U.S. patent application number 10/662194 was filed with the patent office on 2005-01-13 for bone support plate assembly.
Invention is credited to Paul, Kamaljit S..
Application Number | 20050010227 10/662194 |
Document ID | / |
Family ID | 34991061 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050010227 |
Kind Code |
A1 |
Paul, Kamaljit S. |
January 13, 2005 |
Bone support plate assembly
Abstract
A sliding bone support plate assembly comprises at least first
and second plates which slide with respect to each other, varying
the length of the plate assembly by plate-on-plate sliding after
bone screws mount the plate assembly to vertebrae in a recipient.
The plates comprise cooperating sliding structures which cooperate
with each other to interconnect the plates to each other and to
facilitate sliding movement of the plates with respect to each
other. Such sliding accommodates varying the length of the plate
assembly, and relieving stress which would otherwise be imposed on
the plate assembly by post-procedural settling of respective
vertebrae to which the plates are mounted without requiring any
movement of a plate with respect to a bone to which that plate is
mounted. The plate assembly is fabricated using bio-compatible,
bio-stable materials which are safe for extended use in a living
human, and which are not generally assimilated.
Inventors: |
Paul, Kamaljit S.; (Oshkosh,
WI) |
Correspondence
Address: |
WILHELM LAW SERVICE, S.C.
100 W LAWRENCE ST
THIRD FLOOR
APPLETON
WI
54911
|
Family ID: |
34991061 |
Appl. No.: |
10/662194 |
Filed: |
September 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
60486539 |
Jul 10, 2003 |
|
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60491642 |
Jul 30, 2003 |
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Current U.S.
Class: |
606/71 |
Current CPC
Class: |
A61B 17/8023 20130101;
A61B 17/8042 20130101; A61B 17/7059 20130101 |
Class at
Publication: |
606/071 |
International
Class: |
A61B 017/56 |
Claims
1-92. (canceled).
93. A bone support plate assembly, comprising: (a) a bone support
plate; (b) a second plate element, mounted to said bone support
plate, said bone support plate assembly being designed and adapted
to receive bone fasteners therethrough thus to fasten said bone
support plate assembly to first and second underlying bone
structures of a recipient user thereof, said bone support plate
assembly being adapted to accommodate, when mounted to such first
and second underlying bone structures, post procedural settling of
at least one of such first and second bone structures with respect
to the other of such first and second bone structures.
94. A bone support plate as in claim 93 wherein said bone support
plate assembly comprises a spinal plate assembly and wherein such
first and second underlying bone structures comprise first and
second vertebrae.
95. A bone support plate as in claim 93, said second plate element
engaging said bone support plate so as to slide with respect to
said bone support plate.
96. A bone support plate as in claim 93, further comprising
bone-fastener-receiving apertures in at least one of said bone
support plate and said second plate element, thereby to effect the
fastening of said bone support plate assembly to such first and
second underlying bone structures of such recipient user.
97. A bone support plate assembly as in claim 93, further
comprising apertures in at least one of said first and second
plates, said apertures being adapted to receive bone fasteners
therethrough thus to fasten said bone support plate assembly to
such first and second underlying bone structures.
98. A bone support plate assembly, comprising: (a) a first plate;
(b) a second plate mounted to said first plate and engaged with
said first plate so as to slide with respect to said first plate;
and (c) apertures in at least one of said first and second plates,
said apertures being adapted to receive bone fasteners therethrough
thus to fasten said bone support plate assembly to first and second
underlying bone structures of a recipient user thereof, said bone
support plate assembly being adapted to accommodate, when mounted
to such first and second underlying bone structures, post
procedural settling of at least one of such first and second bone
structures with respect to the other of such first and second bone
structures.
99. A bone support plate assembly as in claim 98 wherein said bone
support plate assembly comprises a spinal plate assembly and
wherein such first and second underlying bone structures comprise
first and second vertebrae.
100. A bone support plate assembly as in claim 98, further
comprising apertures in at least one of said first and second
plates, said apertures being adapted to receive bone fasteners
therethrough thus to fasten said bone support plate assembly to
such first and second underlying bone structures.
101. A bone support plate assembly as in claim 93 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
102. A bone support plate assembly as in claim 94 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
103. A bone support plate assembly as in claim 95 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
104. A bone support plate assembly as in claim 96 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
105. A bone support plate assembly as in claim 97 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
106. A bone support plate assembly as in claim 98 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
107. A bone support plate assembly as in claim 99 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
108. A bone support plate assembly as in claim 100 wherein said
first and second plates are made from material selected from the
group consisting of titanium and stainless steel.
Description
BACKGROUND
[0001] The present invention relates to devices for the fixation
and/or support of bones. In particular, the present invention
relates to bone support plate assemblies for the fixation and/or
support of bones of the spinal column, thus spinal plate
assemblies. The plate assemblies of the present invention have
particular application in situations where compressional or
"settling" forces, as well as torsional and flexing forces on a
spinal plate, which supports "fixed" vertebrae, cause significant
stressing, and potential failure of the spinal plate and/or plate
components.
[0002] Vertebral fixation has become a common approach to treating
spinal disorders, fractures, and the like, and for fusion of
vertebrae at the time such fixation is instituted. Namely, one or
more vertebrae are fixed in position relative to one or more other
vertebrae above, e.g. toward the head from, and/or below, e.g.
toward the coccyx from, the vertebrae being fixed. Generally, a
spinal plate is the device of choice used for mechanically
supporting such vertebral fixation. A typical spinal plate includes
a plate having a plurality of bone support apertures therethrough.
A plurality of fasteners, i.e., bone screws, are generally
positioned into and through respective bone support apertures of
the plate to secure the spinal plate to bone, such as to respective
upper and lower supporting adjacent spinal vertebrae. The screws
are fastened to the respective support vertebrae to secure the
spinal plate to the respective vertebrae. In general, such plate
and screw assemblies can be utilized for e.g. anterior fixation of
the e.g. cervical, lumbar, and/or thoracic portions of the
spine.
[0003] The basis of anterior fixation or plating is to approach the
spine from an anterior or anterio-lateral direction, and to use the
screws to solidly mount the spinal plate to the affected vertebrae.
In some instances, in addition to the application of a spinal
plate, graft material may be incorporated into the procedure in an
attempt to permanently fuse together adjacent vertebrae. The graft
material can be e.g. of bone grafts obtained from bones of the
recipient or from another individual.
[0004] A first common and undesirable result associated with use of
conventional such spinal plates is the tendency of the bone screws
to "back out," or pull away from the bone into which they are
fixed. This problem occurs primarily as a result of the normal
torsional and bending motions of the human body and spine as the
recipient/patient goes about routine daily activities. This is a
particularly important problem because, as the screws become loose
and pull away from the bone, the heads of the screws can rise above
the surface of the spinal plate and can even work their way
completely out of the bone. While this condition can cause extreme
discomfort for the recipient, this condition can also create a
number of potentially serious physiological problems given the
significant amount of nervous and vascular structures located at or
near the potential locations of anterior spinal plate
fixations.
[0005] A number of designs have been proposed in attempts to
prevent screws from pulling away from the bone and/or to prevent
the screws from backing out or pulling away from the surface of the
spinal plate. Such mechanisms used to prevent bone screws from
pulling out of bones include cams which engage and lock the screws,
and the use of expanding head screws which expand outwardly when
adequate force is applied thereto to engage the holes in the spinal
plate. All of these designs have detriments including potential for
breakage or requiring particular precision and alignment in their
application in order to work correctly. Additionally, loose
components and accessories of spinal plates which address the
"backing-out" problem can get dropped and/or misplaced while the
vertebral fixation surgical procedure is taking place, prolonging
and complicating the procedure as well as creating substantial risk
of harm to the recipient.
[0006] A second common result associated with use of such spinal
plates is the tendency of the vertebrae being "fixed" to settle
after the spinal plate affixation procedure. Such settling of the
"fixed" vertebrae relative to each other is a response to the
normal loading of the spine as the recipient/patient carries on
routine daily activities. Such settling of the "fixed" vertebrae
adds compression forces to the above-listed forces which cause the
bone screws to "back out" or pull away from the bone into which
they were fixed. Zdeblick et al (U.S. Pat. No. 5,324,290) attempted
to address the problem of compression forces in the context of
treating vertebral burst fractures, but fails to provide any
functional means to prevent the screws pulling away as a result of
torsional and flexing forces. Zdeblick et al also fails to provide
any structure in the plate assembly which relieves the stress
imposed on the plate by the vertebral settling.
[0007] My U.S. Pat. No. 6,503,250 teaches use of slot-shaped
apertures which enables longitudinal translation of the bone screws
in the slot-shaped apertures with respect to the plate in
cooperation with post-procedural settling of the vertebrae. Such
translation of the bone screws requires that the bone screws not be
locked to the plate, and is accompanied by movement of the bone
screws with respect to the plate, along the longitudinal axes of
the slots, typically along the longitudinal axis of the plate. Such
settling of the bones, such movement of the bone screws with
respect to the plate, is also accompanied by movement of the plate
with respect to one or more of the vertebrae to which the plate is
mounted. Such movement of the plate with respect to the bone can,
in some instances, have undesirable consequences.
[0008] Therefore, it is an object of the invention to provide
spinal plate assemblies which accommodate rigid bone-to-bone
fixation and provide bone support for such fixation, such as e.g.
adjacent or second adjacent vertebrae, while allowing
post-procedural compression between the respective bones, e.g. post
procedural bone-to-bone movement, without requiring any movement of
any bone screw in a slot-shaped aperture with respect to the
respective plate.
[0009] It is a further object of the invention to provide spinal
plate assemblies wherein the bone screws do not need to move with
respect to the plate assembly in order for stress, potentially
imposed on the plate assembly by post-procedural settling of the
vertebrae, to be relieved or avoided.
[0010] Yet a further object of the invention is to provide spinal
plate assemblies having first and second sliding plates which are
adapted and configured to provide plate-on-plate sliding of the
first and second plates, with respect to each other, in order to
relieve a substantial portion of the stress which would otherwise
be imposed on the respective plate assembly by post-procedural
vertebral settling.
[0011] Still a further object of the invention is to provide spinal
plate assemblies which accommodate bone-to-bone settling while
providing bone support for such fixation, while accommodating post
procedural compression between the respective bones, and while
maintaining rigid, unmoving fixation between the plate and the
respective bones/vertebrae.
[0012] It is a further object of the invention to provide bone
support plate assemblies, e.g. spinal plate assemblies, which
accommodate bone-to-bone settling while providing bone support for
such fixation, while accommodating post procedural compression
between the respective bones, without requiring, or enabling, any
movement of any plate with respect to a bone to which such plate is
mounted.
SUMMARY
[0013] A sliding bone support plate assembly comprises at least
first and second plates which slide with respect to each other,
thus to vary the overall length of the bone support plate assembly
by plate-on-plate sliding. The first and second plates comprise
cooperating first and second sliding structures which cooperate
with each other both to interconnect the plates to each other and
to facilitate sliding movement of the first and second plates with
respect to each other. Such sliding movement accommodates varying
the first overall length of the bone support plate assembly, in
order to relieve a substantial portion of the stress which would
otherwise be imposed on the bone support plate assembly by
post-procedural settling of respective vertebral structure to which
the plates are mounted. The bone support plate assembly is
fabricated using bio-compatible and bio-stable materials which are
safe for use in a living human body for an extended period of time,
and which materials are not generally assimilated into the living
human body.
[0014] Preferably, the plate-on-plate sliding is accomplished by
one or more insert-accepting tracks on the first plate, and one or
more sliding inserts on the second plate, and wherein at least one
of the sliding inserts extends continuously between opposing sides
of the respective sliding insert.
[0015] In a first family of embodiments, a sliding bone support
plate assembly has a first overall length, and comprises first and
second plates which slide with respect to each other thus to vary
the overall length of the bone support plate assembly. The first
plate has at least a first bone fastener aperture for receiving
therethrough at least a first bone fastener adapted to fasten the
first plate to a first vertebra. The second plate has at least a
second bone fastener aperture for receiving therethrough at least a
second bone fastener adapted to fasten the second plate to a second
vertebra. The first and second plates comprise cooperating first
and second sliding structures which cooperate with each other and
thereby enable interconnecting the first and second plates with
corresponding longitudinal sliding movement of the first and second
plates with respect to each other, thus to accommodate varying the
first overall length of the bone support plate assembly. The plate
assembly is fabricated using bio-compatible and bio-stable
materials which are safe for use in a living human body for an
extended period of time, and which are not assimilated into such
living human body. The sliding of the first and second plates with
respect to each other facilitates post-procedural settling of the
first and second vertebrae with respect to each other, preferably
post-procedural compression of the respective vertebrae, and
relieving, from the plate assembly, of a substantial amount,
typically all, of the stress potentially imposed on the plate by
post-procedural vertebral settling.
[0016] The recited post-procedural settling typically, and
desirably, results in maintaining the respective e.g. first and
second vertebrae under post-procedural axial loading.
[0017] In some embodiments, the sliding bone support plate assembly
further comprises cover apparatus associated with at least one of
the bone fastener apertures, the cover apparatus automatically
extending over a bone fastener which is driven in a respective one
of the bone fastening apertures, when a cover land associated with
the respective bone fastener moves past the cover apparatus.
[0018] In some embodiments, the sliding bone support plate assembly
further comprises temporary length retention structure, effective
to temporarily fix the first overall length of the sliding bone
support plate assembly at a temporary overall length prior to
and/or during installation of the sliding bone support plate
assembly in a recipient user.
[0019] In some embodiments, the temporary length retention
structure comprises at least one set screw.
[0020] In some embodiments, the first plate comprises a first
coupling screw aperture, and the second plate comprises a second
coupling screw aperture adapted to be aligned with the first
coupling screw aperture at the temporary overall length, and the
temporary length retention structure comprises a coupling screw
adapted to connect the first and second coupling screw apertures to
each other, thereby to fix the overall length of the sliding bone
support plate assembly at the temporary overall length.
[0021] In some embodiments, the sliding structure on the first
plate comprises a channel, and the sliding structure on the second
plate comprises a rail sliding in the channel.
[0022] In some embodiments, the sliding structure on the first
plate comprises first and second channels, and the sliding
structure on the second plate comprises first and second rails
sliding in the first and second channels.
[0023] In some embodiments, the sliding structure on the first
plate comprises first and second channels, and the sliding
structure on the second plate comprises first and second opposing
lateral sides, the first and second channels on the first plate
receiving the opposing lateral sides of the second plate, the
opposing lateral sides of the second plate sliding with respect to
the channels of the first plate.
[0024] In some embodiments, the sliding structures of the first and
second plates comprise cooperating tongue and groove
structures.
[0025] In some embodiments, the first plate comprises a first major
surface, the second plate comprises a second major surface, a first
portion of the first major surface of the first plate facing a
second portion of the second major surface of the second plate, at
least substantial portions of the cooperating sliding structures on
the first and second plates being embodied in the facing major
surfaces of the first and second plates.
[0026] In some embodiments, the cooperating sliding structures
comprise dovetail structures as parts of the facing portions of the
facing major surfaces. Preferably, the cooperating sliding
structures comprise at least two female dovetail sliding elements,
and at least two male dovetail sliding elements cooperating with
the at least two female dovetail sliding elements, on the facing
portions of the facing major surfaces.
[0027] In preferred embodiments, each of the at least first and
second plates comprises at least first and second bone fastener
apertures adapted to receive bone fasteners therethrough, each of
the first and second plates further comprising a retainer which
extends between the respective first and second bone fastener
apertures, and which automatically extends over a land associated
with a compatible bone fastener which is driven through one of the
first and second bone fastener apertures, when the land associated
with the respective bone fastener moves past the retainer.
[0028] In preferred embodiments, the first and second plates are
adapted to slide with respect to each other during post-procedural
settling of the first and second vertebrae with respect to each
other, without corresponding movement of the first and second
plates with respect to underlying ones of the first and second
vertebrae to which the first and second plates are mounted.
[0029] In a second family of embodiments, the invention comprehends
a sliding bone support plate assembly having a first overall
length, and comprising first and second plates which slide with
respect to each other thus to vary the first overall length of the
bone support plate assembly. The first plate has at least a first
insert accepting track, each insert accepting track having a first
interior side X and a second interior side Y. The second plate has
at least a first insert structure. Each insert structure has a
first lateral side X' and a second lateral side Y'. Side X' of the
first insert structure is in sliding communication with side X of
the first insert accepting track. Side Y' of the first insert
structure is in sliding communication with side Y of the first
insert accepting track. At least one insert structure extends
continuously between side X' and side Y', and each of the first and
second plates further comprises at least one bone fastener aperture
adapted to receive a bone fastener therethrough thus to facilitate
mounting the respective plate to at least first and second
vertebrae. The plate assembly is structured from bio-compatible and
bio-stable materials which are safe for use in a living human body
for an extended period of time, and which are not assimilated into
the living human body.
[0030] In some embodiments, the sliding plate assembly includes
temporary length retention structure, which optionally comprises at
least one coupling screw, optionally a set screw.
[0031] In some embodiments, the first plate comprises a first
coupling screw aperture, and the second plate comprises a second
coupling screw aperture adapted to be aligned with the first
coupling screw aperture at a temporary overall length, and wherein
the temporary length retention structure comprises a coupling screw
adapted to connect the first and second coupling screw apertures to
each other, thereby to fix the overall length of the sliding bone
support plate assembly at the temporary overall length.
[0032] In some embodiments, the insert-accepting track on the first
plate comprises first and second channels, and the insert structure
on the second plate comprises first and second rails sliding in the
first and second channels.
[0033] In some embodiments, the insert-accepting track on the first
plate comprises first and second channels, and the insert structure
on the second plate comprises first and second opposing lateral
sides, the first and second channels on the first plate receiving
the opposing lateral sides of the second plate, and the opposing
lateral sides of the second plate sliding with respect to the
channels of the first plate.
[0034] In some embodiments, the sliding insert-accepting track of
the first plate and the insert structure of the second plate
comprise cooperating tongue and groove structures.
[0035] In some embodiments, at least substantial portions of the
insert-accepting track and the insert structure are embodied in
facing major surfaces of the first and second plates.
[0036] In preferred embodiments, the insert-accepting track and the
insert structure comprise dovetail structures on facing portions of
facing major surfaces of the first and second plates. Preferably,
the insert-accepting track and the insert structure comprise at
least two female dovetail sliding elements, and at least two male
dovetail sliding elements cooperating with the at least two female
dovetail sliding elements, on the facing portions of the facing
major surfaces.
[0037] In a third family of embodiments, the invention comprehends
a sliding bone support plate assembly having a first overall
length, and comprising first and second plates which slide with
respect to each other thus to vary the first overall length of the
bone support plate assembly. The first plate has one or more
longitudinally extending sliding apertures. The second plate has
one or more longitudinally extending sliding inserts, each having a
width extending between opposing outer sides thereof. Each
combination of one of the one or more sliding apertures and one of
the one or more sliding inserts is adapted and configured with one
or more insert-accepting tracks which facilitate sliding engagement
of the respective sliding insert and sliding aperture, at least one
of the one or more sliding inserts, in the sliding apertures,
extending continuously between the opposing sides of the respective
sliding insert; the plate assembly being structured from
bio-compatible and bio-stable materials which are safe for use in a
living human body for an extended period of time, and which are not
assimilated into the living human body.
[0038] In some embodiments, the first plate comprises a first
coupling screw aperture, and the second plate comprises a second
coupling screw aperture adapted to be aligned with the first
coupling screw aperture at the temporary overall length, and
wherein the temporary length retention structure comprises a
coupling screw adapted to connect the first and second coupling
screw apertures to each other, thereby to fix the overall length of
the sliding bone support plate assembly at the temporary overall
length.
[0039] In a fourth family of embodiments, the invention comprehends
a sliding bone support plate assembly having a first overall
length, and comprising first and second plates which slide with
respect to each other thus to vary the first overall length of the
bone support plate assembly. The first plate has a first length,
first opposing side edges, and at least a first bone fastener
aperture adapted to receive a first bone fastener therethrough thus
to facilitate mounting the first plate to a first vertebra of a
recipient user. The first plate comprises a first major surface,
and a male dovetail structure extending outwardly from the first
major surface and along the first length of the first plate. The
first major surface comprises a wing element thereof between the
male dovetail structure and a respective one of the first side
edges. The second plate has a second length, second opposing side
edges, and at least a second bone fastener aperture adapted to
receive a second bone fastener therethrough thus to facilitate
mounting the second plate to a second vertebra of the recipient
user. The second plate comprises a second major surface facing the
first major surface of the first plate, and a female dovetail
structure extending inwardly from the second major surface and
along the second length of the second plate. The second major
surface comprises a plate land element thereof between the female
dovetail structure and a respective one of the second side edges
adjacent the wing element of the first major surface. The male and
female dovetail structures cooperate with each other and thereby
enable interconnecting and engagement of the first and second
plates to each other along the male and female dovetail structures,
as well as along the first and second major surfaces, including
engagement of the wing element and the plate land element with each
other, such that longitudinal sliding movement of the first and
second plates with respect to each other is facilitated, thus to
accommodate varying the first overall length of the bone support
plate assembly. As with other embodiments, the plate assembly can
be fabricated using bio-compatible and bio-stable materials which
are safe for use in a living human body for an extended period of
time, and which are not assimilated into such living human body.
Sliding of the first and second plates with respect to each other
facilitates post-procedural settling of the first and second
vertebrae with respect to each other, and corresponding
post-procedural compression of the respective vertebrae, and
relieving, from the plate assembly, of stress imposed by such
post-procedural vertebral settling.
[0040] In preferred embodiments, when the first and second plates
are mounted to underlying first and second bones, magnitude of
movement of the first and second plates with respect to each other
corresponds generally with magnitude of movement of the underlying
first and second bones with respect to each other.
[0041] In a fifth family of embodiments, the invention comprehends
sliding bone support plate assembly having a first overall length,
and comprising first and second plates which slide with respect to
each other thus to vary the first overall length of the bone
support plate assembly. The first plate has at least a first bone
fastener aperture for receiving therethrough at least a first bone
fastener adapted to fasten the first plate to a first vertebra, and
the second plate has at least a second bone fastener aperture for
receiving therethrough at least a second bone fastener adapted to
fasten the second plate to a second vertebra, the first and second
plates comprising cooperating first and second sliding structures
which enable interconnecting the first and second plates with
corresponding longitudinal sliding movement of the first and second
plates with respect to each other, thus to accommodate varying the
first overall length of the bone support plate assembly, the plate
assembly being structured from bio-compatible and bio-stable
materials which are safe for use in a living human body for an
extended period of time, and which are not assimilated into such
living human body, sliding of the first and second plates with
respect to each other facilitating post-procedural settling of such
first and second vertebrae with respect to each other, the first
and second plates being adapted to slide with respect to each other
during post-procedural settling of the first and second vertebrae,
without corresponding movement of the first and second plates with
respect to underlying ones of the first and second vertebrae to
which the first and second plates are mounted.
[0042] In a sixth family of embodiments, the invention comprehends
a method of installing a bone support plate assembly in a recipient
thereof, the bone support plate assembly having a first overall
length, and comprising first and second plates which are slidingly
engaged with each other, so as to slide with respect to each other
thus to vary the first overall length of the bone support plate
assembly. The method comprises placing the bone support plate
assembly at a mounting location in a recipient user of the bone
support plate assembly; fastening the first and second plates to
first and second bones of the recipient user of the bone support
plate assembly; and releasing, as necessary, any fixation structure
or device which temporarily fixes the overall length of the bone
support plate assembly, so as to accommodate sliding of the first
and second plates with respect to each other, and correspondingly
accommodating post-procedural settling of such first and second
bones with respect to each other.
[0043] In a seventh family of embodiments, the invention
comprehends a method of installing a bone support plate assembly in
a recipient thereof, the bone support plate assembly having a first
overall length, and comprising first and second plates which are
slidingly engaged with each other, so as to slide with respect to
each other thus to vary the first overall length of the bone
support plate assembly. The method comprises temporarily fixing the
overall length of the bone support plate assembly; placing the bone
support plate assembly at a mounting location in a recipient user
of the bone support plate assembly; fastening the first and second
plates to first and second bones of the recipient user of the bone
support plate assembly; and releasing the length fixation so as to
accommodate sliding of the first and second plates with respect to
each other, and correspondingly accommodating post-procedural
settling of such first and second bones with respect to each
other.
[0044] In preferred embodiments, the method comprises providing, as
the bone support plate assembly, a bone support plate assembly
wherein the first and second plates are adapted to slide with
respect to each other during post-procedural settling of the first
and second vertebrae with respect to each other, without
corresponding movement of the first and second plates with respect
to underlying ones of the first and second vertebrae to which the
first and second plates are mounted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 shows a pictorial exploded view of a first embodiment
of spinal plate assemblies of the invention.
[0046] FIG. 2 shows a cross-section of the first plate of the bone
support plate assembly of FIG. 1, taken at 2-2 of FIG. 1.
[0047] FIG. 3 shows a pictorial view of a coupling assembly screw
useful in the bone support plate assembly of FIGS. 1 and 2.
[0048] FIG. 4 shows a top view of a second bone support plate
assembly of the invention.
[0049] FIG. 5 shows a cross-section of the bone support plate
assembly of FIG. 4 and is taken at 5-5 of FIG. 4.
[0050] FIG. 6 shows a pictorial view of a set screw useful in the
bone support plate assembly of FIGS. 4 and 5.
[0051] FIG. 7 shows a top view of a third bone support plate
assembly of the invention.
[0052] FIG. 8 shows a cross-section of the bone support plate
assembly of FIG. 7 and is taken at 8-8 of FIG. 7.
[0053] FIG. 9 shows a top view of a fourth bone support plate
assembly of the invention.
[0054] FIG. 10 shows a cross-section of the bone support plate
assembly of FIG. 9 and is taken at 10-10 of FIG. 9.
[0055] FIGS. 11 and 1 2 show top and side views of a plate assembly
as in FIGS. 4-6, and including retainer slots and retainers as in
FIGS. 1-3.
[0056] FIGS. 13 and 14 show top and side views of a plate assembly
as in FIGS. 7 and 8, and including retainer slots and retainers as
in FIGS. 1-3.
[0057] FIGS. 15 and 16 show top and side views of a plate assembly
as in FIGS. 9 and 10, and including retainer slots and retainers as
in FIGS. 1-3.
[0058] The invention is not limited in its application to the
details of construction or the arrangement of the components set
forth in the following description or illustrated in the drawings.
The invention is capable of other embodiments or of being practiced
or carried out in other various ways. Also, it is to be understood
that the terminology and phraseology employed herein is for purpose
of description and illustration and should not be regarded as
limiting. Like reference numerals are used to indicate like
components.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0059] FIGS. 1-3 illustrate a first embodiment of spinal plate
assemblies of the invention which are used for long-term support of
bone structures, especially bone structures of the spine. As with
all embodiments of the invention, the components of the bone
support plate assembly of FIGS. 1-3 are fabricated of, structured
from, materials which are bio-compatible and bio-stable with
respect to the human body, e.g. which are safe for use in a living
human body for extended periods of time, and which are not
routinely assimilated by the living human body.
[0060] In general, in the embodiment of FIGS. 1-3, male dovetail
structure extends as ridges from a first major surface of a first
plate and slides with respect to female dovetail structure which
extends as channels from a second major surface of a second plate,
thus to facilitate longitudinal plate-to-plate sliding of the
plates with respect to each other while coupling the plates
together, and to accommodate extensions and retractions of the
overall length of the plate assembly.
[0061] A coupling screw cooperates with aligned apertures in the
first and second plates to set a temporary overall length of the
plate assembly.
[0062] FIGS. 4-6 illustrate a second embodiment of spinal plate
assemblies of the invention. In general, in the embodiment of FIGS.
4-6, outer edges of sliding inserts on the first plate are received
in, and slide with respect to, insert accepting tracks at a sliding
aperture on the second plate, thus to facilitate longitudinal
plate-to-plate sliding of the plates with respect to each other
while the plates are engaged with each other, and to accommodate
extensions and retractions of the overall length of the plate
assembly.
[0063] A coupling set screw in the second plate can be tightened to
bear against a major surface of the first plate, thus to set a
temporary overall length of the plate assembly.
[0064] FIGS. 7-8 illustrate a third embodiment of spinal plate
assemblies of the invention. In general, in the embodiment of FIGS.
7-8, rails on the outer edges of sliding inserts on the first plate
are received in, and slide with respect to, channels which act as
insert accepting tracks at a sliding aperture on the second plate,
thus to facilitate longitudinal plate-to-plate sliding of the
plates with respect to each other while the plates are engaged with
each other, and to accommodate extensions and retractions of the
overall length of the plate assembly.
[0065] FIGS. 9-10 illustrate a fourth embodiment of spinal plate
assemblies of the invention. In general, in the embodiment of FIGS.
9-10, rails on the outer edges of sliding inserts on the first
plate are received in, and slide with respect to, channels which
act as insert accepting tracks at a sliding aperture on the second
plate, thus to facilitate longitudinal plate-to-plate sliding of
the plates with respect to each other while the plates are engaged
with each other, and to accommodate extensions and retractions of
the overall length of the plate assembly.
[0066] An expansion coupling screw in the first plate can be
tightened to urge the sliding inserts against the channels, thus to
bring the inserts into frictional engagement with the channels, and
to enable the using surgeon to temporarily fix the overall length
of the plate assembly.
[0067] When the expansion coupling screw is advanced, the screw
urges the left and right elements/rails of the sliding insert on
the second plate laterally against the left and right channels in
the receiving aperture on the first plate, whereby the sliding
inserts on the second plate are temporarily held against sliding
movement with respect to the channels of the receiving aperture on
the first plate. The first and second plates are thus coupled, by
frictional engagement, and prevented from sliding movement with
respect to each other while the expansion coupling screw is in an
advanced location.
[0068] This frictional coupling engagement, and corresponding
temporary fixation of length of the plate assembly, is released,
and ongoing sliding of the first and second plates with respect to
each other is enabled, by retracting and/or removing the expansion
coupling screw, which enables the inherent resilience of the rails
of the second plate to withdraw the rails from their frictional,
coupling engagement with the channels on the first plate, whereby
the rails freely slide with respect to the channels.
[0069] Any of the embodiments can be modified, as necessary, to
provide or accommodate temporarily fixing the overall length of the
plate assembly. Such temporary length fixation can be achieved, on
the one hand, by internal plate assembly structure such as by
cooperation of the combined features of coupling screw 28 and
coupling apertures 30, 36.
[0070] On the other hand, such temporary length fixation can be
achieved externally e.g. by engaging one or more plate installation
tools, not shown, with the plate assembly and employing one or more
features of such tool or tools to temporarily fix the length of the
plate assembly while the plate assembly is in the process of being
installed in the recipient user. In either case, the temporary
length can be adjusted from time to time, as desired, by the
surgeon during the installation procedure.
[0071] While the length of the plate assembly is temporarily fixed,
in any of the embodiments, and whether by using internal or
external temporary length fixation, or no length fixation, the
plates can be mounted, as desired, to the vertebrae of a
recipient/patient of the bone support plate assembly. Prior to
completion of the surgical procedure, the surgeon releases such
temporary length fixation, and can optionally remove the coupling
screw or other length fixing structure from the assembly, such that
the plates can slide with respect to each other after completion of
the surgical procedure, whereby the plates can thereby accommodate
post-procedural settling of the so-treated bones with respect to
each other.
[0072] The above described plate-to-plate sliding feature, of
extension and retraction in plate assemblies of the invention,
accommodates post-procedure settling of the vertebrae which are
being supported by the plate assembly, without putting undue stress
on the plate assembly, or on the bone screws which mount the plate
assembly to the bone structure of the recipient user of the plate
assembly and without requiring, typically without allowing, any
movement of a plate with respect to any bone/vertebra to which that
particular plate is mounted e.g. by a bone screw.
[0073] Typically, the bone screw apertures are circular, and are
not elongated. While some aperture elongation can be employed,
while slotted apertures are within the scope of the invention, in
preferred embodiments, the bone screws do not, in general, move
with respect to a plate, and the plates do not move with respect to
the bones/vertebrae to which they are mounted, after the plate is
attached to a vertebra of a recipient/patient. Namely, the bone
screws and bone screw apertures are preferably cooperatively
adapted to retain the bone screws in fixed location with respect to
the plate, the plate in fixed location with respect to the bone to
which the plate is mounted, once the bone screws are screwed into
bone structure of the recipient user/patient.
[0074] The above described capacity for the first and second plates
to slide with respect to each other in the plate assemblies of the
invention enables the individual plates, which are mounted to
respective individual vertebrae, to move, concurrently with
movement of the respective vertebrae, with concurrent
plate-to-plate sliding of the plates with respect to each other,
without plate-to-bone sliding with respect to each other.
[0075] The concurrent plate-to-plate sliding of the plates results
in the overall length of the plate assembly automatically adjusting
to the movement of the respective vertebrae without any movement
between vertebrae and the respective plates. Namely, as the
distance between the vertebrae changes, the overall length of the
plate changes by about a corresponding amount. This adjustment of
the overall length of the plate to vertebral distance changes
avoids substantial build-up of stress in the connection between
plate assembly and vertebrae, namely in the bone screws, as well as
avoiding the corresponding plate-to-bone movement where a plate is
affixed to the respective underlying bone, as the distance between
vertebrae changes. While some nominal amount of residual stress may
be present in the plate or bone screws, the majority of the
potential stress is dissipated by the sliding of the plates with
respect to each other.
[0076] Referring specifically, now, to the drawings, FIGS. 1-3
illustrate a first embodiment of 2-plate spinal plate assemblies 10
of the invention. Assembly 10 includes a first plate 12A, a second
plate 12B, first and second retainers 13, and coupling screw 28.
Each plate 12A, 12B includes first and second bone screw apertures
14 and opposing side edges 15. Each plate includes sliding
structure 16 which facilitates sliding of the plates with respect
to each other when the plates are assembled to each other to form
the assembly 10. Plate 12A has a distal end 23A and a proximal end
42A. Plate 12B has a distal end 23B and a proximal end 42B.
[0077] Sliding structure 16 on the first plate 12A is illustrated
in FIG. 1 as first and second female dovetail channels 18 which
extend from a first major surface 43 along the length of plate 12A.
Sliding plate lands 44 extend, as part of the first major surface
43 of plate 12A, between each of channels 18 and the adjacent side
edges 15 of the first plate.
[0078] Sliding structure 16 on the second plate 12B is illustrated
in FIG. 1 as first and second male dovetail ridges 20 which extend
from second major surface 45 along the length of plate 12B. A
sliding wing 47 extends, as part of the second major surface 45 of
plate 12B, between each of ridges 20 and the adjacent side edge 15
of the second plate.
[0079] Retainer 13 resides in a retainer slot 22 associated with
each plate 12A or 12B. Referring to FIGS. 1 and 2, slot 22 extends
downwardly from the top surface of the plate, and thence left and
right toward bone screw apertures 14 a distance sufficient to
extend into the respective apertures 14, while providing an outer
wall 24 against which retainer 13 is biased. Slot 22 extends to
distal end 23A of plate 12A, whereby retainer 13 can be inserted
into slot 22 from end 23. Slot 22 terminates in a dead end, short
of proximal end 25 of sliding structure 16. The proximal end of
slot 22 includes a relatively constricted neck portion.
[0080] Retainer 13 includes left and right retainer bands 26, and a
spring 29, integral with and connected to each of bands 26. Spring
29 biases the bands 26 against the outer walls 24 of slot 22, thus
bringing the bands into blocking positions extending across
portions of apertures 14, as shown. Retainer 13 is thus held
longitudinally in slot 22 by the resilient expansive force of
spring 29 in combination with the blocking surfaces of slot 22
presented at the neck, and the dead end of the slot.
[0081] Overlying coupling apertures 30 extend along a corresponding
longitudinal axis "LB" of plate 12B, at the top major surface 32 of
plate 12B, through the thickness of the plate and to the bottom
major surface 34.
[0082] Underlying coupling apertures 36 are spaced along a
corresponding longitudinal axis "LA" of plate 12A, at the top major
surface 38 of plate 12A, and extend to the bottom surface of the
plate. While apertures 36 preferably extend entirely through the
thickness of plate 12A to bottom major surface 40, the invention
comprehends embodiments wherein apertures 36 in plate 12A are
dead-end apertures; namely apertures 36 which extend into, but not
through, underlying plate 12A.
[0083] FIG. 1 shows the head of coupling screw 28 overlying one of
the coupling apertures 30 in plate 12B.
[0084] Plate assembly 10 is assembled and used as follows. Plates
12A and 12B are brought together with the facing proximal ends 42A
and 42B of the respective plates 12A and 12B generally facing each
other, and with the male and female dovetails aligned for
cooperative sliding with respect to each other. The end portions of
the male and female dovetail elements are then engaged, whereupon
the male and female dovetail elements facilitate plate-to-plate
sliding of the plates with respect to each other, while the
dovetail structures slidingly couple the plates to each other. In
the resulting plate assembly, the dovetail structures provide
primary prevention of the plates becoming separated from each other
along directions transverse to longitudinal axes "LA" and "LB".
Sliding wings 47 and sliding plate lands 44 on the first and second
major surfaces are engaged with each other, outwardly of the
dovetail structure, to provide substantial engagement to assist in
resisting of twisting movement of plates 12A and 12B with respect
to each other e.g. about longitudinal axes "LA" and "LB". Placement
of twisting resistance outwardly of the dovetail structure, namely
toward side edges 15 from the dovetail structure, enhances the
sensitivity of the plate assembly to twisting, and enables the
plate to more effectively resist twisting, for a given clearance
between the plates at the sliding interface. Further, employment of
wings 47 and plate lands 44 can take advantage of the entire widths
of plates 12A, 12B with respect to twisting resistance.
[0085] Returning specifically to the process of assembling plate
assembly 10, once engaging of the dovetail structures is initiated,
sliding of the plates with respect to each other is continued along
the interconnected dovetail structures until a selected one of
overlying coupling apertures 30 comes into overlying alignment with
a selected one of underlying apertures 36, thus to define a
temporary overall length of the bone support plate assembly. With
the temporary length thus defined, and with overlying and
underlying coupling apertures thus aligned on plates 12A and 12B,
coupling screw 28 is advanced through the respective overlying
coupling aperture 30 and into the respective underlying coupling
aperture 36, thus temporarily fixing the length of the bone support
plate assembly.
[0086] With two coupling apertures as shown in each of plates 12A
and 12B, and wherein the two pairs of apertures are not
simultaneously aligned, the surgeon who is installing the bone
support plate assembly has 4 temporary plate assembly overall
lengths from which to select before advancing the screw through one
of apertures 30 and into one of apertures 36. The number of
aperture-to-aperture optional temporary lengths from which the
surgeon can select can be increased by increasing the number of
coupling apertures in either or both of the plates. Such increased
number of coupling apertures are preferably arrayed in alignment
with the apertures shown, e.g. along the respective longitudinal
axis.
[0087] Once the particular vertebral arrangement in the recipient
user is determined during surgery, the surgeon sets an initial
temporarily fixed length for the plate assembly by aligning an
aperture 30 in plate 12B with an aperture 36 in plate 12A, then
inserting screw 28 into the selected aperture 30. Screw 28 is then
advanced through the respective overlying coupling aperture 30 and
into the respective underlying aperture 36, thus to fix the
temporary length of the assembly for purposes of initial
installation, namely mounting the plate assembly to vertebrae of
the recipient user.
[0088] Referring to the respective vertebrae being treated, as
designated with respect to each other, the vertebra relatively
closer to the skull is called the overlying vertebra and the
vertebra relatively closer to the coccyx is referred to as the
underlying vertebra.
[0089] With the temporary length set, whether an initial length or
a revised length, the surgeon places the bone support plate
assembly 10 on location in the recipient user, and checks that the
plate assembly, at the temporarily fixed length enables advancing
bone screws through apertures 14 and into bone structure of the
underlying vertebra of the recipient user at optimal locations,
thus to mount at least one of plate 12A or 12B, and correspondingly
the assembly, to the recipient user.
[0090] If, after bone screws are advanced through plate 12A into
bone of the recipient user, remaining ones of the apertures 14 are
not suitably aligned with structure of the vertebrae, coupling
screw 28 is loosened enough to enable sliding of plate 12B with
respect to plate 12A, and the overall length of the plate assembly
is thus adjusted as necessary so as to establish a suitable revised
overall temporarily fixed length which accommodates securing bone
screws to the vertebrae at desirable locations through plate
12B.
[0091] When a suitable revised overall temporarily fixed length has
been achieved, which provides the desired alignment between the
vertebrae and apertures 14 which are yet to receive bone screws,
coupling screw 28 is advanced until the end of the coupling screw
enters an aperture 36, or impacts upper major surface 38 of plate
12B. Where screw 28 impacts surface 38, screw 28 acts as a set
screw, fixing a revised temporary overall length of the plate
assembly. While the coupling screw 28 holds the revised overall
length, screw holes are drilled through respective ones of
apertures 14 and into the bone structure of the recipient user, and
bone screws are advanced through the respective apertures 14 and
into the bone structure, thus mounting plate 12B to the
vertebra.
[0092] As an alternative procedure, the surgeon can set a temporary
overall length of the plate assembly, suitable for installing bone
screws in all of the apertures, prior to installing any of the bone
screws. Thus, the adjustment of plate length, referred to above as
occurring after installation of bone screws in plate 12A, can be
effected prior to any of the bone screws being installed in bone
structure of the recipient user.
[0093] As a bone screw is advanced past a respective band 26,
spring 29 flexes resiliently, enabling the respective band 26 to
move out of the way of the advancing head, or other land, of the
screw. Once the head or other land passes the band, spring 29
pushes the respective band back over the head or other land and
blocks reverse-direction movement of the head or other land which
would tend to release the screw from the bone. Retainer 13, through
bands 26, thus prevents the screws from backing out of apertures
14.
[0094] In a typical surgical procedure, and with plates 12A and 12B
slidingly coupled to each other, e.g. plate 12A is first mounted to
the vertebra of the recipient user which underlies the plate,
whereby the vertebra of the recipient user is correspondingly
temporarily mounted to the respective plate 12A or 12B.
[0095] Subsequently, bone screws are advanced through apertures 14
in the remaining plate, e.g. plate 12B, to mount the remaining
plate to a second vertebra which underlies the remaining plate.
[0096] With both of plates 12A and 12B mounted to vertebrae which
underlie the respective plates, coupling screw 28 is withdrawn from
its fixation of the overall length of the plate assembly, and is
preferably removed from the plate assembly, whereupon plates 12A
and 12B are free to slide with respect to each other along the
respective sliding structures as the respective vertebrae, to which
they are mounted, move with respect to each other after completion
of the surgical procedure, the plates being coupled, and held, to
each other by the dovetail design of sliding structures 16.
[0097] Post procedure, and now referring to the spinal column as a
whole, and the vertebrae directly affected by the bone support
plate assembly, it is desirable to enable the overlying vertebra,
which is disposed relatively toward the skull to settle with
respect to the underlying vertebra, which is disposed relatively
toward the coccyx, whereby the overlying vertebra exerts
compression loading on the underlying vertebra, namely axial
loading on the underlying vertebra.
[0098] Such compression loading is accompanied by a tendency, while
the recipient user is in an upright orientation, for the overlying
vertebra to move downwardly under the force of gravity toward the
underlying vertebra, thus to reduce the distance between the
overlying and underlying vertebrae. However, as the overlying
vertebra tends to settle, the overlying vertebra urges downwardly
the bone screws in the overlying vertebra. This downward force
causes the respective overlying plate, e.g. plate 12A, toward the
skull, to slide downwardly with respect to the underlying plate,
e.g. plate 12B, toward the coccyx, namely along the length of the
plate assembly toward apertures 14 in plate 12B.
[0099] Accordingly, such capacity for sliding movement of plate 12A
toward plate 12B accommodates post-procedural compression of the
respective underlying and overlying vertebrae, which is considered
to be a desirable response of the vertebrae being so treated.
[0100] While the above description has related to the embodiments
of FIGS. 1-3, a wide variety of sliding structures, and locations
of sliding structures are contemplated as being within the scope of
the invention. Referring to dovetail structures 18, 20, the
structures of the dovetails, themselves, can be modified in any way
desired so long as the dovetail structures cooperate to retain the
plates together, and accommodate longitudinal sliding movement of
the plates with respect to each other.
[0101] Further, the locations of the sliding structures can be
moved away from the major faces of the plates, and onto edges of
the plates. Indeed, the embodiments of FIGS. 4-10 disclose various
other sliding structures, generally located at the outer edges of
plate 12B.
[0102] Finally, the location, and especially the structure, of
coupling screw 28, if any, can take on a variety of embodiments,
also as illustrated in the embodiments of FIGS. 4-10.
[0103] Turning now to the embodiments of FIGS. 4-6, a 3-plate
assembly 10 is illustrated. The plate assembly of FIGS. 4-6
includes a first end plate 12A, a 20 second end plate 12B, and an
intermediate plate 12C. Plate 12A has female sliding apertures 18
proximate the outer edges of the plate. Plate 12B has a male
sliding insert 20. Plate 12C has a second male sliding insert 20C
at outer edges of the plate end which is received in, engages with,
and cooperates with, aperture 18 of plate 12A. Plate 12C further
has a second female sliding aperture 18C at the end of plate 12C
which cooperates with insert 20C on plate 12C.
[0104] As illustrated in FIG. 5, outer edges 46 of the male sliding
inserts function as the male sliding structure 20 which interfaces
with, and slides with respect to, the female apertures 18. The
embodiments of male sliding structures 20 in e.g. FIG. 5 extend
generally at right angles to the major surfaces 32 and 34 of e.g.
plate 12B, between surfaces 32 and 34.
[0105] Referring to FIGS. 4 and 5, female aperture 18, e.g.
aperture 18C of plate 12C, is defined in general as an opening on
the end of plate 12C which faces plate 12B. Aperture 18, as
illustrated, also includes a second portion of the opening at the
bottom of plate 12C adjacent surface 34 of plate 12B, the second
portion of the opening extending along the underside of plate 12C
and being defined at edges 48.
[0106] Plates 12A and 12C can be thought of as each having a
receiving end 35 associated with the respective apertures 18; and
plates 12B and 12C can be thought of as each having an insert end
37 associated with the respective male inserts 20. Each such
aperture end has an overlying coupling aperture 30 extending
therethrough. Coupling set screws 28 are positioned in the coupling
apertures. With the insert ends of plates 12B and 12C in the
respective apertures, and extending to at least beyond apertures 30
on plates 12A and 12C, such that insert ends of plates 12B, 12C
underlie the respective apertures 30, coupling set screws 28 can be
advanced into frictional engagement with the underlying inserts at
the insert ends of plates 12B and 12C, thus to set a temporarily
fixed overall length of the plate assembly.
[0107] As with the embodiment of FIGS. 1-3, with the temporarily
fixed length preferably set, the surgeon places the bone support
plate assembly 10 on location in the recipient user. The surgeon
then checks that the plate assembly, at the temporarily fixed
length, enables advancing bone screws through apertures 14 of
plates 12A, 12B, and 12C as desired, and into bone structure of the
underlying vertebra of the recipient user at optimal locations,
thus to suitably mount plates 12A, 12B, and optionally 12C, and
correspondingly the assembly, to the recipient user.
[0108] If the apertures are suitably aligned, the surgeon proceeds
with installation. If some, but not all, of the apertures are
suitably aligned with bone structure, one or both of coupling
screws 28 are loosened enough to enable sliding of plates 12A, 12B,
and/or 12C with respect to each other in order to bring apertures
14 in each of plates 12A, 12B, and 12C, as desired, into alignment
with suitable vertebrae to facilitate mounting the plate assembly
to respective ones of the vertebrae in the recipient user. The
plates are then slid to desired locations to bring apertures 14
into alignment with desired vertebral structure for inserting bone
screws into the vertebrae.
[0109] Once the surgeon is satisfied with the alignment of
apertures 14, the coupling screws are again advanced to fix the
length of the overall plate structure, and the surgeon proceeds
with installing the plate assembly in the recipient user as
described with respect to FIGS. 1-3.
[0110] In the 3-plate assembly, each of the top and bottom plates,
namely plates 12A and 12B are necessarily mounted to vertebrae;
while mounting plate 12C to a vertebra is optional. Plate 12C may
or may not be mounted directly to a vertebra through apertures 14,
depending on the needs of the surgical procedure, and the judgement
of the surgeon.
[0111] As an alternative, the surgeon can mount any one of plates
12A, 12B, 12C to an underlying vertebra, and then adjust the length
of the plate assembly to bring the bone screw apertures 14 into
alignment with vertebrae as desired, and subsequently mount bone
screws through such apertures 14. After such adjustment of length,
the length can again be temporarily fixed if desired, or not if the
surgeon prefers to be able to make length adjustments in real time
during the installation procedure.
[0112] With plates 12A and 12B, and optionally 12C mounted to
vertebrae in the recipient user, such coupling screws 28 as are
still tight to control length of the plate assembly, whether in
whole or in part, are loosened, and are preferably removed from the
plate assembly, whereupon plates 12A, 12B, and 12C are free to
slide/move with respect to each other as the respective vertebrae,
to which the plates are mounted, move with respect to each other,
after completion of the surgical procedure.
[0113] The sliding and compression loading with the embodiments of
FIGS. 4-6 work the same in the embodiments of FIGS. 4-6 as in the
embodiments of FIGS. 1-3.
[0114] Turning now to the embodiments of FIGS. 7-8, another 3-plate
assembly 10 is illustrated. The plate assembly of FIGS. 7-8
includes a first end plate 12A, a second end plate 12B, and an
intermediate plate 12C. Plate 12A has inwardly-disposed sliding
channels 50 which extend along the length of the aperture end of
the plate and which operate as female sliding structure. Plate 12B
has outwardly-disposed rails 52 which extend along the length of
the insert end of the plate and which operate as male sliding
structure. Plate 12C has a second set of rails 52 at outer edges of
the plate end which are received in, and which cooperate with,
channels 50 of plate 12A. Plate 12C further has a second set of
channels 50 at the end of plate 12C, which cooperate with rails 52
of plate 12B.
[0115] FIG. 8 illustrates the cooperation of the channels and rails
in cooperating sliding engagement with each other. Rails 52
function as the male sliding structure.
[0116] Channels 50 interface with, and slide with respect to, rails
52. Channels 50 and rails 52 extend generally along the lengths of
the respective plates. In the embodiments of FIGS. 7-8, the female
end of a respective plate 12A or 12C extends generally alongside
and outwardly of the male insert of corresponding plate 12B or 12C;
whereas in the embodiments of FIGS. 4-6 the female end of a
respective plate generally extends over the top, as viewed in FIG.
5, of the male insert.
[0117] Plates 12A and 12C can be thought of as each having a
receiving end 35 associated with the respective channels 50. Plates
12B and 12C can be thought of as each having an insert end 37
associated with the respective rails 52.
[0118] As with the embodiments of FIGS. 1-6, the surgeon places the
bone support plate assembly 10 on location in the recipient user.
The surgeon adjusts the length of the plate assembly so as to
enable advancing bone screws through apertures 14 of plates 12A,
12B, and 12C as desired, and into bone structure of the underlying
vertebra of the recipient user at optimal locations, thus to
suitably mount plates 12A, 12B, and optionally 12C, and
correspondingly the assembly, to the recipient user.
[0119] In the 3-plate assembly, each of the top and bottom plates,
namely plates 12A and 12B are necessarily mounted to vertebrae;
while mounting of plate 12C to a vertebra is optional. Plate 12C
may or may not be mounted directly to a vertebra through apertures
14, depending on the needs of the surgical procedure, and the
judgement of the surgeon.
[0120] With plates 12A and 12B, and optionally 12C mounted to
vertebrae in the recipient user, plates 12A, 12B, and 12C are free
to slide/move with respect to each other as the respective
vertebrae, to which the plates are mounted, move with respect to
each other, after completion of the surgical procedure.
[0121] The sliding and compression loading with the embodiments of
FIGS. 7-8 work the same in the embodiments of FIGS. 7-8 as in the
embodiments of FIGS. 1-6.
[0122] Turning now to the embodiments of FIGS. 9-10, a 3-plate
assembly 10 is illustrated. The plate assembly of FIGS. 9-10
includes a first end plate 12A, a second end plate 12B, and an
intermediate plate 12C. Plate 12A has inwardly-disposed sliding
channels 50 which extend along the length of the aperture end of
the plate and which operate as female sliding structure. Plate 12B
has outwardly-disposed rails 52 which extend along the length of
the insert end of the plate and which operate as male sliding
structure. Plate 12C has a second set of rails 52 at outer edges of
the plate end which are received in, and which cooperate with,
channels 50 of plate 12A. Plate 12C further has a second set of
channels 50 at the end of plate 12C which cooperate with, and
receive, rails 52 of plate 12B.
[0123] FIG. 10 illustrates in cross-section the cooperation of the
channels and rails in cooperating sliding engagement with each
other. Rails 52 function as the male sliding structure. Channels 50
interface with, and slide with respect to, rails 52. Channels 50
and rails 52 extend generally along the lengths of the respective
plates. In the embodiments of FIGS. 9-10, the female end of a
respective plate 12A or 12C extends generally alongside and
outwardly of the corresponding male insert in plate 12B or 12C.
[0124] Plates 12A and 12C can be thought of as each having a
receiving end 35 associated with the respective channels 50. Plates
12B and 12C can be thought of as having an insert end 37 associated
with the respective rails 52.
[0125] The insert ends are each divided into first and second
prongs 54A and 54B. Each insert end includes a coupling aperture 56
between the respective prongs. A coupling set screw 28 in aperture
56 can be advanced to spread prongs 54A and 54B away from each
other, and can be retracted to release prongs 54A and 54B from such
spread. As prongs 54A and 54B are spread, the rails 52 on the outer
edges of the prongs frictionally engage, and thereby become coupled
to, plates 12A or 12B as indicated at respective channels 50 of the
receiving ends of the corresponding plates 12A, 12B. With rails 52
in channels 50, the coupling set screw is advanced sufficiently to
frictionally engage and couple the rails in the channels thereby to
temporarily fix the overall length of the plate assembly at an
initial setting.
[0126] The embodiment of FIGS. 9-10 differs from the previous
embodiments in that the insert structure at insert ends 37 in FIGS.
9-10 is discontinuous from side to side, e.g. rail to rail. By
contrast, the insert structure of the embodiments of FIGS. 1-8 is
continuous between opposing sides of the insert structure. For
example, referring to FIG. 1, each of the male dovetails 20, acting
as an insert, is continuous between a first side "X'" and a second
side "Y'". Each of the female dovetails 18, acting as an insert
accepting track, has a first interior side "X" and a second
interior side "Y" which engagingly mate with the male sides "X'"
and "Y'" of dovetail 18, for sliding communication therewith.
[0127] Similarly, the inserts of the embodiments of FIGS. 4-8 are
continuous between left and right opposing edges of the inserts.
While discontinuous inserts are thus contemplated as included
within the scope of the invention, continuous inserts are preferred
as having superior strength where material selection and dimensions
are otherwise equal.
[0128] As with the embodiments of FIGS. 1-8, with the temporarily
fixed length set, the surgeon places the bone support plate
assembly 10 on location in the recipient user. The surgeon then
checks that the plate assembly, at the temporarily fixed length, is
compatible with advancing bone screws through apertures 14 of at
least one of plates 12A and 12B, and 12C as desired, and into bone
structure of the underlying vertebrae of the recipient user at
optimal locations, thus to suitably mount plates 12A and 12B, and
optionally 12C, and correspondingly the assembly, to the recipient
user.
[0129] If the apertures are suitably aligned, the surgeon proceeds
with installation. If one or more of the apertures are not suitably
aligned with bone structure, one or both of the coupling screws 28
in plates 12B and 12C are loosened enough to enable sliding of at
least one of plates 12A, 12B, and/or 12C with respect to at least
one other of the plates in order to bring apertures 14 in each of
plates 12A, 12B, and 12C, as desired, into alignment with suitable
vertebrae to facilitate mounting the plate assembly to respective
ones of the vertebrae in the recipient user. The plates are then
slid to desired locations to bring apertures 14 into alignment with
desired vertebral structure for inserting bone screws into the
vertebrae.
[0130] Once the surgeon is satisfied with the alignment of the
apertures 14 of interest, the coupling screws are again advanced to
fix the length of the overall plate structure, and the surgeon
proceeds with installing the plate assembly, or completion of
installing of the plate assembly, in the recipient user.
[0131] With plates 12A and 12B, and optionally 12C mounted to
vertebrae in the recipient user, coupling screws 28 are loosened,
and are preferably removed from the plate assembly, whereupon
plates 12A, 12B, and 12C are free to slide/move with respect to
each other as the respective vertebrae, to which the plates are
mounted, move with respect to each other, after completion of the
surgical procedure.
[0132] The sliding and compression loading with the embodiments of
FIGS. 9-10 work the same in the embodiments of FIGS. 9-10 as in the
embodiments of FIGS. 1-8.
[0133] FIGS. 11 and 12 show top and side views of a 3-plate
assembly as in FIGS. 4-6, and include retainer slots 22 and
retainers 26 as in FIGS. 1-3.
[0134] FIGS. 13 and 14 show top and side views of a 3-plate
assembly as in FIGS. 7 and 8, and including retainer slots 22 and
retainers 26 as in FIGS. 1-3.
[0135] FIGS. 15 and 16 show top and side views of a 3-plate
assembly as in FIGS. 9 and 10, and including retainer slots 22 and
retainers 26 as in FIGS. 1-3.
[0136] While a single embodiment of retainer structure 13 is
illustrated in FIGS. 1-2, a wide variety of retainer structures are
known, and all conventional retainer structures and cover
structures are contemplated to be compatible with respective
embodiments of the plate-to-plate sliding assemblies disclosed
herein. In addition to the illustrated embodiment, there can be
mentioned, for example and without limitation, cover plates,
locking heads, locking inserts including snap locks, covering
screws, covering cams, and the like. Preferred retainer structures
automatically cover the screw head or other screw land when the
respective screw land is driven past the retaining structure,
thereby ensuring accomplishment of an additional step in the
surgical procedure.
[0137] While channels 50 have been shown at the receiving end of
the plate and rails 52 have been illustrated at the insert end of
the plate, such channels and rails can well be reversed. Indeed,
mating structure other than channels and rails can be used, so long
as the respective structure assists in mounting the plates to each
other, and accommodates the recited sliding movement of the plates
with respect to each other.
[0138] The plates of the plate assemblies of the invention are so
joined to each other, e.g. by such cooperating lengths of channels
50 and rails 52, that the plates can slide with respect to each
other while the axes of the respective plates remain in relatively
fixed relation with respect to each other. Thus, plate assemblies
of the invention resist bending and/or twisting loads while
providing sufficient clearance between the sliding elements thereof
to accommodate the recited sliding movement without binding of the
sliding elements with respect to each other.
[0139] A salient feature of all embodiments of the invention is
that the distance of post-procedural movement of any of e.g. plates
12A, 12B, 12C with respect to any underlying bone to which the
respective plate is mounted, is limited to less, preferably
substantially less, than the most extreme normal distance, of
contemplated post-procedural bone settling.
[0140] While post-procedural bond-to-bone settling is highly
desirable, post-procedural movement of a bone, with respect to a
plate to which the bone is mounted, is generally undesirable.
Accordingly, in the most highly preferred embodiments of this
invention, such bone-to-plate movement is nil, or substantially
nil.
[0141] Those skilled in the art will now see that certain
modifications can be made to the apparatus and methods herein
disclosed with respect to the illustrated embodiments, without
departing from the spirit of the instant invention. And while the
invention has been described above with respect to the preferred
embodiments, it will be understood that the invention is adapted to
numerous rearrangements, modifications, and alterations, and all
such arrangements, modifications, and alterations are intended to
be within the scope of the appended claims.
[0142] To the extent the following claims use means plus function
language, it is not meant to include there, or in the instant
specification, anything not structurally equivalent to what is
shown in the embodiments disclosed in the specification.
* * * * *