U.S. patent application number 10/351288 was filed with the patent office on 2004-05-13 for spinal plate system for stabilizing a portion of a spine.
Invention is credited to Agricola, Jon P., Freid, James M., Wagner, Erik J..
Application Number | 20040092939 10/351288 |
Document ID | / |
Family ID | 27663191 |
Filed Date | 2004-05-13 |
United States Patent
Application |
20040092939 |
Kind Code |
A1 |
Freid, James M. ; et
al. |
May 13, 2004 |
Spinal plate system for stabilizing a portion of a spine
Abstract
A spinal plate system that maintains intervertebral spacing and
spinal stability is provided. In an embodiment, a spinal
compression plate may include two or more plates coupled together
form an adjustable-length plate. Compression of a spinal
compression plate movement may mimic natural settling of bones in a
spine and/or distribute at least a portion of a vertebral load to
an implant positioned between two vertebrae. Maintaining at least a
portion of the vertebral load on an insert may increase bone growth
and increase fusion between an implant and surrounding
vertebrae.
Inventors: |
Freid, James M.; (Round
Rock, TX) ; Wagner, Erik J.; (Austin, TX) ;
Agricola, Jon P.; (Camillos, NY) |
Correspondence
Address: |
ERIC B. MEYERTONS
MEYERTONS, HOOD, KIVLIN, KOWERT & GOETZEL, P.C.
P.O. BOX 398
AUSTIN
TX
78767-0398
US
|
Family ID: |
27663191 |
Appl. No.: |
10/351288 |
Filed: |
January 24, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60353272 |
Feb 1, 2002 |
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Current U.S.
Class: |
606/79 |
Current CPC
Class: |
A61B 2017/00473
20130101; A61B 2017/00469 20130101; A61B 17/1728 20130101; A61B
2017/922 20130101; A61B 17/1757 20130101; A61B 17/809 20130101;
A61B 17/8888 20130101; A61B 17/808 20130101; A61B 17/8009 20130101;
A61B 17/8085 20130101; A61B 17/7059 20130101; A61B 90/92 20160201;
A61B 17/8894 20130101; A61B 90/94 20160201; A61B 17/1735 20130101;
A61B 17/8047 20130101; A61B 17/8023 20130101; A61B 17/8625
20130101; A61B 2017/00858 20130101 |
Class at
Publication: |
606/079 |
International
Class: |
A61B 017/00 |
Claims
What is claimed is:
1. A spinal plate system for a human spine, comprising: a first
plate configured to be coupled to human bone, wherein the first
plate comprises extensions; a second plate configured to be coupled
to human bone, wherein the second plate comprises slots; and
wherein at least one of the extensions on the first plate is
configured to couple to at least one of the slots on the second
plate to form an adjustable-length spinal plate.
2. The spinal plate system of claim 1, wherein at least one of the
extensions on the first plate is configured to mate with at least
one of the slots on the second plate.
3. The spinal plate system of claim 1, wherein two extensions on
the first plate are configured to be coupled to two slots on the
second plate.
4. The spinal plate system of claim 1, wherein two extensions on
the first plate are configured to mate with two slots on the second
plate.
5. The spinal plate system of claim 1, wherein extensions on the
first plate are coupled to slots on the second plate.
6. The spinal plate system of claim 1, wherein the spinal plate
system is configured to couple to two human vertebrae.
7. The spinal plate system of claim 1, wherein one extension on the
first plate is configured to be coupled to one slot on the second
plate.
8. The spinal plate system of claim 1, wherein the spinal plate
system is configured to compress along a longitudinal axis such
that lordotic alignment is maintained during use.
9. The spinal plate system of claim 1, wherein the spinal plate
system is configured to compress to correspond to bone settling
during use.
10. The spinal plate system of claim 1, wherein at least one of the
slots and at least one of the extensions have mating stepped
portions.
11. The spinal plate system of claim 1, further comprising a pin
configured to inhibit decoupling of the first plate and the second
plate during use.
12. The spinal plate system of claim 1, wherein the first plate is
configured to conform to a lordotic curvature of a spine.
13. The spinal plate system of claim 1, wherein the second plate is
configured to conform to a lordotic curvature of a spine.
14. The spinal plate system of claim 1, wherein the
adjustable-length spinal plate is configured to conform to a
curvature of a spine.
15. The spinal plate system of claim 1, wherein the spinal plate
system is configured to conform to a radial curvature of a
spine.
16. The spinal plate system of claim 1, wherein the spinal plate
system is configured to provide structural support for a spinal
implant.
17. The spinal plate system of claim 1, further comprising at least
one bending region on the adjustable-length spinal plate, wherein
the bending region is configured to facilitate bending of the
adjustable-length spinal plate.
18. The spinal plate system of claim 1, further comprising at least
one groove on the adjustable-length spinal plate, wherein at least
one groove is configured to facilitate bending of the
adjustable-length spinal plate.
19. The spinal plate system of claim 1, wherein the first plate
comprises texturing to inhibit motion of the first plate relative
to the second plate.
20. The spinal plate system of claim 1, wherein the second plate
comprises texturing to inhibit motion of the second plate relative
to the first plate.
21. A spinal plate system for a human spine, comprising: a first
plate configured to be coupled to human bone, wherein the first
plate comprises an opening; a second plate configured to be coupled
to human bone, wherein the second plate comprises an opening;
wherein the first plate is configured to be coupled to the second
plate to form an adjustable-length spinal plate with at least one
opening through the adjustable-length spinal plate; and a retainer
configured to be positioned in at least one opening through the
adjustable-length spinal plate.
22. The spinal plate system of claim 21, wherein the first plate is
coupled to the second plate.
23. The spinal plate system of claim 21, wherein the retainer is
positioned in the opening in the first plate.
24. The spinal plate system of claim 21, wherein the retainer is
positioned in the opening in the second plate.
25. The spinal plate system of claim 21, wherein the opening is
located at or near a center of the adjustable-length spinal
plate.
26. The spinal plate system of claim 21, wherein the first plate
comprises at least one extension.
27. The spinal plate system of claim 21, wherein the second plate
comprises at least one slot.
28. The spinal plate system of claim 21, wherein the first plate
comprises at least one extension and the second plate comprises at
least one slot, and wherein at least one extension of the first
plate is configured to be coupled to at least one slot of the
second plate.
29. The spinal plate system of claim 21, wherein the first plate
comprises at least one extension and the second plate comprises at
least one slot, and wherein at least one extension of the first
plate is configured to be coupled to at least one slot of the
second plate
30. The spinal plate system of claim 21, wherein the retainer is
substantially ring-shaped.
31. The spinal plate system of claim 21, wherein the retainer is
configured to inhibit backout of a fastener when the fastener is
positioned in the opening.
32. The spinal plate system of claim 21, wherein the retainer is
configured to inhibit backout of a fastener when the fastener is
positioned in the opening, and wherein the fastener couples to the
spinal plate to bone during use.
33. The spinal plate system of claim 21, further comprising a
coupling member, wherein the coupling member is configured to
couple the first plate to the second plate such that at least a
portion of the first plate overlays at least a portion of the
second plate.
34. The spinal plate system of claim 21, wherein the
adjustable-length spinal plate is configured to compress to
correspond to bone settling during use.
35. The spinal plate system of claim 21, wherein the
adjustable-length spinal plate is configured to conform to a
curvature of a spine.
36. The spinal plate system of claim 21, wherein the spinal plate
system is configured to compress along a longitudinal axis such
that lordotic alignment is maintained during use.
37. The spinal plate system of claim 21, wherein the first plate
comprises texturing to inhibit motion of the first plate relative
to the second plate.
38. The spinal plate system of claim 21, wherein the second plate
comprises texturing to inhibit motion of the second plate relative
to the first plate.
39. A spinal plate system for a human spine, comprising: a first
plate configured to be coupled to human bone; a second plate
configured to be coupled to human bone; wherein the first plate is
configured to be coupled to the second plate to form an
adjustable-length spinal plate; wherein the adjustable-length
spinal plate comprises at least one elongated opening; and wherein
a retainer is configured to be positioned in at least one elongated
opening such that the retainer can longitudinally move.
40. The spinal plate system of claim 39, wherein the first plate
comprises at least one extension.
41. The spinal plate system of claim 39, wherein the second plate
comprises at-least one slot.
42. The spinal plate system of claim 39 wherein the first plate
comprises at least one extension and the second plate comprises at
least one slot, and wherein at least one extension of the first
plate is configured to be coupled to at least one slot of the
second plate.
43. The spinal plate system of claim 39, wherein the retainer is
substantially ring-shaped.
44. The spinal plate system of claim 39, wherein the retainer
comprises projections.
45. The spinal plate system of claim 39, wherein the retainer is
configured to inhibit backout of a fastener from the at least one
elongated opening.
46. The spinal plate system of claim 39, wherein the retainer is
configured to inhibit backout of a fastener from the at least one
elongated opening, and wherein the fastener couples the spinal
plate to bone during use.
47. The spinal plate system of claim 39, wherein the first plate
comprises texturing to inhibit motion of the first plate relative
to the second plate.
48. The spinal plate system of claim 39, wherein the second plate
comprises texturing to inhibit motion of the second plate relative
to the first plate.
49. A spinal plate system for a human spine, comprising: a first
plate configured to be coupled to human bone; a second plate
configured to be coupled to human bone; wherein the first plate is
configured to be coupled to the second plate to form an
adjustable-length spinal plate; wherein the adjustable-length
spinal plate comprises at least one elongated opening; and wherein
a retainer is configured to be positioned in at least one of the
elongated openings such that the retainer can uni-directionally
move during use.
50. The spinal plate system of claim 49, wherein unidirectional
movement comprises longitudinal movement.
51. The spinal plate system of claim 49, wherein the retainer
comprises serrations.
52. The spinal plate system of claim 49, wherein at least one
elongated opening comprises serrations.
53. The spinal plate system of claim 49, wherein the retainer
comprises serrations, wherein at least one elongated opening
comprises serrations, and wherein serrations of the retainer
contact serrations of at least one elongated opening.
54. The spinal plate system of claim 49, wherein the first plate
comprises at least one extension.
55. The spinal plate system of claim 49, wherein the second plate
comprises at least one slot.
56. The spinal plate system of claim 49 wherein the first plate
comprises at least one extension and the second plate comprises at
least one slot, and wherein at least one extension of the first
plate is configured to be coupled to at least one slot of the
second plate.
57. The spinal plate system of claim 49, wherein the retainer is
substantially ring-shaped.
58. The spinal plate system of claim 49, wherein the retainer is
configured to inhibit backout of a fastener from the elongated
opening.
59. The spinal plate system of claim 49, wherein the retainer is
configured to inhibit backout of a fastener from the elongated
opening, and wherein the fastener couples the plate to the bone
during use.
60. The spinal plate system of claim 49, wherein the first plate
comprises texturing to inhibit motion of the first plate relative
to the second plate.
61. The spinal plate system of claim 49, wherein the second plate
comprises texturing to inhibit motion of the second plate relative
to the first plate.
62. A spinal plate system for a human spine, comprising: a first
plate configured to be coupled to human bone; a second plate
configured to be coupled to human bone; wherein the first plate is
configured to be coupled to the second plate to form an
adjustable-length spinal plate; and a spacer configured to
establish a length of the adjustable-length spinal plate during
use.
63. The spinal plate system of claim 62, wherein the first plate is
coupled to the second plate.
64. The spinal plate system of claim 62, wherein the spacer is
configured to establish a separation distance between the first
plate and the second plate during use.
65. The spinal plate system of claim 62, wherein the spacer
establishes a separation distance between the first plate and the
second plate during use.
66. The spinal plate system of claim 62, wherein the spacer is
configured to establish a separation distance of about 4 mm between
the first plate and the second plate during use.
67. The spinal plate system of claim 62, wherein the spacer
establishes a separation distance of about 4 mm between the first
plate and the second plate during use.
68. The spinal plate system of claim 62, wherein the spacer is
coupled to the adjustable-length spinal plate before insertion of
the adjustable-length spinal plate into a patient.
69. The spinal plate system of claim 62, wherein the spacer is
configured to establish a length of an adjustable-length spinal
plate to facilitate coupling of the adjustable-length spinal plate
to two or more vertebrae.
70. The spinal plate system of claim 62, wherein the spacer is
coupled to an opening in the adjustable-length spinal plate during
use.
71. The spinal plate system of claim 62, wherein the first plate
comprises texturing to inhibit motion of the first plate relative
to the second plate.
72. The spinal plate system of claim 62, wherein the second plate
comprises texturing to inhibit motion of the second plate relative
to the first plate.
73. A spacer for establishing a length of an adjustable-length
spinal plate, comprising: a coupling portion, wherein the coupling
portion is configured to couple the spacer to the adjustable-length
spinal plate during use; and a spacing portion, wherein the spacing
portion is configured to establish a space between components of
the adjustable-length spinal plate during use.
74. The spacer of claim 73, wherein the coupling portion is
threaded.
75. The spacer of claim 73, wherein the coupling portion is pointed
for insertion into bone.
76. The spacer of claim 73, further comprising a guidepost, wherein
an end of the guidepost comprises the coupling portion.
77. The spacer of claim 73, further comprising a guidepost, wherein
the guidepost is configured to be coupled to a fastener guide.
78. The spacer of claim 73, wherein the spacing portion establishes
a separation of about 4 mm between components of the
adjustable-length spinal plate.
79. The spacer of claim 73, further comprising a guidepost, wherein
the guidepost is configured to be coupled to a handle.
80. The spacer of claim 73, wherein the spacing portion contacts at
least two components of the adjustable-length spinal plate during
use.
81. The spacer of claim 73, further comprising an alignment
portion, wherein the alignment portion is configured to position
the spacer relative to the adjustable-length spinal plate.
82. The spacer of claim 73, wherein the spacer may be used to
facilitate positioning of the adjustable-length spinal plate during
insertion.
83. A spinal plate system for a human spine, comprising: two or
more plates configured to be coupled to human bone; wherein the two
or more plates are configured to be coupled together to form an
adjustable-length spinal plate; and wherein at least one of the two
or more plates comprises one or more bending regions configured to
facilitate bending of the adjustable-length spinal plate at one or
more bending regions to achieve a desired curvature.
84. The spinal plate system of claim 83, wherein at least one of
the one or more bending regions comprises a groove.
85. The spinal plate system of claim 83, wherein one of the two or
more plates comprises two bending regions.
86. The spinal plate system of claim 83, wherein two of the two or
more plates each comprise two bending regions.
87. The spinal plate system of claim 83, wherein a first plate
comprises texturing to inhibit motion of the first plate relative
to a second plate.
88. A spinal plate system, comprising: a first plate configured to
be coupled to human bone; a second plate configured to be coupled
to human bone; wherein the first plate and the second plate are
configured to be coupled together to form an adjustable-length
spinal plate; wherein at least a portion of the first plate couples
with at least a portion of the second plate to form a coupling
interface; and wherein at least a portion of the coupling interface
comprises friction texturing.
89. The spinal plate system of claim 88, wherein at least a portion
of the first plate mates with at least a portion of the second
plate to form a mating interface.
90. The spinal plate system of claim 88, wherein at least a portion
of the first plate mates with at least a portion of the second
plate to form a mating interface, and wherein at least a portion of
the mating interface comprises friction texturing.
91. The spinal plate system of claim 88, wherein at least a portion
of the first plate comprises friction texturing.
92. The spinal plate system of claim 88, wherein at least a portion
of the second plate comprises friction texturing.
93. The spinal plate system of claim 88, wherein at least a portion
of the first plate and at least a portion of the second plate
comprise friction texturing.
94. A spinal plate system for a human spine, comprising: two or
more plates configured to be coupled to human bone; wherein the
first plate and the second plate are configured to be coupled
together to form an adjustable-length spinal plate; and wherein the
adjustable-length spinal plate comprises at least one irregularly
shaped opening configured to facilitate insertion of a retainer
into the opening.
95. The spinal plate system of claim 94, wherein the retainer is
substantially ring-shaped.
96. The spinal plate system of claim 94, wherein a first portion of
at least one irregularly shaped opening may have a radius of
curvature larger than a radius of curvature of a second portion of
the opening.
97. The spinal plate system of claim 94, wherein a first plate
comprises texturing to inhibit motion of the first plate relative
to a second plate.
98. A spinal plate system for a human spine, comprising: three or
more plates configured to be coupled to human bone; wherein the
three or more plates are configured to be coupled together to form
an adjustable-length spinal plate; and wherein the
adjustable-length spinal plate is configured to be fastened to at
least four adjacent vertebrae.
99. The spinal plate system of claim 98, wherein the spinal plate
system is configured to span three vertebral levels.
100. The spinal plate system of claim 98, wherein the spinal plate
system is spans three vertebral levels.
101. The spinal plate system of claim 98, wherein the spinal plate
system is configured to span four vertebral levels.
102. The spinal plate system of claim 98, wherein the spinal plate
system is configured to span four vertebral levels.
103. The spinal plate system of claim 98, adjustable-length spinal
plate comprises at least three openings.
104. The spinal plate system of claim 98, wherein a first plate of
the three or more plates comprises texturing to inhibit motion of
the first plate relative to an adjacent plate of the three or more
plates.
105. An adjustable-length spinal plate kit for a human spine,
comprising: an adjustable-length spinal plate comprising at least
one opening; and a spacer configured to establish a length of the
adjustable-length spinal plate during use.
106. The kit of claim 105, further comprising a plate insertion
instrument for inserting the spinal plate into a patient.
107. The kit of claim 105, further comprising two or more
spacers.
108. The kit of claim 105, wherein the spacer is configured to
establish a separation between components of the adjustable-length
spinal plate during use.
109. The kit of claim 105, wherein the spacer is configured to
establish a separation of about 4 mm between components of the
adjustable-length spinal plate during use.
110. The kit of claim 105, further comprising a fastener guide to
facilitate positioning of a fastener in at least one opening of the
spinal plate.
111. An adjustable-length spinal plate kit for a human spine,
comprising: an adjustable-length spinal plate comprising one or
more openings; and a fastener guide with at least one guide member,
the fastener guide being configured to guide insertion of fasteners
in one or more of the openings during use.
112. The kit of claim 111, wherein the fastener guide comprises at
least two guide members.
113. The kit of claim 111, further comprising a plate insertion
instrument.
114. The kit of claim 111, further comprising at least one drill
configured to be inserted in the fastener guide.
115. The kit of claim 111, further comprising at least one tap
configured to be inserted in the fastener guide.
116. An adjustable-length spinal plate kit for a human spine,
comprising: an adjustable-length spinal plate; a spacer configured
to establish a length of the adjustable-length spinal plate during
use; and a positioner configured to position a portion of an
adjustable-length spinal plate in a patient.
117. The kit of claim 116, further comprising a plate insertion
instrument.
118. The kit of claim 116, wherein the positioner comprises a
pointed end for penetration of a bone.
119. The kit of claim 116, further comprising two or more
spacers.
120. The kit of claim 116, wherein the spacer is configured to
establish a separation between components of the adjustable-length
spinal plate during use.
121. The kit of claim 116, wherein the spacer is configured to
establish a separation of about 4 mm between components of the
adjustable-length spinal plate during use.
122. The kit of claim 116, further comprising a fastener guide to
facilitate positioning of a fastener in at least one opening of the
spinal plate.
123. A method of stabilizing a portion of a spine, comprising:
establishing a separation distance between a first plate and second
plate of an adjustable-length spinal plate with a spacer; coupling
the adjustable-length spinal plate to vertebrae; and removing the
spacer.
124. The method of claim 123, wherein removing the spacer allows
the first plate to move relative to the second plate to accommodate
reduction of a separation distance between the vertebrae during
use.
125. The method of claim 123, wherein coupling the
adjustable-length spinal plate to vertebrae comprises attaching a
fastener to a fastener insertion tool; using the insertion tool to
position the tool in an opening in a vertebra below an opening
through the adjustable-length spinal plate; and using the insertion
tool to thread the fastener into the vertebra to draw the
adjustable-length spinal plate against the vertebra.
126. The method of claim 125, wherein a head of the fastener is
inserted into a retainer positioned in the opening through the
adjustable-length spinal plate.
127. A method of monitoring compression of a first vertebra
relative to a second vertebra, comprising: taking an initial x-ray
image of an installed spinal compression plate; measuring a
distance between an end of an opening in a first plate and an end
of a member of a second plate from the x-ray image to determine an
initial separation distance; taking a second x-ray image of the
installed spinal compression plate at a subsequent time; measuring
a distance between the end of the opening in the first plate and
the end of the member of the second plate from the second x-ray
image to determine a second separation distance; calculating an
amount of compression of the spinal compression plate using the
initial separation distance and the second separation distance.
Description
PRIORITY CLAIM
[0001] This application claims priority to Provisional Patent
Application No. 60/353,272 entitled "SPINAL PLATE SYSTEM FOR
STABILIZING A PORTION OF A SPINE" filed on Feb. 1, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to bone fixation
systems. An embodiment of the invention relates to a compression
plate for a spinal fixation system. The compression plate may be
installed using an anterior procedure. The compression plate may be
used in conjunction with one or more spinal implants that fuse
vertebrae together.
[0004] 2. Description of Related Art
[0005] An intervertebral disc may be subject to degeneration caused
by trauma, disease, and/or aging. A degenerated intervertebral disc
may have to be partially or fully removed from a spinal column.
Partial or full removal of an intervertebral disc may destabilize a
spinal column. Destabilization of a spinal column may alter a
natural separation distance between adjacent vertebrae. Maintaining
a natural separation distance between vertebrae may help prevent
pressure from being applied to nerves that pass between vertebral
bodies. Excessive pressure applied to the nerves may cause pain
and/or nerve damage. During a spinal fixation procedure, a spinal
implant may be inserted in a space created by removal or partial
removal of an intervertebral disc between adjacent vertebrae. A
spinal implant may maintain the height of the spine and restore
stability to the spine. Intervertebral bone growth may fuse the
implant to adjacent vertebrae.
[0006] A spinal implant may be inserted during a spinal fixation
procedure using an anterior, lateral, or posterior spinal approach.
In some situations, an anterior approach may result in an easier
approach, less muscle damage, less tissue damage, and/or less bone
removal than other approaches.
[0007] A discectomy may be performed to remove or partially remove
a defective and/or damaged intervertebral disc. A discectomy
creates a disc space for a spinal implant. After a discectomy, a
spinal implant may be inserted into the disc space. One or more
spinal implants may be inserted between a pair of vertebrae. Spinal
implants may be inserted into disc spaces prepared between more
than one pair of vertebrae during a spinal fusion procedure.
[0008] A spinal plate may be coupled to vertebrae after insertion
of one or more spinal implants. A spinal plate may stabilize the
vertebrae and inhibit backout of the spinal implant from between
vertebrae. A spinal plate may share a compressive load applied to
one or more spinal implants inserted between vertebrae. Fasteners
(e.g., bone screws) may couple the spinal plate to vertebrae.
Spinal plates may stabilize sections of cervical spine and/or
sections of lumbar spine.
[0009] Fastening systems may attach a spinal plate to vertebrae
without allowing fasteners of the fastening systems to back out
from the vertebrae. A fastening system may include a fastener and a
retainer. The retainer may be positioned in an opening of the
spinal plate. Backout of fasteners from the spinal plate may be
inhibited without immovably fixing the fasteners or the retainers
to the spinal plate. U.S. Pat. No. 6,331,179 to Freid et al. and
U.S. Pat. No. 6,454,679 to Wagner et al., both of which are
incorporated by reference as if fully set forth herein, describe
bone plate systems including fasteners and retainers.
[0010] U.S. Pat. No. 6,328,738 to Suddaby, which is incorporated by
reference as if fully set forth herein, describes an anterior
cervical fusion compression plate and screw guide. The anterior
cervical fusion compression plate has a pair of slideable inserts.
Each insert is situated in a recess at an end of the plate to allow
vertebral compression. During an insertion procedure, a pliers-like
tool is used to move the inserts toward the center of the plate.
After a desired compression is achieved, central screws are
tightened to fix the position of the inserts. Lateral screws may be
driven into the inserts to anchor the vertebrae to the plate.
SUMMARY
[0011] An adjustable-length spinal compression plate may be used to
stabilize vertebrae and/or apply a compressive load to a spinal
implant positioned in a disc space between a pair of vertebrae. One
or more fasteners may couple a first plate to a vertebra above a
spinal implant. One or more fasteners may couple a second plate to
a vertebra below a spinal implant. The first plate may be coupled
to the second plate so that the first plate is able to move toward
and/or away from the second plate. In some embodiments, motion of
the first plate relative to the second plate may be restricted to
allow only unidirectional motion (i.e., only compression of the
spinal compression plate) during use. Movement of the first plate
toward the second plate may allow the spinal plate system to
accommodate settling and/or subsidence of the vertebrae while
maintaining a compressive load on the spinal implant. In some
embodiments, three or more plates may be coupled together to form
an adjustable-length spinal compression plate that spans two or
more vertebral levels.
[0012] Plates of a spinal plate system may be curved to maintain a
lordotic curvature of a human spine during compression of the
spinal plate system. Plates may be provided with preformed
curvatures to accommodate lordotic and/or radial vertebrae
curvature. In some embodiments, a plate of a spinal compression
plate may have one or more grooves to facilitate bending of the
spinal compression plate to achieve a desired lordotic
curvature.
[0013] Plates of a spinal plate system may be available in various
sizes. The size of a plate utilized may depend on the number of
vertebrae to be immobilized and/or the size of a patient. Plates
may have an anterior side, a posterior side, and two ends. A spinal
plate system may be coupled to vertebrae using one or more openings
through the plates. Openings may be located at various positions
along the plate. A spinal plate system may have a center opening.
An opening in a spinal compression plate may have a regular or an
irregular shape. An opening in a spinal compression plate may be
substantially circular or elongated. In some embodiments, a portion
of a plate may form a wall of an opening. Alternatively, a liner, a
cover, and/or a coating may form a wall of an opening.
[0014] Plates of a spinal plate system may be coupled together
using coupling mechanisms to form a spinal compression plate. A
coupling mechanism may include one or more coupling members and one
or more coupling cavities. A coupling mechanism may include mating
slots and extensions that allow movement of a plate of a spinal
compression plate relative to another plate of the spinal
compression plate. In some embodiments, a portion of a first plate
may overlay a portion of a second plate. In some embodiments, one
or more mating surfaces of plates of a spinal compression plate may
have friction texturing. Plates may be coupled so that the plates
can move in a longitudinal direction during use. A spinal
compression plate may be compressed along a longitudinal axis
during use. Movement of the plates may be restricted by the size of
a coupling cavity.
[0015] In some embodiments, a spinal compression plate may compress
longitudinally during use; however, the spinal compression plate
may be inhibited from expanding longitudinally during use. A
movement mechanism may inhibit expansion during use. In some
embodiments, a movement mechanism may include one or more
protrusions on the spinal compression plate. Protrusions may be
positioned on surfaces of the plates that normally contact each
other. Some embodiments include a protrusion on a first plate that
engages one or more protrusions (e.g., serrations) on a second
plate to maintain a distance between the vertebrae after
compression. In some embodiments, at least a portion of a serrated
surface of a movement mechanism may be curved to increase an area
of the movement mechanism and thus enhance stability of a spinal
compression plate.
[0016] A probe may be inserted into an opening in a spinal
compression plate to release a movement mechanism (e.g., a
ratcheting system) to allow expansion of the spinal compression
plate. In an embodiment, an opening in a spinal compression plate
may be used for monitoring the amount of compression of a spinal
compression plate in a patient after insertion of the spinal
compression plate. When the spinal compression plate compresses, a
portion of a first plate may extend into an opening in the second
plate. The position of the portion of the first plate relative to
the opening in the second plate may be monitored using x-ray
imaging to determine the amount of compression of the spinal
compression plate.
[0017] Some spinal plate systems may include an engagement
mechanism that inhibits separation of a first plate from a second
plate of the spinal compression plate. An engagement mechanism may
inhibit separation of the plates while allowing the plates to
adjust for lordotic alignment as the spinal compression plate is
compressed. In some embodiments, an engagement mechanism may
include a protruding member of a first plate that engages
serrations in a second plate.
[0018] In some embodiments, a spinal compression plate may freely
compress and expand unencumbered by a movement mechanism. In some
embodiments, a first plate may not include protrusions to engage
protrusions on a second plate. In an embodiment, a second plate may
not have protrusions to engage protrusions on a first plate.
Compression and expansion of a spinal compression plate may allow
the plate to accommodate natural vertebral movement. A coupling
cavity may restrict the range of motion of a first plate relative
to a second plate of a spinal compression plate and/or inhibit
separation of the first plate from the second plate. In some
embodiments, portions of the first plate that engage the second
plate and/or portions of the second plate that engage the first
plate, may be textured to alter frictional properties of the first
plate relative to the second plate.
[0019] A spacer may set an initial separation between a first plate
and a second plate of a spinal compression plate. The spacer may
have an insertion end, an alignment portion, and a guidepost. The
spacer may couple to a spinal compression plate. A fastener guide
may be coupled to a guidepost of the spacer.
[0020] A positioner may be used to help position a spinal
compression plate in a desired location in a patient. The position
may have an engagement end, and alignment portion, and a guidepost.
A fastener guide may be coupled to a guidepost of a positioner.
[0021] A plate insertion instrument may couple with a guide opening
of a spinal compression plate to allow positioning of the spinal
compression plate within a patient. In some embodiments, an
engagement end of the plate insertion instrument may be press-fit
into the guide opening of the spinal compression plate. In some
embodiments, a plate insertion instrument may be attached to a
portion of a spacer or positioner that is coupled to the spinal
compression plate.
[0022] Spinal plate systems may be utilized in conjunction with
implants and/or other medical devices. In certain instances, it may
be beneficial for a spinal plate system to share at least some of
the load experienced by a spinal plate system with a medical
device. Bone growth may be increased around and through an implant
that is carrying a load. Therefore, spinal plate systems may be
designed to share a portion of the load from surrounding vertebrae
with a spinal implant positioned between the vertebrae.
[0023] In some spinal plate system embodiments, a portion of a
plate forms a wall of an opening. A recess may be positioned in a
wall to engage a retainer that inhibits removal of a fastener from
a plate. A recess may be biased to allow the fastener to enter a
vertebra at a desired angle. Allowing a fastener to enter a spinal
compression plate at an angle may facilitate establishment of a
secure connection between the spinal compression plate and the
vertebra. A recess may have a larger height than a height of the
portion of a retainer that fits within the recess. The greater
height of the recess may allow for some angulation adjustment of a
fastener positioned through the retainer into a vertebra. In some
embodiments, openings on a superior end of a spinal compression
plate may allow for greater angulation of fasteners than openings
on an inferior end of the spinal compression plate.
[0024] In some embodiments, a portion of an opening may have a
spherically shaped contour to permit a fastener to be "obliquely
angulated" relative to a plate. Herein, an "obliquely angulated"
fastener refers to a fastener that may be positioned at a wide
range of angles relative to a plate. In some embodiments, a range
of angles may be from 0.degree. to about 20.degree. from an axis
perpendicular to a plate.
[0025] A fastener may be secured in a plate using a retainer, such
as a ring. A retainer may be positioned in an opening of a spinal
compression plate. The opening of the spinal compression plate may
be elongated to allow longitudinal movement of the retainer in the
opening. An inner surface of a retainer may be shaped to accept
head of a fastener while an outer surface of the retainer may be
shaped to fit in an opening of the plate. In some embodiments, a
serrated surface of a retainer may contact a serrated surface of an
elongated opening of a plate to provide uni-directional
longitudinal movement of the retainer in the opening. In some
embodiments, a surface of a retainer may be textured (e.g., scored,
peened, implanted with particles) to increase a frictional
coefficient relative to a surface defining the opening so that
motion of the retainer relative to the plate is inhibited but not
prevented.
[0026] In certain embodiments, a fastener may include a head and a
shank. An outer surface of a fastener head may be tapered such that
an upper portion of the fastener head is larger than a lower
portion of the fastener head. In some embodiments, a retainer may
have projections extending from an inner surface of the ring. The
projections may engage a fastener head should the fastener move in
a direction that would result in removal of the fastener from the
opening. An outer surface of a retainer may include protrusions
that engage a wall of an opening. In some embodiments, an inner
surface of a retainer may include projections.
[0027] A retainer may have a gap that allows the retainer to
radially expand and/or contract. A retainer may engage a fastener
to inhibit backout of the fastener from a plate. Engaging a
retainer with a fastener may inhibit a fastener head from rising
above an upper surface of the plate even if the fastener loosens in
the bone. Retaining a fastener below the upper surface of a plate
may inhibit contact of adjacent tissue with the fastener and/or
fastener head during use. Damage of adjacent tissue may be
minimized or eliminated by inhibiting contact of adjacent tissue
with the fastener and/or fastener head during use.
[0028] In some embodiments, a retainer may be positioned in an
opening of a spinal compression plate prior to surgical insertion
of the compression plate in a patient. A spinal compression plate
may be positioned adjacent to a portion of the spine that requires
spinal fixation. Holes may be drilled, tapped, and/or otherwise
formed in a portion of a vertebra underlying each opening.
Fasteners may be inserted through the openings and into the holes.
Fastener heads may be positioned in the openings so that retainers
surround at least a portion of the fastener heads. Advantageously,
a fastener may be held within the opening by a retainer. A spinal
compression plate with a pre-positioned retainer may reduce
concerns about positioning and/or dropping retainers during
surgery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Advantages of the present invention will become apparent to
those skilled in the art with the benefit of the following detailed
description and upon reference to the accompanying drawings in
which:
[0030] FIG. 1 depicts a perspective view of an embodiment of a
spinal compression plate.
[0031] FIG. 2 depicts a perspective view of an embodiment of a
spinal compression plate.
[0032] FIG. 3 depicts a perspective cross-sectional view of a
posterior side of a spinal compression plate.
[0033] FIG. 4 depicts a perspective cross-sectional view of a
spinal compression plate in an expanded position.
[0034] FIG. 5 depicts a perspective cross-sectional view of a
spinal compression plate, including an inset view showing a
magnified portion of spinal plates.
[0035] FIG. 6 depicts an exploded view of an embodiment of a spinal
compression plate.
[0036] FIG. 7 depicts an embodiment of a plate insertion
instrument.
[0037] FIG. 8 depicts an engagement end of the plate insertion
instrument shown in FIG. 7.
[0038] FIG. 9 depicts a cross-sectional view of a serrated
retainer.
[0039] FIG. 10 depicts a perspective view of an embodiment of
spinal compression plate.
[0040] FIG. 11 depicts a perspective view of an embodiment of a
spinal compression plate.
[0041] FIG. 12 depicts a top view of the spinal compression plate
shown in FIG. 11.
[0042] FIG. 13 depicts a top view of an embodiment of a spinal
compression plate shown in an expanded position.
[0043] FIG. 14 depicts a perspective view of an embodiment of a
multi-level spinal compression plate.
[0044] FIG. 15 depicts a side view of an embodiment of a spinal
compression plate.
[0045] FIG. 16 depicts a top view of an embodiment of a spinal
compression plate with a spacer.
[0046] FIG. 17 depicts a side view of an embodiment of spinal
compression plate with a spacer.
[0047] FIG. 18 depicts a perspective view of a spacer and a
positioner aligned for insertion in a spinal compression plate.
[0048] FIG. 19 depicts a perspective view of a handle for engaging
a guidepost.
[0049] FIG. 20 depicts a perspective view of a fastener guide.
[0050] FIG. 21 depicts a perspective view of an embodiment of a
spinal compression plate.
[0051] FIG. 22 depicts a perspective cross-sectional view of an
embodiment of a spinal plate system.
[0052] FIG. 23 depicts a perspective view of an embodiment of a
fastener.
[0053] FIG. 24 depicts a cross-sectional view of an embodiment of a
portion of a spinal compression plate.
[0054] FIG. 25 depicts a perspective view of an embodiment of a
retainer for a spinal compression plate.
[0055] FIG. 26 depicts a perspective view of an embodiment of a
retainer for a spinal compression plate.
[0056] FIG. 27 depicts a perspective view of an embodiment of a
retainer for a spinal compression plate.
[0057] FIG. 28 depicts a perspective view of an embodiment of a
retainer for a spinal compression plate.
[0058] FIG. 29 depicts a side view of an embodiment of a spinal
plate system coupled to two adjacent vertebrae.
[0059] FIG. 30 depicts a front view of a fastener insertion
instrument with a cross-sectional inset view that shows details of
a tip of the fastener insertion instrument.
[0060] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof are shown by
way of example in the drawings and will herein be described in
detail. The drawings may not be to scale. It should be understood
that the drawings and detailed description thereto are not intended
to limit the invention to the particular form disclosed, but on the
contrary, the intention is to cover all modifications, equivalents,
and alternatives falling within the spirit and scope of the present
invention as defined by the appended claims.
DETAILED DESCRIPTION OF EMBODIMENTS
[0061] A spinal plate system may be used to stabilize a portion of
a spine. A spinal plate system may include a spinal compression
plate and fasteners that couple the spinal compression plate to
vertebrae. Components of a spinal plate system may include
materials such as, but not limited to, stainless steel, titanium,
titanium alloys, ceramics, and/or polymers. Some components of a
spinal plate system may be made of materials that may be autoclaved
and/or chemically sterilized. Some components of a spinal plate
system may be formed of materials unable to be autoclaved and/or
chemically sterilized. Components unable to be autoclaved and/or
chemically sterilized may be made of sterile materials and placed
in working relation to other sterile components during assembly of
a spinal plate system.
[0062] Spinal plate systems may typically be used to correct
problems in lumbar and cervical portions of a spine resulting from
injury and/or disease. For example, a spinal plate system may be
implanted anterior to a spine to maintain distraction between
adjacent vertebral bodies in a cervical portion of the spine. A
spinal compression plate of a spinal plate system may provide
stability to one or more vertebral levels. A spinal compression
plate may also facilitate bone fusion (e.g., spinal fusion). In
some embodiments, a spinal compression plate may be used in
conjunction with a spinal implant inserted in an intervertebral
space between vertebrae. Spinal compression plates may accommodate
settling and/or subsidence of a vertebra or vertebrae. Spinal
compression plates may allow stress to be applied to a spinal
implant. Stress applied to a spinal implant may promote bone growth
between the spinal implant and the vertebrae.
[0063] FIG. 1 and FIG. 2 depict embodiments of spinal compression
plates. Spinal compression plates 30 may be used to provide
stability to a single vertebral level. A single vertebral level
includes a first vertebra and a second vertebra adjacent to the
first vertebra. An intervertebral disc and/or a spinal implant may
be located between the vertebrae. Spinal compression plate 30 may
include first plate 32, second plate 34, coupling member 36,
coupling cavity 38, and/or openings 40. In some embodiments, spinal
compression plate 30 may also include one or more protrusions or
spikes on a lower surface that penetrate vertebral surfaces when
the spinal compression plate is installed. In some embodiments,
first plate 32 and/or second plate 34 may include an opening to
couple spinal compression plate 30 to an implant, bone graft, or
other material positioned between vertebrae.
[0064] Coupling member 36 may join first plate 32 and second plate
34 while allowing movement of the first plate toward the second
plate. In certain embodiments, coupling member 36 may be coupled to
second plate 34. Coupling member 36 may be positioned in coupling
cavity 38 of first plate 32. Coupling member 36 may have a head
height that is reduced or eliminated by recessed surface 42 of
coupling cavity 38 of first plate 32. In an embodiment, coupling
member 36 is a pin positioned through coupling cavity 38 of first
plate 32 into an opening of second plate 34. Coupling member 36 may
be press-fit, welded, threaded, glued, or otherwise fixed to second
plate 34. Coupling member 36 may inhibit separation of first plate
32 from second plate 34.
[0065] In some spinal compression plate embodiments, coupling
member 36 may be positioned in first plate 32. Second plate 34 may
have coupling cavity 38. As depicted in FIG. 1 and FIG. 2, coupling
cavity 38 may be a closed slot. In other embodiments, coupling
cavity 38 may be an open slot. As used herein, "slot" generally
refers to an elongated opening of any size or shape, including an
opening that deviates from an opening having a regular shape (such
as a square or a circle) by elongation along at least one axis.
Movement of coupling member 36 in coupling cavity 38 may allow
longitudinal movement of first plate 32 relative to second plate
34. Coupling cavity 38 may include recessed surface 42. Recessed
surface 42 may minimize or eliminate extension of coupling member
36 above spinal compression plate 30.
[0066] In some embodiments, a longitudinal length of coupling
cavity 38 may limit motion of first plate 32 relative to second
plate 34. In an embodiment, a portion of first plate 32 may contact
a portion of second plate 34 to provide a boundary for a range of
motion of the first plate relative to the second plate. FIG. 1
depicts spinal compression plate 30 in a fully compressed position.
FIG. 2 depicts spinal compression plate 30 in an expanded position.
In some embodiments, first plate 32 may be able to move about 8 mm
relative to second plate 34. In some embodiments, first plate 32
may be able to move about 4 mm relative to second plate 34. In some
embodiments, a range of motion of first plate 32 relative to second
plate 34 may be smaller than about 4 mm or greater than about 8
mm.
[0067] Spinal compression plate 30 may include openings 40
extending through the plate. Fasteners inserted into openings 40
may couple spinal compression plate 30 to vertebrae. Portions of
first plate 32 and second plate 34 may form walls 44 of openings
40. In some embodiments, walls 44 of openings 40 may be formed by
liners, coatings, and/or coverings to modify frictional and/or
other physical properties of the openings relative to fasteners
inserted into the openings.
[0068] Openings 40 may be placed at various locations on first
plate 32 and/or second plate 34. In some plate embodiments,
openings 40 may be placed along midline axes of first plate 32 and
second plate 34. Openings 40 may be symmetrically positioned about
a midline axis of a plate near an end of the plate. In some
embodiments, openings 40 may be positioned randomly or
asymmetrically. In some embodiments, center openings may be
positioned proximate a midpoint of spinal compression plate 30. A
first center opening may be located in first plate 32. A second
center opening, corresponding to the first center opening in first
plate 32, may be located in second plate 34. The first center
opening may at least partially align with the second center opening
of assembled spinal compression plate 30. The first center opening
and/or the second center opening may be elongated to accommodate
movement of the first plate relative to the second plate.
[0069] As depicted in FIG. 2, retainer 46 may be positioned in
opening 40 of spinal compression plate 30. In some embodiments,
opening 40 may have an irregular shape to facilitate insertion of
retainer 46 into the opening. Retainers 46 may include, but are not
limited to, rings, c-rings, one or more crescents,.annuli,
cinctures, tabs, tangs, ridges, and/or shelves. In an embodiment, a
portion of a retainer may be threaded. Retainer 46 may fit between
wall 44 of opening 40 and a fastener. In some embodiments, wall 44
of opening 40 may engage retainer 46. In an embodiment, wall 44 of
opening 40 may be smooth. In certain embodiments, wall 44 of
opening 40 may be biased to engage a portion of a fastener used to
couple spinal compression plate 30 to bone. Wall 44 of opening 40
may be curved and/or angled to allow angulation of a fastener into
bone.
[0070] Wall 44 may have one or more indentions configured to engage
a portion or portions of retainer 46. In some embodiments, one or
more indentions may form recess 48. In some embodiments, a portion
of retainer 46 may fit in recess 48. The shape of a portion of
retainer 46 that fits in recess 48 may inhibit removal of the
retainer from spinal compression plate 30. In some embodiments,
retainer 46 may be free to rotate in opening 40.
[0071] In some embodiments, a wall of opening 40 defining recess 48
may have a spherical contour that corresponds to a contour of a
spherical portion of a retainer. The spherical portion of the
retainer may have a height that is less than a height of the
recessed portion to allow for some polyaxial motion of the retainer
when the retainer is positioned in recess 48. In some embodiments,
the polyaxial motion allowed by recess 48 and a retainer may allow
a fastener positioned in the retainer to be angled in a conic range
of motion. In some embodiments, the range of motion of the fastener
may be up to about 15.degree. relative to a central axis normal to
the center of an opening. In some embodiments, the range of motion
of the fastener may be up to about 9.degree. relative to a central
axis normal to the center of the opening. In some embodiments, the
range of motion of the fastener may be up to about 3.degree.
relative to a central axis normal to the center of the opening.
Larger or smaller ranges of motion may be accommodated by
controlling the difference between the height of the recess and the
height of the spherical portion of the retainer that resides in
recess.
[0072] Retainer 46 may inhibit backout of a fastener from opening
40. In an embodiment, retainer 46 is a ring positioned in opening
40. Shape of the ring and the shape of the opening may inhibit
removal of the ring from the opening.
[0073] Retainer 46 may include projections 50. Projections 50 of
retainer 46 may deflect outward when a head of a fastener is
inserted into the retainer during coupling of spinal compression
plate 30 to a vertebra. After a portion of a fastener head passes
projections 50, the projections may contract so that the
projections extend over a portion of the head of the fastener. When
a fastener is fully inserted into a vertebra, projections 50 may
extend over a portion of a head of the fastener that is positioned
in an opening of a spinal compression plate. Should the fastener
move in a direction out of the opening of the spinal compression
plate, a portion of the fastener head may contact projections 50 of
retainer 46 that extend over the fastener head. Because the shape
of retainer 46 inhibits removal of the retainer from the opening,
contact of the fastener with projections 50 will inhibit removal of
the fastener from the opening.
[0074] Retainer 46 may engage a head of a fastener without the
retainer binding to spinal compression plate 30. Engagement of the
fastener and retainer 46 may allow the fastener and retainer
combination to pull spinal compression plate 30 against the
vertebra. In some embodiments, fastener head may expand retainer 46
against wall 44 of opening 40 after the fastener and retainer
combination pulls the spinal compression plate against the
vertebra.
[0075] In some spinal compression plate embodiments, first plate 32
may move freely toward and away from second plate 34. In some
embodiments, a unidirectional movement mechanism may limit movement
of first plate 32 toward second plate 34. FIG. 2 depicts a spinal
compression plate embodiment with a ratcheting mechanism as a
uni-directional movement mechanism. Movement mechanism 52 may limit
the direction that first plate 32 moves relative to second plate 34
(i.e., movement of the first plate may be uni-directional). In an
embodiment, movement mechanism 52 may inhibit the motion of first
plate 32 relative to second plate 34 until a desired load is
applied to spinal compression plate 30. Inhibiting the motion of
first plate 32 relative to second plate 34 until a desired load is
applied to spinal compression plate 30 may accommodate normal
motion of a patient without altering a distance between the first
and second plates. First plate 32 may move closer to second plate
34 when adjacent vertebrae move closer together. In some
embodiments, movement mechanism 52 may accommodate settling and/or
subsidence of vertebrae after insertion of a spinal compression
plate into a patient.
[0076] In an embodiment, first plate 32 may include serrations.
Second plate 34 may include a protrusion that fits in serrations of
first plate 32. In some embodiments, second plate 34 may include
serrations and first plate 32 may include a protrusion that fits in
the serrations. The serrations may have an equilateral shape to
allow movement of first plate 32 toward or away from second plate
34. In some embodiments, serration shape may facilitate movement of
first plate 32 toward second plate 34. In some embodiments,
serration shape may inhibit movement of first plate 32 away from
second plate 34.
[0077] FIG. 3 depicts a portion of an embodiment of spinal
compression plate 30. A lower surface of first plate 32 may include
serrations 54. Protrusion 56 of second plate 34 may extend into a
space between serrations 54. Protrusion 56 may be located on a
flexible arm. In some spinal compression plate embodiments, second
plate 34 may include two or more protrusions 56 that engage
serrations 54. Orientation of serrations 54 and protrusion 56 may
allow uni-directional movement of first plate 32 toward second
plate 34 (i.e., inhibiting movement of the first plate away from
the second plate). Serrations 54 and protrusion 56 may be sized so
that first plate 32 is not able to move toward second plate 34
until a desired compressive load is applied to spinal compression
plate 30.
[0078] In some spinal compression plate embodiments, an engagement
mechanism may limit a range of motion of first plate 32 relative to
second plate 34. An engagement mechanism may include one or more
protruding members 58 that extend through one or more openings 60
in second plate 34 into one or more chambers 62 of first plate 32.
Protruding members 58 may include, but are not limited to, pins,
rivets, and/or screws. Protruding members 58 may inhibit rotation
of first plate 32 relative to second plate 34. In addition,
protruding members 58 may provide one or more boundaries that limit
a range of motion of first plate 32 relative to second plate 34.
Chamber 62 may be curved and/or angled to accommodate curvature of
spinal compression plate 30. In some embodiments, protruding member
58 may be a guide pin. A guide pin may enter chamber 62 and
facilitate coupling of first plate 32 and second plate 34.
Protruding member 58 may enhance stability of spinal compression
plate 30.
[0079] In some embodiments, spinal compression plate 30 may include
one or more protrusions 64. Protrusions 64 may be securely
positioned in openings of first plate 32 and/or second plate 34.
Protrusions 64 may be, but are not limited to being, press-fit,
welded, glued, and/or otherwise affixed to first plate 32 and/or
second plate 34. Protrusions 64 may be driven into a vertebra to
initially couple spinal compression plate 30 to the vertebra. After
spinal compression plate 30 is initially coupled to the vertebra,
the spinal compression plate may be more securely coupled to the
vertebra with fasteners.
[0080] In some spinal compression plate embodiments, first plate 32
and/or second plate 34 may include indentions 66, as shown in FIG.
2 and FIG. 3. Indentions 66 may facilitate proper positioning of
first plate 32 and second plate 34 during an insertion procedure.
Indentions 66 may provide an engagement surface for a spacer that
sets a position of first plate 32 relative to second plate 34
(i.e., establishes a length of the spinal compression plate) prior
to and/or during insertion of spinal compression plate 30.
[0081] FIG. 4 depicts a cross section of a perspective view of an
embodiment of spinal compression plate 30. First plate 32 and
second plate 34 may have retainers 46 positioned in openings 40.
Movement of first plate 32 relative to second plate 34 may be
limited by movement mechanism 52. Movement mechanism 52 may include
a protrusion on flexible arm 68 of second plate 34 that engages
serrations 54 on first plate 32.
[0082] FIG. 5 depicts a cross section of a perspective view of
spinal compression plate 30, including a detailed view of a portion
of the spinal compression plate. Movement mechanism 52 of spinal
compression plate 30 may include protrusion 56 that extends from
flexible arm 68 of second plate 34 and engages serrations 54 on a
lower surface of first plate 32. Protrusion 56 (e.g., a tooth) and
serrations 54 allow relative movement of first plate 32 and second
plate 34 toward each other.
[0083] In some embodiments, protrusion 56 may have first angled
surface 70 that engages angled surface 72 of serrations 54. Contact
of angled surface 70 of protrusion 56 with angled surface 72 of
serrations 54 may allow second plate 34 to move toward first plate
32. Protrusion 56 may also include straight surface 74 that engages
straight surface 76 of a tooth of serrations 54. If force is
applied to second plate 34 to move the second plate away from first
plate 32, straight surface 74 of protrusion 56 may contact straight
surface 76 of a tooth of serrations 54. In some embodiments,
contact of protrusions 56 and serrations 54 may inhibit movement of
second plate 34 away from first plate 32. When coupled to
vertebrae, the relative movement of first plate 32 and second plate
34 may accommodate settling and/or subsidence of the vertebrae
after insertion of spinal compression plate 30.
[0084] FIG. 6 depicts an exploded view of an embodiment of spinal
compression plate 30. Spinal compression plate 30 may include first
plate 32 and second plate 34. First plate 32 and second plate 34
may be coupled together with coupling members 36 in coupling
cavities 38 proximate sides of the first plate. Coupling cavities
38 proximate sides of first plate 32 may inhibit rotation and/or
torquing of spinal compression plate 30 during use. Coupling cavity
38 may have recessed surface 42. One or more coupling members 36
may be used in each coupling cavity 38. In an embodiment, coupling
cavity 38 is tapered. During assembly of spinal compression plate
30, coupling member 36 may be placed through coupling cavity 38
into coupling member opening 78. Coupling member 36 may be attached
to coupling member opening 78 on second plate 34 using a weld, an
adhesive, threading, and/or a frictional lock. As spinal
compression plate 30 is compressed, tab 80 on second plate 34 may
enter an undercut portion of first plate 32.
[0085] In the spinal compression plate embodiment of FIG. 6, spinal
compression plate 30 may include movement mechanism 52. First plate
32 may have serrations 54 that engage protrusion 56 on flexible arm
68 of second plate 34. A movement mechanism may inhibit first plate
32 from moving away from second plate 34. In some spinal
compression plate embodiments, first plate 32 and second plate 34
may be able to move freely relative to each other. First plate 32
and/or second plate 34 may include one or more guide openings 82.
Guide opening 82 may allow proper positioning of instrumentation
(e.g., insertion instruments, drills, and/or tap guides) during an
insertion procedure.
[0086] FIG. 7 depicts an embodiment of a plate insertion instrument
that may be positioned in a guide opening. Plate insertion
instrument 84 may include actuator surface 86, shaft 88, handle 90,
slots 92, and engagement end 94. Engagement end 94 may fit in an
opening (e.g., a guide opening) of a spinal compression plate.
Slots 92 may be compressed when engagement end 94 is placed in an
opening of a spinal compression plate to form a press-fit
engagement between plate insertion instrument 84 and the spinal
compression plate.
[0087] Handle 90 of insertion instrument 84 may extend away from
shaft 88 of the insertion instrument. Handle 90 may allow a spinal
compression plate to be properly positioned on vertebrae within a
surgical opening. When a spinal compression plate is properly
positioned, a user may push or strike actuator surface 86 to drive
at least one spike of the spinal compression plate into at least
one vertebra.
[0088] In some embodiments, a tip of an engagement end of a plate
insertion instrument may include a spike. FIG. 8 depicts spike 96
on engagement end 94 of a plate insertion instrument. Spike 96 may
facilitate temporary placement of a spinal compression plate during
insertion. A press-fit connection between a spinal compression
plate and plate insertion instrument 84 may be removed by moving
the plate insertion instrument away from the spinal compression
plate.
[0089] In some procedures, a tamp or other instrument may be held
against a spinal compression plate to ensure that a press-fit
connection between the spinal compression plate and an insertion
instrument is removed when the insertion instrument is lifted from
the spinal compression plate. A guide opening of a spinal
compression plate may be used as a viewport to observe an implant
positioned between adjacent vertebrae. A guide opening may help to
reduce a weight of a spinal compression plate. In some embodiments,
a fastener may be positioned through a guide opening to couple a
spinal compression plate to a spinal implant, a vertebra
displacement construct, or other device to be positioned between
vertebrae.
[0090] In some embodiments, a plate bender may be provided in an
instrumentation set to allow a spinal compression plate to be bent
to accommodate a lordotic angle of a patient. As shown in FIG. 6,
first plate 32 of spinal compression plate 30 may include grooves
98. Grooves 98 may allow first plate 32 to be bent prior to
fixation to a vertebra. Spinal compression plate 30 may be bent
along grooves 98 to conform the plate to a vertebra or vertebrae.
In some embodiments, a second plate may include grooves that
facilitate bending of the spinal compression plate.
[0091] In some embodiments, a spinal compression plate may be
curved to correspond to a lordotic curvature and/or medio-lateral
curvature of a spine. Bending of a spinal compression plate may
allow proper lordotic curvature of a spine to be maintained.
Several spinal compression plates with different lordotic
curvatures may be provided to a surgeon who will install a spinal
compression plate in a patient. Spinal compression plates may have
various widths, lengths, and/or curvatures. The surgeon may choose
a spinal compression plate that will provide a desired lordotic
curvature for the patient. Indicia may be etched or otherwise
marked (e.g., color coded) on a spinal compression plate to
indicate an amount of curvature in the plate. In some embodiments,
spinal compression plates may be provided with lordotic angles from
about 0.degree. to about 18.degree. in about 3.degree. increments.
For example, a spinal compression plate may have a length of about
28 mm, a maximum width of about 15 mm, and a 12.degree. lordotic
curvature.
[0092] A width of a spinal compression plate may affect intrusion
of the spinal compression plate into surrounding tissue. In an
embodiment, a spinal compression plate may have a width less than
about 40 mm. In some embodiments, a spinal compression plate may
have a width less than about 35 mm. Larger or smaller widths may be
used to accommodate specific needs. In certain embodiments, width
of a spinal compression plate may vary along a midline axis of the
spinal compression plate. Variance along a midline axis may reduce
intrusion of a spinal compression plate into surrounding tissue,
reduce the weight of the plate, and/or improve viewing of the
intervertebral space during insertion. In some embodiments,
openings may be formed in a spinal compression plate to reduce
weight and/or increase visibility of a surgical site.
[0093] A height of a spinal compression plate may affect a profile
of the spinal compression plate on the spine. In some embodiments,
an average height of greater than about 6.0 mm may be used. In
other embodiments, spinal compression plates may have an average
height of less than about 6.0 mm. For example, a height of a spinal
compression plate may be less than about 5.0 mm, less than about
3.5 mm, or less than about 2.7 mm. A height of a spinal compression
plate may vary along a length and/or width of the spinal
compression plate.
[0094] Some spinal compression plate embodiments may be curved to
accommodate radial curvature of vertebrae. Spinal compression
plates may be provided with varying amounts of radial curvature.
For example, spinal compression plates may be provided in large,
medium and small radial curvature sizes. An indication of the
radial curvature provided by a spinal compression plate may be
etched or otherwise marked on the spinal compression plate.
[0095] As shown in FIG. 6, spinal compression plate 30 may include
at least one center opening 100 positioned proximate a center of
the spinal compression plate. In some embodiments, center opening
100 may be positioned proximate a center of first plate 32 and/or
second plate 34. A center opening in first plate 32 may align or
partially align with a center opening in second plate 34. Center
openings may include, but are not limited to substantially oval,
circular, square, and rectangular shapes, oblong shapes, irregular
shapes, and open or closed slots. An oblong or elongated opening
may be defined as an opening that deviates from an opening having a
regular shape (such as a square or circle) by elongation along at
least one axis. In some embodiments, a first axis of center opening
100 may be larger than a second axis of the center opening,
allowing a large center opening without significant loss in
structural strength of spinal compression plate 30.
[0096] In certain embodiments, center opening 100 may have recess
102. A back portion of a retainer may fit in recess 102 of center
opening 100. Shapes of recess 102, of center opening 100 and of a
retainer positioned in the center opening may inhibit removal of
the retainer from spinal compression plate 30. The retainer may be
free to rotate in recess 102. In some embodiments, center opening
100 may be elongated. A retainer in an elongated or oblong center
opening may slide freely in a longitudinal direction. The retainer
may inhibit backout of a fastener positioned in center opening. In
an embodiment in which a spinal compression plate spans more than
two vertebrae, a fastener positioned in center opening 100 of the
spinal compression plate may couple the spinal compression plate to
a vertebra or a spinal implant.
[0097] In certain embodiments, a retainer may have restricted
movement in an opening of a spinal compression plate. FIG. 9
depicts a cross-sectional view of serrated retainer 46 taken
essentially along line 9-9 of spinal compression plate 30 in FIG.
12. Serrations 106 on a surface of center opening 100 may engage
serrations 108 on a bottom surface of retainer 46. Engagement of
serrations 106, 108 may restrict longitudinal movement of retainer
46 in opening 100. In some embodiments, longitudinal movement of
retainer 46 may be unidirectional. In some embodiments, movement of
retainer 46 may occur only after a compressive load on a spinal
compression plate reaches a certain threshold.
[0098] FIG. 10 depicts a perspective view of an embodiment of
spinal compression plate 30. Spinal compression plate 30 may
include first plate 32 and second plate 34. Second plate 34 may be
similar to a second plate in a spinal compression plate with
uni-directional movement, shown in FIG. 6. Without serrations on
movement mechanism 52 to engage protrusion 56 on flexible arm 68 of
second plate 34, first plate 32 may freely move toward and/or away
from the second plate to accommodate motion of vertebrae. In some
spinal compression plate embodiments, movement mechanism 52 on
first plate 32 may have serrations, but second plate 34 may not
have flexible arm 68 and/or protrusion 56. Movement of first plate
32 relative to second plate 34 may be limited by coupling cavity 38
and coupling member opening 78. A coupling member positioned in
coupling cavity 38 may define a minimum and/or maximum separation
between first plate 32 and second plate 34 while inhibiting
separation of first plate 32 from second plate 34 and/or rotation
of the first plate relative to the second plate.
[0099] A spinal compression plate embodiment may include an
internal tongue and groove, a pin in slot, and/or other types of
connections between first plate 32 and second plate 34 to inhibit
rotation of the first plate relative to the second plate. FIG. 11
depicts a perspective view of spinal compression plate 30 with
tongue and groove connections between first plate 32 and second
plate 34. Extensions 110 of second plate 34 may fit securely in
open slot coupling cavities 38 of first plate 32 to form spinal
compression plate 30. As used herein, an "extension" generally
refers to an elongated portion of a body. An elongated portion of a
body may be defined as a portion of a body that deviates from a
regular shape (such as a square or circle) by elongation along at
least one axis. In some embodiments, a first axis of an extension
may be larger than a second axis of the extension.
[0100] Extensions 110 may have stepped portions 112 that mate with
stepped portions 114 of coupling cavities 38. Stepped portions 112,
114 may enhance stability of spinal compression plate 30 by
inhibiting torque moments applied to first plate 32 and/or second
plate 34 during expansion or compression of the spinal compression
plate. In some embodiments, stepped portions 112, 114 may be
textured with a friction texturing to reduce slippage between first
plate 32 and second plate 34. The friction texturing may be, but is
not limited to, scored surfaces, peened surfaces, and/or surfaces
with particles implanted into the surfaces.
[0101] Spinal compression plate 30 may have movement mechanism 52
on first plate 32. In some embodiments, a lower surface of movement
mechanism 52 may have serrations 54. Movement mechanism 52 may have
extended portion 116 that fits in cavity 118 of second plate 34. An
edge of extended portion 116 of movement mechanism 52 may be
substantially flat. Sides of movement mechanism 52 may be curved to
allow extended portion 116 to approach openings 40 of second plate
34. Extended portion 116 of movement mechanism 52 may increase a
serrated surface area of the movement mechanism and thus enhance
coupling stability between first plate 32 and second plate 34.
[0102] Protrusion 56 on an upper surface of flexible arm 68 of
second plate 34 may engage serrations 54 on first plate 32 to
provide unidirectional movement of the first plate toward second
plate 34. In certain embodiments, a shape of serrations 54 may
allow spinal compression plate 30 to compress and/or expand. In
some spinal compression plate embodiments, movement mechanism 52
may not be serrated. In some spinal compression plate embodiments,
second plate 34 may not have protrusion 56 and/or flexible arm 68.
In certain spinal compression plate embodiments, cross pin 120 may
extend from an upper surface of first plate 32 through stepped
portion 114 of coupling cavity 38 into a longitudinal slot in
stepped portion 112 of extension 110 of second plate 34. A length
of the longitudinal slot in stepped portion 112 of extension 110
may limit a range of motion of first plate 32 relative to second
plate 34.
[0103] Spinal compression plate 30 may have slot 122 in movement
mechanism 52 of first plate 32. In some embodiments, protrusion 56
may be disengaged from serrations 54 by insertion of a tip of a
probe (e.g., a screwdriver blade) in slot 122. A user may slide
first plate 32 and second plate 34 apart while applying a slight
pressure to flexible arm 68 of second plate 34. The probe may be
removed from slot 122 (i.e., to release flexible arm 68) when a
desired separation between first plate 32 and second plate 34 is
achieved.
[0104] In some spinal compression plate embodiments, slot 122 may
be used as a viewport to monitor compression of spinal compression
plate 30 after a spinal stabilization procedure. A length of slot
122 may be a known distance (e.g., 8 mm, 6 mm, 4 mm, or other
length) so that a scale factor can be calculated for lengths
determined from x-ray images taken of the spinal compression plate.
When a maximum allowable compression distance of spinal compression
plate is set using a spacer, an end of flexible arm 68 may be
visible in slot. After installation of spinal compression plate is
complete, an initial x-ray image of the installed spinal
compression plate may be taken. Distance from the end of flexible
arm 68 to an end of slot 122 may be determined from the x-ray image
to provide a value for the initial separation distance. At a later
time, another x-ray image may be taken. Distance from the end of
flexible arm 68 to the end of slot 122 may be determined from the
x-ray image to provide a second distance. The difference between
the initial separation distance and the second distance measures
the amount of compression of the spinal compression plate.
Additional x-ray images may be taken at subsequent times to monitor
the amount of compression as a function of time.
[0105] FIG. 12 depicts a top view of a spinal compression plate
embodiment with first plate 32 and second plate 34 of spinal
compression plate 30 coupled with mating open slot coupling
cavities 38 and extensions 110. Spinal compression plate 30 has
irregularly shaped openings 40 and elongated center opening 100.
Irregularly shaped opening 40 may be configured to facilitate
insertion of a retainer into the opening. In an embodiment, a
portion of opening 40 may have a larger radius of curvature than
another portion of the opening.
[0106] FIG. 13 depicts an expanded top view of an embodiment of a
spinal compression plate that may be used to immobilize two
vertebral levels. Multi-level spinal compression plate 30 may
include two or more plates. In some embodiments, spinal compression
plate 30 may include first plate 32, second plate 34, and third
plate 124. Plates 32, 34, 124 may be coupled to vertebrae when
using spinal compression plate 30 to stabilize a spine. Fasteners
positioned in openings 40 of first plate 32, second plate 34, and
third plate 124 may couple spinal compression plate 30 to
vertebrae. First plate 32 and third plate 124 may be coupled to
second plate 34 using coupling members 36 in coupling cavities 38.
Portions of first plate 32 and third plate 124 may overlap portions
of second plate 34. After insertion, spinal compression plate 30
may be compressed from an expanded form to accommodate vertebral
settling and/or subsidence.
[0107] In some embodiments, spinal compression plate 30 may have
one or more movement mechanisms to restrict movement between plates
32, 34, and 124. Serrations on a plate may engage one or more
protrusions on another plate. In an embodiment, a movement
mechanism may allow a spinal compression plate to compress and may
restrict movement of the plates away from each other. In some
embodiments, second plate 34 may have protrusions on opposing sides
to engage first plate 32 and third plate 124. In an embodiment,
first plate 32 may have serrations to engage a protrusion on second
plate 34. Third plate 124 may not have serrations. First plate 32
may move only toward second plate 34, and third plate 124 may move
toward and away from the second plate. In an embodiment, first
plate 32, second plate 34, and third plate 124 may be allowed to
compress or expand to accommodate movement of vertebrae.
[0108] In certain embodiments, plates of a multi-level spinal
compression plate may be coupled together without coupling members
(e.g., with mating slots and extensions). FIG. 14 depicts
uni-directional multi-level spinal compression plate 30 with first
plate 32, second plate 34, and third plate 124. Multi-level spinal
compression plate 30 may be used to span three vertebral levels. In
other embodiments, multi-level spinal compression plates may be
used to span four vertebral levels. Extensions 110 of first plate
32 and third plate 124 may fit securely in open slot coupling
cavities 38. In some embodiments, plates of spinal compression
plate 30 may move freely with respect to each other.
[0109] FIG. 15 depicts a side view of an embodiment of multi-level
spinal compression plate 30. First plate 32 and third plate 124 may
include overlay sections 126 that are shaped to conform to underlay
sections 128 on second plate 34. Upper and lower surfaces of the
plates may be curved to correspond to a desired lordotic curvature.
Distance 130 indicates an initial separation between first plate 32
and second plate 34. Distance 132 indicates an initial separation
between second plate 34 and third plate 124. A maximum compression
of spinal compression plate 30 may be equal to the sum of distance
130 and distance 132.
[0110] FIG. 16 depicts an embodiment of spinal compression plate 30
with spacer 134. First plate 32 and second plate 34 may be
positioned for a desired length of spinal compression plate 30
prior to insertion of the spinal compression plate in a patient.
Spacer 134 may position first plate 32 relative to second plate 34
to establish an initial (i.e., maximum) separation distance between
the first plate and the second plate. Spacer 134 may have a length
that allows for an initial separation distance of about 8 mm. In
some embodiments, spacer 134 may allow a pre-set initial separation
of about 4 mm. Spacers 134 of various lengths may be included in an
instrumentation set provided with spinal compression plate 30.
[0111] FIG. 17 depicts a side view of an embodiment of spinal
compression plate 30. Spinal compression plate 30 may be expanded
before insertion to accommodate settling and/or subsidence after
installation of the spinal compression plate. Protrusion 56
positioned on underlay section 128 of first plate 32 may engage
serrations 54 on overlay section 126 of second plate 34. Spinal
compression plate 30 may have a curvature to accommodate lordotic
curvature of a spine. Spinal compression plate 30 may have spacer
134, coupling cavity 38, one or more coupling members 36, and/or
movement mechanism 52 to restrict movement between first plate 32
and second plate 34.
[0112] Spacer 134 depicted in FIG. 16 and FIG. 17 may be used to
establish an initial separation distance between first plate 32 and
second plate 34 of spinal compression plate 30 (i.e., establish an
initial length of an adjustable-length spinal compression plate).
Spacer 134 may be removed from spinal compression plate 30 before
insertion of the plate into a patient. In other embodiments, a
spacer used to establish an initial separation distance between
plates of a spinal compression plate may remain coupled to the
spinal compression plate during a portion of an insertion
procedure. In some embodiments, a spacer may be used during an
insertion-procedure to guide placement of a spinal compression
plate in a patient. In certain embodiments, a portion of a spacer
may be used to position a fastener guide for placement and
angulation of holes for fasteners.
[0113] FIG. 18 depicts spacer 136 aligned for coupling to spinal
compression plate 30. Spacer 136 may include body 138 and guidepost
140. Pin 142 may couple guidepost 140 to spacer 136 (i.e., inhibit
removal of the guidepost from the spacer) while allowing rotational
and longitudinal movement of the guidepost. Rotational movement of
guidepost 140 in spacer 136 may be unrestricted, while longitudinal
movement of the guidepost in the spacer may be limited. Insertion
end 144 of guidepost 140 may be sized for insertion into opening
146 of spinal compression plate 30. Alignment portion 148 of spacer
136 may be sized for positioning in indention 66 of spinal
compression plate 30. Positioning of alignment portion 148 in
indention 66 may promote coupling of spacer 136 to spinal
compression plate 30. Separator 150 of spacer 136 may fit in cavity
118 to establish an initial separation distance between first plate
32 and second plate 34 of spinal compression plate 30. In some
embodiments, separator 150 may overlay arm 68 of second plate
34.
[0114] In some embodiments, insertion end 144 of guidepost 140 may
be pointed. Insertion end 144 of guidepost 140 may have sharpness
sufficient to penetrate a vertebra of a patient to temporarily
couple spinal compression plate 30 to the vertebra. In some
embodiments, opening 146 of spinal compression plate 30 may have a
smooth inner surface. In some embodiments, insertion end 144 of
guidepost 140 may be keyed or threaded to temporarily attach to the
spinal compression plate. In certain embodiments, insertion end 144
of guidepost 140 may be threaded above a pointed region. Opening
146 may have threading complementary to threading of insertion end
144 of guidepost 140. Insertion end 144 of guidepost 140 may be
fastened (e.g., threaded) into opening 146 to affix spacer 136 to
spinal compression plate 30.
[0115] Placement of alignment portion 148 in indention 66, and
insertion of insertion end 144 in opening 146 of expanded spinal
compression plate 30, may hold securing end 152 of separator 150
against second plate 34. Securing end 152 of separator 150 may fit
in cavity 118 of second plate 34. Securing end 152 may have a shape
complementary to a shape of cavity 118. With spacer 136 secured to
second plate 34 of expanded spinal compression plate 30, first
plate 32 may be moved toward the second plate such that an edge of
movement mechanism 52 of the first plate contacts contacting end
154 of separator 150. Contacting end 154 of separator 150 may have
groove 156. An edge of movement mechanism 52 of first plate 32 may
have a shape complementary to groove 156, such that the projection
fits securely in the groove. With securing end 152 of separator 150
against second plate 34 and an edge of movement mechanism 52 of
first plate 32 against contacting end 154 of separator 150, a
separation distance of first plate 32 and second plate 34 equal to
a length of separator 150 may be achieved.
[0116] FIG. 18 depicts positioner 158 aligned above opening 160 of
first plate 32 of spinal compression plate 30. Positioner 158 may
have body 138 with alignment portion 148 and guidepost 140.
Insertion end 144 of guidepost 140 may be pointed and/or threaded.
Insertion end 144 of guidepost 140 may be inserted through opening
160 of first plate 32. Positioner 158 may be secured to spinal
compression plate 30 in a manner similar to that described for
spacer 136. In some embodiments, insertion end 144 of guidepost 140
may penetrate a vertebra of a patient. Positioner 158 may hold
spinal compression plate 30 in place temporarily during insertion
of the plate. Guidepost 140 may be used to position a fastener
guide for placement and angulation of holes for fasteners.
[0117] Handle 162, depicted in FIG. 19, may be affixed to guidepost
140. Handle 162 may be used to position a spinal compression plate
that guidepost 140 is coupled to during an insertion procedure.
After positioner 158 is secured to spinal compression plate 30,
insertion end 164 of handle 162 may be affixed to attachment end
166 of guidepost 140. Release 168 may be activated to disconnect
handle 162 from guidepost 140 after positioning spinal compression
plate 30. In some embodiments, release 168 may be pulled towards a
grip of handle 162 to release disconnect the handle from a
guidepost positioned in insertion end 164.
[0118] A fastener guide for positioning an instrument designed to
facilitate insertion of fasteners in bone may be affixed to a
guidepost. An embodiment of a fastener guide is depicted in FIG.
20. Fastener guide 170 may include guidepost holder 172 with
through hole 174. A guidepost of a positioner or spacer may fasten
securely in through hole 174 of guidepost holder 172. A body of a
positioner or a spacer may fit securely in slot 176 of fastener
guide 170. Fastener guide 170 may have hollow guide members 178.
Distal openings of hollow guide members 178 may align with fastener
openings in a spinal compression plate. An instrument inserted in
hollow guide member 178 may pass through a fastener opening in a
spinal compression plate to form a hole for a fastener. After one
or more holes are formed as needed, fastener guide 170 may be
removed from a guidepost of a spacer or a positioner. In some
embodiments, a tap may be inserted through hollow guide member 178
to form threading in a vertebra.
[0119] FIG. 21 depicts spinal compression plate 30 that may be used
for stabilizing two vertebral levels. Spinal compression plate 30
may include first plate 32, second plate 34, and third plate 124.
Plates 32, 34, 124 may include openings 40 to couple spinal
compression plate 30 to vertebrae. Spinal compression plate 30 may
include movement mechanism 52 with serrations 54. Movement
mechanism 52 may include arm 68 with protrusion 56. Serrations 54
of extension 180 may engage protrusion 56. In some embodiments, a
portion of movement mechanism 52 may be positioned on an upper
surface of second plate 34. Arm 68 may have a thin section to
promote deflection of the arm. As spinal compression plate 30 is
compressed during use, protrusion 56 may advance and move over
serrations 54. As a load on spinal compression plate 30 decreases,
forces may promote expansion of the plate. In certain embodiments,
a protrusion may inhibit expansion of spinal compression plate 30
during use. In some embodiments, movement mechanism 52 may be
positioned on a lower side of spinal compression plate 30. As shown
in the embodiment in FIG. 21, movement mechanism 52 may be
positioned on lateral sides of spinal compression plate 30. In
certain embodiments, movement mechanism 52 may be located in
coupling cavity 38.
[0120] FIG. 22 depicts a perspective cross-sectional view of an
embodiment of spinal compression plate 30 including fasteners 182
and retainers 46 positioned in openings 40 of the spinal
compression plate. Spinal compression plate 30 may have a curvature
to match a curvature of one or, more vertebrae. Spinal compression
plate 30 may have spacer 134 preset to an initial separation
distance between first plate 32 and second plate 34. In some
embodiments, openings may be biased or angled to allow angulation
of fasteners 182 into a vertebra. Fasteners 182 placed in spinal
compression plate 30 may be positioned in vertebral bone in
converging or diverging orientations relative to one another. In
some embodiments, fasteners 182 may be placed into a vertebra so
that shanks of the fasteners are oriented parallel or substantially
parallel to each other.
[0121] A range of motion of a fastener may be up to 15.degree.
relative to a central axis normal to a center of opening 40 and/or
center opening 100. In an embodiment, a range of motion of a
fastener may be up to about 6.degree. relative to a central axis
normal to a center of opening 40 and/or center opening 100. A range
of motion of a fastener may be up to about 3.degree. relative to a
central axis normal to a center of opening 40 and/or a center of
center opening 100. Adjusting a difference between a height of a
recess in an opening and a height of a portion of a retainer
positioned in the recess may result in a larger or smaller range of
motion of a fastener in the opening.
[0122] Fasteners used to couple a plate to a vertebra may include,
but are not limited to, screws, nails, rivets, trocars, pins,
and/or barbs. FIG. 23 depicts an embodiment of fastener 182.
Fastener 182 may include head 184 and shank 186. Shank 186 may have
threading 188 to engage a vertebra. Head 184 may include tapered
section 190, engagement section 192, and fastening section 194.
Head 184 may include tool portion 196 and recessed portion 197 (the
recessed portion depicted in FIG. 22) to engage an insertion and/or
removal device. Tool portion 196 may be a shape including, but not
limited to, hexagonal, star-shaped, or square. In some embodiments,
recessed portion 197 may have threading to engage an insertion tool
and/or a removal tool. Engagement section 192 may be located at an
interface of tapered section 190 and fastening section 194.
Retainer projections may engage engagement section 192 to inhibit
removal of fastener 182 from a spinal compression plate.
[0123] Rescue fasteners may be provided in an instrumentation set.
A rescue fastener may be positioned in a deformed fastener opening
in a vertebra. The rescue fastener thread may have the same thread
pitch as regular fasteners. The rescue fasteners may have a larger
thread major diameter and the same thread minor diameter as regular
fasteners. For example, if a regular fastener has about a 4 mm
major thread diameter and about a 2.5 mm minor thread diameter, a
corresponding rescue fastener may have about a 4.5 mm major thread
diameter and about a 2.5 mm minor thread diameter. Rescue fasteners
may be distinguished from regular fasteners in an instrumentation
set. Rescue fasteners may be a distinctly different color than
regular fasteners. For example, rescue fasteners may be blue while
other fasteners may be silver. Different thread lengths may be
indicated by different shades of a rescue fastener.
[0124] In a spinal plate system embodiment, a retainer may be
positioned on a head of a fastener. An opening in a spinal
compression plate for a fastener may include a recess to engage the
retainer. The fastener may be inserted into the spinal compression
plate with the retainer coupled to the fastener. The retainer may
be compressed. As the fastener advances into bone, the retainer may
expand into a recess of the opening. The fastener may be able to
rotate in the opening while being driven into the bone, allowing
the plate to be secured against the bone. Expansion of a retainer
in a recess of an opening may inhibit backout of a fastener from a
spinal compression plate if a portion of the fastener loosens from
a bone.
[0125] FIG. 24 depicts a cross-sectional view of opening 40 of
spinal compression plate 30. Opening 40 may be defined by wall 44.
Wall 44 may include recess 48. A portion of a retainer (e.g., a
ring) may fit in recess 48 to inhibit removal of the retainer
and/or the fastener coupled to the retainer from the plate. Recess
48 may have lower shoulder 198 and upper shoulder 200. Lower
shoulder 198 and upper shoulder 200 may engage a portion of a
retainer to inhibit removal of the retainer from opening 40.
[0126] In some embodiments, a retainer may be able to swivel in an
opening in a spinal compression plate. A reduced width of opening
40 proximate upper and lower surfaces of the opening may inhibit
removal of a retainer and/or inhibit a retainer from falling out of
the opening. In an embodiment, a width of opening 40 proximate
upper and lower surfaces of a spinal compression plate may be less
than or about equal to an outer width of a retainer to inhibit
removal of the retainer from the plate. When removal of a retainer
from a plate is inhibited, a risk of losing the retainers in a
surgical opening during insertion may be significantly decreased
and/or eliminated.
[0127] A portion of a retainer that fits in recess 48 may be
thinner than a height of the recess to allow some angulation of a
fastener positioned through the retainer into a vertebra. In some
embodiments, a thickness of a portion of a retainer that fits in
recess 48 may allow up to about 15.degree. of angulation of a
fastener positioned in the retainer. In some embodiments, a
thickness of a portion of a retainer that fits in recess 48 may
allow less than about 6.degree. of angulation, less than about 20
of angulation, or substantially no angulation of a fastener
positioned in the retainer.
[0128] FIG. 25 depicts an embodiment of retainer 46 in the form of
a ring. Retainer 46 may have projections 50, fingers 202, upper
surface 204, lower surface 206, inner surface 208, and outer
surface 210. Retainer 46 may be substantially circular to surround
at least a portion a fastener head. Retainer 46 may have width 212
suited to an intended application of the retainer. For example,
width 212 of retainer 46 designed for insertion in an elongated
opening of a spinal compression plate may exceed a width of a
retainer designed for use in a substantially circular opening of a
spinal compression plate. Increased width 212 of retainer 46 may
enhance stability of the retainer in a recess of an opening.
Enhanced stability may be advantageous for a retainer in an
elongated opening.
[0129] In certain embodiments, a portion of retainer 46 may be
deflectable. Retainers 46 capable of deflection may allow entry of
fasteners, positioning of retainers in openings, and/or removal of
retainers from openings. Retainer 46 may include gap 214 to
facilitate deflection. In a spinal compression plate embodiment, a
retainer positioned in an opening may radially expand as a fastener
enters the opening. A retainer may contract and couple to a
fastener during insertion of the fastener into the spinal
compression plate.
[0130] In some embodiments, projections 50 may be spaced around
retainer 46. Projections 50 may include tapered inner surface 216
to facilitate fastener entry. In addition, outer surface 218 of
projections 50 of retainer 46 may be tapered to increase deflection
capability of the projections. In an embodiment, fingers 202 may
inhibit removal of a fastener from retainer 46 during use.
[0131] As depicted in FIG. 26, indentions 220 may be positioned on
outer surface 210 of retainer 46. Indentions 220 may increase a
deflection capability of retainer 46. In some embodiments, retainer
46 may contain one or more partial slots to facilitate expansion
and contraction of the retainer. Partial slots may approach, extend
down to, or extend beyond a half-height of retainer 46. In some
embodiments, retainer 46 may have single deflectable portion 222
depicted in FIG. 27.
[0132] FIG. 28 depicts retainer 46 as a ring with projections 50
and outer projections 224. In some embodiments, one or more outer
projections 224 of retainer 46 may include overhang 226. Overhang
226 of outer projections 224 may engage a recess in an opening in a
spinal compression plate. Valleys 228 between projections 50 and
outer projections 224 may allow deflection of the projections and
the outer projections.
[0133] In some spinal compression plate embodiments, a retainer may
be positioned in each opening of the spinal compression plate prior
to insertion of the plate into a patient. In certain embodiments,
retainers may be positioned in spinal compression plates before the
plates are sent to a surgeon or hospital for insertion into a
patient. In an embodiment, retainers may be provided to a surgeon
independently of spinal compression plates. Before insertion of a
spinal compression plate, the surgeon, or support personnel, may
place retainers in openings in the spinal compression plate.
[0134] FIG. 29 depicts an embodiment of spinal compression plate 30
coupled to adjacent vertebrae 230. A fastener driven through a
center opening in spinal compression plate 30 may couple the spinal
compression plate to spinal implant 232. In an embodiment, at least
a portion of vertebral load may be transferred to a spinal implant.
Maintaining at least a portion of the vertebral load on an implant
may increase bone growth and increase fusion between an implant and
surrounding vertebrae. Spinal implant 232 may include, but is not
limited to, a bone implant (e.g., allograft), metal implants,
and/or carbon fiber implants. Fasteners 182 positioned in openings
40 may couple spinal compression plate 30 to vertebrae 230.
[0135] During surgery, holes may be drilled, tapped, and/or
otherwise formed in vertebrae for attachment of a spinal
compression plate. The spinal compression plate may be positioned
adjacent to the vertebrae. In some embodiments, a fastener may be
positioned in an opening in a spinal compression plate. In an
embodiment, a fastener positioned in an opening in a spinal
compression plate may be advanced to drive the fastener into a
vertebra. As the fastener is advanced into the vertebra, the
fastener head may engage a retainer. Movement of the fastener head
into the retainer may couple the fastener to the spinal compression
plate.
[0136] An insertion tool may be used to insert a fastener through a
retainer and into a vertebra. FIG. 30 depicts an embodiment of
insertion tool 234. Insertion tool 234 may include outer shaft 236
and inner shaft 238. Outer shaft 236 may include handle 240. Handle
240 may be a grip that allows a user to securely hold insertion
tool 234 and easily apply sufficient torque to a fastener to drive
the fastener into a vertebra. Outer shaft 236 may have sufficient
length to allow handle 240 to be operated above an incision in a
patient while maintaining good visibility of the operating
area.
[0137] An end of outer shaft 236 may include drive section 242 and
tapered section 244. Drive section 242 may mate with a tool portion
of a fastener. When drive section 242 is placed in a tool portion
of a fastener, rotation of handle 240 will rotate the fastener.
Tapered section 244 may contact portions of a retainer during
insertion or removal of a fastener. Tapered section 244 may force
fingers of a retainer outwards. Tapered section 244 may allow a
fastener to be removed from the retainer.
[0138] A portion of inner shaft 238 may interact with a stop in
handle 240 or another portion of outer shaft 236 to inhibit
separation of the inner shaft from the outer shaft, while still
allowing for some axial movement of the inner shaft relative to the
outer shaft. Inner shaft 238 may have knob 246 at a first end and
threaded section 248 at a second end. Threaded section 248 may mate
with threading in a recessed portion of a fastener.
[0139] To use insertion tool 234, knob 246 may be moved away from
drive section 242 of outer shaft 236. Drive section 242 may be
placed in a recessed portion of a fastener. Knob 246 may be moved
toward drive section 242 and rotated so that threaded section 248
of inner shaft 238 engages threading in a recessed portion of the
fastener. Attaching threaded section 248 of inner shaft 238 to
threading in a recessed portion of the fastener couples the
fastener to insertion tool 234 and inhibits unintentional
separation of the fastener from the insertion tool.
[0140] Insertion tool 234 may be used to position the fastener
through a retainer positioned in a spinal compression plate. Handle
240 of insertion tool 234 may be rotated to drive the fastener into
a vertebra. Handle 240 may be rotated until interaction of the
fastener with the retainer and/or the spinal compression plate
draws the spinal compression plate against the vertebra. Knob 246
may be rotated in a direction to separate threading of inner shaft
238 from threading in the recessed portion of the fastener.
Insertion tool 234 may then be removed from the fastener.
[0141] To remove a fastener from a vertebra and from a spinal
compression plate, drive section 242 of insertion tool 234 may be
placed in the opening of the fastener to be removed. Knob 246 may
be rotated to engage threading of inner shaft 238 with threading in
a recessed portion of the fastener. Knob 246 may include indicia
that indicate the proper rotational direction to turn the knob to
couple inner shaft 238 to the fastener. As threading of inner shaft
238 engages threading in the fastener, tapered section 244 of outer
shaft 236 may force fingers of the retainer outwards. When the
inner shaft is secured to the fastener, handle 240 may be rotated
to remove the fastener from the vertebra, spinal compression plate,
and retainer.
[0142] A spinal compression plate may be used to stabilize a
portion of a spine. A discectomy may be performed to remove all or
a portion of a damaged intervertebral disc. The approach to the
intervertebral disc may be an anterior or lateral approach. One or
more spinal implants may be inserted into the disc space formed by
the discectomy.
[0143] A spinal compression plate having an appropriate lordotic
and radial curvature may be chosen. If needed, plate benders may be
used to adjust the curvature of the spinal compression plate to
conform to the curvature of vertebrae that the spinal compression
plate is to be attached to. A separation distance between a first
plate and a second plate may be chosen. In some embodiments, no
separation is desired, and a fully compressed spinal compression
plate may be inserted into a patient. In other embodiments, a
spacer may be used to establish the desired separation distance. In
some embodiments, a spacer and a positioner may be coupled to the
spinal compression plate.
[0144] The spinal compression plate may be attached to a handle
and/or a plate insertion instrument. The handle and/or plate
insertion instrument may be used to position the spinal compression
plate at a desired location on the vertebrae so that the spinal
compression plate will inhibit expulsion of the spinal implant or
spinal implants from the vertebrae. The spinal compression plate
may be temporarily coupled to the vertebrae. In an embodiment,
pointed ends of portions of the spacer and/or the positioner may
temporarily fix the spinal compression plate to the vertebrae. In
some embodiments, protruding members positioned in openings of the
spinal compression plate may be used to temporarily fix the spinal
compression plate to the vertebrae.
[0145] In some embodiments, a guide may be used to form openings in
the vertebrae for fasteners. In some embodiments, a surgeon may
form openings for the fasteners without the use of a guide.
[0146] A fastener may be attached to a fastener insertion tool. The
fastener may be inserted into an opening in the spinal compression
plate. The fastener insertion tool may be used to drive the
fastener into an opening in a vertebra. The fastener insertion tool
may be disconnected from the fastener. When the fastener insertion
tool is removed from the fastener, a portion of a retainer in the
opening may extend over a head of the fastener. Should the fastener
loosen within the opening in the vertebra, contact between the
portion of the retainer and the fastener head will inhibit backout
of the fastener from the opening in the spinal compression plate.
The fastener insertion tool may be used to insert additional
fasteners into openings in the spinal compression plate to secure
the plate to the vertebrae.
[0147] The spacer and the positioner may be removed from the spinal
compression plate. The surgery opening may be closed. At a later
time, should portions of the vertebrae that the spinal compression
plate is attached to subside and/or settle, a first plate of the
spinal compression plate may move towards a second plate. Movement
of the first plate towards the second plate may accommodate
subsidence and/or settling of the vertebrae.
[0148] Further modifications and alternative embodiments of various
aspects of the invention will be apparent to those skilled in the
art in view of this description. Accordingly, this description is
to be construed as illustrative only and is for the purpose of
teaching those skilled in the art the general manner of carrying
out the invention. It is to be understood that the forms of the
invention shown and described herein are to be taken as the
presently preferred embodiments. Elements and materials may be
substituted for those illustrated and described herein, parts and
processes may be reversed, and certain features of the invention
may be utilized independently, all as would be apparent to one
skilled in the art after having the benefit of this description of
the invention. Changes may be made in the elements described herein
without departing from the spirit and scope of the invention as
described in the following claims.
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