Note: Descriptions are shown in the official language in which they were submitted.
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CUSTOMIZED TIBIAL TRAYS, METHODS,
AND SYSTEMS FOR KNEE REPLACEMENT
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application perfects and claims the priority benefit of U.S.
Provisional Patent
Application No. 63/027,098, filed May 19, 2020, entitled "Customized Tibial
Trays, Methods,
And Systems For Knee Replacement," which application is hereby incorporated
herein by
reference in its entirety.
[0002] This application is a continuation-in-part application of
International Patent
Application No. PCT/U52020/020279 filed February 28, 2020, entitled
"Customized Tibial
Trays, Methods, And Systems For Knee Replacement" and published under the PCT
Articles in
English as WO 2020/176824 on September 3, 2020 (atty. dock. no. 5247.004AW0),
which
International application perfects and claims priority benefit of U.S.
Provisional Patent
Application No. 62/811,855, filed February 28, 2019, entitled "Customized
Tibial Trays
Contactable With An Underlying Cortical Bone, Methods, And Systems For Knee
Replacement"
(atty. dock. no. 5247.004P), and which International application perfects and
claims priority
benefit of U.S. Provisional Patent Application No. 62/879,800, filed July 29,
2019, entitled
"Customized Tibial Trays, Methods, And Systems For Knee Replacement" (atty.
dock. no.
5247.004P2), and which applications are hereby incorporated herein by
reference in their
entirety.
FIELD OF THE DISCLOSURE
[0003] The present disclosure relates generally to surgical implants,
methods, and systems
for use in repairing knee joints, and more particularly to patient specific
surgical procedures and
customized tibial trays for use in the replacement of knee joints.
BACKGROUND
[0004] Typically, the most common indication for revision surgery of Total
Knee
Arthroplasties is aseptic loosening (29.8%) and subsidence. Aseptic loosening
is also a major
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cause of post-operative pain. These failures are tied to poor
osseointegration, imperfect implant
coverage, limited support and shear forces introduced by a flat resection
plane.
SUMMARY
[0005] Shortcomings of the prior art are overcome and additional advantages
are provided
through the provision, in one embodiment, of a tibial tray system for a
resected portion extending
transversely across a proximal portion of a tibia of a patient for use in a
total knee replacement,
the resected proximal portion of the tibia having a resected cancellous bone
surface, a resected
peripheral cortical bone surface, and at least one cavity formed in the
underlying periphery of the
resected cancellous bone, the tibial tray system includes for example, a
tibial tray an at least one
screw. The tibial tray includes a body comprising a superior portion and an
inferior tibia-
engaging portion. The superior portion comprising a superior surface and a
peripheral edge, and
at least one passageway extending therethrough. The inferior tibia-engaging
portion includes a
peripheral inferior surface supportable on the resected peripheral cortical
bone surface, a center
inferior surface disposable on the resected center cancellous bone surface,
and at least one
inferiorly-extending wall spaced inwardly from the peripheral inferior surface
and extending
around at least a portion of the center inferior surface, the at least one
inferiorly-extending wall
being receivable in the at least one cavity formed in the periphery of the
resected cancellous bone
surface. The at least one screw is extendable through the at least one
passageway of the tibial
tray. In the total knee replacement, the at least one screw extends through
the tibial tray and into
the cancellous bone to inhibit lift-off of the tibial tray, and a greater
portion of a shearing force
acting transversely to the tibial tray and the resected portion of the
proximal portion of the tibia
of the patient is resisted by the at least one inferiorly-extending wall and
the periphery of the
resected proximal portion of the tibia compared to a portion of the shearing
force being resisted
along the center inferior surface of the tibial tray and the resected
cancellous bone surface.
[0006] In another embodiment, a method includes, for example, resecting a
proximal portion
of a tibia of a patient, the resected proximal portion of the tibia having a
transverse resected
cancellous bone surface, a transverse resected peripheral cortical bone
surface, and at least one
cavity formed in the periphery of the resected cancellous bone, providing a
tibial tray having at
least one inferiorly-extending wall spaced inwardly from a peripheral edge of
the tibial tray and
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extending around at least a portion of a center inferior surface, and at least
one passageway
extending therethrough, inserting the at least one inferiorly-extending wall
in the at least one
cavity formed in the periphery of the resected cancellous bone surface,
disposing the peripheral
edge of the tibial tray on the transverse resected peripheral cortical bone
surface, and the center
inferior surface on the transverse resected cancellous bone surface, securing
at least one screw in
the at least one passageway and into the cancellous bone, and wherein, in the
total knee
replacement, the at least one screw inhibits lift-off of the tibial tray, and
a greater portion of a
shearing force acting transversely on the tibial tray and the resected portion
of the proximal
portion of the tibia of the patient is resisted by the at least one inferiorly-
extending wall and the
periphery of the resected proximal portion of the tibia compared to a portion
of the shearing
force being resisted along the center inferior surface of the tibial tray and
the resected cancellous
bone surface.
[0007] In another embodiment, a method for forming a patient specific
tibial tray for a total
knee replacement of a patient includes, for example, obtaining first data, via
at least one
processor, representing a proximal portion of the tibia of the patient, the
first data corresponding
to the proximal portion of the tibia of the patient having an inner cancellous
bone, and a
peripheral cortical bone having an outer surface and an inner surface,
determining, via the at
least one processor, second data representing a patient specific resected
proximal portion of the
tibia of the patient based on the first data, the resected proximal portion of
the tibia of the patient
having a center cancellous bone surface, a peripheral cortical bone surface,
and at least one
cavity formed in the underlying periphery of the resected cancellous bone, the
at least one cavity
having in outer contoured surface portion corresponding to an adjacent inner
surface portion of
the resected cortical bone, forming, via the at least one processor, the
patient specific tibial tray
based on the second data, the patient specific tibial tray comprising a body
having a superior
portion including a superior surface and an inferior tibia-engaging portion,
the inferior tibia
engaging portion having a center portion contactable with the resected center
cancellous bone
surface, at least one inferiorly-extending wall receivable in the at least one
cavity, and at least
one passageway extending from the superior surface to the inferior surface,
and wherein, in the
total knee replacement, the at least one screw inhibits lift-off of the tibial
tray, and a greater
portion of a shearing force acting transversely on the patient specific tibial
tray and the resected
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portion of the proximal portion of the tibia of the patient is resistible by
the at least one
inferiorly-extending wall and the periphery of the resected proximal portion
of the tibia
compared to a portion of the shearing force being resistible along the center
inferior surface of
the tibial tray and the resected cancellous bone surface.
[0008] Shortcomings of the prior art are overcome and additional advantages
are provided
through the provision, in one embodiment, of a tibial tray for a resection
extending transversely
across a proximal portion of a tibia of a patient for use in a total knee
replacement. The resected
proximal portion of the tibia includes a resected cancellous bone surface, a
resected peripheral
cortical bone surface, and at least one cavity formed in the underlying
periphery of the resected
cancellous bone. The tibial tray includes a body comprising a superior portion
and an inferior
tibia-engaging portion. The superior portion includes a superior surface and a
peripheral edge.
The inferior tibia-engaging portion includes a peripheral inferior surface
supportable on the
resected peripheral cortical bone surface, a center inferior surface
disposable on the resected
center cancellous bone surface, and at least one inferiorly-extending wall
spaced inwardly from
the peripheral inferior surface and extending around at least a portion of the
center inferior
surface. The at least one inferiorly-extending wall is receivable in the at
least one cavity formed
in the periphery of the resected cancellous bone surface. The body includes a
thickness between
the superior surface and the center inferior surface, the at least one
inferiorly-extending wall has
a depth from the center inferior surface, and the depth being greater than the
thickness. In the
total knee replacement, a greater portion of a shearing force acting
transversely on the tibial tray
and the resected portion of the proximal portion of the tibia of the patient
is resisted by the at
least one inferiorly-extending wall and the periphery of the resected proximal
portion of the tibia
compared a portion of the shearing force being resisted along the center
inferior surface of the
tibial tray and the resected cancellous bone surface.
[0009] In another embodiment, a method including, for example, resecting a
proximal
portion of a tibia of a patient, the resected proximal portion of the tibia
having a transverse
resected cancellous bone surface, a transverse resected peripheral cortical
bone surface, and at
least one cavity formed in the underlying periphery of the resected cancellous
bone, providing a
tibial tray having at least one inferiorly-extending wall spaced inwardly from
a peripheral edge
of the tibial tray and extending around at least a portion of a center
inferior surface, inserting the
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at least one inferiorly-extending wall in the at least one cavity formed in
the underlying
periphery of the resected cancellous bone surface, and disposing the center
inferior surface
against the transverse resected cancellous bone surface, wherein in a total
knee replacement, a
greater portion of a shearing force acting transversely on the tibial tray and
the resected portion
of the proximal portion of the tibia of the patient is resisted by the at
least one inferiorly-
extending wall and the periphery of the resected proximal portion of the tibia
compared to a
portion of the shearing force being resisted along the center inferior surface
of the tibial tray and
the resected cancellous bone surface.
[0010] In another embodiment, a method for forming a patient specific
tibial tray for a total
knee replacement of the patient, includes for example, obtaining first data,
via at least one
processor, representing a proximal portion of the tibia of the patient, the
first data corresponding
to the proximal portion of the tibia of the patient having an inner cancellous
bone, and a
peripheral cortical bone having an outer surface and an inner surface,
determining, via the at
least one processor, second data representing a patient specific resected
proximal portion of the
tibia of the patient based on the first data, the resected proximal portion of
the tibia of the patient
having a center cancellous bone surface, a peripheral cortical bone surface,
and at least one
cavity formed in the underlying periphery of the resected cancellous bone, the
at least one cavity
having in outer contoured surface portion corresponding to an adjacent inner
surface portion of
the resected cortical bone, forming, via the at least one processor, the
patient specific tibial tray
based on the second data, the patient specific tibial tray comprising a body
having a superior
portion having a superior surface and an inferior tibia-engaging portion, the
inferior tibia
engaging portion having a center portion contactable with the resected center
cancellous bone
surface, and at least one inferiorly-extending wall receivable in the at least
one cavity, and
wherein, in the total knee replacement, a greater portion of a shearing force
acting transversely
on the patient specific tibial tray and the resected portion of the proximal
portion of the tibia of
the patient is resistible by the at least one inferiorly-extending wall and
the periphery of the
resected proximal portion of the tibia compared to a portion of the shearing
force being resistible
along the center inferior surface of the tibial tray and the resected
cancellous bone surface.
[0011] Shortcomings of the prior art are overcome and additional advantages
are provided
through the provision, in one embodiment, of a tibial tray for a resected
proximal portion of a
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tibia of a patient for a knee replacement. The resected proximal portion of
the tibia includes a
center cancellous bone surface, a peripheral cortical bone surface, and at
least one cavity formed
in the cancellous bone exposing at least a portion of an underlying inner
surface of the cortical
bone. The tibial tray includes a body having a superior portion with a
superior surface, and an
inferior tibia-engaging portion. The inferior tibia-engaging portion includes
a center portion
having a center surface contactable with the center cancellous bone surface,
and a peripheral,
inferiorly-extending portion receivable in the at least one cavity formed in
the cancellous bone.
A surface of the peripheral inferiorly-extending portion is contactable with
the exposed
underlying inner surface of the cortical bone of the tibia of the patient.
[0012] In another embodiment, a method for forming a patient specific
tibial tray for a knee
replacement for the patient includes, for example, determining a patient
specific resected
proximal portion of a tibia of the patient, the resected proximal portion of
the tibia of the patient
having a superior center cancellous bone surface, a peripheral cortical bone
surface, and one or
more cavities and/or openings in the cancellous bone exposing at least a
portion of an underlying
inner surface of the cortical bone of the tibia, and forming the patient
specific tibial tray
comprising a body having an superior portion with a superior surface and an
inferior tibia-
engaging portion, the inferior tibia engaging portion having a center portion
contactable with the
cancellous bone surface, and a peripheral, inferiorly-extending portion
receivable in the one or
more cavities and/or openings and having one or more surfaces contactable with
the exposed
underlying inner surface of the cortical bone of the tibia of the patient.
[0013] In another embodiment, a robotic method for resecting a proximal
portion of a tibia of
a patient for a knee replacement includes, for example, obtaining, via a
processor, first data
representing a proximal portion of the tibia of the patient comprising
centralized cancellous bone
and peripheral cortical bone, determining, via the processor, second data of a
patient specific
resected proximal portion of the tibia of the patient having a center
cancellous bone surface, a
peripheral cortical bone surface, and at least one cavity formed in the
cancellous bone exposing
at least a portion of an underlying inner surface of the cortical bone based
on the first data, and
forming, via the processor, the tibia of the patent based on the second data
of the patient specific
resected proximal portion of the tibia, the resected proximal portion of the
tibia of the patient
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having the center cancellous bone surface, a peripheral cortical bone surface,
and the at least one
cavity exposing the inner surface of the cortical bone of the tibia.
[0014] Shortcomings of the prior art are also overcome and additional
advantages are
provided through the provision, in one embodiment, of a tibial tray for a
resected proximal
portion of a tibia of a patient for a total knee replacement. The resected
proximal portion of the
tibia includes a center cancellous bone surface, a peripheral cortical bone
surface, and at least
one cavity formed in the periphery of the cancellous bone which is spaced
apart from the cortical
bone exposing an underlying portion of the cancellous bone of the tibia. The
tibial tray includes a
body having a superior portion with a superior surface, and an inferior tibia-
engaging portion.
The inferior tibia-engaging portion includes a center portion having a center
surface contactable
with the center cancellous bone surface, and a peripheral, inferiorly-
extending portion receivable
in the at least one cavity formed in the cancellous bone surface so that the
peripheral inferiorly-
extending portion is spaced apart from the underlying inner surface of the
cortical bone of the
tibia of the patient.
[0015] In another embodiment, a method for forming a patient specific
tibial tray for a total
knee replacement for the patient includes, for example, determining a patient
specific resected
proximal portion of a tibia of the patient, the resected proximal portion of
the tibia of the patient
having a superior center cancellous bone surface, a peripheral cortical bone
surface, and at least
one cavity formed in the periphery of the cancellous bone exposing an
underlying portion of the
cancellous bone of the tibia, and forming the patient specific tibial tray
comprising a body having
a superior portion with a superior surface and an inferior tibia-engaging
portion, the inferior tibia
engaging portion having a center portion contactable with the center
cancellous bone surface,
and a peripheral, inferiorly-extending portion receivable in the at least one
cavity so that the
peripheral inferiorly-extending portion is spaced apart from the exposed
underlying inner surface
of the cortical bone of the tibia of the patient.
[0016] In another embodiment, a robotic method for resecting a proximal
portion of a tibia of
a patient for a total knee replacement includes, for example, obtaining, via a
processor, first data
representing a proximal portion of the tibia of the patient comprising
centralized cancellous bone
and peripheral cortical bone, determining, via the processor, second data of a
patient specific
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resected proximal portion of the tibia of the patient having a center
cancellous bone surface, a
peripheral cortical bone surface, and at least one cavity formed in the
periphery of the cancellous
bone spaced apart from the cortical bone exposing an underlying portion of the
cancellous bone
based on the first data, and forming, via the processor, the tibia of the
patent based on the second
data representing the patient specific resected proximal portion of the tibia,
the resected proximal
portion of the tibia of the patient having a center cancellous bone surface, a
peripheral cortical
bone surface, and at least one cavity formed in the periphery of the
cancellous bone spaced apart
from the cortical bone exposing an underlying portion of the cancellous bone
of the tibia.
[0017] Shortcomings of the prior art are also overcome and additional
advantages are
provided through the provision, in one embodiment, of a tibial tray for a
resected proximal
portion of a tibia of a patient for a total knee replacement. The resected
proximal portion of the
tibia includes a center cancellous bone surface, a peripheral cortical bone
surface, and at least
one cavity formed in the periphery of the cancellous bone which is spaced
apart from the cortical
bone exposing an underlying portion of the cancellous bone of the tibia. The
tibial tray includes a
body having a superior portion with a superior surface, and an inferior tibia-
engaging portion.
The inferior tibia-engaging portion includes a center portion having a center
surface contactable
with the center cancellous bone surface, and a peripheral, inferiorly-
extending portion receivable
in the at least one cavity formed in the cancellous bone surface so that the
peripheral inferiorly-
extending outer surface portion corresponds to the contour of the underlying
inner surface of the
cortical bone of the tibia of the patient. In other embodiments, the
peripheral, inferiorly-
extending portion includes at least a portion of the peripheral inferiorly-
extending outer surface
portion extending from a proximal portion of the peripheral, inferiorly-
extending portion to a
distal portion of the peripheral, inferiorly-extending portion contoured to
correspond to a contour
of a superior edge portion of the cortical bone along the resection plane so
that the at least the
portion of the peripheral inferiorly-extending outer surface portion is
disposable adjacent to a
underlying concave inner surface of the cortical bone.
[0018] Shortcomings of the prior art are also overcome and additional
advantages are
provided through the provision, in one embodiment, of a tibial tray for a
resected medial or
lateral proximal portion of a tibia of a patient for a partial knee
replacement, The resected medial
or lateral proximal portion of the tibia has a central cancellous bone
surface, a partial peripheral
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cortical bone surface, and at least one cavity formed in the periphery of the
cancellous bone in
the resected medial or lateral proximal portion of the tibia. The tibial tray
includes a body having
a superior portion with a superior surface, and an inferior tibia-engaging
portion. The inferior
tibia-engaging portion includes a center portion having a center surface
contactable with the
resected central cancellous bone surface, and a peripheral, inferiorly-
extending portion
receivable in the at least one cavity formed in the resected cancellous bone
surface so that the
peripheral inferiorly-extending outer surface portion corresponds to the
contour of the underlying
inner surface of the cortical bone of the tibia of the patient.
[0019] Shortcomings of the prior art are also overcome and additional
advantages are
provided through the provision, in one embodiment, of a cutting guide for
forming at least one
cavity in a resected proximal portion of a tibia of a patient for knee
replacement. The resected
proximal portion of the tibia has a center cancellous bone surface and a
peripheral cortical bone
surface. The cutting guide includes a planar member having a first planar
surface and a second
planar surface. The planar member has a peripheral outer edge, a portion of
which corresponding
to at least a portion of an outer peripheral cortical bone along the resection
of the proximal
portion of the tibial of the patient, and at least one U-shaped opening
extending through the
planar member from the first planar surface to the second planar surface and
spaced from the
peripheral outer edge. The U-shaped opening defines a U-shaped axis, and the U-
shaped opening
has a constant width normal to the U-shape axis. The U-shaped opening has an
inner edge and an
outer edge, and the outer edge being parallel to the peripheral outer edge.
The cutting guide can
further include a milling tool having a proximal diameter sized larger than
the width of the
opening, and a distal diameter sized for passing through the opening.
[0020] Shortcomings of the prior art are also overcome and additional
advantages are
provided through the provision, in one embodiment, a cutting guide for forming
a pair of cavities
in a resected proximal portion of a tibia of a patient for total knee
replacement, the resected
proximal portion of the tibia having a center cancellous bone surface and a
peripheral cortical
bone surface. The cutting guide includes a planar member having a first planar
surface and a
second planar surface. The planar member includes a peripheral outer edge
corresponding to an
outer peripheral cortical bone along the resection of the proximal portion of
the tibial of the
patient. A pair of U-shaped openings extend through the planar member from the
first planar
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surface to the second planar surface and spaced from the peripheral outer
edge. Each of the pair
of U-shaped openings define a U-shaped axis, and the U-shaped opening has a
constant width
normal to the U-shape axis. Each of the pair of the U-shaped openings having
an inner edge and
an outer edge, and the outer edge is parallel to the peripheral outer edge.
The cutting guide can
further include a milling tool having a proximal diameter sized larger than
the width of opening,
and a distal diameter sized for passing through the opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The subject matter which is regarded as the disclosure is
particularly pointed out and
distinctly claimed in the concluding portion of the specification. The
disclosure, however, may
best be understood by reference to the following detailed description of
various embodiments
and the accompanying drawings in which:
[0022] FIG. 1 is a frontal cross-sectional view of a resected proximal
portion of a tibia of a
patient and a tibial tray, according to an embodiment of the present
disclosure;
[0023] FIG. 2 is a superior view of a resected proximal portion of a tibia
of a patient,
according to an embodiment of the present disclosure;
[0024] FIG. 3 is a frontal cross-sectional view of a resected proximal
portion of a tibia of a
patient and a tibial tray, according to an embodiment of the present
disclosure;
[0025] FIG. 4 is a frontal cross-sectional view of a resected proximal
portion of a tibia of a
patient and a tibial tray, according to an embodiment of the present
disclosure;
[0026] FIG. 5 is a superior view of a resected proximal portion of a tibia
of a patient,
according to an embodiment of the present disclosure;
[0027] FIG. 6 is a flowchart of a process for repairing a knee joint of a
patient, according to
an embodiment of the present disclosure;
[0028] FIG. 7 is a block diagram of a system for repairing a knee joint of
a patient, according
to an embodiment of the present disclosure;
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[0029] FIG. 8 is a block diagram of a system for repairing a knee joint of
a patient, according
to an embodiment of the present disclosure;
[0030] FIG. 9 is a graphical representation of a proximal portion of a
tibia of a patient,
according to embodiment of the present disclosure;
[0031] FIG. 10 illustrates two bone-to-implant interfaces for support pins,
according to
embodiment of the present disclosure;
[0032] FIG. 11 is a flowchart of a robotic process for repairing a knee
joint of a patient,
according to an embodiment of the present disclosure;
[0033] FIGS. 12-14 are superior, posterior perspective, and inferior views
of a tibial tray,
according to an embodiment of the present disclosure;
[0034] FIGS. 15-19 are superior, posterior perspective, inferior, posterior
perspective, and
anterior perspective views of a tibial tray, according to an embodiment of the
present disclosure;
[0035] FIGS. 20 and 21 are cross-sectional views of the tibial tray of FIG.
16 disposed on a
resected proximal portion of a tibia;
[0036] FIG. 22 is a frontal cross-sectional view of a tibial tray,
according to an embodiment
of the present disclosure;
[0037] FIG. 23 is a superior view of the tibial tray of FIG. 22, according
to an embodiment
of the present disclosure;
[0038] FIG. 24 is a frontal cross-sectional view of a resected proximal
portion of a tibia of a
patient and a tibial tray, according to an embodiment of the present
disclosure;
[0039] FIG. 25 is a frontal cross-sectional view of a resected proximal
portion of a tibia of a
patient and a tibial tray, according to an embodiment of the present
disclosure;
[0040] FIG. 26 is a cross-sectional view of a tibial tray disposed on a
resected proximal
portion of a tibia of a patient, according to an embodiment of the present
disclosure;
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[0041] FIG. 27 is an inferior perspective view of the tibial tray of FIG.
26, according to an
embodiment of the present disclosure;
[0042] FIG. 28 is a superior view of the resected proximal portion of the
tibia of FIG. 26 for
receiving the tibial tray of FIG. 27, according to an embodiment of the
present disclosure;
[0043] FIG. 29 is a cross-sectional view of a tibial tray disposed on a
resected proximal
portion of a tibia of a patient, according to an embodiment of the present
disclosure;
[0044] FIG. 30 is an inferior perspective view of the tibial tray of FIG.
29, according to an
embodiment of the present disclosure;
[0045] FIG. 31 is an inferior perspective view of a tibial tray, according
to an embodiment of
the present disclosure;
[0046] FIG. 32 is a superior view of the resected proximal portion of a
tibia for receiving the
tibial tray of FIG. 31, according to an embodiment of the present disclosure;
[0047] FIG. 33 is a flowchart of a process for repairing a knee joint of a
patient, according to
an embodiment of the present disclosure;
[0048] FIG. 34 is a flowchart of a robotic process for repairing a knee
joint of a patient,
according to an embodiment of the present disclosure;
[0049] FIG. 35 is an elevational anterior view of a proximal portion of a
tibia of a patient for
a knee replacement, according to an embodiment of the present disclosure;
[0050] FIG. 36 is a diagrammatic illustration of a portion of a tibial
tray, according to an
embodiment of the present disclosure;
[0051] FIG. 37 is a diagrammatic illustration of a portion of a tibial
tray, according to an
embodiment of the present disclosure;
[0052] FIG. 38 is an elevational anterior view of a tibial tray for knee
replacement, according
to an embodiment of the present disclosure;
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[0053] FIG. 39 is a diagrammatic illustration of a portion of a tibial
tray, according to an
embodiment of the present disclosure;
[0054] FIG. 40 is an anterior, in part cross-sectional, view of a distal
portion of a femur and a
partial resected proximal portion of a tibia of a patient, and a femoral
component and a tibial tray
for a partial knee replacement, according to an embodiment of the present
disclosure;
[0055] FIG. 41 is a side view of the tibial tray of FIG. 40, according to
an embodiment of the
present disclosure;
[0056] FIG. 42 is an inferior view of the tibial tray of FIG. 40, according
to an embodiment
of the present disclosure;
[0057] FIG. 43 is a superior perspective view of a tibia cavity cutting
guide for the tibial tray
of FIG. 40, according to an embodiment of the present disclosure;
[0058] FIG. 44 is a perspective view of a milling tool, according to an
embodiment of the
present disclosure;
[0059] FIG. 45 are perspective views of the three components for a total
knee replacement,
according to an embodiment of the present disclosure;
[0060] FIG. 46 is a perspective view of the components for a partial knee
replacement,
according to an embodiment of the present disclosure;
[0061] FIG. 47 is an inferior perspective view of a tibial tray, according
to an embodiment of
the present disclosure;
[0062] FIG. 48 is a superior perspective view of the tibial tray of FIG.
47, according to an
embodiment of the present disclosure;
[0063] FIG. 49 is another inferior perspective view of the tibial tray of
FIG. 47, according to
an embodiment of the present disclosure;
[0064] FIG. 50 is cross-sectional anterior view of a resected proximal
portion of a tibia and
the tibial tray of FIG. 47, according to an embodiment of the present
disclosure;
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[0065] FIG. 51 is a superior perspective view of a tibial tray, according
to an embodiment of
the present disclosure;
[0066] FIG. 52 is an inferior perspective view of the tibial tray of FIG.
51, according to an
embodiment of the present disclosure;
[0067] FIG. 53 is a posterior elevational view of the tibial tray of FIG.
51, according to an
embodiment of the present disclosure;
[0068] FIG. 54 is a superior view of the tibial tray of FIG. 51, according
to an embodiment
of the present disclosure;
[0069] FIG. 55 is an inferior view of the tibial tray of FIG. 51, according
to an embodiment
of the present disclosure;
[0070] FIG. 56 is a side elevational view of the tibial tray of FIG. 51,
according to an
embodiment of the present disclosure;
[0071] FIG. 57 is a superior perspective view of a tibial tray, according
to an embodiment of
the present disclosure;
[0072] FIG. 58 is a side elevational view of the tibial tray of FIG. 57,
according to an
embodiment of the present disclosure;
[0073] FIG. 59 is a superior view of the tibial tray of FIG. 57, according
to an embodiment
of the present disclosure;
[0074] FIG. 60 is a posterior view of the tibial tray of FIG. 57, according
to an embodiment
of the present disclosure;
[0075] FIG. 61 is another inferior view of the tibial tray of FIG. 57,
according to an
embodiment of the present disclosure;
[0076] FIG. 62 is a superior perspective view of a tibia cavity cutting
guide for the tibial tray
of FIG. 47, according to an embodiment of the present disclosure;
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[0077] FIG. 63 is a flowchart of a method, according to an embodiment of
the present
disclosure;
[0078] FIG. 64 is an inferior perspective view of a tibial tray system
having a tibial tray and
screw, according to an embodiment of the present disclosure;
[0079] FIG. 65 is a superior perspective view of the tibial tray of FIG.
64, according to an
embodiment of the present disclosure;
[0080] FIG. 66 is an inferior perspective view of the tibial tray of FIG.
64, according to an
embodiment of the present disclosure;
[0081] FIG. 67 is a cross-sectional anterior view of a resected proximal
portion of a tibia and
the tibial tray system of FIG. 64, according to an embodiment of the present
disclosure;
[0082] FIG. 68 is an inferior perspective view of a tibial tray system
having a tibial tray and
a plurality of screws, according to an embodiment of the present disclosure;
[0083] FIG. 69 is a superior perspective view of the tibial tray of FIG.
68, according to an
embodiment of the present disclosure;
[0084] FIG. 70 is an inferior perspective view of the tibial tray of FIG.
68, according to an
embodiment of the present disclosure;
[0085] FIG. 71 is a cross-sectional anterior view of a resected proximal
portion of a tibia and
the tibial tray system of FIG. 68, according to an embodiment of the present
disclosure;
[0086] FIG. 72 is a cross-sectional anterior view of a tibial tray system,
in part cross-section,
having a tibial tray and at least one screw. according to an embodiment of the
present disclosure;
[0087] FIG. 73 is an elevational view of a portion of a screw for use in a
tibial tray system,
according to an embodiment of the present disclosure; and
[0088] FIG. 74 is a flowchart of a method, according to an embodiment of
the present
disclosure.
DETAILED DESCRIPTION
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[0089] Generally stated, disclosed herein are resected proximal portions of
tibias, tibial trays,
and methods and robotic systems for forming the same.
[0090] In this detailed description and the following claims, the words
proximal, distal,
anterior, posterior, medial, lateral, superior, and inferior are defined by
their standard usage for
indicating a particular part of a bone or implant according to the relative
disposition of the
natural bone or directional terms of reference.
[0091] Positions or directions may be used herein with reference to
anatomical structures or
surfaces. For example, as the current devices and methods are described herein
with reference to
use with the bones of the knee, the bones of the knee may be used to describe
the surfaces,
positions, directions or orientations of the tibial trays, tibial tray
installation, and surgical
methods. Further, the devices and surgical methods, and the aspects,
components, features and
the like thereof, disclosed herein are described with respect to one side of
the body for brevity
purposes. However, as the human body is relatively symmetrical or mirrored
about a line of
symmetry (midline), it is hereby expressly contemplated that the devices and
surgical methods,
and the aspects, components, features and the like thereof, described and/or
illustrated herein
may be changed, varied, modified, reconfigured or otherwise altered for use or
association with
another side of the body for a same or similar purpose without departing from
the spirit and
scope of the disclosure. For example, the apparatus and surgical methods, and
the aspects,
components, features and the like thereof, described herein with respect to a
left knee may be
mirrored so that they likewise function with a right knee and vice versa.
[0092] Referring to the drawings, wherein like reference numerals are used
to indicate like or
analogous components throughout the several views, and with particular
reference to, for
example, FIGS. 1, 3, 4, 12-14, 15-21, 22 and 23, 24, and 25 therein
illustrated are exemplary
embodiments of tibial trays installed on a resected proximal portion of a
tibia in which portions
of the tibial tray are engageable and/or contactable with an underlying inner
surface of the
cortical bone for use in a knee replacement. As will be appreciated from the
description below,
the hard cortical bone of the tibia may provide fixation such as press fitting
into this dense bone
versus conventional tibial trays which rest on top of the hard cortical bone
with a keel in the
center in the softer cancellous bone. For example, the present disclosure may
result in improved
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fixation of uncemented tibial trays. FIG. 6 illustrates a method for use in
knee replacement
surgery, and FIG. 7 illustrates a system for effecting the resecting of the
proximal portion of a
tibia of a patient and for forming a corresponding, orientated, or matching
tibial tray. The
methods and systems may be operable for obtaining fully autonomous and
automatic resected
proximal tibias and corresponding tibial trays from, for example, CT scan
data. With reference to
FIGS. 26-30, therein illustrated are exemplary embodiments of tibial trays
installed on a resected
proximal portion of a tibia in which portions of the tibial tray are spaced
from and disposed
closely adjacent to an underlying inner surface of the cortical bone for use
in a knee replacement.
As will be appreciated from the description below, the peripheral cancellous
bone adjacent to the
cortical bone of the tibia may provide fixation to the proximal tibia versus
conventional tibial
trays which rest on top of the cortical bone with a keel disposed in the
center of the softer
cancellous bone. For example, the present disclosure may result an in improved
fixation of
uncemented tibial trays. FIG. 33 illustrates a method for use in knee
replacement surgery, for
example employing the tibial trays of FIGS. 26-30, which includes effecting
the resecting of the
proximal portion of a tibia of a patient, and for forming a corresponding,
orientated, or matching
tibial tray. FIG. 34 illustrates a robotic method for use in knee replacement
surgery, which
includes effecting the resecting of the proximal portion of a tibia of a
patient. The methods and
systems may be operable for obtaining fully autonomous and automatic resected
proximal tibias
and corresponding tibial trays from, for example, CT scan data.
[0093] In some embodiments, for example, a patient specific tibial tray
design may mitigate
aseptic loosening and subsidence through a combination of high peripheral
surface area contact,
underside surface geometry, and patient matched pegs that interface with
cortical metaphyseal
bone. The present disclosure may solve and/or overcome a primary cause for
knee implant
failure, namely, aseptic loosening of the tibial component and subsidence.
[0094] In some embodiments, the present disclosure is directed to methods
for generating a
three-dimensional model of a tibia and generating a cut plan for excavating a
portion of the tibia
with a robot or robotic excavator according to the cut plan to allow for the
insertion of a custom
tibial tray designed to increase or maximize cortical contact with the
periphery of the inner tibial
wall.
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[0095] In some embodiments, a technique of the present disclosure is
directed to maximizing
cortical contact of a tibial tray along the underlying inner surface of the
cortical wall of the tibia.
A virtual model of the proximal portion of a tibia bone may be used to
determine an improved
implant that is designed to achieve a higher level of cortical contact. A
processor may be
employed and configured to generate an excavation protocol for excavating bone
from the tibia
such that the amount of bone contact between the bone and the implant is
increased, such as 10
percent or greater, compared to convention tibial trays.
[0096] FIG. 1 illustrates a tibial tray 20 fitted to a resected proximal
portion of a tibia 10 for
a knee replacement, according to an embodiment of the present disclosure. In
this illustrated
embodiment, at least a portion of the tibial tray 20 when operably attached to
the resected
proximal portion of the tibia 10 interfaces and increases contact with an
inner surface or side
portion of the cortical bone 12 of the proximal portion of the tibia 10.
[0097] For example, the tibial tray 20 may include a body 22 having a
superior portion 24
and an inferior tibia-engaging portion 26. The superior portion 24 may include
a generally planar
superior surface 25 for supporting a plastic bearing spacer (not shown in FIG.
1). In some
embodiments, the surface 25 includes a peripheral upwardly-extending lip 27
for attaching via a
typical snap fit connection and restraining the plastic bearing spacer.
[0098] The tibia engaging portion 26 may include a center tibia engaging
portion 30 and a
peripheral tibia engaging portion 40. In this embodiment, the center tibia
engaging portion 30
may include a planar surface contactable with the center cancellous bone
surface of the resected
proximal portion of the tibia of the patient.
[0099] The peripheral tibia-engaging portion 40 may include at least one
inferiorly-extending
wall 50. The inferiorly-extending wall 50 may include an inner wall surface 52
and an outer wall
surface 54. The inner wall surface 52 may be disposed normal or at 90 degrees
to the superior
surface 25, or at any suitable angle or angles. The outer wall surface 54 may
be able to be
aligned with and abutting or contacting an inner surface 13 of the cortical
bone 12.
[00100] For example, the outer wall surface 54 may be disposed at an angle Al,
which may be
angled at about 25 degrees to about 45 degrees, about 30 degrees to about 40
degrees, about 35
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degrees, or other suitable angles relative to the superior surface 25 of the
tibial tray 20. The wall
50 is received in a cavity formed in the resected proximal portion of the
tibia 10. The cavity may
be formed in the cancellous bone, trabecular bone, spongy bone, or light
porous bone of the tibia.
The wall may increase the contact area with the inner surface 13 of the
cortical bone 12. A depth
D1 of the wall 50 may extend about 0.5 millimeters (mm) to about 75 mm, about
1 mm to about
50 mm, about 2 mm to about 40 mm, about 4 mm to about 20 mm, exceed 0.5 mm,
about 1 mm,
about 2 mm, about 3 mm, about 5 mm, about 7 mm, or other suitable depths. In
some
embodiments, the inferiorly-extending wall 50 may extend along at least 25
percent of the
periphery of the body 22, along at least 50 percent of the periphery of the
body 22, extend along
the entire periphery of the body 22, or extend along another suitable amount
along the periphery
of the body 22. The width W1 of the wall 50 may be about 5 mm to about 6 mm
and is desirably
greater than about 0.5 mm and less than about 50 mm. In some embodiments, the
peripheral edge
29 of the tibial tray 20 may include a lower surface 28 that extends over the
superior cut cortical
bone 19, e.g., edge 18. In some embodiments, the tibial tray 20 may feature a
keel 32 (shown in
dashed lines in FIG. 1) and support pins (not shown in FIG. 1). The access
cavity in the proximal
portion of the tibia and the tibial tray may be sized and formed manually by a
surgeon or as
described below, prepared automatically or fully automatically by a robot.
[00101] FIG. 2 illustrates a superior view of a resected proximal portion of a
tibia 110 of a
patient for a knee replacement, according to an embodiment of the present
disclosure. In this
illustrated embodiment, the resected proximal portion of the tibia 110 may
include a center
cancellous surface 111, and a cortical bone edge surface 118, a first U-shaped
cavity 115
disposed along one side of the proximal portion of the tibia 110, and a second
U-shaped cavity
117 disposed along an opposite side of the proximal portion of the tibia 110.
The cavities 115
and 117 may extend into the cancellous bone, trabecular bone, spongy bone, or
light porous bone
of the proximal portion of the tibia 110 adjacent to the inner surface of the
cortical bone 112 of
the proximal portion of the tibia 110. A depth of the cavity may extend about
0.5 millimeters
(mm) to about 75 mm, about 1 mm to about 50 mm, about 2 mm to about 40 mm,
about 4 mm to
about 20 mm, about 1 mm, about 2 mm, about 3 mm, about 5 mm, about 7 mm, or
other suitable
depth. The width W2 of the wall may be about 5 mm to about 6 mm and is
desirably greater than
about 0.5 mm and less than about 50 mm. A corresponding tibial tray (not shown
in FIG. 2) may
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have a peripheral edge portion of the tibial tray designed such that the outer
edge portion
approximates the shape of the tibial edge portion along a resection plane
parallel to the tibial
tray. As described in greater detail below, the proximal portion of the tibia
may be resected or
resurfaced manually or robotically such as fully automatically to receive a
corresponding tibial
tray.
[00102] FIG. 3 illustrates a tibial tray 320 fitted to a resected proximal
portion of a tibia 210
for a knee replacement, according to an embodiment of the present disclosure.
In this illustrated
embodiment, at least a portion of the tibial tray 320 when operably attached
to the resected
proximal portion of the tibia 210 interfaces and increases the contact area
with an inner side
portion of the cortical bone 212 of the proximal portion of the tibia 210.
[00103] The tibial tray 320 may include a body 322 having a superior portion
324 and an
inferior tibia-engaging portion 326. A superior surface 325 of the superior
portion 324 may be a
generally planar surface for supporting a plastic bearing spacer (not shown in
FIG. 3). In some
embodiments, the superior surface include a peripherally-extending lip for
securing the plastic
bearing spacer.
[00104] The tibia engaging portion 326 may include a tibia engaging center
portion 330
defining a recess 340 relative to a peripheral tibia-engaging portion 350. The
peripheral tibia-
engaging portion 350 may be a wall or a flat portion disposed around some or
all of the tibia
engaging center portion 330 and at an elevation different than the tibia
engaging center portion
330. The peripheral tibia-engaging portion 350 may be disposed in a cavity
formed in the
cancellous bone, trabecular bone, spongy bone, or light porous bone of the
proximal portion of
the tibia adjacent to the inner surface of the cortical bone of the proximal
portion of the tibia. The
peripheral tibia-engaging portion 350 may include an inner wall surface 352
and an outer wall
surface 354. The inner wall surface 352 may be disposed normal or at 90
degrees to the superior
surface 325 of the superior portion 324. The outer wall surface 354 may be
able to be aligned
with and abutting to an inner side surface 213 of the inner surface of the
cortical bone 212. A
depth D2 of the peripheral tibia-engaging portion 350 may exceed 0.5 mm and
may not exceed
75 mm. The geometric resurfacing of the proximal portion of the tibia may
result in the superior
and inferior portions along a resection plane (excluding a keel and pins)
having a depth D3
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greater than about 0.5 mm and less than about 15 mm. In some embodiments, a
tibial tray may
feature a keel and support pins. As described in greater detail below, the
proximal portion of the
tibia 210 may be resected manually or robotically to receive the corresponding
manually or
robotically formed tibial tray 320.
[00105] FIG. 4 illustrates a tibial tray 420 fitted to a resected proximal
portion of the tibia 410
for a knee replacement, according to an embodiment of the present disclosure.
In this illustrated
embodiment, the tibial tray 420 is designed to interface with curved surface
geometries and
support cavities of the resected proximal portion of the tibia 410.
[00106] For example, a typical proximal portion of the tibia bone may feature
a concave
minimum near the lateral condyle, a convex maximum near the intercondyle
eminence, and a
concave minimum near the medial condyle. The resected proximal portion of the
tibia 410 for a
knee replacement of the present disclosure may remove the damaged bone from
the proximal
portion of the tibia while shaping the bone to include a similar general
contour of a typical tibia
bone. The resurfaced proximal portion of the tibia bone 410 may feature a
concave minimum
416 near the lateral condyle, a convex maximum 417 near the intercondyle
eminence, and a
concave minimum 418 near the medial condyle. The concave minimum 416, the
convex
maximum 417, and/or the concave minimum 418 may extend into the cancellous
bone,
trabecular bone, spongy bone, or light porous bone of the proximal portion of
the tibia, which
lateral portions of the concave minimum 416, the convex maximum 417, and the
concave
minimum 418 may be disposed adjacent to and/or in contact with the underlying
inner surface of
the cortical bone 412 of the proximal portion of the tibia 410. The tibial
tray 420 may include an
inferior tibia-engaging portion having an inferior convex surface 426, an
inferior convex surface
428, and an inferior concave surface 427 disposed therebetween. The radius of
the concave
surfaces and the radius of the convex surface may be constant radiuses or have
varying
curvature. The outer edges of the convex surfaces, when viewed from below, may
have an oval
or a generally egg-shaped configuration.
[00107] The tibial tray 420 may include one or more pins 490 designed to
interface with the
underlying cortical bone 412. For example, as shown in FIG. 5, an array of
four holes 419 may
be located in each quadrant of the resected proximal portion of the tibia 410,
which holes 419
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receive pins 490 (FIG. 4). With reference again to FIG. 4, a bottom portion of
the pins 490 may
include an outer cylindrical portion that engages the sides of an opening in
the cortical bone 412.
Such contact area may be with the sides of the opening extending through the
cortical bone,
including contacting inner edge portions of the openings of the cortical bone,
and/or the inner
surfaces or surface portions of the cortical bone around the opening in the
inner surface of the
cortical bone. An inferior edge 492 of the pins 490 may be aligned with the
outer surface 411 of
the cortical bone 412. The periphery of the tibial tray 420 may define a shelf
or lip having a
thickness T, for example, of about 4 mm and a width W3 of about 2 mm.
[00108] The presently disclosed tibial trays may be operable with
conventional plastic spacers
and femoral components. For example, the superior surface of the presently
disclosed tribal trays
may include a surface having a general symmetrical or kidney bean shape
designed for
engagement with a standard plastic spacer component such as in a snap fit
manner. A tibial tray
with a variable thickness (by way of nonlimiting example, a rim) may exist at
the periphery of
the tibial tray such that tibial tray coverage is maximized along the
resection plane, but such that
engagement of a plastic spacer component is not compromised. The thickness of
the tibial rim
may be about 4 mm. In other embodiment the rim may exceed about 0.5 mm and be
less than
about 25 mm.
[00109] The tibial trays of the present disclosures may include a one-
piece, monolithic, or
integral body, or may be formed from two or more components. The tibial tray
may be made out
of a standard metallic implant material, such as titanium, cobalt chrome, or
other acceptable
stainless steels. In other embodiments, the tibial tray may of the present
disclosure may be made
out of a plastic or polymeric material.
[00110] FIG. 6 illustrates a method 600 for use in knee replacement surgery,
according to an
embodiment of the present disclosure. In this illustrated embodiment, the
method 600 is operable
in providing a customized cut plan of the proximal portion of the tibia for a
patient and providing
a corresponding customized tibial tray.
[00111] The method 600 may include, for example, at 610 obtaining first data
representing a
proximal portion of the tibia of the patient. At 620, second data of a patient
specific resected
proximal portion of the tibia of the patient is determined based on the first
data. The resected
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proximal portion of the tibia of the patient has a superior surface and one or
more cavities or
openings exposing an inferior portion of an underlying inner surface of the
cortical bone of the
tibia. At 630, a patient specific tibial tray having an inferior surface is
determined based on the
second data. At 640, the patient's tibia is resected based on the second data.
At 650, the tibial tray
is formed based on the second data, and at 660, the formed tibial tray is
secured onto the formed
resected proximal portion of the tibia so that an inferior portion of the
tibial tray extends into the
one or more cavities and/or openings and contacts the underlying inner surface
of the cortical
bone of the tibia.
[00112] FIG. 7 illustrates a block diagram of a system 700 for implementing,
for example, the
method 600 (FIG. 6) for use in knee replacement surgery, according to an
embodiment of the
present disclosure. In this illustrated system 700, for example, at least a
portion of a tibial tray
when operably attached to a resected proximal portion of the tibia of a
patient may interface and
increase the contact area with an underlying inner surface of the cortical
bone of the proximal
portion of the tibia of the patient. System 700 may generally include a
processing unit or
processor 710, input/output devices 720, and memory 730.
[00113] For example, tibia data 702 such as first data representing a proximal
portion of a
tibia of the patient (block 610 in FIG. 6) may be inputted to system 700.
Tibia data 702 may
include three-dimensional data obtained by, for example, a Computed Tomography
(CT) scan, a
Computerized Axial Tomography (CAT) scan, a Magnetic Resonance Imaging (MM)
scan, or
other suitable two-dimensional imaging or three dimensional imaging or
processing. Such data
may be provided directly from an imaging machine or retrievable from a
database of stored
medical image data. Further input data may include surgeon input 704 such as a
desired general
configuration of the tibial tray, desired tibial cuts, and/or other
information. The processor 710
may be a computer operating, for example, WINDOWS, OSX, UNIX or Linux
operating system.
In some embodiments, the processor 710 may be a portable or hand held
computing device. In
other embodiments, the processing unit 710 may be one or more operably
connected processing
units, computing devices, servers, linked or operating over one or more
networks such a global
communications network, e.g., the Internet.
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[00114] The memory 730 may include various modules for processing the input
data. For
example, the memory 730 may include a tibia cut generator 740, a robotic tibia
cut plan
generator 750, and a tibial tray generator 760.
[00115] The tibia cut generator 740 may be operable for determining the second
data
representative of the patient specific resected proximal portion of the tibia
of the patient based on
the first data (block 620, FIG. 6). For example, the second data may be based
on the first data,
which the first data includes the outer shape of the proximal portion of the
tibia, shape of the
intercondylar eminence, the lateral condyle, medial condyle, diseased or
damaged portions
thereof, inner surface of the cortical bone portion, spongy bone portion, and
other features. For
example, the second data may be identified with sub-voxel (e.g. volumetric
pixel data) accuracy
of the location of "cortical bone" (e.g., the location of the inner surface of
the cortical bone
region) relative to "outer surface of the cortical bone" (e.g., the location
of the outer surface of
the cortical bone region). Using such a high fidelity bone model, suitable
programing may be
provided for forming a virtual representation of a proposed resected proximal
portion of the tibia
for receiving a tibial tray that may be generated with a high degree of
compatibility with the
patient's bone. The resected proximal portion of the tibia of the patient may
include a superior
surface and one or more openings or cavities exposing an inferior or
underlying surface of the
cortical bone.
[00116] The cut generator 740 may include various modules such as a resection
surface
generator 742, a cavity generator 744, and an optimizing generator 746. The
resection generator
742 may allow for a surgeon to indicate, for example, a resection plane or
such plane may be
automatically generated provided, e.g., by input by a surgeon, or based on or
utilizing
predetermined data. For example, the resection plane may be determined as
disclosed in U.S.
patent application serial no. 16/153,334, entitled, "Apparatus, Method and
System for Providing
Customizable Bone Implants", the entire subject matter of which is
incorporated herein by
reference. The cavity generator 744 may include receiving initial inputs from
a surgeon such as
locations, widths, lengths, depths, or may be based on or utilizing
predetermined data.
Optimizing generator 746 may take the inputted or generated configuration of
the tibial tray, and
virtually test or compare such tibial tray installed in the resected tibia
based on forces likely to be
experienced. Automatically varying of the dimensions may allow for comparison
to previous
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developed configurations to optimize the configuration of the patient specific
resected tibia and
the tibial tray. In some embodiments, optimizing generator 746 may optimize
the depth of the
walls, the thickness of the walls, and the amount and location of the walls
that extend around the
tibial tray to result in a reduce removal amount needed of the cancellous
bone, thereby causing
less trauma to the tibial of the patient. In some embodiments, a suitable
module in the memory
730 may have suitable programming or algorithms for virtually testing a
resultant patient specific
proximal portion of the tibia and corresponding tibial tray, or for comparison
the resultant patient
specific proximal portion of the tibia and corresponding tibial tray against
exemplary acceptable
configurations. Such optimizing techniques are described below.
[00117] The robotic tibia cut plan generator 750 may be operable to determine
data or
instructions for operating a surgical robot 790 or other automated device for
forming the patient's
tibia based on the second data (block 640, FIG. 6). In some embodiments, a 3D
model of the
resected proximal portion of the patient's tibia may be uploaded to the robot
and the surgical
robot being operable to effect a tibia cut plan to resize the proximal portion
of the tibia
autonomously, or semi-autonomously to form, for example, a resection and form
the one or more
cavities or openings or to expose the underlying inner surface or portion of
the cortical bone. The
data or instructions may be combined with data received by the surgical robot
790 such as data
from local cameras imagers or sensors. A suitable surgical robot may be an LBR
iiwa Kuka
robot manufactured by KUKA ROBOTICS Corporation of Shelby Township, Michigan,
and
may be operable with one or more bone saws, rasps, saws, drills, and/or other
devices.
[00118] The tibial tray generator 760 may be operable to determine a
configuration of a
patient specific tibial tray having, for example, an inferior surface based on
the second data
(block 630, FIG. 6). For example, the tibial tray generator 760 may determine
the body of the
tibial tray having a periphery and inferior surface that matches or
corresponds to the resected
proximal portion of the tibia. In some embodiments, a 3D model of the tibial
tray may be used by
a 3D printer 795 or other manufacturing device known in the art for generating
a tibial tray. The
3D printer or manufacturing device may be operable to form the tibial trays,
as described above,
as a one-piece, monolithic, or integral body, or formed from one or more
components, and
formed from a standard metallic material, such as titanium, cobalt chrome, or
other acceptable
stainless steels. Alternative, a prototype or mold may be formed and used for
forming by casting
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or forging the tibial tray implant formed from, for example, a standard
metallic material, such as
titanium, cobalt chrome, or other acceptable stainless steels.
[00119] The technique of the present disclosure may solve the problem by more
closely
matching the native anatomy of the joint and thereby increasing the surface
area contact for
osseointegration and reducing shear forces along the implant to bone interface
plane.
Osseointegration (organic fixation) may occur from cortical contact. For
example, the system
may introduce patient specific wall, supports, or pegs that interface with the
underlying cortical
metaphyseal bone to add stability and resist subsidence. By mapping the
contours of the
metaphyseal bone (the transitional zone at which the diaphysis and epiphysis
of a bone come
together) such that a tibial tray can be formed and readily inserted.
A force F is said to have been resolved into two rectangular
components if its components are directed along the coordinate
axes. Introducing the unit vectors i and j along the x and y axes,
F = Fxi Fyj
Fx = F cos 0 Fy = F sin 0
Fy
Fy tin 0 =
Fx
0 F = "\\/FF, F2y
=
Fx = Fxi
[00120] Programming code or algorithms, such as in the tibia cut generator
750, may include
the introduction of non-planar shapes to the bottom of the tibial tray that
may increase the
surface area contact of the resected tibia significantly. By way of example,
the surface area of a
circle in a plane is characterized by the equation (Area of Circle = nr2). The
surface area of a
semi-spherical shape approximated by a half-sphere is characterized by the
equation (Area of a
half-sphere =2itr2). Thus, the introduction of semi-spherical shapes can
increase the surface area
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contact significantly. By way of nonlimiting example, a half-sphere has twice
the surface area of
a circle of equal radius. The configuration of a normal proximal portion of
the tibia is not a flat
plane, but the anatomy is characterized by concave and convex geometries, and
the tibia cut
generator 750 in determining the resected proximal portion of the tibia may be
based on the
surface area being non-parallel.
[00121] An approximation of these concave and convex surface features 900 is
illustrated in
FIG. 9, and a patient specific knee may be designed such as in the tibia cut
generator 740 (FIG.
7) to generally approximate these anatomical surface features. Notably, these
surface features
may be geometrically approximated such that the minimum height as measured
between the
lowest and highest members along the resection plane excluding the keel and
pins shall exceed
about 0.5 mm and the maximum height as measured between the lowest and highest
members
along the resection plane excluding the keel and pins shall not exceed about
25 mm. It is
understood that the medial and lateral condyles and intercodyle eminence may
generally
approximate regions of local maximum and minimum or minimum and maximum along
the
resection plane. In some embodiments, programming code or algorithms in the
tibia cut
generator 740 (FIG. 7) may determine the resected proximal portion of the
tibia based on one or
more angled surfaces, and the resulting shear forces. For example, the shear
force at any point of
the implant to bone contact plane may be characterized by and based on the
equation Fx =
Fcos(theta) where shear force is reduced as theta is increased.
[00122] FIG. 10 illustrates two bone-to-implant interfaces of the support pins
and the cortical
metaphyseal bone, which may be flat or curved such that the surface area
contact is reasonably
maximized. Such analysis may be employed in the optimizing generator 746 (FIG.
7).
[00123] In other embodiments, auto-segmentation and implant generation
algorithms may be
utilized with a surgical robot to introduce pre-planned semi-oblong irregular
shapes and cavities
into the proximal tibial surface that are designed for engagement with a
conforming patient
specific tibial tray generated by the algorithms. For example, a pre-operative
anatomy of the tibia
is characterized by segmentation and implant generation algorithms, which are
designed to
output a robotic surgical plan and a corresponding patient specific implant.
The algorithm
outputs may be designed to loosely reconstruct the pre-operative curvature of
the native anatomy
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(geometric approximations of the proximal surface of the tibia, specifically
the medial and lateral
condyles, intercondyle eminence and medial and lateral curved plateaus) as
well as may
introduce cavities for pegs of variable length and with high conformity to the
underlying bone.
The algorithm may map the contours of the metaphyseal bone such that a high
conformity
implant can be inserted. The surgical robot may prepare these surface features
with tissue
ablation tooling (for example a burrs, sagittal saws, drills, etc.) and the
implant may be 3D
printed, forged or cast.
[00124] The tibial tray may be aligned at the surgeon's discretion and input
or by system 700.
The total knee arthroplasties (TKA) of the present disclosure may be aligned
with the tibial
component, which is positioned perpendicular to the anatomic axis of the tibia
similar to
conventional TKAs. For example, the anatomic axis may be colinear with the
mechanical axis
unless there is some unusual deformity. Alternatively, a so-called kinematic
or anatomic
technique may be employed in which the goal is to recreate the native sagittal
and coronal
orientation of the tibial joint surface (e.g., restore the joint surface to
where it was before arthritis
set in). There is variation in the native alignment of the tibia. The coronal
alignment typically
averages 3 degrees of varus and the sagittal (posterior slope) averages 7
degrees or so but ranges
widely between 0 and 15+. The algorithms in the tibia cut generator may be
able to apply either
technique.
[00125] FIG. 8 illustrates a block diagram of a system 800 for implementing,
for example, the
method 600 (FIG. 6) for use in knee replacement surgery, according to an
embodiment of the
present disclosure.
[00126] FIG. 11 illustrates a block diagram of a robotic method 1200 for
resecting a tibia of a
patient for a knee replacement. The method 1200 includes, for example, at 1210
obtaining, via a
processor, first data representing a proximal portion of the tibia of the
patient. The method
further may include at 1220 determining, via the processor, second data of a
patient specific
resected proximal portion of the tibia of the patient based on the first data
and based on location
of an inner surface of the cortical bone of the tibia. The method may also
include at 1230
forming, via the processor, the tibia of the patent based on the second data
of the patient specific
resected proximal portion of the tibia, the resected proximal portion of the
tibia of the patient
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having one or more cavities and/or openings exposing an inferior portion of an
inner surface of
the cortical bone of the tibia.
[00127] FIGS. 12-14 illustrate a tibial tray 1320, according to an embodiment
of the present
disclosure. In this illustrated embodiment, at least a portion of the tibial
tray 1320 when operably
attached to a resected proximal portion of a tibia of a patient will interface
and increase the
contact area with a side portion of an inner surface of the cortical bone of a
proximal portion of
the tibia. For example, the tibial tray 1320 may be configured similar to
tibial tray 20 (FIG. 1). In
this embodiment, tibial tray 1320 does not include a keel.
[00128] FIGS. 15-19 illustrate a tibial tray 1420, according to an embodiment
of the present
disclosure. For example, the tibial tray 1420 may be configured similar to
tibial tray 1320 (FIGS.
12-14) with the addition of a keel 1421 (FIGS. 17-20). FIGS. 20 and 21
illustrate tibial tray 1420
disposed on a resected proximal portion of a tibia 1410 of a patient.
[00129] FIGS. 22 and 23 illustrate a tibial tray 1520, according to an
embodiment of the
present disclosure. In this illustrated embodiment, at least a portion of the
tibial tray 1520 when
operably attached to a resected proximal portion of a tibia of a patient will
interface and increase
the contact area with an inner surface of an inner surface of the cortical
bone of a proximal
portion of the tibia. For example, the tibial tray 1520 may be configured
similar to a combination
of tibial tray 20 (FIG. 1) and tibial tray 420 (FIG. 4). In this embodiment,
tibial tray 1520 may
include a tibia engaging portion having peripheral walls and a non-planar
center portion. The
center portion may be designed to interface with curved surface geometries and
support cavities
of a resected proximal portion of a tibia. For example, the center portions of
the tibial tray may
include a convex minimum near the lateral condyle, a concave maximum near the
intercondyle
eminence, and a convex minimum near the medial condyle. The outer edges of the
convex
surfaces, as shown in FIG. 23, may have an oval or a generally egg-shaped
configuration.
[00130] FIG. 24 illustrates a tibial tray 1620, according to an embodiment of
the present
disclosure. In this illustrated embodiment, at least a portion of the tibial
tray 1620 when operably
attached to a resected proximal portion of a tibia 1610 of a patient will
interface and increase the
contact area with an inner surface of a cortical bone of a proximal portion of
the tibia. For
example, the tibial tray 1620 may be configured to be received between inner
surface portions of
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the cortical bone. In this embodiment, a resected portion of the patient's
tibia may be along a
plane P1. Cavities may be provided in the patient's tibia for receiving
inferiorly-extending
peripheral portions 1650 of the tibia engaging portion of the tibial tray
1620. In this embodiment,
the tibial tray does not sit on top of the resected superior edge of the
cortical bone of the patient's
tibia, but instead extends above the top of the resected superior edge of the
cortical bone of the
patient's tibia.
[00131] FIG. 25 illustrates a tibial tray 1720, according to an embodiment of
the present
disclosure. In this illustrated embodiment, at least a portion of the tibial
tray 1720 when operably
attached to a resected proximal portion of a tibia 1710 of a patient will
interface and increase the
contact area with a side portion of an inner surface of the cortical bone of a
proximal portion of
the tibia. For example, the tibial tray 1620 may be configured to be received
between inner
surface portions of the cortical bone. In this embodiment, a resected portion
of the patient's tibia
may be along a plane P1. An initial cavity may be formed having an inferior
surface disposed
along a plane P2, and cavities may be provided in the patient's tibia for
receiving inferiorly-
extending peripheral portions 1750 of the tibia engaging portion of the tibial
tray 1720. In this
embodiment, the tibial tray does not sit on top of the resected superior edge
of the cortical bone
of the patient's tibia, but instead extends generally even with the top of the
resected superior edge
of the cortical bone of the patient's tibia.
[00132] With reference to FIGS. 26-29, therein illustrated are exemplary
embodiments of
tibial trays installed on a resected proximal portion of a tibia in which
portions of the tibial tray
are spaced from and disposed closely adjacent to an underlying inner surface
of the cortical bone
for use in a total knee replacement.
[00133] In some embodiments, for example, a patient specific tibial tray
design may mitigate
aseptic loosening and subsidence through a combination of high underlying
peripheral surface
area contact and underside surface geometry that interfaces more closely with
peripheral
cancellous bone adjacent to the cortical bone. The present disclosure may
solve and/or overcome
a primary cause for knee implant failure, namely, aseptic loosening of the
tibial component and
subsidence.
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[00134] In some embodiments, the present disclosure is directed to methods for
generating a
three-dimensional model of a tibia and generating a cut plan for excavating a
portion of the tibia
with a robot or robotic excavator according to the cut plan to allow for the
insertion of a custom
tibial tray designed with one or more peripheral inferiorly-extending portions
designed to be
spaced from the periphery of the underlying tibial cortical bone.
[00135] In some embodiments, a technique of the present disclosure is directed
to increasing
stability of the tibial tray relative to the resected proximal portion of the
tibia by employing one
or more peripheral inferiorly-extending portions designed to be spaced from
the periphery of the
underlying tibial cortical bone. A virtual model of the proximal portion of a
tibia bone may be
used to determine an improved implant that is designed to achieve a higher
level of stability. A
processor may be employed and configured to generate an excavation protocol
for resecting the
proximal tibia and excavating cancellous bone from the tibia such that the
amount of contact
between the tibia and the implant is increased, by, for example, an amount of
10 percent or
greater contact compared to convention tibial trays.
[00136] FIG.
26 illustrates a tibial tray 2020 fitted to a resected proximal portion of a
tibia
2010 for a total knee replacement, according to an embodiment of the present
disclosure. In this
illustrated embodiment, at least a portion of the tibial tray 2020 when
operably attached to the
resected proximal portion of the tibia 2010 includes peripheral inferiorly-
extending portions
extending onto the cancellous bone 2011 designed to be offset or spaced from
the periphery of
the underlying tibial cortical bone 2012 of the proximal portion of the tibia
2010.
[00137] For example, as shown in FIG. 27, the tibial tray 2020 may include a
body 2022
having a superior portion 2024 and an inferior tibia-engaging portion 2026.
The superior portion
2024 may include a generally planar superior surface 2025 (best shown in FIG.
26) for
supporting a plastic bearing spacer (not shown). In some embodiments, the
planar superior
surface 2025 includes a peripheral upwardly-extending lip 2027 (FIG. 26) for
attaching via a
snap fit connection and restraining the plastic bearing spacer.
[00138] With reference still to FIG. 27, the tibia engaging portion 2026 may
include a center
tibia engaging portion 2030, and a first peripheral tibia engaging portion
2040. In this
embodiment, the center tibia engaging portion 2030 may include a contoured
surface contactable
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with the center cancellous bone surface of the resected proximal portion of
the tibia of the
patient. For example, the center tibia engaging portion may include one or
more concave,
convex, or planar surfaces contactable with the center cancellous bone surface
of the resected
proximal portion of the tibia of the patient as similarly described above.
[00139] The peripheral tibia-engaging portion 2040 may include at least one
inferiorly-
extending wall, and may include a first inferiorly-extending wall 2050 and a
spaced apart second
inferiorly-extending wall 2051. The first inferiorly-extending wall 2050 may
include an inner
wall surface 2052 and an outer wall surface 2054. For example, the walls 2052
and 2054 may be
U-shaped walls facing each other. The second inferiorly-extending wall 2051
may include an
inner wall surface 2053 and an outer wall surface 2055. The walls 2050 and
2051 may be a
mirror image of wall 2050 and may have constant thicknesses, different
thickness, varying
thickness, or other suitable thicknesses. The inner wall surfaces 2052 and
2053 may be disposed
normal or at 90 degrees to the superior surface 2025, or at any suitable angle
or angles. The outer
wall surfaces 2054 and 2055 may be disposed normal or at 90 degrees to the
superior surface
2025. In other embodiments, the outer wall surface may be angled relative to
the superior surface
such as parallel with and spaced from an inner surface 2013 (FIG. 26) of the
cortical bone 2012
(FIG. 26).
[00140] FIG. 28 illustrates a superior view of the resected proximal portion
of the tibia 2010
of FIG. 26 of the patient for the total knee replacement, according to an
embodiment of the
present disclosure. In this illustrated embodiment, the resected proximal
portion of the tibia 2010
may include the cancellous bone 2011 having a center cancellous surface 2015,
and the cortical
bone 2012 having a cortical bone edge surface 2018. The cancellous bone 2011
may include a
first U-shaped cavity 2115 disposed along one side such as the medial side of
the proximal
portion of the tibia 2010, and a second U-shaped cavity 2117 disposed along an
opposite side
such as the lateral side of the proximal portion of the tibia 2010. The first
U-shaped cavity 2115
may include an inner surface 2125 and an outer surface 2126. The second U-
shaped cavity 2117
may include an inner surface 2127 and an outer surface 2128. The cavities 2115
and 2117 may
extend into the cancellous bone 2011 (e.g., trabecular bone, spongy bone, or
porous bone) of the
proximal portion of the tibia 2010 adjacent to the inner surface 2013 of the
cortical bone 2012 of
the proximal portion of the tibia 2010. The walls 2050 and 2051 (FIG. 27) are
receivable in
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cavities 2115 and 2017 formed in the resected proximal portion of the tibia
2010. For example,
cavities 2115 and 2017 may be sized and configured to correspond to and
receive walls 2050 and
2051 (FIG. 27) when tibial tray 2020 is positioned on resected proximal tibia
2010,
[00141] The inner wall surface 2052 of the first wall 2050 may be disposed
adjacent to or abut
the inner surface 2125 of the first U-shaped cavity 2115, the outer wall
surface 2054 of the first
wall 2050 may be disposed adjacent to or abut the outer surface 2126 of the
first U-shaped cavity
2115, the inner wall surface 2053 of the second wall 2051 may be disposed
adjacent to or abut
the inner surface 2127 of the second U-shaped cavity 2117, and the outer wall
surface 2055 of
the second wall 2051 may be disposed adjacent to or abut the outer surface
2128 of the second
U-shaped cavity 2117.
[00142] With reference again to FIG. 26, a depth D5 of the wall 2050 may
extend for
example, about 0.5 millimeters (mm) to about 75 mm, about 1 mm to about 50 mm,
about 2 mm
to about 40 mm, about 4 mm to about 20 mm, exceed 0.5 mm, about 1 mm, about 2
mm, about 3
mm, about 5 mm, about 7 mm, or other suitable depth. A width W5 of the wall
2050 may be, for
example, about 5 mm to about 6 mm and is desirably greater than about 0.5 mm
and less than
about 50 mm. The lower portion of the outer surface 2054 of the wall 2050 may
be spaced from
the inner surface 2013 of the cortical bone 2012 a distance L5 of, for
example, about 0.5 mm,
about 1 mm, about 2 mm, between 0.05 mm and about 10 mm, between about 0.5 mm
and about
mm, between about 1 mm and about 2 mm, or other suitable distance.
[00143] With reference again to FIG. 27, in some embodiments, the inferiorly-
extending walls
2050 and 2051 may extend along, for example, at least 25 percent of the
periphery of the body
2022, along at least 50 percent of the periphery of the body 2022, extend
along the entire
periphery of the body 2022, or extend along another suitable amount along the
periphery of the
body 2022. In some embodiments, a peripheral edge 2029 of the tibial tray 2020
may include a
lower surface 2028 that extends over the superior cut cortical bone 2018 (FIG.
28). In some
embodiments, the tibial tray 2020 may feature a keel (not shown in FIG. 27).
The resection of the
proximal tibia and access cavities in the cancellous bone in the proximal
portion of the tibia and
the corresponding tibial tray may be sized and formed manually by a surgeon or
as described
above, prepared automatically by a robot.
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[00144] FIG.
29 illustrates a tibial tray 3020 fitted to a resected proximal portion of a
tibia
3010 for a total knee replacement, according to an embodiment of the present
disclosure. In this
illustrated embodiment, at least a portion of the tibial tray 3020, when
operably attached to the
resected proximal portion of the tibia 3010, includes peripheral inferiorly-
extending portions
extending onto the cancellous bone 3011. The peripheral inferiorly-extending
portions are
designed to be spaced such as offset and parallel to the periphery of the
underlying tibial cortical
bone 3012 of the proximal portion of the tibia 3010.
[00145] For example, as shown in FIG. 30, the tibial tray 3020 may include a
body 3022
having a superior portion 3024 and an inferior tibia-engaging portion 3026.
The superior portion
3024 may include a generally planar superior surface 3025 (best shown in FIG.
29) for
supporting a plastic bearing spacer (not shown). In some embodiments, the
planar superior
surface 3025 includes a peripheral upwardly-extending lip 3027 (FIG. 29) for
attaching via a
typical snap fit connection and restraining the plastic bearing spacer.
[00146] The tibia engaging portion 3026 may include a center tibia engaging
portion 3030 and
a peripheral tibia engaging portion 3040. In this embodiment, the center tibia
engaging portion
3030 may include a contoured surface contactable with the center cancellous
bone surface of the
resected proximal portion of the tibia of the patient. For example, the center
tibia engaging
portion may include one or more concave, convex, or planar surfaces
contactable with the center
cancellous bone surface of the resected proximal portion of the tibia of the
patient as similarly
described above.
[00147] The peripheral tibia-engaging portion 3040 may include at least one
inferiorly-
extending wall having portions disposed at different depths. Peripheral tibia-
engaging portion
3040 may include, for example, a first inferiorly-extending wall 3050 and a
spaced apart second
inferiorly-extending wall 3051. Peripheral tibia-engaging portion 3040 may
further include a
connecting inferiorly-extending wall 3070, a first inwardly-extending wall
3080, and a second
inwardly-extending wall 3090. The connecting inferiorly-extending wall 3080
may extend
between the first inferiorly-extending wall 3050 and the spaced apart second
inferiorly-extending
wall 3051. The inwardly facing ends 3081 and 3091 of first inwardly-extending
wall 3080 and a
second inwardly-extending wall 3090, respectively, may define a gap G disposed
along the
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posterior side of the tibial tray 3020. The gap G may inhibit the need to
sacrifice tendons and
ligaments at the posterior side of the proximal tibia.
[00148] The first inferiorly-extending wall 3050 may include an inner wall
surface 3052 and
an outer wall surface 3054. The second inferiorly-extending wall 3051 may
include an inner wall
surface 3053 and an outer wall surface 3055. The walls 3050 and 3051 may have
generally
constant thicknesses being rounded at the inferiormost end.
[00149] The inner wall surfaces 3052 and 3053 may be disposed normal or at 90
degrees to
the superior surface 3025, or at any suitable angle or angles. The outer wall
surfaces 3054 and
3055 may be sized and configured to provide a generally constant space S (FIG.
29) between the
outer wall surfaces 3054 and 3055 and the adjacent inner surface 3013 (FIG.
29) of the cortical
bone 3012 (FIG. 29).
[00150] With reference again to FIG. 29, the outer surfaces of the walls may
be spaced from
the inner surface 3031 of the cortical bone, for example, by a distance L6 of
about 0.5 mm, about
1 mm, about 2 mm, between 0.05 mm and about 10 mm, between about 0.5 mm and
about 5
mm, between about 1 mm and about 2 mm, or other suitable distance.
[00151] With reference again to FIG. 30, a depth D6 of the walls 3050 and 3051
may extend,
for example, about 0.5 mm to about 75 mm, about 1 mm to about 50 mm, about 2
mm to about
40 mm, about 4 mm to about 20 mm, exceed about 0.5 mm, about 1 mm, about 2 mm,
about 3
mm, about 5 mm, about 7 mm, or other suitable depths. A depth D7 of the
connecting wall 3070
and inwardly extending walls 3080 and 3090 may extend, for example, about 0.5
mm to about 75
mm, about 1 mm to about 50 mm, about 2 mm to about 40 mm, about 4 mm to about
20 mm,
exceed about 0.5 mm, about 1 mm, about 2 mm, about 3 mm, about 5 mm, about 7
mm, or other
suitable depths. In some embodiments, the depth D7 of the connecting wall 3070
and inwardly
extending walls 3080 and 3090 may be, for example, about 20 percent, about 25
percent, about
30 percent, or other suitable percentage of depth D6. A width W6 of the walls
3050 and 3051
may be, for example, about 5 mm to about 6 mm and is desirably greater than
about 0.5 mm and
less than about 50 mm. A width W7 of the walls 3070, 3080, and 3090 may be,
for example,
about 5 mm to about 6 mm and is desirably greater than about 0.5 mm and less
than about 50
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mm. In some embodiments width W7 may be, for example, less that width W6, such
as width
W7 being half the width compared to width W6.
[00152] With reference again to FIG. 29, the resection of the proximal tibia
3010 and access
cavities in the cancellous bone in the proximal portion of the tibia and the
corresponding tibial
tray 3020 may be sized and formed manually by a surgeon or as described above,
prepared
automatically by a robot.
[00153] FIGS. 31 and 32 illustrate a tibial tray 4020 (FIG. 31) according to
an embodiment of
the present disclosure, which may be fitted to a resected proximal portion of
a tibia 4010 (FIG.
32) of a patient for a total knee replacement. In this illustrated embodiment,
at least a portion of
the tibial tray 4020, when operably attached to the resected proximal portion
of a tibia 4010
(FIG. 32) of a patient, includes peripheral inferiorly-extending portions
extending onto the
cancellous bone 4011 (FIG. 32) in close proximity to the cortical wall of the
resected proximal
tibia. The peripheral inferiorly-extending portions may be designed to be
spaced such as offset
and/or parallel to the periphery of the underlying tibial cortical bone of the
proximal portion of
the tibia of the patient.
[00154] As illustrated in FIG. 31, tibial tray 4020 may have asymmetrical
convex surfaces
4030 and 4031, and asymmetrical peripheral inferiorly-extending portions 4052
and 4053
extending from the undersurface of the tibial tray 4020 to enhance force
distribution over the
medial and lateral compartments, and may further include a rim 4018 that
extends around some,
almost all, or all of the entire periphery of the tibial tray 4020. In
addition to portions of the tibial
tray being asymmetrical, the peripheral inferiorly-extending portion 4052 may
be angled and
thinner that the peripheral inferiorly-extending portion 4053, which is
thicker and aligned more
vertically.
[00155] In the various embodiments, desirably, the cavities and walls do not
penetrate the
outer cortical bone. In other embodiments, a portion of the cavities or walls
such as the lower
portions thereof may contact or extend into the cortical bone.
[00156] FIG. 33 illustrates a method 6000 for use in total knee replacement
surgery, according
to an embodiment of the present disclosure. In this illustrated embodiment,
the method 5000 is
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operable in providing a customized cut plan of the proximal portion of the
tibia for a patient and
in providing a corresponding customized tibial tray. The method 5000 may
include, for example,
at 5100 obtaining first data representing a proximal portion of the tibia of
the patient. At 5200,
second data of a patient specific resected proximal portion of the tibia of
the patient is
determined based on the first data. The resected proximal portion of the tibia
of the patient has a
superior surface and at least one cavity in the cancellous bone exposing a
peripheral underlying
portion of the cancellous bone of the tibia of the patient. At 5300, a patient
specific tibial tray
having an inferior surface is determined based on the second data. At 5400,
the patient's tibia is
resected based on the second data. At 5500, the tibial tray is formed based on
the second data,
and at 5600, the formed tibial tray is secured onto the resected proximal
portion of the tibia so
that a peripheral inferior portion of the tibial tray extends into the at
least one cavity and is
spaced apart from the underlying cortical bone of the tibia of the patient.
[00157] FIG. 34 illustrates a block diagram of a robotic method 6000 for
resecting a tibia of a
patient for a total knee replacement. The method 6000 includes, for example,
at 6100 obtaining,
via a processor, first data representing a proximal portion of the tibia of
the patient having
centralized cancellous bone and peripheral cortical bone. The method further
may include at
6200 determining, via the processor, second data representing a patient
specific resected
proximal portion of the tibia of the patient having a center cancellous bone
surface, a peripheral
cortical bone surface, and at least one cavity formed in the cancellous bone
surface spaced apart
from the cortical bone exposing a peripheral underlying portion of the
cancellous bone of the
tibia of the patient based on the first data. The method may also include at
6300 forming, via the
processor, the tibia of the patent based on the second data representing the
patient specific
resected proximal portion of the tibia, the resected proximal portion of the
tibia of the patient
having a center cancellous bone surface, a peripheral cortical bone surface,
and at least one
cavity exposing a peripheral underlying portion of the cancellous bone spaced
apart from the
underlying inner surface of the cortical bone of the tibia of the patient.
[00158] In further embodiments, a patient matched or customized tibial tray
may include, for
example, inferiorly-extending pegs, flanges, fins, etc. that are positioned at
or near the peripheral
edge of the tibial tray and which, when installed, is received in one or more
cavities or holes in
the cancellous bone spaced apart from and in close proximity with the
underlying inner surface
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of the cortical bone in the resected proximal portion of the patient's tibia.
An alternative
embodiment of the tibial tray may have, for example, asymmetrical convex
elements extending
from the undersurface of the tray to enhance force distribution over the
medial and lateral
compartments and a rim that extends around all, almost the entire, or a
portion of the peripheral
superior surface of the resected cortical bone.
[00159] The present disclosure is also directed to methods and systems for
generating a three
dimensional cut plan for excavating portions of the proximal tibia for a total
knee replacement
using a robot or robotic excavator according to the cut plan to create
cavities that allow for the
insertion of the custom tibial trays shown and described in connection with
FIGS. 26-30, which
may be effected using the system 700 of FIG. 7 and system 800 of FIG. 8, and
which may result
in increased or maximized stabilization of the tibial tray post-implantation.
The robot may
employ images or cameras for optical tracking to navigate the anatomy and may
actively create
the custom cavities, for example, may not need to rely on haptic feedback or a
surgeon to
execute the cuts.
[00160] FIG. 35 illustrates a proximal portion of a tibia 7000 of a patient
for a total knee
replacement, according to an embodiment of the present disclosure. The lateral
portion and/or
the medial portion may include a portion of the cortical bone 7012 that
extends inwardly towards
the uppermost portion of the tibia 7000. For example, as show in FIG. 35, a
proximal lateral
portion 7015 of the cortical bone 7012 of the tibia 7000 may extend inwardly
towards the
uppermost portion of the tibia 7000 resulting in an inner surface 7016 of the
cortical bone 7012
having an inner concave surface.
[00161] As
described above, the tibial trays according to the present disclosure for use
in a
total knee replacement may include one or more inferiorly-extending walls with
an outer wall
surface and an inner wall surface. The outer wall surface may be configured to
correspond and
contact an underlying inner surface of the cortical bone or be spaced from and
disposed closely
adjacent to an underlying inner surface of the cortical bone. It will be
appreciated that a tibial
tray having an inferiorly-extending wall corresponding to the location of the
lateral cortical bone
having an inner concave surface 7016 below a resection plane RP 1 may result
in the one or more
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inferiorly-extending walls of the tibial tray not being insertable in the
resected proximal tibia
with one or more cavities for receiving the one or more inferiorly-extending
walls.
[00162] As shown in FIG. 35, a flat resection plane may be resection plane RP
1 that is
positioned perpendicular to an anatomic axis A of the tibia 7000. With
reference to FIG. 36, in
order for a tibial tray 8000 to be insertable close proximity to the inner
surface of the cortical
bone 7012 (FIG. 35), an angle a between a bottom surface 8003 of the tibial
tray 8000, which
bottom surface 8003 rests on the flat resection plane RP 1, and an outer
surface 8054 of the one
or more inferiorly-extending walls 8050 must be equal to or greater than 90
degrees. For the
tibial tray 8000 to be insertable the angle I between the bottom surface 8003
of the tibial tray
8000 and an inner surface 8052 of the one or more inferiorly-extending walls
8050 must be equal
to or greater than 90 degrees.
[00163] With reference to FIG. 37, in the design and/or fabrication of a
tibial tray, for
example, using the system 700 (FIG. 7) or system 800 (FIG. 8) the method may
include
algorithms or programing code to maintain the ability to insert a tibial tray
8500 with the one or
more inferiorly-extending walls 8550 in a resected proximal portion of a
tibia. To maintain the
ability to insert the tibial tray implant, one of more constraints may be
imposed on the design of
the outer surface of the one or more inferiorly-extending walls 8550 of the
tibial tray 8500. For
example, in the design and/or fabrication of the one or more inferiorly-
extending walls 8550 of
the tibial tray 8500 where the cortical bone underlying a resection plane
defines an inner concave
surface (e.g., inner concave surface 7016 in FIG. 35), the superior edge 7400
(FIG. 35) of the
cortical bone 7012 (FIG. 35) along the resection plane RP 1 (FIG. 35) may
define a constraint so
that the resulting outer surface 8554 of the inferiorly-depending wall 8550 is
vertical or extends
inwardly. In some embodiments, relative to an anatomic axis A (or other
arbitrary axis or vertical
reference) of the tibia 7000, horizontal distances dl and d2 between the outer
surface of the
inferiorly-extending wall and the anatomic axis A may decrease from the
proximal portion of the
outer surface of the inferiorly-extending wall to the distal portion of the
outer surface of the
inferiorly-extending wall.
[00164] As shown in FIG. 38, a tibial tray 8700 may be designed and/or
fabricated with
constraints on the outer surface of the inferiorly-extending wall 8750 based
on an underlying
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contoured cortical bone inner surface. For example, an outer surface portion
8757 of the
inferiorly-extending wall 8750 may be configured to correspond to the shape of
the underlying
contoured cortical bone inner surface. Outer surface portion 8759 of the
inferiorly-extending
wall 8750 may be constrained by the superior edge 7400 (FIG. 35) of the
cortical bone 7012
(FIG. 35) along the resection plane RP1 (FIG. 35) resulting in the outer
surface portion 8759
having an outer vertical wall surface or a curved outer wall surface
perpendicular to the bottom
surface of the tibial tray.
[00165] In some embodiments, for example, for clinical reasons a resection
plane may not be
flat, but instead need to be disposed on an angle. If the implant was designed
assuming a flat
resection plane, but inserted onto an angled resection plane, clinical
problems may be introduced.
For example, the inferiorly-extending wall may not accurately correspond to
the inner surface of
a cortical wall and/or may even contact and/or penetrate the cortical bone.
[00166] With reference to FIG. 39, in some embodiments, due to clinical
reasons such as
injury or disease, a resection plane RP2 may be required and designed and/or
fabricated using the
system 700 (FIG. 7) or system 800 (FIG. 8) to be on an angle, e.g., a
resection plane RP2 may be
resection plane that is positioned at a non-perpendicular angle to the
anatomic axis A of the tibia.
To compensate for this approach, a tibial tray 9000 design process may account
for the angle of
the resection plane relative to the anatomic axis A of the tibia, which angle
may be determined
pre-operatively by algorithms or program code and/or by a surgeon. In the
event of an angled
resection plane, the insertion calculations described above may be employed,
but amended to
account for the angle 0, between the resection plane RP2 and a horizontal
plane HP
perpendicular to the anatomic axis A of the tibia. For example, angle 0 may be
added to angle a
and angle (3.
[00167] FIG. 40 illustrates a tibial tray 10020 fitted to a partial
resected proximal portion of a
tibia 10010 for a partial knee replacement, according to an embodiment of the
present disclosure.
As illustrated, such a partial unicompartmental knee replacement (PUKR)
replaces only a portion
of a proximal portion of a damaged tibia as it leaves intact at least one of
the natural bearing
surfaces of the knee. For example, the tibial tray 10020 may replace either an
inside (medial) part
of a proximal tibia or an outside (lateral) part of a proximal part of a
tibia. In this illustrated
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embodiment, at least a portion of the tibial tray 10020 when operably attached
to the resected
proximal portion of the tibia 10010 interfaces and increases contact with or
may be spaced
closely to an inner surface or side portion of the cortical bone 100012 of the
proximal portion of
the tibia 10010.
[00168] For example, as shown in FIGS. 41 and 42, the tibial tray 10020 may
include a body
10022 having a superior portion 10024 (FIG. 41) and an inferior tibia-engaging
portion 10026.
The body 10022 may include a peripheral edge 10023 that corresponds to a
portion of the outer
surface of the cortical bone along the resected surface of the tibia, and a
peripheral edge 10024
that spans across the center of the resected surface of the tibia. Peripheral
edge 10024 may be
disposed across the axis A (FIG. 40) of the tibia or spaced from the axis A
(FIG. 40) of the tibia.
[00169] The superior portion 10024 may include a generally planar superior
surface 10025
(FIG. 41) for supporting a plastic bearing spacer (not shown). In some
embodiments, the planar
superior surface 10025 may include a peripheral upwardly-extending lip (not
shown) for
attaching via a snap fit connection and restraining the plastic bearing
spacer.
[00170] With reference again to FIG. 41, the tibia engaging portion 10026 may
include a
center tibia engaging portion 10030, and a peripheral tibia engaging portion
10040. In this
embodiment, the center tibia engaging portion 10030 may include a surface
contactable with a
center cancellous bone surface of the resected proximal portion of the tibia
of the patient. For
example, the center tibia engaging portion may include one or more concave,
convex, or planar
surfaces contactable with the center cancellous bone surface of the partial
resected proximal
portion of the tibia of the patient as similarly described above. As
illustrated in FIG. 41 and 42,
center tibia engaging portion 10030 may include a convex surface 10031. The
convex
undersurface may be designed to maximize surface area contact and reduce shear
forces along
the resection plane.
[00171] The peripheral tibia-engaging portion 10040 may include an inferiorly-
extending wall
10050. The inferiorly-extending wall 10050 may include an inner wall surface
10052 (FIG. 42)
and an outer wall surface 10054. For example, the wall surfaces 10052 and
10054 may be U-
shaped walls. The wall 10050 may have a constant thickness, different
thicknesses, varying
thicknesses, or other suitable thicknesses. The inner wall surface 10052 may
be disposed normal
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or at 90 degrees to the superior surface 10025, or at any suitable angle or
angles. The outer wall
surfaces 10054 may be disposed normal or at 90 degrees to the superior surface
10025. In other
embodiments, the outer wall surface may be angled relative to the superior
surface such as
parallel with and spaced from an inner surface 10013 (FIG. 40) of the cortical
bone 10012 (FIG.
40). As described above, outer wall surface 10054 may be configured to contact
the inner surface
of the cortical bone or may be configured to be closely spaced from the inner
cortical bone.
[00172] As described above, various surgical robot methods may be employed for
excavating
the one or more cavities in the cancellous bone in the resected proximal
portion of the tibia for
insertion of the various tibial components as described above.
[00173] FIG. 43 illustrates a patient specific jig or tibia cavity cutting
guide 11000 with
openings 11050 to accommodate a non-robotic burr or milling tool 12000 (FIG.
44) to allow a
surgeon to manually excavate the cavities as described above. For example,
cutting guide 11000
may be used by a surgeon for forming at least one cavity in a resected
proximal portion of a tibia
of a patient for knee replacement. The resected proximal portion of the tibia
includes a center
cancellous bone surface and a peripheral cortical bone surface as described
above. The cutting
guide 11000 may include a planar member 11020 having a first planar surface
11022 and a
second planar surface (not shown in FIG. 43).
[00174] Planar member 11020 may include a peripheral outer edge 11023, which
corresponds
to an outer peripheral cortical bone along the resected proximal portion of
the tibial of the
patient. A pair of U-shaped openings 11050 extends through the planar member
from the first
planar surface 11022 to the second planar surface (not shown) and is spaced
from the peripheral
outer edge. Each of the pair of U-shaped openings 11050 defines a U-shaped
axis 11060, and the
U-shaped opening has a constant width W8 normal to the U-shape axis. Width W8
desirably
corresponds to the width of the inferiorly-extending portions of corresponding
patient specific
tibial tray. Each of the pair of U-shaped openings have an inner edge 11061
and an outer edge
11062. The outer edge 11062 may be disposed parallel to the peripheral outer
edge 11023.
Cutting guide 11000 may be, for example, a patient specific cutting guide and
which may be
effected using the system 700 of FIG. 7 and system 800 of FIG. 8. For example,
suitable
algorithms and programming code stored in memory 730 (FIG. 7) along with the
patient tibia
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data 702 (FIG. 7) and the surgeon input 704 (FIG. 7) may be operably processed
in processor
710 (FIG. 7) to generate a patient specific cutting guide, which cutting guide
may be produced or
manufactured using 3D printer 795 (FIG. 7).
[00175] With reference to FIG. 44, the milling tool 12000 includes a proximal
diameter X1
sized larger than the width W8 (FIG. 43) of U-shaped openings 11050, and a
distal diameter X2
sized for passing through the width W8 of the U-shaped openings 11050. As
such, patient
specific tibia cavity cutting guide 11000 (FIG. 43) with openings 11050 into
which the milling
tool 12000 fits, constrains movement of the milling tool 12000 in a fixed
shape. With reference
again to FIG. 43, cutting guide 11000 may include one or more fixing holes
11070 to
accommodate temporary fixation, e.g., via screws, of the cutting guide to the
resected tibia. The
periphery of the cutting guide may be sized to match the outer periphery of
the resected tibia
such that visual alignment and proper placement on the resected tibia is
readily performed.
[00176] With reference again to FIG. 44, a manual excavation of the cavities
for the
inferiorly-extending portions of the tibial tray may be made to the proper
depth. For example, the
cutting portion for of the milling guide 12000 may be sized to extend a length
L that correspond
to the depth of the inferiorly-extending portions of the tibial tray and to
allow for receipt of the
inferiorly-extending portions of the tibial tray when the tibial tray is
placed on the resected
proximal portion of the patient's tibia.
[00177] FIG. 45 illustrates a patient specific implant system 13000 for a
total knee
replacement, according to an embodiment of the present disclosure. For
example, the patient
specific implant system 13000 may include a tibial tray 13020, such as
configured and
manufactured as described above, a spacer 13025, a femoral implant component
13050, and a
patellar implant component 13070.
[00178] FIG. 46 illustrates a patient specific implant system 14000 for a
partial total knee
replacement, according to an embodiment of the present disclosure. For
example, the patient
specific implant system 14000 may include a partial tibial tray 14020, such as
configured and
manufactured as described above, a spacer 14025, and a partial femoral implant
component
14050.
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[00179] FIGS. 47-50 illustrate a tibial tray 15000, according to an embodiment
of the present
disclosure. For example, the tibial tray 15000 may be configured similar to
tibial tray 2020
(FIGS. 26-28) with the exception of having a circumferential wall or fin
15040. Tibial tray
15000 may be installed on a resected proximal portion of a tibia in which the
circumferential
wall or fin 15040 is disposed closely adjacent to an underlying inner surface
of the cortical bone
for use in a total knee replacement.
[00180] In this illustrated embodiment, the tibial tray 15000 may include a
body 15022 having
a superior portion 15024 and an inferior tibia-engaging portion 15026. The
superior portion
15024 may include a generally planar superior surface 15025 (best shown in
FIG. 48) for
supporting a plastic bearing spacer (not shown). In some embodiments, the
planar superior
surface 15025 may include a peripheral upwardly-extending lip (not shown) for
attaching via a
snap fit connection and restraining a plastic bearing spacer.
[00181] The inferior tibia-engaging portion 15026 may include the
circumferential wall or fin
15040, which when operably attached to the resected proximal portion of a
tibia 10 (FIG. 50)
extends into the cancellous bone of the resected tibia. The circumferential
wall or fin 15040 may
be designed to be offset or spaced from the periphery of the underlying tibial
cortical bone of the
proximal portion of the tibia.
[00182] As shown in FIG. 47, the tibia engaging portion 15026 may include a
center tibia
engaging portion 15030, and the single inferiorly-extending circumferential
wall or fin 15040. In
this embodiment, the center tibia engaging portion 15030 may include a flat
surface contactable
with the center cancellous bone surface of the resected proximal portion of
the tibia of the
patient. In other embodiments, the center tibia engaging portion may have a
contoured surface as
described above.
[00183] The single inferiorly-extending circumferential wall or fin 15040 may
include an
inner wall surface 15051 and an outer wall surface 15055. For example, the
wall may have a
cross-sectional kidney shape similar to the superior portion 15024. The
superior portion 15024
may have constant thicknesses, different thickness, varying thickness, or
other suitable
thicknesses. The inner wall surface 15051 may be disposed normal or at 90
degrees to the
superior surface 15025, or at any suitable angle or angles. The outer wall
surface 15055 may be
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disposed normal or at 90 degrees to the superior surface 15025. In other
embodiments, the outer
wall surface may be angled relative to the superior surface such as parallel
with and spaced from
an inner surface of the cortical bone as shown in FIG. 50. In other
embodiments, the outer wall
surface 15055 may be configured to rest against the inner surface of the
underlying cortical bone.
[00184] With reference again to FIG. 47, in this illustrated embodiment, the
wall or fin 15040
may be circumferential and extend completely around and located towards a
periphery of the
implant or tibial tray undersurface or inferior surface 15030. The outer
surface of the
circumferential wall or fin may be based on pre-operative imaging data of the
inner cortical wall
of a patient, specifically to design the implant or tibial tray such that the
fin outer wall is a fixed
and a constant distance from the mapped inner surface of the cortical wall.
[00185] An implant ledge width W9 from the location of the mapped inner
cortical wall and
the location of the outer fin wall can be determined. With reference to FIG.
50, for example, an
outer fin wall may be defined having a distance X from the inner cortical
wall. A width Y, based
on generally accepted pre-operative patient sample data for cortical wall
thicknesses may allow
designing an implant ledge W9 such that the width of the ledge is
characterized by the formula:
W9 = X + Y
[00186] For example, a distance X from the inner cortical wall to an outer fin
wall may be
defined as being 3 mm from the inner cortical wall at every point. The
thickness of the cortical
wall may be based on a patient's age. For example, a cortical wall thickness Y
may be 2.2 mm
for a certain age as predetermined based on, e.g., Gosman et al. "Development
of Cortical Bone
Geometry in the Human Femoral and Tibial Diaphysis", The Anatomical Record,
296(5), 774-
787, 2013. Thus, a tibial tray may be designed and configured having a ledge
width W9 of 5.2
mm for example, from the exterior surface of the fin at every point along the
periphery. The
width Y may be variable based on anatomical observation or further study. For
example, further
research may find the average resected wall thickness is not uniform. For
example, if the medial
wall thickness is generally a value different from the lateral thickness, that
information may be
incorporated into the design of the tibial tray. In other embodiments of the
present disclosure, a
patient specific design may employ a mapping of the inner cortical wall to
design a patient
specific tibial tray having a matched wall or fin. An implant ledge width W9
may then be
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determined based on the mapped cortical wall thicknesses and a known distance
of the wall or
fin from the inner cortical wall.
[00187] With reference still to FIG. 50, in a total knee replacement an as
indicated by the
arrows in FIG. 50, a greater portion of a shearing force acting transversely
on the tibial tray and
the resected portion of the proximal portion of the tibia of the patient may
be resisted by the at
least one inferiorly-extending wall and the periphery of the resected proximal
portion of the tibia
compared to a portion of the shearing force being resisted along the center
inferior surface of the
tibial tray and the resected cancellous bone surface. In some embodiments, the
greater portion
may be greater than 50 percent, greater than 60 percent, greater than 70
percent, greater than 80
percent, greater than 90 percent, between 50 percent and 60 percent, between
50 percent and 70
percent, between 50 percent and 80 percent, between 50 percent and 90 percent,
between 60
percent and 70 percent, between 70 percent and 80 percent, between 80 percent
and 90 percent,
between 60 percent and 80 percent, about 60 percent, about 70 percent, about
80 percent, about
90 percent, or other suitable parentage or range of percentages. In the other
described and
illustrated embodiments of the tibial trays in the present disclosure, such a
shearing force may be
similarly counteracted in a total knee replacement. Such embodiments, may not
include a center
keel or may include a center keel such as a shallow keel, wherein such
shearing force is primarily
counteracted along the periphery of the resected proximal portion of the tibia
of the patient.
[00188] FIGS. 51-56 illustrate a bi-cruciate tibial tray 16000, according to
an embodiment of
the present disclosure. For example, in a bi-cruciate retaining knee
replacement both the anterior
cruciate ligament (ACL) and posterior cruciate ligament (PCL) may be
maintained. For example,
this may be provided by bone resections and an implant geometry that
circumvents these
ligaments. The bi-cruciate tibial tray 16000 may include a circumferential or
partially
circumferential wall or fin. The lateral, anterior and medial fin walls are
designed to abut or to be
in close proximity to the inner cortical wall. The posterior portion of the
implant undersurface
may not feature a rim, or feature a rim that is generally inset from and
designed to match the
periphery of the posterior implant surface. The posterior implant surface is
curved such that the
anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are
maintained. In this
illustrated embodiment, the tibial tray 16000 may include a U-shaped body
16022 having a U-
shaped superior portion 16024 and a C-shaped inferior tibia-engaging portion
16026 (best shown
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in FIGS. 52 and 55). The U-shaped superior portion 16024 (FIGS. 51 and 54) may
define
portions (a lateral portion and a medial portion) defining a cavity 16021
therebetween. The
superior portion 16024 may include a generally planar superior surface 16025
(best shown in
FIGS. 51 and 54) for supporting a plastic bearing spacer (not shown). The
superior portion
16024 may include a raised land or portion 16023 (best shown in FIG. 51)
disposed between
lateral portions for the superior portion 16024. In some embodiments, the
planar superior surface
16025 may include a peripheral upwardly-extending lip (not shown) for
attaching via a snap fit
connection and restraining a plastic bearing spacer.
[00189] The inferior tibia-engaging portion 16026 may include the C-shaped
wall or fin
16040, which when operably attached to the resected proximal portion of a
tibia (not shown in
FIGS. 51-56) extends into the cancellous bone of the resected tibia. The wall
or fin 16040 may
be designed to be offset or spaced from the periphery of the underlying tibial
cortical bone of the
proximal portion of the tibia.
[00190] The single inferiorly-extending C-shaped wall or fin 16040 may include
an inner wall
surface 16051 and an outer wall surface 16055. For example, the wall may have
a cross-sectional
shape similar to the cross-sectional U-shaped superior portion 16024 along
with periphery
thereof The superior portion 16024 may have constant thicknesses, different
thickness, varying
thickness, or other suitable thicknesses. The inner wall surface 16051 may be
disposed normal or
at 90 degrees to the superior surface 16025, or at any suitable angle or
angles. The outer wall
surface 16055 may be disposed normal or at 90 degrees to the superior surface
16025. In other
embodiments, the outer wall surface may be angled relative to the superior
surface such as
parallel with and spaced from an inner surface of the cortical bone (not shown
in FIG. 51-56). In
other embodiments, the outer wall surface 15055 may be configured to rest
against the inner
surface of the underlying cortical bone. The outer surface of the
circumferential wall or fin
15055 may be based on pre-operative imaging data of the inner cortical wall of
a patient,
specifically to design the implant such that the fin outer wall is a fixed and
a constant distance
from the mapped inner surface of the cortical wall.
[00191] FIGS. 57-61 illustrate a bi-cruciate tibial tray 17000, according to
an embodiment of
the present disclosure. For example, in a bi-cruciate retaining knee
replacement both the anterior
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cruciate ligament (ACL) and posterior cruciate ligament (PCL) may be
maintained. For example,
this may be provided by bone resections and an implant geometry that
circumvents these
ligaments. The bi-cruciate tibial tray 17000 may include a circumferential or
partially
circumferential wall or fin. The lateral, anterior and medial fin walls are
designed to abut or to be
in close proximity to the inner cortical wall. The posterior portion of the
implant undersurface
may: a) not feature a rim; or b) feature a rim that is generally inset from
and designed to match
the periphery of the posterior implant surface. The posterior implant surface
is curved such that
the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are
maintained.
[00192] In this illustrated embodiment, the tibial tray 17000 may be
essentially the same the
bi-cruciate tibial tray 16000 (FIGS. 51-56) with the exception of a wall 17040
being disposed at
an angle relative to a superior surface 17025 and being spaced from a
plurality of inferiorly-
extending projections or pins 17300. The wall 17040 and the pins 17300 may be
dispose at a
non-perpendicular angle S relative to the superior surface 17000 and to a
medial-lateral direction.
For example, angle S may be between about 70 degrees and 80 degrees, or may be
about 75
degrees, or other suitable non-perpendicular angle.
[00193] During the insertion of a traditional style tibial baseplate with a
post and fins, the tibia
is subluxed in the anterior direction to a great extent to allow the post and
fins to be prepared
with a punch used from the superior direction. The tibia must remain subluxed
anteriorly in order
to place the tibial implant directly onto the resected tibia surface and
seated in a directly inferior
direction. In the embodiment of the tibial tray 17000, the wall and pegs are
angled generally in
the posterior direction to allow the implant to be inserted from the anterior
side on an angle
rather than directly down from the superior direction. This may allow the
surgeon to sublux the
tibia anteriorly less than in some traditional systems in order to insert the
tibial baseplate, which
may cause less soft tissue damage due to extreme subluxation of the tibia.
[00194] FIG. 62 illustrates a patient specific jig or tibia cavity cutting
guide 18000 with a
series of openings 18050 to accommodate a non-robotic burr or milling tool
12000 (FIG. 44) to
allow a surgeon to manually excavate the cavities as described above. For
example, cutting guide
18000 may be used by a surgeon for forming at least one cavity such as a
continuous cavity in a
resected proximal portion of a tibia of a patient for knee replacement. The
resected proximal
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portion of the tibia includes a center cancellous bone surface and a
peripheral cortical bone
surface as described above. The cutting guide 18000 may include a planar
member 18020 having
a first planar surface 18022 and a second planar surface (not shown in FIG.
62).
[00195] Planar member 18020 may include a peripheral outer edge 18023, which
corresponds
to an outer peripheral cortical bone along the resected proximal portion of
the tibial of the
patient. A series curved openings 18050 extends through the planar member from
the first planar
surface 18022 to the second planar surface (not shown) and is spaced from the
peripheral outer
edge. Each of the openings 18050 defines an axis 18060, and the opening has a
constant width
W10 normal to the axis. The width desirably corresponds to the width of the
inferiorly-extending
portions of corresponding patient specific tibial tray. Each of the openings
have an inner edge
18061 and an outer edge 18062. The outer edge 18062 may be disposed parallel
to the peripheral
outer edge 18023. The cutting guide 18000 may include one or more fixing holes
18070 to
accommodate temporary fixation, e.g., via screws, of the cutting guide to the
resected tibia. The
periphery of the cutting guide may be sized to match the outer periphery of
the resected tibia
such that visual alignment and proper placement on the resected tibia is
readily performed.
[00196] Cutting guide 18000 may be, for example, a patient specific cutting
guide and which
may be effected using the system 700 of FIG. 7 and system 800 of FIG. 8. For
example, suitable
algorithms and programming code stored in memory 730 (FIG. 7) along with the
patient tibia
data 702 (FIG. 7) and the surgeon input 704 (FIG. 7) may be operably processed
in processor
710 (FIG. 7) to generate a patient specific cutting guide, which cutting guide
may be produced or
manufactured using 3D printer 795 (FIG. 7).
[00197] The cutting guide 18000 may be operable with a milling tool such as
the milling tool
12000 (FIG. 44). As such, patient specific tibia cavity cutting guide 18000
with openings 18050
into which the milling tool 12000 fits, constrains movement of the milling
tool 1200 in a fixed
shape. A manual excavation of the at least one cavity for the inferiorly-
extending portions of the
tibial tray may be made to the proper depth. For example, the cutting portion
for of the milling
guide 12000 (FIG. 44) may be sized to extend a length L (FIG. 44) that
correspond to the depth
of the inferiorly-extending portion of the tibial tray and to allow for
receipt of the inferiorly-
extending portion of the tibial tray when the tibial tray is placed on the
resected proximal portion
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of the patient's tibia. As will be appreciated, the cutting guide 18000 may be
removed and the
remaining portions between the series of cavities may be removed by a surgeon
to compete the
continuous cavity in the resected portion of the proximal portion of the tibia
of the patient.
[00198] FIG. 63 illustrates a block diagram of a method 19000 for use in a
total knee
replacement. The method 19000 includes, for example, at 19100 resecting a
proximal portion of
a tibia of a patient, the resected proximal portion of the tibia having a
transverse resected
cancellous bone surface, a transverse resected peripheral cortical bone
surface, and at least one
cavity formed in the periphery of the resected cancellous bone, at 19200
providing a tibial tray
having at least one inferiorly-extending wall spaced inwardly from a
peripheral edge of the tibial
tray and extending around at least a portion of a center inferior surface, at
19300 inserting the at
least one inferiorly-extending wall in the at least one cavity formed in the
periphery of the
resected cancellous bone surface, at 19400 disposing the peripheral edge of
the tibial tray on the
transverse resected peripheral cortical bone surface, and the center inferior
surface on the
transverse resected cancellous bone surface, and wherein, in the total knee
replacement, a greater
portion of a shearing force acting transversely on the tibial tray and the
resected portion of the
proximal portion of the tibia of the patient is resisted by the at least one
inferiorly-extending wall
and the periphery of the resected proximal portion of the tibia compared to a
portion of the
shearing force being resisted along the center inferior surface of the tibial
tray and the resected
cancellous bone surface.
[00199] FIGS. 64-71 illustrate tibial tray systems 20001 (FIGS. 64-67), and
tibial tray systems
30001 (FIGS. 68-71), according to embodiments of the present disclosure. In
these
embodiments, the tibial tray systems include a tibial tray and one, two, or
more screws. It has
been found and described below that the wall or fin of the tibial tray may be
sized shorter to
support the shearing forces when using the one or more screws where the one or
more screws
minimize or inhibit lift off of the tibial tray from a resected proximal
portion of a tibia of a
patient compared to a tibial tray having just a wall that may require a
sufficient depth or
minimum depth to operably accommodate both the shear forces and the pull out
or lift off forces.
[00200] For example, as shown in FIGS. 64 and 67, the tibial tray system 20001
may include
a tibial tray 20000 configured similar to tibial tray 15000 (FIGS. 47-50),
with the addition of
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being operable to receive a screw 20500 (FIGS. 64 and 67), according to an
embodiment of the
present disclosure. In this illustrated embodiment. The tibial tray 20000 may
be installed on a
resected proximal portion of a tibia 20010 (FIG. 67) in which a
circumferential wall or fin 20040
is disposed in a cancellous bone 20011 and closely adjacent to an underlying
inner surface 20013
(FIG. 67) of a cortical bone 20012 (FIG. 67) of a resected portion of a tibia
20010 (FIG. 67) of a
patient for use in a total knee replacement. The screw 20500 may minimize or
inhibiting lift off
of the tibial tray 20000 once the tibial tray assembly 20001 is installed on
the resected portion of
tibia 20010 (FIG. 67) of the patient.
[00201] As shown in FIGS. 65 and 66, the tibial tray 20000 may include a body
20022 having
a superior portion 20024 and an inferior tibia-engaging portion 20026. The
superior portion
20024 may include a generally planar superior surface 20025 (best shown in
FIG. 65) for
supporting a plastic bearing spacer (not shown). In some embodiments, the
planar superior
surface 20025 may include a peripheral upwardly-extending lip (not shown) for
attaching, for
example, via a snap fit connection to restrain the plastic bearing spacer.
[00202] The inferior tibia-engaging portion 20026 may include the
circumferential wall or fin
20040, which when operably attached to the resected proximal portion of a
tibia 20010 (FIG. 67)
extends into the cancellous bone 20011 of the resected tibia. The
circumferential wall or fin
20040 may be designed to be offset or spaced from the periphery of the
underlying tibial cortical
bone 20012 of the proximal portion of the tibia 20010 of the patient.
[00203] As shown in FIG. 66, the tibia engaging portion 20026 may include a
center tibia
engaging portion 20030, and the single inferiorly-extending circumferential
wall or fin 20040. In
this embodiment, the center tibia engaging portion 20030 may include a flat
surface contactable
with a resected center cancellous bone surface 20011 (FIG. 67) of the resected
proximal portion
of the tibia 20010 of the patient. In other embodiments, the center tibia
engaging portion may
have a contoured (i.e., convex or concave) surface as described above.
[00204] The single inferiorly-extending circumferential wall or fin 20040 may
include an
inner wall surface 20051 and an outer wall surface 20055. For example, the
wall may have a
cross-sectional kidney shape similar to the superior portion 20024, or mirror
the outer contour of
the superior portion 20024. The superior portion 20024 may have constant
thicknesses, different
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thickness, varying thickness, or other suitable thicknesses. The inner wall
surface 20051 may be
disposed normal or at about 90 degrees to the superior surface 20025, or at
any suitable angle or
angles. The outer wall surface 20055 may be disposed normal or at about 90
degrees to the
superior surface 20025. In other embodiments, the outer wall surface may be
angled relative to
the superior surface such as parallel with and spaced from an inner surface of
the cortical bone
(for example, as shown in FIG. 67). In other embodiments, the outer wall
surface 20055 may be
configured to rest against the inner surface of the underlying cortical bone.
[00205] In this illustrated embodiment, the wall or fin 20040 may be
circumferential and
extend completely around and located towards a periphery of the implant or
tibial tray
undersurface or inferior surface 20030. The outer surface of the
circumferential wall or fin may
be based on pre-operative imaging data of the inner cortical wall of a
patient, specifically to
design the implant or tibial tray such that the fin outer wall is a fixed and
a constant distance
from the mapped inner surface of the cortical wall.
[00206] As shown in FIGS. 65 and 66, the superior portion 20024 may include a
hole or
passageway 20060 extending from the superior surface 20025 (FIG. 65) to an
inferior surface
20033 (FIG. 66). The passageway 20060 may be configured to be a countersunk
hole.
[00207] With reference again to FIGS. 64 and 66, this illustrated tibial tray
system 20001
includes a combination or the tibial tray 20000 having a peripheral wall
20040, and the
releasably (modular) attachable screw 20060 located towards the center of the
tibial tray 20000.
[00208] As will be appreciated from the present description, the peripheral
rim or wall may be
of a reduced or minimum height or depth because the rim or wall 20040 may need
to account for
shear forces, while the screw 20500 is operable to account for lift-off or
pull out forces. For
example, the screw 20500 may have a body 20510 having a proximal or head
portion 20520 and
a threaded shank portion 20540. In other embodiments, the screw 20500 may
include a head; a
non-threaded shank portion, a threaded shank, and a tip. The head portion
20520 may be
disposed below or flush with the superior surface 20025 (FIG. 67) of the
tibial tray 20000. The
proximal or head portion 20520 may have, for example, a cavity or drive
feature for engagement
with a tool such as a hex driver for inserting or removing the screw 20500.
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[00209] With reference to FIG. 67, in some embodiments, the wall 20040 may be
a
continuously surrounding peripheral wall having a depth D8 of about 1
millimeter, about 2
millimeters, about 3 millimeters, about 4 millimeters, about 5 millimeters,
about 6 millimeters,
about 7 millimeters, about 8 millimeters, about 9 millimeters, about 10
millimeters, between
about 1 millimeters and about 10 millimeters, between about 1 millimeters and
about 7
millimeters, between about 1 millimeters and about 5 millimeters, between
about 1 millimeters
and about 3 millimeters, or other suitable sized depth.
[00210] The screw 20500 may have a diameter D9 of about 10 millimeters, about
12
millimeters, about 15 millimeters, between about 10 millimeters to about 15
millimeters, or other
suitable sized diameter.
[00211] The screw 20500 may have a height or depth D10 extending from the
inferior surface
of the tibial tray of about 5 millimeters, about 7 millimeters, about 10
millimeters, about 15
millimeters, about 20 millimeters, about 25 millimeters, between about 5
millimeters and about
25 millimeters, between about 5 millimeters and about 25 millimeters, between
about 5
millimeters and about 20 millimeters, between about 5 millimeters and about 15
millimeters, or
between about 10 millimeters and about 20 millimeters.
[00212] With reference to FIGS. 68 and 69, the tibial tray system 30001 may
include a tibial
tray 30000 configured similar to tibial tray 15000 (FIGS. 47-50), with the
addition of being
operable to receive a plurality of screws 30501 and 30502 (FIGS. 68 and 71),
according to an
embodiment of the present disclosure. In this illustrated embodiment, the
tibial tray 30000 may
be installed on a resected proximal portion of a tibia 30010 (FIG. 71) in
which a circumferential
wall or fin 30040 is disposed into a cancellous bone 30011 and closely
adjacent to an underlying
inner surface 30013 (FIG. 71) of cortical bone 30012 (FIG. 71) of a resected
portion of a tibia
30010 (FIG. 71) of a patient for use in a total knee replacement. The screws
35001 and 30502
may minimize or inhibit lift off of the tibial tray 30000 once the tibial tray
assembly 30001 is
installed on the resected portion of the tibia 30010 (FIG. 71) of the patient.
[00213] As shown in FIGS. 69 and 70, the tibial tray 30000 may include a body
30022 having
a superior portion 30024 and an inferior tibia-engaging portion 30026. The
superior portion
30024 may include a generally planar superior surface 30025 (best shown in
FIG. 69) for
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supporting a plastic bearing spacer (not shown). In some embodiments, the
planar superior
surface 30025 may include a peripheral upwardly-extending lip (not shown) for
attaching, for
example, via a snap fit connection, a plastic bearing spacer.
[00214] The inferior tibia-engaging portion 30026 may include the
circumferential wall or fin
30040, which when operably attached to the resected proximal portion of a
tibia 30010 (FIG. 71)
extends into the cancellous bone 30011 of the resected tibia. The
circumferential wall or fin
30040 may be designed to be offset or spaced from the periphery of the
underlying tibial cortical
bone 30012 of the proximal portion of the tibia 30010 of the patient.
[00215] As shown in FIG. 70, the tibia engaging portion 30026 may include a
center tibia
engaging portion 30030, and the single inferiorly-extending circumferential
wall or fin 30040. In
this embodiment, the center tibia engaging portion 30030 may include a flat
surface contactable
with a resected center cancellous bone surface 30011 (FIG. 71) of the resected
proximal portion
of the tibia 30010 of the patient. In other embodiments, the center tibia
engaging portion may
have a contoured surface as described above.
[00216] The single inferiorly-extending circumferential wall or fin 30040 may
include an
inner wall surface 30051 and an outer wall surface 30055. For example, the
wall may have a
cross-sectional kidney shape similar to the superior portion 30024 or mirror
the outer contour of
the superior portion 30024. The superior portion 30024 may have constant
thicknesses, different
thickness, varying thickness, or other suitable thicknesses. The inner wall
surface 30051 may be
disposed normal or at about 90 degrees to the superior surface 30025, or at
any suitable angle or
angles. The outer wall surface 30055 may be disposed normal or at about 90
degrees to the
superior surface 30025. In other embodiments, the outer wall surface may be
angled relative to
the superior surface such as parallel with and spaced from an inner surface of
the cortical bone
(for example, as shown in FIG. 71). In other embodiments, the outer wall
surface 30055 may be
configured to rest against the inner surface of the underlying cortical bone.
[00217] In this illustrated embodiment, the wall or fin 30040 may be
circumferential and
extend completely around and be positioned towards a periphery of the implant
or tibial tray
undersurface or inferior surface 30030. The outer surface of the
circumferential wall or fin may
be based on pre-operative imaging data of the inner cortical wall of a
patient, specifically to
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design the implant or tibial tray such that the fin outer wall is a fixed and
a constant distance
from the mapped inner surface of the cortical wall.
[00218] As shown in FIGS. 69 and 70, the superior portion 30024 may include a
plurality of
holes or passageways 30061, 30062 extending from the superior surface 30025
(FIG. 69) to an
inferior surface 30033 (FIG. 70). The passageways 30061, 30062 may be
configured to be a
countersunk hole.
[00219] With reference again to FIGS. 68 and 70, in this illustrated tibial
tray system 30001
includes a combination or the tibial tray 30000 having a peripheral wall
30040, and the
releasably attachable screws 30501 and 30502, each of when located in a
different compartment
of the tibial tray 30000.
[00220] As will be appreciated from the present description, the peripheral
rim or wall may be
of a reduced or minimum height or depth because the rim or wall 30040 may need
to account for
shear forces, while the screws 30501 and 30502 are operable to account for
lift-off or pull out
forces. For example, the screws 30501 and 30502 may be essentially the same as
the screw
20500 (FIGS. 64 and 67) having a body with a proximal or head portion and a
threaded shank
portion. In other embodiments, the screws 30501 and 30502 may include a head;
a non-threaded
shank portion, a threaded shank, and a tip. The head portion may be disposed
below or flush with
superior surface 30025 (FIG. 71) of the tibial tray 30000. The proximal or
head portions of the
screws 30501 and 30502 may have, for example, a recess or drive feature for
engagement with a
tool such as a hex driver for inserting or removing the screws 30501 and
30502.
[00221] With reference to FIG. 71, in some embodiments, the wall 30040 may be
a
continuously surrounding peripheral wall having a depth Dll of about 1
millimeter, about 2
millimeters, about 3 millimeters, about 4 millimeters, about 5 millimeters,
about 6 millimeters,
about 7 millimeters, about 8 millimeters, about 9 millimeters, about 10
millimeters, between
about 1 millimeters and about 10 millimeters, between about 1 millimeters and
about 7
millimeters, between about 1 millimeters and about 5 millimeters, between
about 1 millimeters
and about 3 millimeters, or other suitable sized depth.
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[00222] The screws 30501 and 30502 may have a diameter D12 of about 10
millimeters,
about 12 millimeters, about 15 millimeters, between about 10 millimeters to
about 15
millimeters, or other suitable sized diameter.
[00223] The screws 30501 and 30502 may have a height or depth D13 extending
from the
inferior surface of the tibial tray of about 5 millimeters, about 7
millimeters, about 10
millimeters, about 15 millimeters, about 20 millimeters, about 25 millimeters,
between about 5
millimeters and about 25 millimeters, between about 5 millimeters and about 25
millimeters,
between about 5 millimeters and about 20 millimeters, between about 5
millimeters and about 15
millimeters, or between about 10 millimeters and about 20 millimeters.
[00224] FIG. 72 illustrates a tibial tray system 40001 having a tibial tray
40000 and at least
one locking screw 40500 that may interface with at least one threaded hole
40060 in the tibial
tray 40000, according to an embodiment of the present disclosure. For example,
the locking
screw may include a tapered head portion 40505 having external threads. The
tibial tray 40000
may have a corresponding sized and configured tapered passageway 40060 having
internal
threads. When the tibial tray system 40001 is attached to a resected proximal
portion of a tibia of
a patient, upon rotating and securing the screw 40500 in the passageway 40060
in the tibial tray
40000, the head 40505 will seat and lock in the tapered passageway 40060
having the internal
threads. The locking screw 40500 may mitigate the risk of screw toggle and
generally constrain
the screw to the axis normal to the threaded hole 40060 and the superior
surface of the tibial tray.
The locking screw 40500 may lock into threaded hole 40060 and resist lateral
forces for
additional stability.
[00225] FIG. 73 illustrates a conical shaped screw 40700 that may be a locking
or non-locking
conical screw usable in the above discussed tibial tray systems, according to
embodiments of the
present disclosure. In this illustrated embodiment, the conical shaped screw
40700 may taper
toward a distal end 40703. In other embodiments, the screw may have a
corkscrew configuration.
Such a configuration may provide an increased surface area contact of the
threads with the
underlying bone while being minimally invasive the further into the cancellous
bone the screw
40700 extends.
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[00226] In some embodiments, the one or more screws 20500, 30061, 30062, 40700
may be
non-ingrowth, i.e., not designed to facilitate osseointegration so that the
screws may be
removable during a revision. As described above, the one or more screws 20500,
30061, 30062,
40700 may be operable to facilitate a shorter wall or fin by providing initial
stability while bone
growth occurs. For example, the wall or fin height could be reduced to 1 mm to
3 mm in height,
and defined above. Shorter walls or fins may be minimally invasive and
preserve bone.
Furthermore, a shorter wall or fin may facilitate an easier revision. If a
wall or fin is short
enough the revision could be made by directly undercutting the implant. This
would allow for
solid walls or fins that can add to the rigidity of the implant because they
would not need to be
cut through for a revision.
[00227] It will be appreciated that one, two, or more screws 20500, 30061,
30062, 40700 may
be employed with any of the tibial trays described herein, for example, having
a continuous
surrounding peripherally-extending wall, spaced apart U-shaped peripherally-
extending walls,
peripherally-extending wall contactable with the inner cortical bone or spaced
therefrom. The
screws may be locking or non-locking.
[00228] In still other embodiments, tibial trays systems employing one or more
screws may
include one or more walls, such as the walls described above, and in which the
one or more walls
may have a depth of about or less than about 1 millimeter, about or less than
about 2 millimeters,
about or less than about 3 millimeters, about or less than about 4
millimeters, about or less than
about 5 millimeters, greater than about 5 millimeters, about or less than
about 6 millimeters,
about or less than about 7 millimeters, about or less than about 8
millimeters, about or less than
about 9 millimeters, about or less than about 10 millimeters, or other
suitable sized depths.
[00229] In still other embodiments, tibial trays systems employing one or more
screws may
include one or more walls, such as the walls described above and in which the
one or more walls
may have a depth of between about 1 millimeters and about 10 millimeters,
between about 1
millimeters and about 7 millimeters, between about 1 millimeters and about 5
millimeters,
between about 1 millimeters and about 3 millimeters, or other suitable range
of sized depths.
[00230] In still other embodiments, tibial trays systems employing one or more
walls may
include one or more screws, such as the screws described above, and in which
the one or more
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screws may have a height or depth extending from the inferior surface of the
tibial tray of about
or less than about 5 millimeters, about or less than about 7 millimeters,
about or less than about
millimeters, about 15 or less than about millimeters, about or less than about
20 millimeters,
about or less than about 25 millimeters, between about 5 millimeters and about
25 millimeters,
between about 5 millimeters and about 25 millimeters, between about 5
millimeters and about 20
millimeters, between about 5 millimeters and about 15 millimeters, between
about 10 millimeters
and about 20 millimeters, or other suitable heights or ranges of heights.
[00231] In still other embodiments, tibial trays systems employing one or more
walls and one
or more screws, such as the walls and screws described above, and in which the
one or more
screws may have a diameter of about or less than about 3 millimeters, about or
less than about 4
millimeters, about or less than about 5 millimeters, about or less than about
6 millimeters, about
or less than about 7 millimeters, about or less than about 8 millimeters,
about or less than about 9
millimeters, about 10 millimeters, about 12 millimeters, about 15 millimeters,
between about 3
millimeters to about 5 millimeters, between about 3 millimeters to about 10
millimeters, between
about 5 millimeters to about 10 millimeters, between about 10 millimeters to
about 15
millimeters, or other suitable sized diameter.
[00232] In some embodiments, tibial trays may be configured for a resected
medial or lateral
proximal portion of a tibia of a patient for a partial knee replacement,
according to embodiments
of the present disclosure. Such tibial trays may include features fo the above
described tibial
trays and employ one or more screws to inhibit lift off of the partial tibial
tray.
[00233] FIG. 74 illustrates a block diagram of a method 50000 for use in a
total knee
replacement. The method 50000 includes, for example, at 50100 resecting a
proximal portion of
a tibia of a patient, the resected proximal portion of the tibia having a
transverse resected
cancellous bone surface, a transverse resected peripheral cortical bone
surface, and at least one
cavity formed in the periphery of the resected cancellous bone, at 50200
providing a tibial tray
having at least one inferiorly-extending wall spaced inwardly from a
peripheral edge of the tibial
tray and extending around at least a portion of a center inferior surface, at
53000 inserting the at
least one inferiorly-extending wall in the at least one cavity formed in the
periphery of the
resected cancellous bone surface, at 50400 disposing the peripheral edge of
the tibial tray on the
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transverse resected peripheral cortical bone surface, and the center inferior
surface on the
transverse resected cancellous bone surface, and at 50500 securing at least
one screw through the
tibial tray and into the cancellous bone, and wherein, in the total knee
replacement, the screw
inhibits lift-off of the tibial tray, and a greater portion of a shearing
force acting transversely on
the tibial tray and the resected portion of the proximal portion of the tibia
of the patient is
resisted by the at least one inferiorly-extending wall and the periphery of
the resected proximal
portion of the tibia compared to a portion of the shearing force being
resisted along the center
inferior surface of the tibial tray and the resected cancellous bone surface.
[00234] It will be appreciated from the technique of the present disclosure
for the tibial trays
and the resected proximal portion of the tibia that such designs and
techniques may overcome the
problems of conventional non-patient specific tibial trays that are designed
to rest on a flat
resection plane that minimizes surface area contact and maximizes shear
forces, lack redundant
modes of support, provide poor implant surface area coverage influencing the
risk of subsidence.
The patient specific tibial trays and the patent specific resected proximal
portion of the tibia
overcome the problems associated with conventional tibial trays, which
conventional tibial trays
are designed as geometric approximations of multiple bone models that are
manually segmented
from large image databases and proportionally constrained and scaled to
accommodate a range
of implant sizes and resecting of the proximal portion of the tibia being flat
cut often using a
sagittal saw.
[00235] The technique of the present disclosure may provide increased surface
area contact
and/or reduced shear forces along the resection plane of the implant-to-bone
interface resulting
in less failures or loosening by poor alignment and natural lateral loading of
the joint.
[00236] The algorithms of the present disclosure may be operable to generate a
patient
specific tibial tray and robotic cut path of the proximal portion of the tibia
that solves the primary
failures modes of press-fit tibial knee implants by restoring the pre-
operative anatomy and
specifically: 1) maximizing the surface area contact for increased
osseointegration; 2) reducing
shear forces and localizing forces to either side of the intercondylar
eminence; 3) maximizing
cortical contact at the periphery of the implant; and 4) minimizing subsidence
and increasing
stability with patient specific support members.
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[00237] Al. A tibial tray for a resected proximal portion of a tibia of a
patient for a total knee
replacement. The resected proximal portion of the tibia has a center
cancellous bone surface, a
peripheral cortical bone surface, and at least one cavity formed in the
periphery of the cancellous
bone spaced apart from the cortical bone exposing an underlying portion of the
cancellous bone
of the tibia. The tibial tray may include a body having a superior portion
with a superior surface,
and an inferior tibia-engaging portion. The body may include an inferior tibia-
engaging portion
having a center portion having a center surface contactable with the center
cancellous bone
surface, and a peripheral, inferiorly-extending portion receivable in the at
least one cavity formed
in the cancellous bone surface so that the peripheral inferiorly-extending
portion is spaced apart
from the underlying inner surface of the cortical bone of the tibia of the
patient.
[00238] A2. The tibial tray of Al, wherein the inferior tibia-engaging portion
comprises a
peripheral edge portion having an inferior surface supportable on the
peripheral cortical bone
surface of the tibia of the patient, and the peripheral, inferiorly-extending
portion being disposed
inwardly of the peripheral edge portion. A3. The tibial tray of Al or A2,
wherein the center
surface of the inferior tibia-engaging portion comprises a non-planar surface.
A4. The tibial tray
of any of Al through A3, wherein the inferiorly-extending portion of the
inferior tibia-engaging
portion is extendable around at least 10 percent of a perimeter of the
underlying peripheral inner
surface of the cortical bone of the tibia of the patient. A5. The tibial tray
of any of Al through
A4, wherein the inferior tibia-engaging portion comprises an inferior convex
surface, an inferior
concave surface, and/or an inferior convex surface and an inferior concave
surface. A6. The
tibial tray of any of Al through A5, wherein the inferior tibia-engaging
portion comprises a pair
of spaced-apart inferior convex surfaces corresponding in size to a medial
condyle and a lateral
condyle of the proximal portion of the tibia of the patient. A7. The tibial
tray of any of Al
through A6, wherein the peripheral, inferiorly-extending portion comprises a
wall spaced apart
from the inner surface of the cortical bone. A8. The tibial tray of A7,
wherein the wall comprises
a surface configured to be spaced apart from the underlying inner surface of
the cortical bone, is
angled at about 35 degrees relative to the superior surface of the superior
portion of the body,
and extends about 7 mm below the superior surface of the superior portion of
the body. A9. The
tibial tray of any of A7 or A8, wherein the wall extends along at least 30
percent of a perimeter
of the underlying peripheral cancellous bone of the tibia of the patient. A10.
The tibial tray of
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any of A7 through A9, wherein the wall extends along the entire peripheral
portion of the body.
All. The tibial tray of any of Al through A10, wherein the inferiorly-
extending portion
comprises a pair of curved walls configured to be spaced apart from the inner
surface the cortical
bone. Al2. The tibial tray of any of Al through All, wherein the inferiorly-
extending portion
comprises a pair of curved walls configured to be spaced apart from the inner
surface the cortical
bone, and the center surface comprises a pair of spaced-apart inferior convex
surfaces
corresponding in size to a medial condyle and a lateral condyle of the
proximal portion of the
tibia of the patient. A13. The tibial tray of any of Al through Al2, wherein
the peripheral
inferiorly-extending portion defines a constant gap between the peripheral
inferiorly-extending
portion and an inner surface of the cortical bone. A14. The tibial tray of any
of Al through A13,
wherein the center portion of the body comprises an inferiorly-extending keel.
A15. The tibial
tray of any of Al through A14, wherein the body comprises a one-piece body.
[00239] B 1. A method for forming a patient specific tibial tray for a total
knee replacement of
the patient, the method comprising: determining a patient specific resected
proximal portion of a
tibia of the patient, the resected proximal portion of the tibia of the
patient having a center
cancellous bone surface, a peripheral cortical bone surface, and at least one
cavity formed in the
periphery of the cancellous bone spaced apart from the cortical bone exposing
an underlying
portion of the cancellous bone of the tibia; and forming the patient specific
tibial tray comprising
a body having a superior portion having a superior surface and an inferior
tibia-engaging portion,
the inferior tibia engaging portion having a center portion contactable with
the center cancellous
bone surface, and a peripheral, inferiorly-extending portion receivable in the
at least one cavity
so that the peripheral inferiorly-extending portion is spaced apart from the
underlying inner
surface of the cortical bone of the tibia of the patient.
[00240] B2. The method of Bl further comprising, obtaining first data, via a
processor,
representing a proximal portion of the tibia of the patient, and determining,
via the processor,
second data corresponding the patient specific resected proximal portion of
the tibia of the
patient based on the first data, and the forming, via the processor, comprises
3D printing,
forging, casting based on the second data. B2. The method of Bl, wherein the
obtaining first data
comprises obtaining CT scan data and/or X-rays, and the determining comprises
determining the
patient specific resected proximal portion of the tibia of the patient based
on the obtained first
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data. B3. The method of B1 or B2 further comprising, maximizing the size and
shape of the
inferior tibia-engaging portion based on a depth and an amount extending along
the periphery of
the underlying cancellous bone. B20. The method of and of B17 through B19
further comprising,
reducing shear forces and localized forces based on the implant to bone
contact plane based on
the equation Fx = Fcos(theta).
[00241] Cl. A tibial tray for a resected proximal portion of a tibia of a
patient for a total knee
replacement, the resected proximal portion of the tibia having a central
cancellous bone surface,
a peripheral cortical bone surface, and at least one cavity formed in the
periphery of the
cancellous bone. The tibial tray comprising a body the body comprising a
superior portion with a
superior surface; and an inferior tibia-engaging portion. The inferior tibia-
engaging portion
comprises a center portion having a center surface contactable with the
central cancellous bone
surface, and a peripheral, inferiorly-extending portion receivable in the at
least one cavity formed
in the cancellous bone surface so that the peripheral inferiorly-extending
outer surface portion
corresponds to the contour of the underlying inner surface of the cortical
bone of the tibia of the
patient.
[00242] C2. The tibial tray of Cl, wherein the peripheral, inferiorly-
extending portion
comprises at least a portion of the peripheral inferiorly-extending outer
surface portion extending
from a proximal portion of the peripheral, inferiorly-extending portion to a
distal portion of the
peripheral, inferiorly-extending portion contoured to correspond to a contour
of a superior edge
portion of the cortical bone along the resection plane so that the at least
the portion of the
peripheral inferiorly-extending outer surface portion is disposable adjacent
to a underlying
concave inner surface of the cortical bone. C3. The tibial tray of C2, wherein
the contour of the
at least the portion of the peripheral inferiorly-extending outer surface
portion from the proximal
portion to the distal portion of the peripheral, inferiorly-extending portion
is perpendicular to the
resection plane. C4. The tibial tray of Cl, wherein the peripheral, inferiorly-
extending portion
comprises at least a portion of the peripheral inferiorly-extending outer
surface portion extending
from a proximal portion of the peripheral, inferiorly-extending portion to a
distal portion of the
peripheral, inferiorly-extending portion having a proximal portion contoured
to correspond to a
contour of a superior edge portion of the cortical bone along the resection
plane, and a distal
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portion contoured to being disposable inwardly from the contour of the
superior edge portion of
the cortical bone along the resection plane.
[00243] Dl. A tibial tray for a resected proximal portion of a tibia of a
patient for a knee
replacement, the resected proximal portion of the tibia having a center
cancellous bone surface, a
peripheral cortical bone surface, and at least one cavity formed in the
cancellous bone exposing
at least a portion of an underlying inner surface of the cortical bone. The
tibial tray includes a
body comprising a superior portion with a superior surface; and an inferior
tibia-engaging
portion. The inferior tibia-engaging portion comprises a center portion having
a center surface
contactable with the center cancellous bone surface, and a peripheral,
inferiorly-extending
portion receivable in the at least one cavity formed in the cancellous bone
surface, a surface of
the peripheral inferiorly-extending portion contactable with the exposed
underlying inner surface
of the cortical bone of the tibia of the patient.
[00244] D2. The tibial tray of D1 wherein the inferior tibia-engaging portion
comprises: a
peripheral edge portion having an inferior surface supportable on the
peripheral cortical bone
surface of the tibia of the patient, and the peripheral, inferiorly-extending
portion being disposed
inwardly of the peripheral edge portion. D3. The tibial tray of D1 wherein the
center surface of
the inferior tibia-engaging portion comprises a non-planar surface. D4. The
tibial tray of D1
wherein the surface of the inferiorly-extending portion of the inferior tibia-
engaging portion is
contactable with at least 10 percent of a perimeter of the underlying
peripheral inner surface of
the cortical bone of the tibia of the patient. D5. The tibial tray of D1
wherein the inferior tibia-
engaging portion comprises an inferior convex surface, an inferior concave
surface, and/or an
inferior convex surface and an inferior concave surface. D6. The tibial tray
of D1 wherein the
inferior tibia-engaging portion comprises a pair of spaced-apart inferior
convex surfaces
corresponding in size to a medial condyle and a lateral condyle of the
proximal portion of the
tibia of the patient. D7. The tibial tray of D1 wherein the peripheral,
inferiorly-extending portion
comprises a wall contactable against the exposed inner surface of the cortical
bone. D8. The
tibial tray of D7 wherein the wall comprises the surface contactable with the
exposed underlying
inner surface of the cortical bone and is angled at about 35 degrees relative
to the superior
surface of the superior portion of the body and extending about 7 mm below the
superior surface
of the superior portion of the body. D9. The tibial tray of D7 wherein the
wall extends along at
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least 30 percent of a perimeter of the underlying peripheral inner surface of
the cortical bone of
the tibia of the patient. D10. The tibial tray of D7 wherein the wall extends
along the entire
center portion of the body. D11. The tibial tray of D1 wherein the inferiorly-
extending portion
comprises a pair of curved walls contactable against spaced apart portions of
the inner surface
the cortical bone. D12. The tibial tray of D1 wherein the inferiorly-extending
portion comprises a
pair of curved walls contactable against spaced apart portions of the inner
surface the cortical
bone, and the center surface comprises a pair of spaced-apart inferior convex
surfaces
corresponding in size to a medial condyle and a lateral condyle of the
proximal portion of the
tibia of the patient. D13. The tibial tray of D1 wherein the inferiorly-
extending portion comprises
at least one inferiorly-extending pin extendable through an aperture in the
inner cortical bone and
having an edge alignable with an outer surface of the cortical bone. D14. The
tibial tray of D1
wherein the center portion of the body comprises an inferiorly-extending keel.
D15. The tibial
tray of D1 wherein the body comprises a one-piece body.
[00245] El. A method for forming a patient specific tibial tray for a knee
replacement of the
patient, the method comprising: determining a patient specific resected
proximal portion of a
tibia of the patient, the resected proximal portion of the tibia of the
patient having a superior
center cancellous bone surface, a peripheral cortical bone surface, and one or
more cavities
and/or openings in the cancellous bone exposing at least a portion of an
underlying inner surface
of the cortical bone of the tibia; and forming the patient specific tibial
tray comprising a body
having an superior portion having a superior surface and an inferior tibia-
engaging portion, the
inferior tibia engaging portion having a center portion contactable with the
cancellous bone
surface, and a peripheral, inferiorly-extending portion receivable in the one
or more cavities
and/or openings and having one or more surfaces contactable with the exposed
underlying inner
surface of the cortical bone of the tibia of the patient.
[00246] E2. The method of El further comprising obtaining first data, via a
processor,
representing a proximal portion of the tibia of the patient, and determining,
via the processor,
second data corresponding the patient specific resected proximal portion of
the tibia of the
patient based on the first data, and the forming, via the processor, comprises
3D printing,
forging, casting based on the second data. E3. The method of E2 wherein the
obtaining first data
comprises obtaining CT scan data and/or X-rays, and the determining comprises
determining the
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patient specific resected proximal portion of the tibia of the patient based
on the obtained first
data. E4. The method of E2 further comprising maximizing the one or more
surfaces of the
inferior tibia-engaging portion based on a depth and an amount of the surface
extending along
the perimeter of the underlying inner surface portion of the cortical bone.
E5. The method of E2
further comprising reducing shear forces and localized forces based on the
implant to bone
contact plane based on the equation Fx = Fcos(theta).
[00247] As may be recognized by those of ordinary skill in the art based on
the teachings
herein, numerous changes and modifications may be made to the above-described
and other
embodiments of the present invention without departing from the scope of the
invention. The
implants and other components of the devices and/or apparatus as disclosed in
the specification,
including the accompanying abstract and drawings, may be replaced by
alternative component(s)
or feature(s), such as those disclosed in another embodiment, which serve the
same, equivalent
or similar purpose as known by those skilled in the art to achieve the same,
equivalent or similar
results by such alternative component(s) or feature(s) to provide a similar
function for the
intended purpose. In addition, the devices and apparatus may include more or
fewer components
or features than the embodiments as described and illustrated herein.
Accordingly, this detailed
description of the currently-preferred embodiments is to be taken as
illustrative, as opposed to
limiting the invention.
[00248] The terminology used herein is for the purpose of describing
particular embodiments
only and is not intended to be limiting of the invention. As used herein, the
singular forms "a",
"an" and "the" are intended to include the plural forms as well, unless the
context clearly
indicates otherwise. It will be further understood that the terms "comprise"
(and any form of
comprise, such as "comprises" and "comprising"), "have" (and any form of have,
such as "has",
and "having"), "include" (and any form of include, such as "includes" and
"including"), and
"contain" (and any form of contain, such as "contains" and "containing") are
open-ended linking
verbs. As a result, a method or device that "comprises," "has," "includes," or
"contains" one or
more steps or elements possesses those one or more steps or elements, but is
not limited to
possessing only those one or more steps or elements. Likewise, a step of a
method or an element
of a device that "comprises," "has," "includes," or "contains" one or more
features possesses
those one or more features, but is not limited to possessing only those one or
more features.
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Furthermore, a device or structure that is configured in a certain way is
configured in at least that
way, but may also be configured in ways that are not listed.
[00249] The invention has been described with reference to the preferred
embodiments. It will
be understood that the architectural and operational embodiments described
herein are exemplary
of a plurality of possible arrangements to provide the same general features,
characteristics, and
general apparatus operation. Modifications and alterations will occur to
others upon a reading
and understanding of the preceding detailed description. It is intended that
the invention be
construed as including all such modifications and alterations.
* * * * *
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