing a tibial bearing trial component in
a posterior direction into a gap defined between the tibial base
trial component and the femoral trial component, and securing the
tibial bearing trial component to the insert component to prevent
relative movement between the tibial bearing trial component and
the tibial base trial component by engaging the tibial bearing
trial component with a posterior buttress of the insert component
that includes a post sized be received in an opening defined in the
tibial bearing trial component and a pair of arms extending
posteriorly from the post.
[0030] In some embodiments, securing the tibial bearing trial
component to the insert component may further include engaging the
tibial bearing trial component with an anterior buttress of the
insert component. Additionally, inserting the insert component into
the opening defined in the tibial base trial component may include
inserting a keel of the insert component through the opening
defined in the tibial base trial component and into the
surgically-prepared proximal end of the patient's tibia.
[0031] In some embodiments, the method may include moving the
patient's tibia between extension and flexion with the femoral
trial component engaged with the tibial bearing trial component
such that the tibial base trial component rotates on the proximal
end of the patient's tibia. The method may further include
advancing a fixation pin into a posterior fixation pinhole defined
in the tibial base trial component. The tibial base trial component
may rotate on the proximal end of the patient's tibia about the
fixation pin as the patient's tibia is moved between extension and
flexion.
[0032] In some embodiments, the method may include advancing a
second fixation pin into an anterior fixation pinhole of the tibial
base trial component to prevent rotation of the tibial base trial
component.
[0033] Additionally, in some embodiments, the method may include
removing the insert component from the tibial base trial component
after advancing the second fixation pin into the anterior fixation
pinhole, and inserting a keel punch into the patient's tibia to
define a surgically-prepared opening.
[0034] In some embodiments, inserting the insert component into an
opening defined in the tibial base trial component may include
engaging a retention ring of the insert component with the tibial
base trial component.
[0035] According to another aspect, a method of surgically
preparing a patient's bone to receive a knee prosthesis comprises
selecting a tibial bearing trial component, and selecting an insert
component from a plurality of insert components. The plurality of
insert components includes a first insert component configured to
permit the tibial bearing trial component to rotate relative to the
insert component and a second insert component configured to
prevent the tibial bearing trial component from rotating relative
to the insert component. The method further comprises positioning a
tibial base trial component on a surgically-prepared proximal end
of a patient's tibia and advancing the tibial bearing trial
component in a posterior direction to position the tibial bearing
trial component over the selected insert component. When the
selected insert component is the first insert component, the method
includes moving the patient's tibia between extension and flexion
such that the tibial bearing trial component rotates on the tibial
base trial component. When the selected insert component is the
second insert component, the method includes advancing a first
fixation pin into a posterior fixation pinhole defined in the
tibial base trial component, and moving the patient's tibia between
extension and flexion such that the tibial base trial component
rotates on the proximal end of the patient's tibia about the first
fixation pin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The detailed description particularly refers to the
following figures, in which:
[0037] FIG. 1 is an exploded perspective view of an orthopaedic
surgical instrument system;
[0038] FIG. 2 is an exploded perspective view of a tibial base
trial component, a number of tibial evaluation components, and a
number of tibial bearing trial components of the orthopaedic
surgical instrument system of FIG. 1;
[0039] FIG. 3 is a perspective view of a tibial base trial
component of the orthopaedic surgical instrument system of FIGS. 1
and 2;
[0040] FIG. 4 is a top plan view of the tibial base trial component
of FIG. 3;
[0041] FIG. 5 is a perspective view of one of the tibial evaluation
components of FIG. 2;
[0042] FIG. 6 is a perspective view of another tibial evaluation
component of FIG. 2;
[0043] FIG. 7 is a perspective view of another tibial evaluation
component of FIG. 2;
[0044] FIG. 8 is a top plan view of the tibial evaluation component
of FIG. 7;
[0045] FIG. 9 is a bottom view of the tibial evaluation component
of FIG. 7;
[0046] FIG. 10 is a perspective view of another tibial evaluation
component of FIG. 2;
[0047] FIG. 11 is a top plan view of the tibial evaluation
component of FIG. 10;
[0048] FIG. 12 is a perspective view of a posterior fixation pin
and an anterior fixation pin;
[0049] FIG. 13 is a perspective view of one of the fixation pin and
a pin extraction tool of the orthopaedic surgical instrument system
of FIG. 1;
[0050] FIG. 14 is a front elevation view showing the pin extraction
tool of FIG. 11 in a closed position;
[0051] FIG. 15 is a view similar to FIG. 12 showing the pin
extraction tool in an open position; and
[0052] FIGS. 16-22 is views of a patient's femur, tibia, and the
orthopaedic surgical instrument system of FIG. 1 as the orthopaedic
surgical instrument system is used in the performance of a surgical
procedure to implant a knee prosthesis.
DETAILED DESCRIPTION OF THE DRAWINGS
[0053] While the concepts of the present disclosure are susceptible
to various modifications and alternative forms, specific exemplary
embodiments thereof have been shown by way of example in the
drawings and will herein be described in detail. It should be
understood, however, that there is no intent to limit the concepts
of the present disclosure to the particular forms disclosed, but on
the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention as defined by the appended claims.
[0054] Terms representing anatomical references, such as anterior,
posterior, medial, lateral, superior, inferior, etcetera, may be
used throughout the specification in reference to the orthopaedic
implants and surgical instruments described herein as well as in
reference to the patient's natural anatomy. Such terms have
well-understood meanings in both the study of anatomy and the field
of orthopaedics. Use of such anatomical reference terms in the
written description and claims is intended to be consistent with
their well-understood meanings unless noted otherwise.
[0055] Referring to FIGS. 1-15, an orthopaedic surgical instrument
system 10 (hereinafter system 10) is shown. The system 10 is used
during joint arthroplasty procedures, such as a total knee
replacement procedure. It should be appreciated, however, that
although the system 10 is described below in regard to the
performance of a total knee replacement procedure, certain concepts
associated with the system 10 may be utilized in replacement
procedures of numerous other joints throughout the body.
[0056] As shown in FIGS. 1-2, the system 10 has a number of trial
components 12, including a tibial base trial component 14, a number
of insert components 16, a number of tibial bearing trial
components 18, and a femoral trial component 20. In the
illustrative embodiment, the system 10 also includes a number of
fixation pins 250, a tibial keel punch 374, and a number of other
surgical tools, such as, for example, an alignment handle (not
shown), an impaction handle 372, and a fixation pin extraction tool
300, which are used to manipulate the trial components 12, the
fixation pins 250, and the other surgical instruments during the
performance of an orthopaedic surgical procedure, as described in
greater detail below.
[0057] The system 10 may be utilized to size and select the
prosthetic components of a knee prosthesis that will replace the
patient's natural joint. To do so, the femoral trial component 20
is attached to a surgically-prepared distal end 406 of a patient's
femur 404 (see FIGS. 18-20), whereas the tibial base trial
component 14 is attached to a surgically-prepared proximal end 402
of a patient's tibia 400 (see FIGS. 18-20). As shown in FIG. 1, one
of the insert components 16 may be positioned in the tibial base
trial component 14. Further, one of the tibial bearing trial
components 18 may be positioned between the femoral trial component
20 and the tibial base trial component 14. As described in greater
detail below, the surgeon uses the system 10 during a surgical
procedure in, for example, a trial reduction process, to determine
the type and configuration of each of the various types of
prosthetic components that are to be implanted and to surgically
prepare the proximal end 402 of a patient's tibia 400 for
implantation of a tibial prosthetic component.
[0058] Referring to FIG. 2, a number of tibial bearing trial
components 18 of the system 10 are shown. In the illustrative
embodiment, each tibial bearing trial component 18 is a multi-piece
assembly that is configured to assist the surgeon in selecting a
size and configuration of a prosthetic tibial bearing component of
the knee prosthesis, as described in greater detail below. In other
embodiments, each tibial bearing trial component 18 may be a
unitary solid piece. The tibial bearing trial components 18 may
include fixed tibial bearing trial components or mobile tibial
bearing trial components of different sizes for different patients.
An exemplary fixed tibial bearing trial component is shown on the
left in FIG. 2. The term "fixed tibial bearing trial component" as
used herein refers to the tibial bearing trial component 18 that is
fixed in position relative to the tibial base trial component 14
when it is attached to a tibial base trial component 14. In other
words, a fixed tibial bearing trial component is configured to not
substantially rotate or move in the anterior-posterior direction or
medial-lateral direction relative to the tibial base trial
component 14. Such a fixed bearing trial component 18 may be
embodied as a cruciate retaining trial, a posterior stabilized
trial, a revision trial, or other surface trial configuration, per
the surgeon's preference.
[0059] An exemplary mobile tibial bearing trial component is shown
on the right in FIG. 2. The term "mobile tibial bearing trial
component" as used herein refers to a tibial bearing trial
component 18 that is permitted to rotate relative to the tibial
base trial component 14 when it is attached a tibial base trial
component 14. In other words, a mobile tibial bearing trial
component is configured to substantially rotate or move in the
anterior-posterior direction or the medial-lateral direction
relative to the tibial base trial component 14. The mobile bearing
trial component 18 may be embodied as a cruciate retaining trial, a
posterior stabilized trial, a revision trial, or other surface
trial configuration, per the surgeon's preference.
[0060] Regardless of the type of the tibial bearing trial component
18, the same tibial base trial component 14 may be attached to the
surgically-prepared proximal end 402 of a patient's tibia 400. It
should be appreciated that the tibial base trial component 14, like
the other trial components 18, 20, may be formed in a number of
different sizes to accommodate bones of various sizes. As shown in
FIGS. 3-4, the tibial base trial component 14 includes a plate 22
having a superior surface 24, an inferior surface 26, and an outer
sidewall 28 extending between the surfaces 24, 26. The plate 22
includes a plate opening 30 defined in the superior surface 24. The
plate opening 30 has a central opening 40 and a pair of elongated
openings 42 extending laterally and outwardly from the central
opening 40. An inner wall 44 extends downwardly from the plate
opening 30 to define a passageway 46 through the plate 22. The
inner wall 44 includes an upper wall 48 and a lower wall 50 that is
offset or otherwise spaced inwardly from the upper wall 48. The
upper wall 48 and the lower wall 50 cooperate to define a shelf
surface 54 positioned between the inferior surface 26 and the
superior surface 24. As will be discussed in greater detail below,
the configuration of the passageway 46 permits the advancement of
various surgical drills, punches, and other instruments into the
proximal end 402 of the patient's tibia 400.
[0061] The upper wall 48 of the plate 22 defines a number of slots
60 that are positioned in an anterior aspect 62 and a posterior
aspect 64 of the plate 22. As shown in FIGS. 3-4, the slots 60
include a pair of anterior slots 66 that are positioned on each
side of a lever-receiving notch 68 defined in the outer sidewall 28
of the plate 22. A pair of posterior slots 70 are positioned
adjacent to each of the elongated openings 42. In the illustrative
embodiment, all slots 60 extend downwardly from the plate opening
30 to the shelf surface 54.
[0062] As shown in FIGS. 3-4, the plate 22 of the tibial base trial
component 14 further includes a pair of posterior fixation pinholes
80 and a pair of anterior fixation pinholes 82 that receive
corresponding fixation pins 250 to secure the tibial base trial
component 14 to the patient's tibia 400. The posterior fixation
pinholes 80 have the same shape as the anterior fixation pinholes
82 but are uniquely sized. In the illustrative embodiment, each
posterior fixation pinhole 80 has a matching diameter, but each
anterior fixation pinhole 82 has a diameter that is greater than
the diameters of the posterior fixation pinholes 80 to prevent the
surgeon from inserting the wrong fixation pin 250, as described in
greater detail below. It should be appreciated that in other
embodiments the fixation pinholes 80, 82 may have rectangular,
square, triangular, or other geometric shape. Additionally,
although the fixation pinholes 80, 82 have the same shape in the
illustrative embodiment, it should be appreciated that in other
embodiments each opening may have a unique shape.
[0063] In the illustrative embodiment, the pair of posterior
fixation pinholes 80 is defined in the posterior aspect 64 of the
tibial base trial component 14 in a section of the shelf surface
54. Each posterior fixation pinhole 80 extends downwardly from an
opening defined in the shelf surface 54 through the inferior
surface 26 of the plate 22 to permit a fixation pin to advance into
a patient's bone. In the illustrative embodiment, each posterior
fixation pinhole 80 includes a pinhole upper wall 84 and a pinhole
lower wall 86. The pinhole upper wall 84 extends downwardly from
the shelf surface 54 to a pinhole shelf surface 88. The pinhole
lower wall 86 extends downwardly from the pinhole shelf surface 88
to the inferior surface 26 of the plate 22 of the tibial base trial
component 14. As shown in FIGS. 3-4, each posterior fixation
pinhole 80 has a longitudinal axis 90 extending perpendicular to
the superior surface 24.
[0064] The pair of anterior fixation pinholes 82 are defined in a
pair of anterior tabs 100 extending anteriorly from the plate 22 of
the tibial base trial component 14. As shown in FIGS. 3-4, one tab
100 is positioned on each side of the lever-receiving notch 68.
Each anterior tab 100 has a superior inclined surface 102 that is
angled relative to the substantially planar superior surface 24 and
substantially planar inferior surface 26. Each anterior fixation
pinhole 82 is defined in the center of the inclined surface 102 by
an inner sidewall 104 that extends downwardly from the inclined
surface 102 of each anterior tab 100 to an inferior surface 106.
Each anterior fixation pinhole 82 has a longitudinal axis 108 that
extends perpendicular to the inclined surface 102 and at an angle
relative to the axes 90 of the posterior fixation pinholes 80. As
shown in FIG. 4, the axes 108 of each anterior fixation pinhole 82
are angled relative to each other. In that way, a fixation pin
positioned in either anterior fixation pinhole 82 is engaged with
the proximal end 402 of the patient's tibia 400 at an oblique
angle, as will be described in detail below.
[0065] Returning to FIG. 2, the system 10 includes a number of
insert components 16 of the system 10, which are selected according
based on the type of the tibial bearing trial component 18 selected
for a particular patient. Specific exemplary insert components 16
are shown and described in detail in FIGS. 5-11, as will be
described in greater detail below. Generally, the insert component
16 is embodied as a tibial evaluation component or "evaluation
bullet." Each tibial evaluation component 16 is configured to be
positioned separately in the plate opening 30 of the tibial base
trial component 14. Each tibial evaluation component 16 has a base
plate 120 having a central platform 122 and a pair of prongs 124
that extend outwardly from the central platform 122. A post 126
extends upwardly from the central platform 122 of each tibial
evaluation component 16.
[0066] As shown in FIG. 2, the tibial evaluation components 16
include a pair of mobile bearing evaluation components 132, 134,
which may be used with the mobile tibial bearing trial component,
and a pair of the fixed bearing evaluation components 136, 138,
which may be used with the fixed tibial bearing trial component. As
shown in detail in FIG. 5, the mobile bearing evaluation component
132 includes a pair of mounting spikes 140 that extend downwardly
from the prongs 124. Each spike 140 includes an upper cylindrical
section 142 and a pointed conical tip 144 configured to engage the
proximal end 402 of the patient's tibia 400, thereby temporarily
securing the tibial evaluation component 132 and the tibial base
trial component 14 to the proximal end 402 of the patient's tibia
400. In that way, the assembly formed by the components 14, 132 may
be prevented from moving relative to the patient's tibia. The post
126 of the mobile bearing evaluation component 132 includes a
connector 148 that is formed in its superior end. The connector 148
is configured to receive a locking flange associated with an
impaction handle 372 so as to secure the tibial evaluation
component 16 to the impaction handle 372. The connector 148
includes a flange 150 that extends anteriorly away from the
longitudinal axis of the post 126. The flange 150 has a ramp
surface 152 defined therein. In particular, an inferior surface 154
of the flange 150 extends substantially parallel to a superior
surface 156 of the tibial evaluation component's base plate 120,
whereas the flange's superior surface 158 inclines superiorly in
the anterior-to-posterior direction. The ramp surface 152
facilitates installation of the tibial bearing trial assembly and
is further described in co-pending U.S. patent application Ser. No.
14/265,960, entitled "TIBIAL TRIAL SYSTEM FOR A KNEE PROSTHESIS" by
David Waite et al. and filed on Apr. 30, 2014, which is
incorporated herein by reference.
[0067] Referring now to FIG. 6, another mobile evaluation component
134 is shown. The evaluation component 134 shares many common
features with the tibial evaluation component 132, and the same
reference numbers will be used to describe those common features.
Additionally, the component 134, like the other evaluation
components 16, includes a base plate 120 having a central platform
122 and a pair of prongs 124 that extend outwardly from the central
platform 122. A post 126 extends upwardly from the central platform
122 of each tibial evaluation component 16 and, like the other
mobile evaluation component 132, also includes a connector 148 that
is formed in its superior end. The connector 148 is configured to
receive a locking flange associated with the impaction handle 372.
The connector 148 includes a flange 150 that extends anteriorly
away from the longitudinal axis of the post 126. The flange 150 has
a ramp surface 152 defined therein. In particular, an inferior
surface 154 of the flange 150 extends substantially parallel to a
superior surface 156 of the tibial evaluation component's base
plate 120, whereas the flange's superior surface 158 inclines
superiorly in the anterior-to-posterior direction.
[0068] The mobile evaluation component 134 also includes a sleeve
160 that extends downwardly from the central platform 122 and the
prongs 124. The sleeve 160 includes a central stem 162 sized to be
received in the central opening 40 of the tibial base trial
component 14. The sleeve 160 further includes a pair of prongs 164
that extend outwardly from the central stem 162, which are sized to
be received in the elongated openings 42 of the tibial base trial
component 14. As described in greater detail below, the sleeve 160
is sized to extend through the tibial base trial component 14 and
into a surgically-prepared opening in the patient's tibia and
thereby prevent the components 14, 134 from rotating on the
patient's tibia.
[0069] Returning to FIG. 2, the tibial evaluation components 16
also include the pair of fixed bearing elevation components 136,
138. Each of the evaluation components 136, 138 has a base plate
120 having a central platform 122 and a pair of prongs 124 that
extend outwardly from the central platform 122. A post 126 extends
upwardly from the central platform 122 of each tibial evaluation
component 16. In the illustrative embodiment, the post 126 of each
of the evaluation components 136, 138 is included in a posterior
buttress 170. In addition to the post 126, each posterior buttress
170 includes a pair of arms 172, 174 that extend posteriorly from
the post 126 to cantilevered tips 176, 178. Each of the evaluation
components 136, 138 also includes an anterior buttress 180. As
described in greater detail below, the buttresses 170, 180
cooperate to prevent rotation and movement of the fixed bearing
trial component 18 relative to the tibial base trial component
14.
[0070] Referring now to FIGS. 7-9, the fixed evaluation component
136 is illustratively spikeless. As a result, when the fixed
evaluation component 136 is attached to the tibial base trial
component 14 on a patient's tibia, the assembly is permitted move
relative to the patient's tibia unless restrained by a fixation pin
250. As described above, the evaluation component 136 includes a
base plate 120 that has a superior surface 182 and an inferior
surface 184 positioned opposite the superior surface. An aperture
186 extends through the surfaces 182, 184 in the central platform
122 of the base plate 120. In the illustrative embodiment, the
aperture 186 is sized to receive a tip (not shown) of a removal
tool to detach the evaluation component 136 from the tibial base
trial component 14.
[0071] As described above, the evaluation component 136 also has a
posterior buttress 170 that includes a post 126 and a pair of arms
172, 174 extending posteriorly from the post 126 to cantilevered
tips 176, 178, respectively. As shown in FIG. 7, the post 126 is
positioned on the posterior edge 188 of the base plate 120. The arm
172 defines a lateral-most sidewall 190 of the posterior buttress
170, which extends along a straight imaginary line 192. The other
arm 174 defines a medial-most sidewall 194 of the posterior
buttress 170, which extends along another straight imaginary line
196. As shown in FIG. 8, the pair of arms 172, 174 are positioned
such that the imaginary line 192 intersects the other imaginary
line 196 to define an angle .alpha.. In the illustrative
embodiment, the angle .alpha. may have a magnitude of between 45
and 145 degrees, thereby giving the posterior buttress 170 a
generally Y-shape.
[0072] As described above, the evaluation component 136 also
includes an anterior buttress 180. As shown in FIGS. 7-8, the
anterior buttress 180 includes a pair of arms 200, 202, which
extend anteriorly from the anterior edge 204 of the base plate 120
to cantilevered end 206, 208, respectively. Each arm 200, 202 has a
tab 210 that extends superiorly from the respective ends 206, 208
of the arms 200, 202. In the illustrative embodiment, the tabs 210,
post 126, and arms 172, 174 cooperate to define a retention
mechanism that engages a fixed bearing trial component 18 and
prevents rotation and movement of the fixed bearing trial component
18 relative to the tibial base trial component 14.
[0073] Referring now to FIG. 9, the base plate 120 of the tibial
evaluation component 126 further includes an attachment mechanism
220 to secure the evaluation component 126 to the tibial base trial
component 14. In the illustrative embodiment, the attachment
mechanism 220 includes a retention ring 222 and a pair of blocks
224 extending downwardly from the base plate 120. The retention
ring 222 extends from the inferior surface 184 of the central
platform 122, and each of the blocks 224 is positioned on the
inferior surface 184 of each prong 124. When the tibial evaluation
component 136 is seated on the tibial base trial component 14, the
central platform 122 of the tibial evaluation component 126 is
received in the central opening 40 of the tibial base trial
component 14, and the prongs 124 are received in the elongated
openings 42 of the tibial base trial component 14.
[0074] As shown in FIG. 3, the tibial base trial component 14
includes an annular flange 230 that extends around the central
opening 40. When the tibial evaluation component 136 is seated on
the tibial base trial component 14, the retention ring 222 of the
evaluation component 126 extends through the central opening 40 of
the tibial base trial component 14 and engages the annular flange
230, thereby securing the components 14, 136 together. Further, the
pair of blocks 224 extend into the elongated openings 42 of the
tibial base trial component 14. The retention ring 222 and blocks
224 are sized to not extend beyond the inferior surface 26 of the
tibial base trial component 14 such that when the fixed evaluation
component 136 is attached to the tibial base trial component 14 on
a patient's tibia 400, the assembly is permitted to move relative
to the patient's tibia 400 unless restrained by a fixation pin
250.
[0075] As described above, the instrument system 10 also includes
another fixed evaluation component 138, which is shown in FIGS.
10-11. The evaluation component 138 shares many common features
with the other evaluation components 132, 134, 136, and the same
reference numbers will be used to describe those common features.
As described above, the evaluation component 138 includes a base
plate 120 that has a superior surface 182 and an inferior surface
184 positioned opposite the superior surface. An closed aperture
240 is defined in the superior surface 182 of the central platform
122 of the base plate 120. In the illustrative embodiment, the
aperture 240 is sized to receive a tip of a removal tool, such as,
for example, impaction handle 372, to detach the evaluation
component 138 from the tibial base trial component 14.
[0076] As described above, the evaluation component 136 also has a
posterior buttress 170 that includes a post 126 and a pair of arms
172, 174 extending posteriorly from the post 126 to cantilevered
tips 176, 178, respectively. As shown in FIG. 10, the post 126 is
positioned on the posterior edge 188 of the base plate 120. The arm
172 defines a lateral-most sidewall 190 of the posterior buttress
170, which extends along a straight imaginary line 192. The other
arm 174 defines a medial-most sidewall 194 of the posterior
buttress 170, which extends along another straight imaginary line
196. As shown in FIG. 11, the pair of arms 172, 174 are positioned
such that the imaginary line 192 intersects the other imaginary
line 196 to define an angle .alpha.. In the illustrative
embodiment, the angle .alpha. may have a magnitude of between 45
and 145 degrees, thereby giving the posterior buttress 170 a
generally Y-shape.
[0077] As described above, the evaluation component 138 also
includes an anterior buttress 180. As shown in FIGS. 10-11, the
anterior buttress 180 includes a pair of arms 200, 202, which
extend anteriorly from the anterior edge 204 of the base plate 120
to cantilevered end 206, 208, respectively. Each arm 200, 202 has a
tab 210 that extends superiorly from the respective ends 206, 208
of the arms 200, 202. In the illustrative embodiment, the tabs 210,
post 126, and arms 172, 174 cooperate to define a retention
mechanism that engages a fixed bearing trial component 18 and
prevents rotation and movement of the fixed bearing trial component
18 relative to the tibial base trial component 14.
[0078] Like the mobile evaluation components 132, 134, the
evaluation component 138 also includes a connector 148 that is
formed at the superior end of the post 126. The connector 148 is
configured to receive a locking flange associated with the
impaction handle 372. In the illustrative embodiment, the connector
148 includes a flange 150 that extends anteriorly away from the
longitudinal axis of the post 126. As shown in FIGS. 10-11, the
flange 150 is positioned above the closed aperture 240.
[0079] The fixed evaluation component 138 also includes a sleeve
160 that extends downwardly from its central platform 122 and
prongs 124. The sleeve 160 includes a central stem 162 sized to be
received in the central opening 40 of the tibial base trial
component 14. The sleeve 160 further includes a pair of prongs 164
that extend outwardly from the central stem 162, which are sized to
be received in the elongated openings 42 of the tibial base trial
component 14. As described in greater detail below, the sleeve 160
is sized to extend through the tibial base trial component 14 and
into a surgically-prepared opening in the patient's tibia and
thereby prevent the components 14, 138 from rotating on the
patient's tibia.
[0080] As described above, the surgical instrument system 10 also
includes a number of fixation pins 250 for use with the tibial base
trial component 14. As shown in FIG. 12, the fixation pins 250
include a posterior fixation pin 252 that is sized to be received
in either of the posterior fixation pinholes 80 of the tibial base
trial component 14 and an anterior fixation pin 254 that is sized
to be received in either of the anterior fixation pinholes 82. Each
of the fixation pins 252, 254 includes a pin head 260 and a
cylindrical shaft 262 that extends from the pin head 260 to a
pointed conical tip 264 that is configured to engage the proximal
end 402 of the patient's tibia 400. The shaft 262 of the pin 252
defines a length 266 that is shorter than a corresponding length
268 defined by the shaft 262 of the pin 254. Additionally, in the
illustrative embodiment, the shaft 262 of the pin 252 has a
diameter 270 that is smaller than a corresponding diameter 272 of
the shaft 262 of the other pin 254.
[0081] As shown in FIG. 12, the pin head 260 of each of the pins
252, 254 has a similar configuration. The pin head 260 includes an
outer ring 280 and an inner ring 282 that is spaced apart from the
outer ring 280. A groove 284 is defined between the rings 280, 282.
The rings 280, 282 have the same diameter in size, which is greater
than the diameters 270, 272 of either of the pins 252, 254. As
described in greater detail below, the surgeon positions a portion
of a pin extraction tool 300 into the groove 284 to manipulate the
pins 252, 254.
[0082] As shown in FIG. 13, the pin extraction tool 300 includes an
elongated body 302 that extends from a proximal end 304 to a distal
end 306. The extraction tool 300 also includes a lever arm 308 that
is pivotally coupled to the elongated body 302. A pair of opposing
jaws 310, 312 are defined on the distal ends of the elongated body
302 and lever arm 308, respectively. As described in greater detail
below, the jaws 310, 312 are configured to engage the pin heads 260
of the fixation pins 252, 254.
[0083] The elongated body 302 includes an impaction plate 314 that
is positioned at the proximal end 304 and a grip 316 sized to
receive a hand of a user. A longitudinal channel 318 is defined in
the body 302, which is sized to receive the lever arm 308. The
lever arm 308 includes a push button 320 that is positioned near
the proximal end 304 of the body 302, and the lever arm 308 is
coupled to the elongated body 302 via a locking pin 322. As shown
in FIG. 13, the locking pin 322 defines an axis of rotation 324
about which the lever arm 308 pivots to move between an engaged
position (FIG. 14) in which the jaws 310, 312 capture a pin head
260 of one of the fixation pins 252, 254 and a disengaged position
(FIG. 15) in which the pin head 260 may be detached from the tool
300.
[0084] As shown in FIG. 14, the lower jaw 310 includes a distal
face 330 of the elongated body 302. The distal face 330 is
semi-circular and has an annular flange or lip 332 extending
outwardly therefrom. A groove 334 is defined between the face 330
and the lip 332, which is sized to receive the outer ring 280 of
fixation pin 252 or fixation pin 254. In the illustrative
embodiment, the lip 332 extends over only a portion of distal face
330. As shown in FIG. 14, the lip 332 defines an arc that is less
than 180 degrees.
[0085] The upper jaw 312 includes a distal face 340 of the lever
arm 308. The distal face 340 is semi-circular and has an annular
flange or lip 342 extending outwardly therefrom. A groove 344 is
defined between the face 340 and the lip 342, which is sized to
receive the outer ring 280 of fixation pin 252 or fixation pin 254.
In the illustrative embodiment, the lip 342 extends over the distal
face 340 such that a pair of gaps 346, 348 is defined between the
lips 332, 342. As shown in FIG. 14, the lip 342 is
semi-circular.
[0086] In use, a user may depress the push button 320 in the
direction indicated by arrow 350 in FIG. 13 to actuate the lever
arm 308. The lever arm 308 may then pivot about the axis 324 to
move the jaws 310, 312 apart, as shown in FIG. 15. In the
disengaged position shown in FIG. 15, a surgeon may advance a pin
head 260 between the jaws 310, 312 and move the outer ring 280 into
engagement with the lower lip 332 of the lower jaw 310. When the
surgeon releases the push button 320, a spring or other biasing
member (not shown) causes the lever arm 308 to pivot back to the
engaged position shown in FIG. 14, thereby advancing the upper lip
342 of the upper jaw 312 into engagement with the outer ring 280 of
the pin head 260. In that way, the jaws 310, 312 cooperate to
provide positive engagement with the pin head 260, and the fixation
pin is retained in the extraction tool 300 and may be implanted or
extracted from the patient's body.
[0087] Referring now to FIGS. 16-22, portions of an orthopaedic
surgical procedure utilizing the system 10 are shown. The surgeon
may first perform a resection of the distal end 406 of the
patient's femur 404 and a resection of the proximal end 402 of the
patient's tibia 400 to surgically prepare those ends for trial
reduction and subsequent attachment of the knee prosthetic
components. For example, as shown in FIG. 16, the
surgically-prepared proximal end 402 of the patient's tibia 400
includes a resected surface configured to receive the tibial base
trial component 14.
[0088] The surgeon may position the tibial base trial component 14
on the resected surface of the patient's tibia 400. The surgeon may
then select one of the tibial evaluation components 16 to be placed
in the central opening 40 of the tibial base trial component 14. If
the surgeon desires the fixed bearing trial component 18, the
surgeon may select the spikeless tibial evaluation component 136
and position it in the central opening 40 by hand so that the
inferior surface 184 of the tibial evaluation component engages the
shelf surface 54 of the tibial base trial component 14. If the
surgeon desires a mobile bearing trial component 18, the surgeon
may select the spiked tibial evaluation component 132. In some
embodiments, the surgeon may use the spiked tibial evaluation
component 132 for initial trial reduction before using the fixed
tibial evaluation component 136. The use of mobile bearing trial
component and the spiked tibial evaluation component is further
described in co-pending U.S. patent application Ser. No.
14/265,960, entitled "TIBIAL TRIAL SYSTEM FOR A KNEE PROSTHESIS" by
David Waite et al. and filed on Apr. 30, 2014.
[0089] In the illustrative embodiment, the surgeon may grip the
selected tibial evaluation component 136 by the posterior buttress
170 and position it over the plate opening 30 of the tibial base
trial component 14. The surgeon may then apply force in the
direction indicated by arrow 410 to the superior surface 182 of the
evaluation component 136 to engage the inferior surface 184 of the
tibial evaluation component 136 with the shelf surface 54 of the
tibial base trial component 14, as shown in FIG. 17.
[0090] Once the tibial evaluation component 136 is properly
received in the central opening 40 of the tibial base trial
component 14, the surgeon may inferiorly advance a fixation pin 252
through one of the pinholes 80 of the tibial base trial component
14 into the proximal end 402 of the patient's tibia 400. When the
posterior fixation pin 252 is properly inserted into the tibial
base trial component 14, a longitudinal axis 264 of the posterior
fixation pin 252 is perpendicular to the proximal surface of the
patient's tibia 400 and is relatively parallel to a longitudinal
axis 266 of the patient's tibia 400. The posterior fixation pin 252
temporarily anchors one end of the tibial base trial component 14
to the proximal end 402 of the patient's tibia 400. Inserting only
one posterior fixation pin 252 in one of the posterior fixation
pinhole 80 permits the tibial base trial component 14 to rotate
about the fixation pin 252 while the surgeon performs the trial
reduction.
[0091] Once the posterior fixation pin 252 is properly inserted,
the surgeon may assemble a fixed bearing trial component 18 or a
mobile bearing trial component 18. The fixed bearing trial
component 18 is shown in FIG. 17. As described above, the tibial
bearing trial component 18 is a multi-piece assembly. Accordingly,
a given tibial bearing trial component 18 may be assembled with one
of a number of tibial bearing surface trial components 412 and one
of a number of a plurality of trial shims 414, as shown in FIG. 22.
In a single kit of trial components, the tibial bearing surface
trial components 412 may be provided in different sizes and/or
configurations, and each trial shim 414 may have a different
thickness. Because each trial shim 414 is configured to be secured
to each tibial bearing surface trial component 412, the surgeon is
able to assemble a tibial bearing trial component 18 of one size
and configuration, evaluate the performance of that tibial bearing
trial component 18, and then modify the tibial bearing trial
component 18 as necessary to determine intraoperatively the type
and configuration of the prosthetic tibial bearing component to be
implanted.
[0092] The surgeon may assemble one of the trial shim 414 with one
of the tibial bearing surface trial components 412 to form a tibial
bearing trial component 18. For example, the surgeon may select one
of the fixed bearing surface trial components 412 and secure the
trial shim 414 thereto to form a fixed bearing trial component 18.
During a surgical trialing procedure, the fixed bearing trial
component 18 is advanced such that the post 126 of the posterior
buttress 170 of the tibial evaluation component 16 is received in a
central passageway 416 of the trial shim 414. The trial shim 414
further includes two posterior sidewalls 418, 420 which are
configured to cooperate with the anterior sidewalls 190, 194 of the
arms 172, 174, respectively, of the posterior buttress 170 of the
tibial evaluation component 136 to prevent the fixed tibial bearing
trial component from rotating relative to the tibial base trial
component 14.
[0093] As shown in FIG. 18, the fixed bearing trial component 18 is
selected and the surgeon advances the posterior edge 422 of the
assembled tibial bearing surface trial component 412 and trial shim
414 into the gap between the tibial base trial component 14 and the
femoral trial component 20. The shape of the posterior buttress 170
of the tibial evaluation component 136 allows the fixed bearing
trial component 18 to advance in the posterior direction between
the tibial base trial component 14 and the femoral trial component
20, as shown in FIGS. 18-19. When the tibial bearing trial
component 18 is seated between the tibial base trial component 14
and the femoral trial component 20, the posterior sidewalls 418,
420 of the trial shim 414 engage anterior sidewalls 190, 194 of the
arms 172, 174 of the posterior buttress 170 of the tibial
evaluation component 136, respectively.
[0094] When the fixed bearing trial component 18 is in place, the
surgeon may perform the trial reduction. In doing so, the surgeon
uses the system 10 to evaluate and check the stability and
kinematics of the patient's femur 404 and tibia 400 for
implantation of a fixed bearing knee prosthesis or a mobile bearing
knee prosthesis. Particularly, the surgeon carefully extends the
knee of the patient, noting the anteroposterior stability,
medial-lateral stability, and overall alignment in the
anterior-posterior plane and medial-lateral plane. Rotational
alignment of the tibial base trial component 14 relative to the
femoral trial component 20 may be adjusted with the knee in full
extension. The rotation of the tibial base trial component 14 is
usually centered on the junction between the medial and central
one-third of a tibial tubercle.
[0095] As the range of motion is evaluated, a load on the femoral
trial component 20 translates posteriorly as the knee is moved
between extension and flexion. To improve performance, the surgeon
may remove the tibial bearing trial component 18 from the tibial
base trial component 14 to exchange the trial shim 414 and/or the
tibial bearing surface trial component 412. A removal tool (not
shown) may be used to detach the tibial bearing trial component 18
from the tibial base trial component 14. The surgeon may use a
separator tool (not shown) to detach the trial shim 414 from the
tibial bearing surface trial component 412. The surgeon may then
select another trial shim 414 having a different thickness or
choose a tibial bearing surface trial component 412 with an
alternative configuration, for example, a tibial bearing surface
trial component 412 that is cruciate retaining or posterior
stabilized. The surgeon may continue to try various combinations of
trial shim 414 and tibial bearing surface trial component 412 to
ascertain which final implant will have the best stability in
flexion and extension while permitting full extension. Once the
revised combination of trial shim 414 and tibial bearing surface
trial component 412 is selected, the two components are assembled
to one another and anteriorly advanced in the gap between tibial
base trial component 14 and the femoral trial component 20 in the
manner previously discussed.
[0096] Once the surgeon is satisfied with the trial reduction,
without removing any of the trial components 12, the surgeon may
inferiorly advance the fixation pin 254 through one of the pinholes
82 of the tibial base trial component 14 and into the proximal end
402 of the patient's tibia 400. As described above, the anterior
fixation pinhole 82 is positioned in the center of the inclined
surface 102 of the anterior tab 100 of the tibial base trial
component 14. The anterior tab 100 extends from the anterior aspect
62 of the tibial base trial component 14, such that the anterior
tabs 100 project outward from an anterior edge of the proximal end
402 of the patient's tibia 400, as shown in FIG. 18. The projected
anterior tab 100 is exposed throughout the trial reduction process
to allow the surgeon to secure the anterior fixation pin 254 in the
proximal end 402 of the patient's tibia 400 while the tibial
bearing trial components 18 and the femoral trial component 20
remain positioned on the tibial base trial component 14.
[0097] Unlike the posterior fixation pinhole 80, the anterior
fixation pinhole 82 is not positioned directly perpendicular to the
proximal surface of the patient's tibia 400. Because an inferior
surface 58 of the anterior tab 100 extends anteriorly outward from
the anterior edge of the proximal end 402 of the patient's tibia
400, an anterior portion of the inferior surface 58 does not
contact the proximal end 402 of the patient's tibia 400.
Accordingly, an inferior opening (not shown) of the anterior
fixation pinhole 82 does not wholly rest on the proximal end 402 of
the patient's tibia 400. In order to secure the anterior fixation
pin 254 in the proximal end 402 of the patient's tibia 400, the
anterior fixation pinhole 82 is designed so that when the anterior
fixation pin 254 is received in the anterior fixation pinhole 82,
the longitudinal axis 368 of the anterior fixation pin 254 is
positioned at oblique angles relative to the anterior surface of
the proximal end 402 of the patient's tibia. The position of the
anterior fixation pinhole 82 allows the anterior fixation pin 254
to advance into the proximal end 402 of the patient's tibia 400 to
further secure the tibial base trial component 14 on the proximal
end 402 of the patient's tibia 400. After performance of the trial
reduction, the surgeon may then continue surgical preparation of
the proximal end 402 of the patient's tibia 400.
[0098] Subsequently, the surgeon may utilize the keel punch 374
seated on the tibial base trial component 14 in the proximal end
402 of the patient's tibia 400 to enlarge the opening in the
patient's tibia 400, as shown in FIG. 21. With the tibial base
trial component 14 and a guide tower 370 are positioned on the
proximal end 402 of the patient's tibia 400, the surgeon may use
the tibial base trial component 14 and the guide tower 370 to
guide, for example, a surgical drill (not shown) while reaming the
proximal end 402 of the patient's tibia 400. Thereafter, the keel
punch 374 may be impacted into the proximal end 402 of the
patient's tibia 400 before the guide tower 370 is removed, as shown
in FIG. 21.
[0099] The keel punch 374 is configured to be inserted through the
central opening 40 of the tibial base trial component 14 into the
proximal end 402 of the patient's tibia 400 to prepare the
patient's tibia 400 for a prosthetic component. The keel punch 374
has a base plate 376 having a peripheral rim 380 defined therein.
The rim 380 has an inferior surface 382 configured to engage the
shelf surface 54 of the tibial base trial component 14 when the
keel punch 374 is seated on the tibial base trial component 14. The
base plate 376 also includes a central platform 384 sized to be
received in the central opening 40 of the tibial base trial
component 14, along with a pair of prongs 386 that extend laterally
outward from the central platform 384. The prongs 386 are sized to
be received in the elongated openings 42 of the tibial base trial
component 14. An exemplary procedure for reaming the patient's
tibia 400 and installing the keel punch 374 is set forth in U.S.
patent application Ser. No. 13/530,945, entitled "METHOD OF
SURGICALLY PREPARING A TIBIA FOR IMPLANTATION OF A PROSTHETIC
COMPONENT" filed by David Waite et al. and filed on Jun. 28, 2012,
which is incorporated herein by reference.
[0100] When the keel punch 374 is impacted into and removed from
the proximal end 402 of the patient's tibia 400, the resulting
proximal end 402 of the patient's tibia 400 includes an opening
408, as shown in FIG. 22. The surgeon may again repeat the trial
reduction by assembling the fixed bearing trial component 18 or the
mobile bearing trial component 18. This time, the surgeon may use
the tibial evaluation component 138, 134 with the sleeve 160, such
that the sleeve 160 is received in the opening 408 of proximal end
402 of the patient's tibia 400. For example, the surgeon may choose
to assemble one of the trial shims 414 with one of the fixed
bearing surface trial components 412 to form a fixed bearing trial
component 18. The surgeon then positions the sleeve 160 of the
tibial evaluation component 138 into the opening 408 of proximal
end 402 of the patient's tibia 400. The surgeon subsequently places
the fixed bearing trial component 18 over the tibial base trial
component 14, such that the post 126 is received in the central
passageway 416 of the trial shim 414 and the posterior sidewalls
418, 420 of the trial shim 414 engages anterior sidewalls 190, 194
of the arms 172, 174 of the posterior buttress 170 of the tibial
evaluation component 138, respectively.
[0101] The surgeon may then repeat the trial reduction until
satisfied with the alignment and the stability of the knee. When
the additional trial reduction is complete, the surgeon may use the
impaction handle 372 to remove the keel punch 374 from the
patient's tibia 400. The surgeon may further use the pin extraction
tool 300 to extract the posterior fixation pin 252 and/or the
anterior fixation pin 254 from the patient's tibia 400. The
resultant features surgically formed in the proximal end 402 of the
patient's tibia 400 are configured to receive a tibial tray of a
fixed bearing knee prosthesis or a mobile bearing knee prosthesis.
The surgeon then completes the surgical procedure of the remaining
components of the prosthesis.
[0102] Alternatively or additionally, as shown in FIG. 22, the
surgeon may choose to assemble one of the trial shims 414 with one
of the mobile bearing surface trial components 412 to form a mobile
bearing trial component 18. The surgeon may then position the
sleeve 160 of the tibial evaluation component 134 into the opening
408 of proximal end 402 of the patient's tibia 400 and place the
mobile bearing trial component 18 over the tibial base trial
component 14. The surgeon may then move the patient's leg between
flexion and extension to evaluate the range of motion. As described
above, the configuration of the evaluation component 134 permits
the mobile bearing trial component 18 to rotate relative to the
patient's tibia as the leg is moved between flexion and extension.
It should be appreciated that in other embodiments the trial shim
414 may be positioned on the tibial base trial 14 prior to
attaching the bearing surface trial 412 thereto.
[0103] While the disclosure has been illustrated and described in
detail in the drawings and foregoing description, such an
illustration and description is to be considered as exemplary and
not restrictive in character, it being understood that only
illustrative embodiments have been shown and described and that all
changes and modifications that come within the spirit of the
disclosure are desired to be protected.
[0104] There are a plurality of advantages of the present
disclosure arising from the various features of the method,
apparatus, and system described herein. It will be noted that
alternative embodiments of the method, apparatus, and system of the
present disclosure may not include all of the features described
yet still benefit from at least some of the advantages of such
features. Those of ordinary skill in the art may readily devise
their own implementations of the method, apparatus, and system that
incorporate one or more of the features of the present invention
and fall within the spirit and scope of the present disclosure as
defined by the appended claims.
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