U.S. patent application number 11/610698 was filed with the patent office on 2007-05-31 for capless multiaxial screw and spinal fixation assembly and method.
This patent application is currently assigned to X-SPINE SYSTEMS, INC.. Invention is credited to David Louis Kirschman.
Application Number | 20070123867 11/610698 |
Document ID | / |
Family ID | 37416181 |
Filed Date | 2007-05-31 |
United States Patent
Application |
20070123867 |
Kind Code |
A1 |
Kirschman; David Louis |
May 31, 2007 |
CAPLESS MULTIAXIAL SCREW AND SPINAL FIXATION ASSEMBLY AND
METHOD
Abstract
A bone fixation assembly and capless multi-axial screw system
and method are shown. The assembly comprises a receiver having a
rotary lock which in one embodiment includes a plurality of
channels which urge and lock the elongated member to the screw
using a bayonet type connection.
Inventors: |
Kirschman; David Louis;
(Centerville, OH) |
Correspondence
Address: |
MATTHEW R. JENKINS, ESQ.
2310 FAR HILLS BUILDING
DAYTON
OH
45419
US
|
Assignee: |
X-SPINE SYSTEMS, INC.
Centerville
OH
|
Family ID: |
37416181 |
Appl. No.: |
11/610698 |
Filed: |
December 14, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11193523 |
Jul 29, 2005 |
|
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11610698 |
Dec 14, 2006 |
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Current U.S.
Class: |
606/266 |
Current CPC
Class: |
A61B 17/7002 20130101;
A61B 17/7037 20130101; A61B 17/7032 20130101 |
Class at
Publication: |
606/061 |
International
Class: |
A61F 2/30 20060101
A61F002/30 |
Claims
1. A capless multiaxial screw system comprising: a receiver
comprising a receiver end comprising a receiver bore for receiving
a threaded portion of a screw having a screw head; and a sleeve
having a sleeve end for situating against at least a portion of
said screw head after said threaded portion is received in said
receiver bore, said sleeve having a sleeve bore associated with
said sleeve end; said receiver having a channel for receiving an
elongated member; said sleeve being adapted to permit said
elongated member to engage said at least of portion of said screw
head when said elongated member is received in said channel and
said receiver is rotated to a locked position.
2. The capless multiaxial screw system as recited in claim 1
wherein said sleeve end comprises an outer end surface that is
tapered or concave, said outer end surface engaging said at least a
portion of said screw head.
3. The capless multiaxial screw system as recited in claim 1
wherein said sleeve end comprises an inner end surface, said at
least a portion of said screw head extending through said sleeve
bore beyond said inner end surface when said receiver is in said
locked position.
4. The capless multiaxial screw system as recited in claim 1
wherein said receiver comprises a plurality of channels for
receiving said elongated member.
5. The capless multiaxial screw system as recited in claim 4
wherein each of said plurality of channels defines an intermediate
area for capturing said elongated member to facilitate adjusting a
position of said elongated member before it is locked in said
receiver.
6. The capless multiaxial screw system as recited in claim 5
wherein said plurality of channels are defined by a first surface
and a second surface, each of said plurality of channels having an
intermediate step for defining said intermediate area.
7. The capless multiaxial screw system as recited in claim 6
wherein at least one of said first or second surfaces is not
planar.
8. The capless multiaxial screw system as recited in claim 1
wherein said channel is a helical channel defined by at least one
surface of said receiver.
9. The capless multiaxial screw system as recited in claim 1
wherein said sleeve end comprises a generally concave or
semispherical seat, at least a second portion of said screw head
having a curvature that generally complements said generally
concave or semispherical seat.
10. The capless multiaxial screw system as recited in claim 1
wherein said channel comprises a receiving area that is generally
parallel to an axis of said receiver and comprises a locking area
that spirals about said axis of said receiver when moving in an
axial direction.
11. The capless multiaxial screw system as recited in claim 10
wherein said locking area extends in a direction that is generally
not parallel to said axis of said receiver.
12. The capless multiaxial screw system as recited in claim 1
wherein said receiver comprises at least one camming surface that
cooperates with an opposing surface for defining said channel, said
at least one camming surface facilitates compressing said elongated
member directly against said at least a portion of said screw
head.
13. The capless multiaxial screw system as recited in claim 1
wherein said receiver comprises a plurality of camming surfaces
that cooperate with a plurality of opposing surfaces, respectively,
to define said channel, said plurality of camming surfaces for
camming against said elongated member and forcing it into
compression against said at least a portion of said screw head.
14. The capless multiaxial screw system as recited in claim 13
wherein said locking channel comprises a first locking channel area
and a second locking channel area, said receiver comprises a first
camming surface generally opposed to a first opposing surface to
define said first locking channel area and a second camming surface
generally opposed to a second opposing surface to define said
second locking channel area, said first and second camming surfaces
camming against said elongated member to cause said elongated
member to apply a compressive force against said screw head when
said receiver is rotated.
15. The capless multiaxial screw system as recited in claim 1
wherein said channel comprises a lock member associated therewith
for facilitating retaining said receiver in a locked position.
16. The capless multiaxial screw system as recited in claim 15
wherein said lock member cooperates with an end wall of said
channel to define a locking area at which said receiving member is
locked when it is in said locked position.
17. The capless multiaxial screw system as recited in claim 1
wherein said channel lies in a first plane that is generally planar
and said receiver further comprising a locking channel that lies in
a second plane that is non-planar.
18. The capless multiaxial screw system as recited in claim 1
wherein said receiver comprises a locking channel that spirals
about an axis of said retainer.
19. The capless multiaxial screw system as recited in claim 1
wherein said receiver comprises a seat, said screw head having a
screw head end that is generally spherical or semispherical and
said seat is adapted to receive and complement said screw head
end.
20. The capless multiaxial screw system as recited in claim 1
wherein said screw head comprises a plurality of recessed areas in
at least a portion of said screw head adapted to receive a tool for
driving said screw.
21. The capless multiaxial screw system as recited in claim 1
wherein said screw head comprises a simple recessed area adapted to
receive a tool for driving said screw.
22. The capless multiaxial screw system as recited in claim 1
wherein said at least a portion of said screw head comprises an
outer surface that is arcuate, curved, semispherical or
spherical.
23. The capless multiaxial screw system as recited in claim 22
wherein said outer surface is spherical.
24. The capless multiaxial screw system as recited in claim 1
wherein said sleeve end is adapted to permit direct engagement or
compression of said elongated member against said at least a
portion of said screw head.
25. The capless multiaxial screw system as recited in claim 1
wherein said screw head is adapted to permit point contact and
compression of said elongated member against said at least a
portion of said screw head when a screw axis of said screw is not
coaxial with a receiver axis of said receiver.
26. The capless multiaxial screw system as recited in claim 3
wherein said sleeve bore is adapted to permit said at least a
portion of said screw head to extend into said sleeve bore a
predetermined distance such that it extends into said channel.
27. The capless multiaxial screw system as recited in claim 1
wherein said sleeve comprises two generally opposing walls that
stabilize and align said elongated member in said receiver.
28. The capless multiaxial screw system as recited in claim 27
wherein said at least a portion of said screw head comprises an
outer surface that is arcuate, curved, semispherical or spherical
in cross section.
29. A bone fixation assembly comprising: a receiver having a
receiver bore for receiving a screw having a screw head and a
receiver channel in communication with said receiver bore for
receiving an elongated member; and a stabilizer adapted to be
received in said receiver bore, said stabilizer having a stabilizer
channel and a stabilizer bore through said stabilizer, said
stabilizer adapted to permit direct contact between at least a
portion of said screw head and said elongated member; said receiver
being capable of rotating relative to said elongated member after
said elongated member is received in said receiver channel to force
said elongated member into contact with said at least a portion of
said screw head.
30. The bone fixation assembly as recited in claim 29 wherein said
receiver comprises at least one engaging surface for engaging said
elongated member and for locking said elongated member to said at
least a portion of said screw head when said receiver is rotated to
a locked position.
31. The bone fixation assembly as recited in claim 29 wherein said
receiver is generally cylindrical and said receiver bore extends
along an axis of said receiver, said receiver comprising a first
locking aperture in communication with said receiver bore and a
second locking aperture in communication with said receiver bore;
said first and second locking apertures cooperating to define a
locking channel.
32. The bone fixation assembly as recited in claim 31 wherein said
locking channel is defined by a first channel in a wall of said
receiver and a second channel in said wall of said receiver, said
first and second channels being generally opposed.
33. The bone fixation assembly as recited in claim 32 wherein said
first channel and said second channel extend away from said
receiver channel about a receiver axis of said receiver such that
rotation of the receiver will cause said elongated member to move
to a locked position whereupon it engages said at least a portion
of said screw head.
34. The bone fixation assembly as recited in claim 32 wherein said
first channel and said second channel spiral in a common direction
about a receiver axis of said receiver.
35. The bone fixation assembly as recited in claim 29 wherein said
receiver comprises a wall that lies in a generally circular or
arcuate plane about a receiver axis of said receiver and said
receiver channel being by said wall.
36. The bone fixation assembly as recited in claim 29 wherein said
screw head comprises a plurality of recessed areas.
37. The capless multiaxial screw system as recited in claim 29
wherein said screw head comprises a single recessed area adapted to
receive a tool for driving the screw.
38. The bone fixation assembly as recited in claim 29 wherein an
outer surface of said at least a portion of said screw head is
arcuate, curved, spherical or semispherical in cross section.
39. The bone fixation assembly as recited in claim 29 wherein an
outer surface of said at least a portion of said screw head is
arcuate or spherical at said at least a portion of said screw
head.
40. The bone fixation assembly as recited in claim 39 wherein said
screw has a truncated area for permitting maximal polyaxial
movement of said receiver relative to said screw head.
41. The bone fixation assembly as recited in claim 29 wherein said
stabilizer bore of said stabilizer is adapted to permit point
contact of said elongated member against said at least a portion of
said screw head.
42. The bone fixation assembly as recited in claim 39 wherein said
stabilizer bore of said stabilizer is adapted to permit point
contact of said elongated member against said at least a portion of
said screw head.
43. The bone fixation assembly as recited in claim 29 wherein said
screw head and said stabilizer bore are adapted to permit point
contact of said elongated member against said at least a portion of
said screw head and when a screw axis of said screw is not coaxial
with a receiver axis of said receiver.
44. The bone fixation assembly as recited in claim 29 wherein said
stabilizer bore is adapted to permit said at least a portion of
said screw head to extend into said receiver bore a predetermined
distance.
45. The bone fixation assembly as recited in claim 29 wherein said
stabilizer comprises an inner end surface, said at least a portion
of said screw head extends beyond said inner end surface and into
said stabilizer bore when said elongated member is in a locked
position in said receiver.
46. The bone fixation assembly as recited in claim 29 wherein said
stabilizer comprises a first wall and a generally opposed second
wall for defining a stabilizer receiving area or channel for
receiving said elongated rod.
47. The bone fixation assembly as recited in claim 46 wherein said
stabilizer bore is in communication with said stabilizer receiving
area, said stabilizer bore being adapted to permit said at least a
portion of said screw head to be received in said stabilizing bore
so that said elongated member directly engages or is engaged by
said at least a portion of said screw head when said receiver is
rotated to a locked position.
48. The bone fixation assembly as recited in claim 47 wherein said
stabilizer comprises a generally cylindrical wall that defines said
stabilizer bore.
49. The bone fixation assembly as recited in claim 48 wherein said
generally cylindrical wall comprises an inner diameter that
generally corresponds to a distance between said first and second
walls.
50. An intermediate member for use with a polyaxial screw having a
head that is generally spherical comprising: a body having a bore;
and a channel for receiving an elongated member; said bone being
adapted to permit at least a portion of a screw head of the
polyaxial screw to enter into said bore.
51. The intermediate member as recited in claim 50 wherein a width
of said channel is at least as large as a radius of said bore.
52. The intermediate member as recited in claim 50 wherein said
intermediate member comprises an end having a frusto-conical, or
spherical or semispherical surface for engaging said screw
head.
53. The intermediate member as recited in claim 50 wherein said
intermediate member comprises an end having an opening adapted to
permit said elongated member to engage or be engaged by at least
one portion of said screw head.
54. A bone fixation assembly comprising: a receiver having a bore
for receiving a screw having a screw head; and an intermediate
member dimensioned to be received in said bore and having a first
end and a second end; said receiver comprising an integral rotary
lock for forcing and locking an elongated member directly against
said screw head when said receiver is rotated.
55. The bone fixation assembly as recited in claim 54 wherein said
integral rotary lock comprises a continuous channel for receiving
said elongated member and for urging said elongated member toward
said screw head when said receiver is rotated.
56. The bone fixation assembly as recited in claim 54 wherein said
integral rotary lock comprises a first channel that extends about a
receiver axis in a first direction and a second channel that
extends about said receiver axis in a second direction and a
receiver channel coupling said first and second channels.
57. The bone fixation assembly as recited in claim 56 wherein said
first and second directions extend away from said receiver channel
about a receiver axis of said receiver such that rotation of said
receiver will move said elongated member from an unlocked position
to a locked position.
58. The bone fixation assembly as recited in claim 56 wherein said
receiver channel lies in a plane that generally extends along an
axis of said receiver.
59. The bone fixation assembly as recited in claim 56 wherein said
first and second channels spiral about said receiver axis.
60. The bone fixation assembly as recited in claim 56 wherein said
first and second channels lie in imaginary planes that intersect an
axis of said receiver at acute angles.
61. The bone fixation assembly as recited in claim 56 wherein said
receiver channel lies in a receiver plane, said first channel lies
in a first plane and said second channel lies in a second plane,
each of said first and second planes intersecting said receiver
plane at an acute angle that extends toward a bone when said screw
is screwed into the bone.
62. The bone fixation assembly as recited in claim 54 wherein said
receiver comprises a removable intermediate member for stabilizing
said elongated member.
63. The bone fixation assembly as recited in claim 62 wherein said
removable intermediate member comprises an end having an opening,
said screw head and said opening being adapted to enable said
elongated member to contact at least one portion of said screw
head.
64. The bone fixation assembly as recited in claim 54 wherein said
screw head is generally spherical.
65. The bone fixation assembly as recited in claim 62 wherein said
screw head is generally spherical.
66. A bone fixation assembly comprising: a receiver having an
opening for receiving a screw having a screw head; and an
intermediate member dimensioned to be received in said opening and
having an intermediate member receiving channel for receiving an
elongated member and a screw head receiving opening adapted to
receive at least a portion of said screw head; said receiver
comprising a receiver channel for receiving said elongated member,
said receiver channel compressing said elongated member against
said screw head when said receiver is rotated from an unlocked
position to a locked position.
67. The spiral fixation assembly as recited in claim 66 wherein
said receiver channel comprises a locking channel that spirals
about an axis of said receiver.
68. The spiral fixation assembly as recited in claim 67 wherein
said locking channel provides a bayonet connection between said
elongated member and said screw.
69. The bone fixation assembly as recited in claim 66 wherein said
receiving channel comprises at least a portion that lies in a first
plane and said intermediate member receiving channel comprises at
least a portion that lies in a second plane, said second plane and
said first plane being generally parallel when said elongated
member is in said unlocked position and generally perpendicular
when said elongated member is in said locked position.
70. The bone fixation assembly as recited in claim 66 wherein when
said receiver is rotated from said unlocked position to said locked
position, said elongated member directly engages said at least a
portion of said screw head and becomes situated closer to said
screw compared to when said elongated member is in said unlocked
position.
71. The bone fixation assembly as recited in claim 70 wherein said
receiver channel is in communication with a locking channel so that
when said receiver is in said unlocked position, said receiving
channel becomes generally aligned with said intermediate member
receiving channel in said intermediate member.
72. The bone fixation assembly as recited in claim 66 wherein said
receiver channel is generally perpendicular to an elongated member
axis of said elongated member when said receiving member is in said
locked position.
73. The bone fixation assembly as recited in claim 66 wherein said
receiver channel comprises a locking channel that spirals from a
first end of said receiver toward a second end of said
receiver.
74. The bone fixation assembly as recited in claim 73 wherein said
locking channel defines a helix.
75. The bone fixation assembly as recited in claim 66 wherein said
receiver channel extends from an end of said receiver in a
direction that is generally parallel to an axis of said receiver
and further comprises a locking channel that extends at least
partially about said axis of said receiver.
76. The bone fixation assembly as recited in claim 66 wherein said
intermediate member receiving channel becomes generally aligned
with said receiver channel when said elongated member is received
in said receiver and said receiver channel and said intermediate
member receiving channel become non-aligned when said receiver is
rotated to said locked position.
77. The bone fixation assembly as recited in claim 66 wherein said
receiver channel comprises a locking channel, said receiver
comprising at least one camming surface that cooperates with an
opposing surface that cooperates to define said receiver channel,
said at least one camming surface camming against said elongated
member to move said elongated member against said screw head when
said receiver is rotated.
78. The bone fixation assembly as recited in claim 66 wherein said
receiver comprises a plurality of camming surfaces that cooperate
with a plurality of opposing surfaces, respectively, to define a
locking channel, said plurality of camming surfaces camming against
said elongated member to cause said elongated member to apply a
compressive force against said screw head when said receiver is
rotated.
79. The bone fixation assembly as recited in claim 66 wherein said
receiver comprises a locking channel comprising a first locking
channel area and a second locking channel area said receiver
comprises a first camming surface generally opposed to a first
opposing surface to define said first locking channel area and a
second camming surface generally opposed to a second opposing
surface to define said second locking channel area, said first and
second camming surfaces camming against said elongated member to
force said elongated member to apply a compressive force against
said screw head when said receiver is rotated.
80. The bone fixation assembly as recited in claim 79 wherein said
receiver comprises a detent or protrusion or a plurality of detents
or protrusions in communication with said locking channel.
81. The bone fixation assembly as recited in claim 79 wherein said
receiver comprises a surface that defines an end wall of said
locking channel to define a locking area at which said elongated
member is locked when it is in said locked position.
82. The bone fixation assembly as recited in claim 66 wherein said
receiver comprises a locking channel, said receiver channel lies in
a first plane that is generally planar and said locking channel
lies in a second plane that is non-planar.
83. The bone fixation assembly as recited in claim 82 wherein said
second plane spirals about an axis of said receiver.
84. The bone fixation assembly as recited in claim 82 wherein said
locking channel extends in a direction that is non-axial relative
to an axis of said receiver.
85. The bone fixation assembly as recited in claim 66 wherein said
screw head is generally arcuate, spherical, semispherical or curved
and said intermediate member comprises an end having an outer end
surface that is generally complementary in shape and adapted to
receive said screw head.
86. The bone fixation assembly as recited in claim 66 wherein said
screw head comprises a plurality of recessed areas surrounding said
at least a portion of said screw head.
87. The bone fixation assembly as recited in claim 66 wherein said
at least a portion of said screw head is spherical in cross
section.
88. The bone fixation assembly as recited in claim 66 wherein said
at least a portion of said screw head is spherical in cross section
at an area where said elongated member directly engages said screw
head.
89. The bone fixation assembly as recited in claim 66 wherein said
outer surface of said screw head is adapted to permit point contact
of said elongated member directly against said at least a portion
of said screw head.
90. The bone fixation assembly as recited in claim 66 wherein said
screw head is adapted to permit point contact of said elongated
portion against said at least a portion of said screw head when a
screw axis of said screw is not coaxial with a receiver axis of
said receiver.
91. The bone fixation assembly as recited in claim 66 wherein said
intermediate member comprising an end having an opening adjusted to
permit an engaging portion of said screw head to extend into said
receiver opening a predetermined distance.
92. The bone fixation assembly as recited in claim 66 wherein said
intermediate member comprises a bottom surface, said at least a
portion of said screw extending beyond said bottom surface and into
said receiver channel when said elongated member is in said locked
position.
93. The bone fixation assembly as recited in claim 66 wherein said
intermediate member comprises an end having an outer end surface
that is frusto-conical.
94. The bone fixation assembly as recited in claim 66 wherein said
screw head comprises an outer surface and at least one tool
aperture or area for receiving a tool.
95. A capless multiaxial screw system comprising: a screw having a
threaded portion and a screw head; a receiver having a receiver
bore for receiving said threaded portion and a receiving channel
for receiving an elongated member, said receiver further comprising
a locking channel in communication with said receiving channel; an
intermediate member adapted to be situated in said receiver bore,
said intermediate member comprising an intermediate member bore for
receiving at least a portion of said screw head; and said
intermediate member bore and said screw head being adapted to
permit said at least a portion of said screw head to extend into
said locking channel so that said elongated member may engage and
compress against said at least a portion of said screw head when
said elongated member is received in said receiving channel and
said receiver is rotated.
96. The capless multiaxial screw system as recited in claim 95
wherein said locking channel comprises a plurality of channels,
each of said plurality of channels defining an intermediate area
for capturing said elongated member to facilitate adjusting a
position of said elongated member before it is locked in said
receiver.
97. The capless multiaxial screw system as recited in claim 96
wherein each of said plurality of channels are defined by a first
surface and a second surface, each of said plurality of channels
having an intermediate step on at least one of said first surface
or said second surface for defining said intermediate area.
98. The capless multiaxial screw system as recited in claim 97
wherein at least one of said first and second surfaces is not
planar.
99. The capless multiaxial screw system as recited in claim 95
wherein said locking channel is a helical channel defined by at
least one surface in a body of said receiver.
100. The capless multiaxial screw system as recited in claim 95
wherein said intermediate member comprises an end having a first
side comprising a generally concave seat, at least a second portion
of said screw head having a curvature that generally complements
said generally concave seat.
101. The capless multiaxial screw system as recited in claim 95
wherein said receiving channel is generally parallel along an axis
of said receiver and said locking channel spirals about said axis
of said receiver when moving in an axial direction.
102. The capless multiaxial screw system as recited in claim 95
wherein said receiving channel extends from an end of said receiver
in a direction that is generally parallel to said axis of said
receiver and said locking channel extends in a direction that is
generally not parallel to said axis of said receiver.
103. The capless multiaxial screw system as recited in claim 95
wherein said receiver comprises at least one camming surface that
cooperates with an opposing surface to define said locking channel,
said at least one camming surface forcing said elongated member
against said at least a portion of said screw head.
104. The capless multiaxial screw system as recited in claim 95
wherein said receiver comprises a plurality of camming surfaces
that cooperate with a plurality of opposing surfaces, respectively,
to define said locking channel, said plurality of camming surfaces
camming against said elongated member to lock said receiver to said
at least a portion of said screw head.
105. The capless multiaxial screw system as recited in claim 95
wherein said locking channel comprises a first locking channel area
and a second locking channel area, said receiver comprises a first
camming surface generally opposed to a first opposing surface to
define said first locking channel area and a second camming surface
generally opposed to a second opposing surface to define said
second locking channel area, said first and second camming surfaces
camming against said elongated member to force said elongated
member against said at least a portion of said screw head when said
receiver is rotated.
106. The capless multiaxial screw system as recited in claim 95
wherein said receiving channel lies in a first plane that is
generally planar and said locking channel lies in a second plane
that is non-planar.
107. The capless multiaxial screw system as recited in claim 106
wherein said second plane spirals about an axis of said
receiver.
108. The capless multiaxial screw system as recited in claim 95
wherein said locking channel spirals about an axis of said
receiver.
109. The capless multiaxial screw system as recited in claim 95
wherein said receiver comprises a seat defining a seat area said
screw head being generally spherical, said seat being adapted to
receive and complement said screw head.
110. The capless multiaxial screw system as recited in claim 95
wherein said screw head comprises a plurality of recessed areas for
receiving a tool used to turn said screw.
111. The capless multiaxial screw system as recited in claim 95
wherein said at least a portion of said screw head is spherical or
semispherical.
112. The capless multiaxial screw system as recited in claim 95
wherein said at least a portion of said screw head is arcuate or
spherical in cross section.
113. The capless multiaxial screw system as recited in claim 95
wherein said intermediate member comprises a seat defining a seat
area adapted to permit point contact between said elongated member
and said at least a portion of said screw head.
114. The capless multiaxial screw system as recited in claim 95
wherein said screw head and said screw head receiving opening are
adapted to permit point contact of said elongated member against
said at least a portion of said screw head when a screw axis of
said screw is not coaxial with a receiver axis of said
receiver.
115. The capless multiaxial screw system as recited in claim 95
wherein said intermediate member comprises an end, said
intermediate member bore being adapted to permit said at least a
portion of said screw head to extend into said locking channel a
predetermined distance.
116. The capless multiaxial screw system as recited in claim 95
wherein said intermediate member comprises a first wall and a
generally opposed second wall for defining an intermediate member
receiving area for receiving said elongated member.
117. The capless multiaxial screw system as recited in claim 95
wherein said intermediate member bore is in communication with said
intermediate member receiving area, said intermediate member bore
being dimensioned to permit said at least a portion of said screw
head to be received in both said receiver bore and said
intermediate member bore so that when said receiver is rotated,
said elongated member engages and locks against said at least a
portion of said screw head.
118. The capless multiaxial screw system as recited in claim 95
wherein said intermediate member is generally cylindrical and
defined by a generally cylindrical wall, an inner diameter of said
generally cylindrical wall being greater than a diameter of said
elongated member.
119. A capless multiaxial screw fixation assembly comprising: a
screw having a threaded portion and a screw head; a receiver having
an aperture for receiving said threaded portion and a receiving
channel for receiving an elongated member, said receiving channel
further comprising a locking channel in communication with said
receiving channel; and a guide for situating in said bore, said
guide comprising: a second receiving channel associated with a
first end of said guide and a seat area associated with a second
end of said guide; said guide being adapted to permit at least a
portion of said screw head to extend into said receiving channel
and said second receiving channel so that said elongated member may
engage said screw head to lock or compress said elongated member to
said screw when said elongated member is received in said first and
second receiving channels and said receiver is rotated from an
unlocked position to a locked position.
120. A bone fixation assembly comprising: a receiver having a
receiver bore for receiving a screw having a screw head, said
receiver further comprising a locking channel and a receiving
channel in communication with said locking channel; and an
intermediate member dimensioned to be received in said receiver
bore, said intermediate member comprising a body having a first end
having an intermediate member channel and a second end having an
intermediate member opening; said intermediate member opening being
adapted to permit at least a portion of said screw head to engage
an elongated member after said elongated member is received in said
receiving channel, said locking channel and said intermediate
member channel and said receiver is moved to a locked position.
121. The bone fixation assembly as recited in claim 120 wherein
said intermediate member comprises a pair of generally opposed
walls that cooperate with said second end to define stabilize and
align the elongated member in said receiver channel.
122. The bone fixation assembly as recited in claim 121 wherein
said intermediate member bore is generally cylindrical and
comprises a diameter substantially the same as a distance between
said pair of generally opposed walls.
123. A method for stabilizing one or more bones, said method
comprising the steps of: placing an elongated member into a
receiving channel of said receiver and channel of said intermediate
member; and rotating said receiver to cause said elongated member
to directly engage at least a portion of said screw head.
Description
RELATED APPLICATION DATA
[0001] This application is a continuation-in-part of application
Ser. No. 11/193,523, filed Jul. 29, 2005, which is incorporated
herein by reference and made a part hereof.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a capless multiaxial screw and
spinal fixation assembly and method, particularly useful for fixing
and/or aligning vertebrae of the spine. The invention permits
multiple angular orientations of an elongated member or rod with
respect to a screw that is screwed into a vertebra.
[0003] Various methods of spinal immobilization have been known and
used in the past. The preferred treatment for spinal stabilization
is immobilization of the joint by surgical fusion or anthrodesis.
This method has been known since development in 1911 by Hibbs and
Albe. However, in many cases, in particular cases involving fusion
across the lumbosacral articulation and where there are many levels
involved, pseudorarthrosis is a problem. It was discovered that
immediate immobilization was necessary in order to allow a bony
union to form. Post operative external immobilization, such as the
use of splints and casts, was a favored method of treatment,
however, as surgical techniques have become more sophisticated,
various methods of internal and external fixation have been
developed.
[0004] Internal fixation refers to therapeutic methods of
stabilization which are wholly internal to the patient and include
commonly known devices such as bone plates and pins. External
fixation, in contrast, involves at least some portion of
stabilization device which is external to the patient's body.
Internal fixation is now the favored method of immobilization
because the patient is allowed greater freedom with the elimination
of the external portion of the device and the possibility of
infection, such as a pin tract infection is reduced.
[0005] There have been numerous systems and methods developed in
the past for correcting and stabilizing and aligning the spine for
facilitating, for example, fusion at various levels or areas of the
spine, such as those devices are shown in U.S. Pat. Nos. 4,085,744;
4,269,178; 4,805,602; 5,466,237; 5,474,555; 5,891,145; and
6,869,433 B2. Bone screws with a polyaxial head are commonly used
in spine surgery today. They are used chiefly in the lumbar spine
and screwed into bone (pedicle) posteriorly. The head of the screw
is attached to the shaft of the screw by means of a ball and
socket. The top of the screw is machined into a ball, and the head
contains a socket into which the ball fits. The screw head further
contains a receiver for receiving a separate rod. The rod is
fastened to the screw head receiver via a threaded cap. The rod is
then fastened to screws placed in adjacent vertebrae thus providing
stabilization. The polyaxial head allows the rod to be placed in a
variety of angles with respect to the screw allowing conformance to
local anatomy.
[0006] When the threaded cap is tightened upon the rod, a
frictional pressure is transmitted from the threaded cap to the rod
thence to the top of the ball, thus locking the ball-in-socket and
preventing motion after tightening has occurred. This concept is
demonstrated in U.S. Pat. Nos. 5,466,237 and 5,474,555, which
illustrate this type of screw.
[0007] U.S. Pat. No. 5,466,237 to Bird et al. discloses a bone
screw having a spherical projection on the top of the bone screw.
An externally threaded receiver member supports the bone screw and
spinal rod on top of the spherical projection. An outer nut is
tightened onto the receiver member to press the spinal rod against
the spherical projection to accommodate various angular
orientations of the bone screw relative to the rod.
[0008] In another approach shown in U.S. Pat. No. 4,946,458 to
Harms, a spherical headed bone screw supported within separate
halves of a receiving member. The bottom of the halves are held
together by a retaining ring. The top of the receiver halves are
compressed about the bone screw by nuts threaded onto a threaded
spinal rod.
[0009] In still another approach taken by Harms et al. in U.S. Pat.
No. 5,207,678, a receiver member is flexibly connected about a
partially spherical head of a bone screw. Conical nuts on opposite
sides of the receiver member threaded onto a threaded rod passing
through the receiver. As the conical nuts are threaded toward each
other, the receiver member flexibly compresses around the head of
the bone screw to clamp the bone screw in its variable angular
position. One detriment of the systems in the two Harms et al.
patents is that the spinal rod must be threaded in order to accept
the compression nuts.
[0010] U.S. Pat. No. 6,869,433 discloses the use of a pedicle screw
assembly that comprises a screw having a head with a convex portion
and a receiver that receives the head. The receiver also receives
an elongated member, such as a spinal fixation rod. The receiver
has a concave portion which has a radius of curvature which is less
than the radius of curvature of the convex portion of the head
whereby to create an interference fit between the convex portion of
the head and the concave portion of the receiver. The device also
includes an internal nut and external nut that compresses the rod
against a pressure disc which in turn compresses the head convex
portion of the screw into the receiver concave portion and locks
the angular position of the receiver with respect to the screw.
[0011] One of the problems with the prior art devices is the number
of parts and components, especially those components that utilize a
threaded cap screw to secure the rod to the anchoring screw,
whether internal or external, to fix the rod relative to the screw.
Problems with the threaded fastener, that is, threaded cap or set
screw, are numerous and include risk of cap loosening, loss of cap
intra-operatively, cross threading, thread failure, failure of the
cap in driving instrument and limitations upon torque
application.
[0012] What is needed, therefore, is a system and method that
provide a lock or connection between the rod and screw without the
use of external nuts, screws, caps or threads of the type shown in
the prior art.
SUMMARY OF THE INVENTION
[0013] The present invention improves the spinal fixation and the
locking between an elongated member or rod and a screw.
[0014] One object of the invention is to provide a system and
method that reduces or eliminates the need for external or internal
caps or screws to lock the relative position of a rod to a
screw.
[0015] Another object of the invention is to provide a simple
bayonet-type connection that eliminates the fixation systems of the
past and/or simplifies the spinal fixation procedure.
[0016] In one aspect, this invention discloses a capless multiaxial
screw system comprising a receiver comprising a receiver end
comprising a receiver bore for receiving a threaded portion of a
screw having a screw head; and a sleeve having a sleeve end for
situating against at least a portion of the screw head after the
threaded portion is received in the receiver bore, the sleeve
having a sleeve bore associated with the sleeve end; the receiver
having a channel for receiving an elongated member; the sleeve
being adapted to permit the elongated member to engage the at least
of portion of the screw head when the elongated member is received
in the channel and the receiver is rotated to a locked
position.
[0017] In another aspect, this invention discloses a spinal
fixation assembly comprising a receiver having a receiver bore for
receiving a screw having a screw head and a receiver channel in
communication with the receiver bore for receiving an elongated
member; and a stabilizer dimensioned to be received in the receiver
bore, the stabilizer having a stabilizer channel associated with a
first end of the stabilizer for receiving the elongated member and
a stabilizer bore through a second end of the stabilizer, the
second end being adapted to permit direct contact between at least
a portion of the screw head and the elongated member; the receiver
being capable of rotating relative to the elongated member after
the elongated member is received in the receiver channel to force
the elongated member into contact with the at least a portion of
the screw head.
[0018] In yet another aspect, this invention relates to a receiver
for use with a polyaxial screw comprising a body having a bore; and
a channel for receiving an elongated member and for compressing it
into engagement with a screw head of the polyaxial screw when the
receiver is rotated.
[0019] In still another aspect, this invention relates to a spinal
fixation assembly comprising a receiver having a bore for receiving
a screw having a screw head; and an intermediate member dimensioned
to be received in the bore and having a first end and a second end;
the receiver comprising an integral rotary lock for forcing and
locking an elongated member directly against the screw head when
the receiver is rotated.
[0020] In another aspect, this invention discloses a spinal
fixation assembly comprising a receiver having an opening for
receiving a screw having a screw head; and an intermediate member
dimensioned to be received in the opening and having an
intermediate member receiving channel for receiving an elongated
member and a screw head receiving opening adapted to receive at
least a portion of the screw head; the receiver comprising a
receiver channel for receiving the elongated member, the receiver
channel forcing the elongated member into contact with the screw
head when the receiver is rotated from an unlocked position to a
locked position.
[0021] In another aspect, this invention relates to a capless
multiaxial screw system comprising a screw having a threaded
portion and a screw head; a receiver having a receiver bore for
receiving the threaded portion and a receiving channel for
receiving an elongated member, the receiver further comprising a
locking channel in communication with the receiving channel; an
intermediate member adapted to be situated in the receiver bore,
the intermediate member comprising an intermediate member bore for
receiving at least a portion of the screw head; and the
intermediate member bore being adapted to permit the at least a
portion of the screw head to extend into the locking channel so
that the elongated member may engage and compress against the at
least a portion of the screw head when the elongated member is
received in the receiving channel and the receiver is rotated.
[0022] In still another aspect, this invention discloses a capless
multiaxial screw fixation assembly comprising a screw having a
threaded portion and a screw head; a receiver having a bore for
receiving the threaded portion and a receiving channel for
receiving an elongated member, the receiving channel further
comprising a locking channel in communication with the receiving
channel; and a guide for situating in the bore, the guide
comprising a second receiving channel associated with a first end
of the guide and a seat area associated with a second end of the
guide; the guide being adapted to permit at least a portion of the
screw head to extend into the second receiving channel so that the
elongated member may engage the screw head to lock the elongated
member to the screw when the elongated member is received in the
first and second receiving channels and the receiver is rotated
from an unlocked position to a locked position.
[0023] In yet another aspect, this invention relates to a spinal
fixation assembly comprising a receiver having a receiver bore for
receiving a screw having a screw head, the receiver further
comprising a locking channel and a receiving channel in
communication with the locking channel; and an intermediate member
dimensioned to be received in the receiver bore, the intermediate
member comprising a body having a first end having an intermediate
member channel and a second end having an intermediate member
opening; the intermediate member opening being adapted to permit at
least a portion of the screw head to engage an elongated member
after the elongated member is received in the receiving, locking
and intermediate member channels and the receiver is moved to a
locked position.
[0024] These and other objects and advantages of the invention will
be apparent from the following description, the accompanying
drawing and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a fragmentary perspective view of a capless
multiaxial screw and fixation assembly mounted on a spinal column
having a plurality of vertebrae;
[0026] FIG. 2 is a perspective view of the system shown in FIG.
1;
[0027] FIG. 3 is an exploded fragmentary perspective view of the
system shown in FIGS. 1 and 2;
[0028] FIG. 4 is a fragmentary perspective view illustrating a rod
received in a receiving channel of a receiver;
[0029] FIG. 5 is a fragmentary plan view of the illustration shown
in FIG. 4;
[0030] FIG. 6 is a fragmentary view similar to FIG. 4, but showing
the receiver rotated approximately 30 degrees about its axis
relative to the rod;
[0031] FIG. 7 is a fragmentary plan view similar to FIG. 5 and
showing the receiver in the position illustrated in FIG. 6;
[0032] FIG. 8 is fragmentary perspective view showing the receiver
in a fully locked position;
[0033] FIG. 9 is a plan view similar to FIGS. 5 and 7 showing the
receiver in a fully locked position;
[0034] FIG. 10 is a view taken along the line 10-10 in FIG. 4;
[0035] FIG. 11 is a view illustrating the rod after it has been
received in the channel of the receiver and supported above a
bottom surface of a compression member;
[0036] FIG. 12 is a sectional view taken along the line 12-12 in
FIG. 8;
[0037] FIG. 13 is a fragmentary view showing the rod in
cross-section and in a fully locked position;
[0038] FIG. 14 is a fragmentary view illustrating various features
of the locking channels;
[0039] FIG. 15 is a plan view showing a compression member received
in a bore of the receiver and illustrating the aperture through
which a tool may be inserted to rotate the screw head before the
rod is positioned in a channel of both the receiver and the
compression member;
[0040] FIG. 16A-16E are various views of the receiver in accordance
with one illustration of the invention;
[0041] FIG. 17 is a sectional view of a compression member in
accordance with one illustration of the invention;
[0042] FIG. 18 is a fragmentary sectional view of another
illustration of the invention, showing a channel having walls that
are generally non-planar to define an intermediate area for loosely
capturing the rod;
[0043] FIG. 19 is a side elevation view of the embodiment shown in
FIG. 18;
[0044] FIG. 20 is a fragmentary sectional view that has been
rotated relative to FIGS. 18 and 19;
[0045] FIG. 21 is an elevational view rotated relative to FIG.
19;
[0046] FIGS. 22-24 are plan views illustrating rotational movement
of the receiver relative to the rod;
[0047] FIGS. 25-27 are side elevation views that generally
correspond to FIGS. 22-24, respectively, illustrating the receiver
in various positions, but with the rod removed for ease of
illustration and understanding;
[0048] FIGS. 28-30 are views similar to FIGS. 25-27, respectively,
illustrating the receiver in various rotational positions relative
to the rod as the rod is moved from a receiving position to a
locked position;
[0049] FIGS. 31-33 are fragmentary sectional views somewhat
enlarged and diagrammatic to simply illustrate the intermediate
capturing step of receiving area for loosely capturing the rod in
the receiver;
[0050] FIG. 34 is a diagrammatic view which is presented for
purposes of illustrating various dimensions of the channels in the
receiver or the second illustrative embodiment;
[0051] FIG. 35A is a perspective view of another embodiment of a
capless multiaxial screw and fixation assembly in accordance with
another embodiment of the invention;
[0052] FIG. 35B is a sectional view of the embodiment illustrated
in FIG. 35A;
[0053] FIG. 35C is a perspective view of sleeve or guide used in
the embodiment illustrated in FIG. 35A;
[0054] FIG. 35D is a sectional view taken along the line 35D-35D in
FIG. 35C;
[0055] FIG. 35E is a plan or top view of a sleeve or guide in
accordance with another embodiment of the invention;
[0056] FIG. 36A is a perspective fragmentary view of screw used in
the embodiment illustrated in FIG. 35A;
[0057] FIG. 36B is a plan or top view of the polyaxial screw shown
in FIG. 36A;
[0058] FIGS. 36C-36H illustrate other representative polyaxial
screw head configurations that may be used to permit maximal
polyaxial movement;
[0059] FIGS. 36I-36L illustrate various tools used to drive the
screws shown in FIGS. 36A-36H;
[0060] FIGS. 37-42 are various views of the embodiments shown in
FIG. 36A illustrating the rotation of the receiver relative to the
rod and the guide or sleeve;
[0061] FIGS. 43-46 are fragmentary sectional views illustrating
various features of the receiver in an unlocked position and a
locked position;
[0062] FIGS. 47-48 illustrate the polyaxial tilting of the receiver
and the rod engaging the screw head directly;
[0063] FIGS. 49-57 are various views illustrating various receiver
positions with and without the rod and using the intermediate
channel or embodiment of the type illustrated in FIGS. 18-34;
[0064] FIG. 58 is a fragmentary perspective view of the capless
multiaxial screw fixation assembly in accordance with the
embodiment illustrated in FIG. 35A mounted on the spinal column
having the plurality of vertebra; and
[0065] FIG. 59 is an exploded fragmentary perspective view of the
system shown in FIG. 58.
DETAILED DESCRIPTION OF THE INVENTION
[0066] Referring now to FIGS. 1-3, a capless multi-axial screw and
spinal fixation assembly 10 and method are shown. The assembly 10
comprises a screw 12 having a threaded portion 12a and a head 12b
that in the embodiment being described, has a rounded profile or
curvature, as best illustrated in FIGS. 3 and 10-13. The screw head
12b comprises a hex female opening 12c for receiving a tool (not
shown) for screwing the screw 12 into an aperture 14a of a spinal
bone 14, such as a vertebra of a spine.
[0067] As illustrated in FIGS. 1 and 2, one feature of the
invention is that it enables a user to fix a relative position of a
plurality of vertebrae, such as vertebrae 14, 16 and 18 in FIG. 1,
in a fixed and stabilized position.
[0068] The system 10 comprises a retainer or receiver 20 having a
generally cylindrical receiver wall 20c (FIG. 4) that defines an
aperture or bore 22 that traverses or extends along a receiver axis
A (FIG. 11) the entire length of the receiver 20, as best
illustrated in FIGS. 4, 10, and 12. The receiver 20 comprises a
first end 20a and a second end 20b, and although not shown, may
comprise a chamfer 21 of about 45 degrees. It should be understood
that the internal wall 20c defines a seat 20d toward the bottom of
the receiver 20 (as viewed in FIGS. 10 and 15) that is arcuate or
curved in cross section. The seat 20d has a radius or curved
surface R1 (FIG. 10). Note that a diameter or distance D1 (FIG. 10)
of bore 22 at the end 20b of the receiver or retainer 20 is
slightly smaller than both a diameter or distance D2 (FIGS. 7 and
10) of the bore 22 at end 20a and a diameter D3 (FIG. 12) of the
rounded screw head 12b so that it defines the receiver seat 20d
(FIGS. 10 and 15) for receiving or capturing the screw head 12b. In
this regard, the screw head 12b has an end 12b1 that is configured
and dimensioned to be received or captured in the seat 20d and that
can be rotated or screwed while in the bore 22 (FIGS. 10 and 15).
The end 12b2 has a curved or arcuate shape that generally
complements the shape of the seat 20d to permit polyaxial and
relative movement between the receiver 20 and screw 12.
[0069] As shown in FIGS. 3 and 11-13, the bore 22 receives the
threaded portion 12a of the screw 12 until the head 12b is received
in the seat 20d (as illustrated in FIGS. 10-13). It should be
understood that the seat 20d cooperates with the end 12b1 of head
12b and permits the retainer or receiver 20 to move polyaxially
about a center of head 12b so that position of the receiver 20 may
be altered relative to the head 12b of screw 12. This allows a
user, such as a surgeon or physician, to change the polyaxial
position of the receiver 20 relative to the screw 12 in order to
adjust an angular position of an elongated member or rod 24
relative to, for example, the vertebrae 14, 16 and 18 illustrated
in FIG. 1. The rod 24 may be any suitable shape in cross section,
such as circular, hexagonal, octagonal, polygonal or the like.
[0070] Note that the receiver 20 comprises a receiving channel or
slot 26 (FIG. 15) defined by wall surfaces 21a, 21b, 21c and 21d
(FIG. 4). The receiver 20 further comprises a lock, locking means,
locking channel, or rotary lock 28 (FIGS. 11 and 12) which is
integral with the receiver 20. In the embodiment being described,
the receiver 20 is manufactured of titanium and is machined to
provide the receiving channel 26, lock 28 and the bore 22 using
conventional machining techniques. Other potential materials
include biocompatible load bearing material, such as metals, metal
alloys, carbon fibers, composites, plastics or hybrid
materials.
[0071] In one embodiment, the lock 28 cooperates and is in
communication with the receiving channel 26 to provide a continuous
channel 30 for receiving the elongated member or rod 24. The lock
28 cooperates with the receiving channel 26 and urges rod 24 toward
the screw head 12b and vertebra, such as one of the vertebra 14-18
in FIG. 1, when the receiver 20 is rotated in a clockwise direction
(as viewed in FIG. 3). The continuous channel 30 comprises a first
channel 32, the channel 26, and the second channel 34. The lock 28
and continuous channel 30 provides a bayonet-type connection for
coupling or fixing the receiver 20, the rod 24 and screw 12
together in the manner described herein.
[0072] Note that the lock 28 comprises the first channel 32 and a
second channel 34 (FIGS. 12 and 13) that extend or spiral, as
illustrated in FIGS. 16A-16E, about the receiver axis A (FIG. 11)
of receiver 20. The first and second channels 32 and 34 generally
spiral or revolve from the first end 20a of receiver 20 toward the
second end 20b, as shown in FIGS. 10-13 and 16A-16D. Thus, in the
embodiment being described, the first and second channels 32 and 34
are non-linear and spiral or revolve in a general helix about the
axis A of the receiver 20. In the illustration, the channels 32 and
34 spiral or revolve in the same direction about the axis A, as
shown in FIGS. 16A-16D. Note that the channels 32 and 34 are in
communication with both the receiver bore 22 and receiving channel
26 of receiver 20. During operation, the channels 32 (FIG. 11) and
34 (FIG. 12) receive the rod 24 after it has been received in
channel 26 and urge or force the rod 24 toward the screw head 12b
and vertebra, such as vertebra 14 in FIG. 1, when the receiver 20
is rotated in a clockwise direction in the illustration being
described.
[0073] As illustrated in FIGS. 11 and 16A, the first channel 32 is
defined by a first surface or wall 20e, a generally opposing second
surface or wall 20g, and a third surface wall 20f that joins the
walls 20e and 20g in the receiver 20. A fourth surface or wall 20h,
a generally opposing fifth wall 20i, and a sixth surface or wall
20j that joins walls 20h and 20i cooperate to define the second
channel 34 (FIGS. 12 and 16D). Note that the walls 20e and 20g are
generally parallel and walls 20h and 20i are generally parallel. In
the illustration being described, the walls 20e and 20g and 20h and
20i are generally planar and have generally constant distance D4
(FIG. 13) and D5 (FIGS. 11 and 12) therebetween. However, in the
illustration described later herein relative to FIGS. 18-32, the
opposing walls 20e, 20g, 20h and 20i may be non-planar so that the
distance or dimensions D9 and D10 vary along the length of the
channels 32 and 34.
[0074] The channels 32 and 34 generally lay in planes P1 and P2
that are at the angles C (FIG. 14) and D, respectively, relative to
the axis A of the receiver 20. As described later herein, the walls
20e and 20h engage and cam against the rod 24 and force or urge it
downward (as viewed in FIGS. 10-15) in response to the rotary
movement of the receiver 20. In another embodiment described later
herein, the walls 20e and 20g and walls 20h and 20i may comprise a
curved or arcuate area and may cooperate to define an intermediate
rod capturing area, as described below relative to FIGS. 18-34.
[0075] As illustrated in FIGS. 4 and 11, note that the channel 32
is defined by the walls 20e, 20f, 20g and generally curved or
arcuate wall portion 50 that couples wall 20g to surface 21b (FIGS.
4 and 16A) of channel 26. The generally curved arcuate wall portion
50 also generally defines an intersection or transition from the
receiving channel 26 to the first locking channel 32 of lock 28.
The channel 34 is defined by 20h, 20i and 20j and a third generally
curved or arcuate wall 52 that joins the wall 20i to walls 21d
(FIGS. 4 and 16C). The wall 52 provides an intersection or
transition between channel 26 and the second locking channel 34.
Notice that the wall portions 20f (FIG. 11) and 20j (FIG. 12) also
each have a radius of curvature that generally complements the
radius of curvature or circumference of the rod 24 so that when the
rod 24 is moved from the unlocked position (illustrated in FIGS. 4,
5, 10 and 11) to a locked position (illustrated in FIGS. 8, 9, 12
and 13), the rod 24 is received and positioned against the wall
portions 20f and 20j as shown.
[0076] The system 10 may further comprise a compression member 40
(FIGS. 3 and 17). The compression member 40 comprises a wall 40a
that defines a second generally U-shaped receiving channel 42. The
compression member 40 also comprises a frusto-conical seat or
concave area 41 (FIGS. 10 and 17), defined by a tapered wall or
surface 40b, that engages the rounded shape of the end 12b1 (FIG.
3) of screw head 12b. Although not shown, the system 10 could be
provided without the compression member 40, so that the rod 24
would engage the screw head 12b directly, for example, when the
receiver 20 is rotated as described later herein.
[0077] The compression member 40 comprises a length D6 (FIGS. 3 and
17) and a diameter D7 (FIG. 17) dimensioned to be received in the
bore 22 as shown. The channel 42 defined by wall 40a comprises a
bottom surface 40c. The channel 42 is generally U-shaped in cross
section and has a width or dimension D8 (FIGS. 3, 7 and 17) and
surface 40c comprises a radius of curvature R5 (FIG. 17) that
generally complements or is slightly larger than the circumference
D9 (FIG. 3) of the rod 24.
[0078] During operation, the compression member 40 is urged
downward (as shown in FIGS. 10-13) in response to the rotary
movement of the receiver 20. The rod 24 engages the bottom surface
40c (FIGS. 12 and 17) of channel 42 of compression member 40. This
in turn causes surface 40b to engage and apply a compressive force
against the end 12b1 of screw head 12b as the rod 24 is driven in
the downward direction (as viewed in FIGS. 10-13) and into the
second channel 42. This movement forces and compresses the seat 20d
against the end 12b2 of screw head 12b of the receiver 20, thereby
locking the screw head 12b to the rod 24 and fixing the
relationship of the receiver 20 relative to the screw head 12b.
[0079] Note that the compression member 40 (FIG. 17) also comprises
a bore or aperture 43 defined by wall 40d. The bore 43 has a
dimension or diameter D10 (FIG. 17). A surgeon or physician may
insert a tool, such as a hex head screwdriver (not shown), through
channel 26, through bore 22 of receiver 20 and through the bore 43
and into the hex female opening 12c (FIG. 15), for example, to
tighten or loosen the screw 12. Thus, it should be understood, as
illustrated in FIG. 15, that the hex female opening 12c of screw
12b is accessible after the screw 12 is inserted through the bone
22 and compression member 40 is situated in the bore 22.
[0080] Referring back to FIGS. 10-16E, the receiving channel 26
(FIG. 11) of receiver 20 extends from an end 20a of receiver 20 in
an axial direction and lies in a plane P3 (FIG. 15) that is
generally planar and extends downward along the axis A (as viewed
in FIG. 14). In contrast, the lock 28 defined by the locking
channels 32 and 34 revolve, spiral or extend laterally or radially
at distances that are generally constant relative to axis A and
that vary, such as increase, relative to end 20a of receiver 20. As
mentioned earlier, each of the channels 32 and 34 spiral in a
general helix downward from the receiving channel 26 and about the
axis A of the receiver 20 as shown in FIGS. 10-13 and 16A-16D. Note
that the channels 32 and 34 lay in the planes P1 and P2 (FIG. 14),
respectively, that intersect axis A at the predetermined angles
indicated by double arrows C and D. The predetermined angles C and
D are acute angles in the embodiment being described.
[0081] As shown in FIGS. 16A and 16B, the channel 32 is inclined
relative to a radial line of receiver 20 at a third angle
(indicated by double arrow E in FIG. 16A) relative to end 20a.
Channel 34 is also inclined relative to a radial line at a fourth
angle F (FIG. 16B). Although not shown, it is contemplated that
other designs, configurations or arrangements of channels 32 and 34
and the lock 28 may be provided, such as channels (not shown) that
extend about axis A, but that do not spiral and/or that are not at
the inclined angles E and F, such as channels that extend at
distances that are generally constant relative to end 20a.
[0082] An operation or method regarding this illustration will now
be described. As illustrated in FIGS. 3-9 and 15, the screw 12,
together with receiver 20 are screwed into vertebra 14 during which
a physician or surgeon screws the threaded portion 12b of screw 12
in the aperture 14a of the vertebra 14 using a tool (not shown),
such as a hex wrench or screwdriver (not shown), that is inserted
through channel 26, bore 22 and bore 43. In one embodiment, the
receiver 20, screw 12 and compression member 40 may be provided in
a pre-assembled unit prior to surgery, so no assembly is required
by the physician. The screw 12 is screwed substantially all the way
into vertebrae 14, but is left with space between the receiver 20
and vertebrae 14 so that an angular or polyaxial position of the
receiver 20 may be adjusted or changed during the operation.
[0083] The channel 26 of receiver 20 and channel 42 of compression
member 40 are provided or arranged in a common plane P3, as shown
in FIGS. 4, 5 and 15. The surgeon then places the rod 24 into the
channels 26 and 42 and adjusts the multi-axial or polyaxial
position of the receiver 20 relative to the rod 24. As mentioned
earlier, the channel 26 and bores 22 (FIG. 10) and 43 (FIG. 17)
provide a continuous opening or area 49 through which the physician
or surgeon may insert a tool, such as a hex tool, to turn, rotate
and/or tighten or loosen the screw 12 in the desired direction
prior to placing the rod 24 into channel 26. At this point, the rod
24 remains in an unlocked position.
[0084] Note that the rod 24 is supported by and between the arcuate
or rounded wall portions 50 and 52, which causes the rod 24 to be
situated above the bottom surface 40c of the channel 42 of
compression member 40, as illustrated in FIGS. 10 and 11. Note that
the arcuate or curved wall portions 50 and 52 each comprise a
radius of curvatures R2 (FIGS. 11, 14 and 16a) and R3 (FIGS. 13 and
14), respectively, that generally complements or is larger than a
radius of curvature or circumference of the rod 24, as illustrated
in FIGS. 11 and 13.
[0085] The camming or bayonet type action of the rotary lock 28 on
receiver 20 forces the rod 24 in an axial direction parallel with
axis A of receiver 20 when the receiver 20 is turned or rotated
with a tool, such as a screwdriver (not shown), placed in channel
26, as illustrated in FIGS. 6 and 7. This rotary movement or action
forces the rod 24 downward (as viewed in FIG. 10) and into the
channels 32 and 34. As the receiver 20 is rotated further, as shown
in FIGS. 8 and 9, the walls 20e and 20g (FIG. 11) of channel 32 and
walls 20h and 20i (FIG. 12) of channel 34 act upon, force or urge
the rod 24 downward (as viewed in FIGS. 10-13) and into the second
channel 42 of compression member 40 until it engages the surface
40c of compression member 40. As the receiver 20 is rotated
further, the rod 24 urges the compression member 40 toward the
screw head 12b1 and forces wall 40b of the compression member 40
against the screw head 12b of screw 12 with a compressive force
which causes the screw head 12b to become fastened or locked to the
rod 24, thereby fixing the receiver 20 and rod 24 to the screw
12.
[0086] It should be appreciated that when the rod 24 is in the
locked position shown in FIGS. 8, 9, 12 and 13, the rod 24 engages
surfaces 20e, 20f, and 20g of channel 32 and surfaces 20h, 20i and
20j of channel 34 and surface 40c of second channel 42. The seat
40d of compression member 40 engages screw head 12b2. These
surfaces cooperate to retain rod 24 in the locked position. The
surfaces 20f and 20j comprise a radius of curvature R4 of about
.PHI..100-.PHI..130 inch. A raised detent portion or bump 59 (which
is only shown in FIG. 13 for ease of illustration) may be provided
in each channel 32 and 34, as shown in FIG. 13 relative to channel
32. The detent 59 is provided to facilitate retaining the rod 24 in
the locked position.
[0087] Thus, as illustrated in FIGS. 1, 2 and 4-9, a surgeon may
use one or a plurality of spinal fixation assemblies 10 during a
spinal fixation procedure. For example, the surgeon may use a
plurality receivers 20 and screws 12 with one rod 24, as
illustrated in FIGS. 1 and 2. In the illustration, the surgeon
screws the screws 12 into a plurality of vertebrae, such as
vertebrae 14, 16 and 18 illustrated in FIG. 1, and generally aligns
the channels 26 of receivers 20. The surgeon then inserts the tool,
such as a hex tool (not shown), through bores 22 and 43 and into
female slot 12c in screw head 12 and screws the screw 12 until the
bottom 20b of the receiver 20 engages or is proximately located
against its respective vertebra.
[0088] If the compression member 40 is being used, compression
member 40 is located in each bore 22 of each receiver 20 and
generally aligns the channels 42 and 26, as illustrated in FIGS. 4,
10 and 15. It should be understood that when the spinal fixation
assembly 10 is in the unlocked position, the channels 26 and 42 are
generally parallel or lie in the common plane P3 as shown in FIG.
15. The rod 24 is then placed in channel 26, whereupon it becomes
supported by walls 50 and 52 (FIG. 4) and by wall portions 50 and
52 (FIGS. 4 and 11). This causes rod 24 to be supported slightly
above the bottom 40c of channel 42 of receiver 40, as mentioned
earlier and as illustrated in FIGS. 10 and 11.
[0089] At this point in the procedure, the surgeon aligns the rod
24 in the receiver 20 to the desired position relative to the
spine, vertebrae and other receivers 20 that are being used. He
positions the rod 24 and polyaxial or angular position of each
receiver(s) 20 relative thereto. It should be understood that the
screws and position of the vertebrae, such as vertebrae 14-18,
relative to each other may also be adjusted. Once the bones 14-18
are adjusted and angular or polyaxial position of each receiver 20
is adjusted, the surgeon locks each receiver 20 to rod 24 by
rotating or turning the receiver 20 with a tool, such as a
screwdriver (not shown), placed in slot 26. This causes the
receivers 20 to become fixed or locked onto their respective screws
12 and the spinal bones 14-18 (FIG. 1) to become aligned and fixed
into the desired position.
[0090] It should be understood that before the rod 24 is placed in
the receiving channel 26 and the receiver 20 is rotated, the
surgeon may tighten one or more screws 12 to a tighter or fixed
seated position by situating the tool, such as a hex wrench (not
shown), through the aperture 43 (FIG. 15) defined by the wall 40d
of the compression member 40 and into the hexagonal female slot 12c
in the screw head 12b. After the screw 12 is tightened to the
desired tightness or torque, the surgeon places the rod 24 into the
channels 26 and 42 (FIGS. 4, 5, 10 and 11) of the one or more of
the receivers 20 being used.
[0091] As mentioned, the surgeon rotates the receiver 20 about its
axis, as illustrated in FIGS. 3, 6 and 7 using a tool, such as a
screwdriver (not shown), in the clockwise direction, as illustrated
in FIGS. 6 and 7. During this rotation of receiver 20, the
compression member 40 and rod 24 do not rotate. As alluded to
earlier, walls 20e and 20g (FIG. 11) and walls 20h and 20i (FIG.
12) urge the rod 24 toward the bottom of channels 32 and 34 and
urge the rod 24 to move downward (as viewed in FIGS. 10 and 12)
toward the surface 40c or bottom of the channel 42 where it engages
the surface 40c, as illustrated in FIGS. 4-9 and 10-13. The rod 24
is also supported by and compresses against the surface 40c of
compression member 40. The seat 40d is caused to engage the screw
head 12b2.
[0092] Thus, when it is desired to lock the receiver 20 and the
screw 12 to the rod 24, the surgeon rotates the receiver 20 in the
clockwise direction, as illustrated in FIGS. 6 and 7, using the
conventional tool, such as a regular screwdriver. The receiver 20
is rotated until it is moved from the unlocked to the locked
position, as illustrated in FIGS. 8, 9, 12 and 13. Note that in the
locked position, the rod 24 is received and engages the walls 20f
and 20j associated with the ends of channels 32 and 34,
respectively.
[0093] Thus, it should be understood that when receiver 20 is
rotated, the walls 20e and 20h provide the camming force necessary
to cam and urge the rod 24 against the receiver 40. This, in turn,
causes the surface or wall 40b of receiver 40 to compress and lock
against the end portion 12b2 (FIG. 3) of screw head 12b. The wall
40b of compression member 40 cooperates with the curved seat
defined by wall 20d (FIG. 10) and traps or locks the screw head 12b
to the rod 24.
[0094] As illustrated in FIGS. 8, 9, 12 and 13, notice that the
channel 26 lies in an imaginary plane that is generally
perpendicular to the imaginary plane in which the channel 42 and an
axis of rod 24 when the receiver 20 is in the locked position.
[0095] It should be appreciated from the foregoing that the
receiving channel 26 is in communication with the channels 32 and
34 of lock 28 and that the lock 28 cooperates with the rod 24 to
not only lock the rod 24 to the screw 12, but also to fix a
position of the vertebrae 14, 16 and 18.
[0096] When it is desired to unlock the rod 24 from the screw 12,
the surgeon simply rotates the receiver 20 in a counterclockwise
direction in the illustration and reverses the procedure.
[0097] Referring now to FIGS. 18-34, another illustrative
embodiment is shown. Those parts that are the same as the parts
relative to FIGS. 1-17 have been labeled with the same part number,
except that the part numbers in the embodiment described in FIGS.
18-34 have a prime mark ("'") associated therewith. The FIGS. 31-34
are diagrammatic enlarged sectional views for ease of
illustration.
[0098] Note in the embodiment in FIGS. 18-34, the receiver 20'
comprises channels 32' and 34' that each have a cross-sectional
dimension that varies over the length of the channels 32' and 34'
to provide an intermediate holding area 60 where the rod 24' is
loosely captured in the channels 32' and 34'. The channels 32' and
34' each have an introducing area 60a, an intermediate holding or
receiving area 60b and a locking area 60c. For ease of illustration
and description, the receiving area 60b will be described relative
to channel 32'; however, it should be understood that the channel
34' in the second illustration comprises substantially the same
configuration.
[0099] It should be appreciated that the intermediate area 60b in
the channels 32' and 34' enable an intermediate step between
initial rod 24' insertion and final rod 24' locking. In other
words, this is a rod 24' capturing step during which the rod 24' is
loosely captured in the receiver 20', but it is not rigidly locked
into place against screw 12' yet. This allows the surgeon greater
ease and flexibility when he adjusts the screws 12' position with
respect to the rod 24' while the rod 24' is in place. For example,
the surgeon may move the screws 12' closer together (compression)
or In the illustration being described, the intermediate capturing
step is accomplished by rotating the receiver 20' partially, such
as approximately 30 degrees in the illustration as shown in FIGS.
23, 26 and 29, which forces the rod 24' from the introducing area
60a into the intermediate area 60b.
[0100] The introduction area comprises an associated dimension D13
(FIG. 34) and the locking area 60c has an associated dimension D14
(FIG. 34). The intermediate area 60b has an associated intermediate
dimension D15 (FIG. 34) between the wall 62 and wall 64 that is
slightly larger than the diameter of the rod 24' and the dimensions
D13 and D14 associated with the introduction area 60a and locking
area 60c, respectively. It is dimensioned to accommodate the rod
24' and to capture the rod 24' loosely so that the rod 24' can
easily slide between the walls 62 and 64 and is not locked. This
facilitates the surgeon adjusting a position of the screws 12' in
vertebrae, such as vertebrae 14'-18', relative to a position of the
rod 24. Once the screws 12' are adjusted to the desired position,
the physician or surgeon may then lock the receiver 20' onto the
screw 12' by inserting a tool, such as a screwdriver (not shown),
into the slot 26' and rotate the receiver 20' in the clockwise
direction as illustrated in FIGS. 22-30.
[0101] In the illustration shown in FIGS. 31-34, the channel 32' is
defined by a wall 62, a generally opposing second wall 64 and a
joining wall 63 that joins walls 62 and 64 as shown. Note that
unlike the embodiment described relative to FIGS. 1-17, the channel
wall 62 has a first wall portion 62a, a second wall portion 62b and
an intermediate wall portion 62c that couples the wall portions 62a
and 62b as shown. The opposing channel wall 64 comprises the first
wall portion 64a, a second wall portion 64b and an intermediate
wall portion 64c that couples the first and second wall portions
64a and 64b as shown. In this regard, note that an intersection 66
is defined between the wall portions 64a and 64c. A second
intersection 68 is defined between the wall portion 62b and 62c as
shown. The intersections 66 and 68 generally define an entrance to
the intermediate area 60. The intermediate wall portions 62c and
64c cooperate to define the intermediate area 60b which receives
the rod 24' and loosely captures the rod 24' in the receiver
20'.
[0102] The channels 32' and 34' are configured such that they
comprise or define the introduction area 60a for receiving the rod
24' in the receiver 20', as illustrated in FIGS. 22, 25 and 28. The
first wall portion 64a provides a ramp 64a1 for directing the rod
24' into the intermediate area 60b when the receiver 20' is rotated
about 20-40 degrees as shown in FIGS. 23, 26 and 29. As shown in
the illustration, the surfaces 62 and 64 are not generally planar
and have areas, such as intermediate wall portions 62c and 64c that
are curved or recessed to facilitate defining the intermediate area
60b.
[0103] During a surgical procedure, the surgeon may make the
desired adjustments of the rod 24' relative to the screws 12' and
vertebrae 14'-18' while the rod 24' is loosely captured in the
intermediate area 60b. The surgeon then uses the tool, such as a
screwdriver (not shown), to rotate the receiver 20' to the locked
position shown in FIGS. 24, 27 and 29. Similar to the embodiment
described earlier herein relative to FIGS. 1-17, the receiver 20'
urges or forces the rod 24' from the intermediate area 60b to the
locking area 60c. The rod 24' becomes situated in the locking area
60c, whereupon the rod 24' becomes locked therein. Note that the
distance or dimension D12 (FIG. 8) between the second wall portions
64b and 62b is substantially the same or may be smaller than the
diameter of the rod 24'. As the receiver 20' is rotated in the
clockwise direction in the illustration being described, the wall
62 slightly deflects upward (as viewed in FIG. 31, for example) to
permit the rod 24 to be captured and locked in the locking area
60c. Note that a wall portions 62, 63 and 64 comprises various
radii of curvature R5-R9 having the illustrative dimensions or
ranges of dimensions set forth in the Table I below. For example,
the radius of curvature R8 generally corresponds to the cross
sectional circumference of the rod 24' so that the rod 24' becomes
captured in the locking area 60c. As in the prior illustration, the
detent 59 (FIG. 33) may be provided in channels 60 and 62 to
further facilitate retaining the rod 24' in the locking area
60c.
[0104] Advantageously, this system and method facilitates providing
a locking receiver 20 that reduces or eliminates the need for
threading, internally or externally.
[0105] Advantageously, the immediate areas 60b of channels 32' and
34' of the second embodiment are dimensioned and configured to
facilitate locking the rod 24' onto the screws 12' while permitting
ease of adjustment between the receiver 20' and the rod 24' when
the rod 24' and receiver 20' are situated in the intermediate area
60b', as illustrated in FIGS. 23, 26 and 29.
[0106] In the embodiments being described, the rod 24, screw 12,
receiver 20 and compression member 40 are all made of titanium
alloy. Other materials may be used such as metals, metal alloys,
carbon fibers, composites, plastics or hybrid materials.
[0107] For example, the screw 12 may have a length D11 (FIG. 3)
ranging from 10 mm-60 mm, and the receiver 20 may have a diameter
D12 (FIG. 8) ranging between 2 mm-10 mm. The compression member 40
may define the channel 42 having the width D8 ranging between 2
mm-12 mm. The channels 32 and 34 may comprise dimensions D5, D6
(FIGS. 3 and 17) ranging between 2 mm-10 mm. It should be
understood, however, the other shapes and dimensions may be used
without departing from the true spirit and scope of the
invention.
[0108] Referring now to FIGS. 35-59, another illustrative
embodiment is shown. As with prior embodiments, those parts that
are the same or similar to the parts shown and described relative
to FIGS. 1-34 have been labeled with the same part number, except
that the part numbers described in FIGS. 35-59 have a double prime
number ("''"). As with the prior embodiments, the FIGS. 35-59 are
diagrammatic in large sectional views for ease of illustration.
[0109] In the embodiment being described, an assembly or system
100'' is shown. As illustrated in FIGS. 58 and 59, the assembly
100'' may be used alone or in combination with other assemblies
100'', with one or more of the assemblies 10 of the embodiments
described earlier herein, or with other spinal fixation devices or
assemblies (not shown). As with prior embodiments, the function of
the assembly is to fix or secure one or more bones, such as the
vertebrae 14'', 16'' and 18'' in the spinal column illustrated in
FIG. 58, in a fixed and stabilized position relative to each other.
As with the prior embodiments, it should be understood that the
embodiment could be used in any environment where it is desired to
fix and stabilize one or more bones or bone segments together.
[0110] In the embodiment illustrated in FIGS. 35-59, note that the
receiver 20'' is substantially the same as in the prior embodiments
shown and described relative to FIGS. 1-34. Also, it should be
understood as with the embodiments illustrated in FIGS. 1-16E, the
embodiment could comprise a substantially straight or planar
channel 32 and 34, alternatively, it could comprise the stepped or
multidimensional channels 32' and 34' (FIGS. 17-34) in receiver
20'. The channels 32' and 34' have a cross-sectional dimension that
varies over the length of the channels 32' and 34' to provide the
intermediate holding area 60' where the elongated member or rod 24'
is loosely captured in the channels 32' and 34'. As mentioned
earlier, the channels 32' and 34' each have the introducing area
60a', the intermediate holding or receiving area 60b' and the
locking area 60c'. The channels 32' and 34' of the embodiment
illustrated in FIGS. 18-34 receive the rod 24' and facilitate
positioning of the rod 24' to the spinal bones, such as bones 14',
16' and 18', prior to the receiver 20' being rotated to the locked
position as being described herein. Channel 32'' and 34'' may have
configurations that are the same or similar to the channel 32, 32',
34, and 34'.
[0111] Referring now to FIGS. 35A and 35B, the system 100''
comprises a stabilizer, intermediate member, second receiver, guide
or sleeve, which shall be referred to as guide or sleeve 104'' for
ease of description, rather than a compression member 40'' of the
type shown in FIGS. 1-34. The guide or sleeve 104'' is received in
the bore 22'' of receiver 20'' and is adapted to receive the rod
24'', which may be cylindrical and elongated as illustrated. In the
embodiment illustrated in FIGS. 35A-59, it should be understood
that the sleeve 104'' is adapted and dimensioned to be received in
the aperture or bore 22'' defined by the receiver wall 20c''. The
guide 104'' is a guide or sleeve that is slidable and rotatable in
the bore 22''.
[0112] The guide 104'' comprises or defines a bore 110'' (FIGS. 35A
and 35E) in communication with a channel 121'' that receives the
rod 24'' and facilitates aligning the rod 24'' in the receiver
20''. In this regard, the sleeve 104'' guides the rod 24'' into the
receiving channel or slot 26'' of the receiver 20''. After the
receiver 20'' is rotated as described herein, the rod 24'' is
cammed, urged or moved toward a head 102a'' of a polyaxial screw
102'' when the receiver 20'' is rotated to the locked position
illustrated in FIGS. 45 and 46. Unlike the embodiment of FIG. 1,
note that the screw 102'' has a ball or head 102a'' that has a full
radius. The full radius and bore 110'' are adapted or dimensioned
such that at least a part of the head 102a'' extends into the bore
110''. The operation and use of the assembly 100'' will be
described in more detail later herein.
[0113] It should be understood that in this illustrative
embodiment, the guide or sleeve 104'' does not function as a
compression member like the compression member 40 and 40' described
earlier herein. Thus, one feature of this embodiment is that the
rod 24'' engages and compresses directly against at least a portion
of the head 102a'' after the receiver 20'' is rotated to the locked
position as described herein.
[0114] The sleeve or guide 104'' comprises a first wall portion
112'' and a generally opposed second wall portion 114'' that are
curved about an axis B (FIG. 35B) of the guide 104'' (FIG. 35B).
The guide or sleeve 104'' comprises generally cylindrical joining
portions 117'' and 119'' that join the first and second wall
portions 112'' and 114'' as illustrated in FIG. 35A. The wall
portions 112'' and 114'' cooperate with the joining portions 117''
and 119'' to define the channel 121''. A pair of edges 112a'' and
114a'' (FIG. 35C) cooperate with joining portion 119'' to define a
first channel opening 111'' to channel 121''. A second pair of
edges 112b'' and 114b'' cooperate with joining portion 117'' to
define a second channel opening 113'' to the opening 121'' for
receiving the rod 24''.
[0115] The guide or sleeve 104'' comprises the bore 110'' having an
inner diameter D16 (FIG. 35D). As illustrated in FIG. 35D, the wall
portions 112'' and 114'' have inner surfaces 112c'' and 114c'',
respectively, that lie in a generally cylindrical or curved plane
and have a diameter D17 (FIG. 35D) that generally corresponds to a
diameter of bore 110''. In the illustration being described, the
channel 121'' has a channel width D18 (FIG. 35E) that generally
corresponds to the diameter of the bore 110''. Unlike the
embodiment illustrated in FIG. 17 described earlier herein, notice
that the bore 110'' is in fluid communication with the channel
121'' and has the dimension D16 that generally corresponds to
dimension D18. Thus, in the illustration being described, the bore
110'' has the dimension B16 (FIG. 35D) that is generally constant
along its length and the diameter of the bore 110'' generally
corresponds or is smaller than the distance between walls 112'' and
114''. In contrast, in the embodiment of FIGS. 1-34, the
compression member 40'' comprises the wall 40b'' that is curved or
tapered inwardly and the dimension D10 is smaller than the
dimension D8.
[0116] Notice that the first wall portion 112'' comprises a first
end 112d'' having a chamfer surface and the second wall portion
114'' comprises a second end 114d'' having a chamfer surface as
shown. The chamfer ends 112d'' and 114d'' facilitate guiding the
rod 24'' into the receiving area 22'' and channel 121'' as
described herein.
[0117] A second end 104b'' (FIG. 35D) of the receiver 104''
comprises a surface 105'' in the wall portions 112'' and 114'' and
the joining portions 117'' and 119'' that define a generally
continuous frusto-conical surface in cross-section that extends
around the bore 110'', as shown in FIGS. 35A and 35E.
Alternatively, surface 105'' could comprise a curved, semispherical
or spherical shape in cross-section or otherwise be shaped to
complement a shape of the screw head 102a''.
[0118] The first wall portion 112'' and generally opposed second
wall portion 114'' have outer surfaces 112d'' and 114d'' that lie
in a cylindrical or circumferential plane that is generally
cylindrical and adapted and dimensioned to be slidably and
rotatably received in the bore 22'' defined by the wall 22c'' of
the receiver 20'', as illustrated in FIGS. 37-57.
[0119] Notice that edges 112a'', 112b'' and 114a'', 114b'' of the
wall portions 112'' and 114'', respectively, and surfaces 117a''
(FIG. 35A) and 119a'' (FIG. 35B) of the joining portions 117'' and
119'', respectively, cooperate with the surface 112c'' of first
curved wall portion 112'' and the surface 114 c'' of the second
curved wall portion 114'', respectively, to define the channel
121'' (FIGS. 35C-35E). The guide or sleeve channel 121'' receives
the rod 24'' as described herein. The surfaces 112c'' and 114c''
could be curved as illustrated in FIGS. 35A-35C or they could be
straight or generally planar, as illustrated in FIGS. 35D and
35E.
[0120] As illustrated in FIGS. 35D-35E, the joining portions 117''
and 119'' each have a dimension D17. The dimension D17 and the
dimension D16 (FIG. 35D) of bore 110'' and shape or radius of head
102a'' are adapted and dimensioned so that at least a portion of
the polyaxial screw head 102a'' protrudes or extends at least
partly into the bore 110'' and into channel 121'' above a plane P5
(FIG. 35E) defined by surfaces 117a'' (FIG. 35C) and 119a'' (FIG.
35D). As will be described later herein, this permits or enables
the rod 24'' to directly engage and compress against at least a
portion, such as a portion or area 120'' (FIG. 36A), of the head
102a'', so that the rod 24'' can become locked directly against the
head 102a'' when the receiver 20'' is rotated as described
herein.
[0121] Notice in FIGS. 35A-35B and 36A and 36B that the head 102a''
has the first engaging surface or contact area 120'', which in the
illustration being described is generally centrally located along
an axis SA (FIGS. 35A and 36A) of a threaded portion 102b'' (FIG.
35A) of the screw 102''.
[0122] The overall shape or configuration of an outer surface
102a1'' (FIG. 36A-36B) of the head 102'' is generally curved,
arcuate or spherical. Notice in FIG. 36B that the head 102''
comprises a plurality of recessed areas 122'', 124'', 126'' and
128'' that are separated by or define a plurality of curved
portions or walls 130'', 132'', 134'' and 136'' as shown. Notice
that the curved walls 130'', 132'', 134'' and 136'' are joined by a
generally cylindrical post or portion 138'' that cooperate to
define a male member 129'' that extends upwardly (as viewed in FIG.
35A) from a plane P4 (FIG. 35B) defined by the surfaces 140'',
142'', 144'' and 146'' (FIG. 36B).
[0123] In the illustration being described, the engaging surface or
portion 120'' has a surface 120a'' that is curved in the
illustration being described. The walls 130'', 132'', 134'', and
136'' each have surfaces or portions 150'', 152'', 154'' and 156'',
respectively, that are also curved in the illustration being
described.
[0124] It should be understood that the head 102a'' may comprise
any suitable configuration or surface shape as may be necessary to
permit the at least a portion 120'' of the head 102a'' to engage or
be engaged by the rod 24''. Although not shown, if the rod 24'' had
a non-curved surface, then it may be desirable to provide a head
(not shown) having a shape that is adapted to directly complement
and engage the non-curved surface. For example, if the rod 24''
were hexagonal, octagonal, square or rectangular in cross section,
then the head 102a'' may have a mating or engaging portion to
facilitate directly engaging the rod 24'' when the receiver 20'' is
moved or rotated to the locked position. Moreover, a radius of
curvature of each of the surfaces 120a'', 150'', 152'', 154'' and
156'' may be generally constant, may vary over its surface, or may
be non-constant if desired. Also, the curvatures or shapes of the
surfaces may be larger or smaller if desired, and they may be
different among them.
[0125] The surface 105'' may be straight or it may comprise a
curvature, arcuate or spherical shape in order to adapt to and
complement the curvature or shape of the head 102a'' and/or
surfaces 150'', 152'', 154'' or 156'' as shown.
[0126] As illustrated in FIGS. 43 and 44, notice that the rod 24''
is received in the receiving area or channel 22'' in the area 110''
and channel 121'' (FIG. 43). The rod 24'' becomes positioned in the
receiver 20'' and against the generally curved or arcuate wall
portions 50'' and 52'' of receiver 20'' as shown. After the
receiver 20'' is rotated from the unlocked position, illustrated in
FIGS. 43 and 44, to a locked position, illustrated in FIGS. 45 and
46, the rod 24'' becomes cammed or urged downward (as viewed in the
Figures) until at least a portion of the rod 24'' engages at least
a portion of the head 102a'', such as one or more of the surfaces
120a'', 150'', 152'', 154'', or 156'' as shown. For example, notice
in FIGS. 45 and 46 that the rod 24'' engages the surface 120a''.
Note that the receiver 20'' cams, urges or forces the rod 24''
downward (as viewed in the FIGS. 45 and 46) until the rod 24''
engages the surface 120a'' and thereby locks the rod 24'' to the
head 102'' after the receiver 20'' is rotated to the locked
position shown in FIGS. 45 and 46.
[0127] As mentioned earlier, the arcuate or curved wall portions
112c'' and 114c'' cooperate with the joining portions 117'' and
119'' to define the aperture or bore 110''. As mentioned earlier
herein, note that the dimension D16 generally corresponds to or is
generally the same as the dimension D18 (FIG. 35E) between the
surfaces 112c'' and 114c'' of walls 112'' and 114'', respectively,
but it could be smaller or larger so that it is adapted and
dimensioned to permit at least a portion of the head 102a'' to be
engages by the rod 24''.
[0128] The dimensions D16 (FIG. 35D), and D18 (FIG. 35E) and the
guide or sleeve member 104'' are selected, adapted and configured
to permit at least a portion, such as the engaging portion 120a''
and/or all of or at least a portion of one or more of the surfaces
of 150'', 152'', 154'' and 156'' to extend through the aperture or
bore 110'' and into channel 121'' and above the plane P5 (FIG.
35D). Thus, the adaptation or configuration of the guide or sleeve
112'', bore 110'' and channel 112'' permits at least a portion of
the head 102a'' to protrude or extend into the channel 121'' so
that it may engage or be engaged by rod 24'' when the receiver 20''
is rotated to the locked position illustrated in FIGS. 45 and
46.
[0129] Unlike prior embodiments described herein, notice that no
compression member 40 is necessary in this embodiment, and although
not shown, the guide or sleeve 104'' is also optional in this
embodiment. In the illustration being described, the guide or
sleeve 104'' comes into direct contact with the head 102a'' of the
screw 102'' when the receiver 20'' is rotated to the locked
position, but the sleeve 104'' itself does not compress against the
head 102a'' to lock the rod 24'' to the head 102a'' as does the
compression member 40'' in the embodiments illustrated in FIGS.
1-34, for example.
[0130] It should be understood that the embodiment being described
relative to FIGS. 35A-59, may be used with a receiver 20 having
channels 32 and 34 of the type shown in FIGS. 1-16E. Alternatively,
the embodiment may be used with a receiver 20' having the channels
32'' and 34'' having the steps or channel areas that are of the
type shown in FIGS. 18-34, namely channels 32'' and 34'' that each
have a cross-sectional dimension that varies over the length of the
channels 32'' and 34''. As mentioned earlier, such shape
facilitates providing the intermediate holding area 60'' where the
rod 24'' is loosely captured in the channels 32'' and 34''. The use
of and installation of the system 100'' is similar to the use and
installation of the embodiments earlier relative to FIGS. 1-34,
which will now be described.
[0131] As with the prior embodiment and as illustrated in FIGS. 1
and 2, one or more of the assemblies or systems 100 may be used
during a surgical procedure as shown in FIGS. 58 and 59. For
example, the surgeon may use a plurality of receivers 20'' and
screws 102'' with a rod 24'' similar to the illustration shown in
FIGS. 1 and 2. In the illustration being described relative to the
embodiment of FIGS. 35A-59, the surgeon positions the screw 102''
into bore 110'' and screws the screws 102'' for each assembly 100''
into each of the plurality of vertebrae, respectfully, such as
vertebrae 14'', 16'' and 18'' illustrated in FIG. 58. He then
situates the guide or sleeve 104'' into bore 22'' and generally
aligns the channel 121'' of the sleeve or guide 104'' with the
receiving channel 26'' of the receiver 20'' as illustrated in FIGS.
37, 38, 43, 44, 49 and 55. The surgeon then inserts a tool 125''
(FIG. 36I) that is capable of rotatably driving the screw 102''
into bone or into the bore 110'' and drives screw 102'' until the
bottom 20b'' of the receiver 20'' engages or is approximately
located adjacent to or against its respective vertebrae.
[0132] Note that the guide sleeve 104'' is located in the bore 22''
of the receiver 20'' and provides a guide for the rod 24'' to
become aligned and positioned in receiver 20'', as illustrated in
FIGS. 37, 43-46, 49-51 and 55-57. The walls 112'' and 114'' of the
guide or sleeve 104'' perform lateral stabilization and alignment
of the rod 24''. It should be understood that when the assembly
100'' is in the unlocked position (as illustrated, for example, in
FIGS. 37, 38, 43, 44, 49 and 55), the channels 121'' and 26''
become generally parallel and lie in a common plane P6 (FIG. 38).
After the rod 24'' is placed in the channels 26'' and 121'', it is
supported by the walls 50'' and 52'' of receiver 20 and between
walls 112'' and 114'', as best illustrated in FIGS. 43 and 44. This
causes the rod 24'' to be supported slightly above the surfaces
117a'' (FIG. 35C) and 119a'' (FIG. 35D). As mentioned earlier, the
shape and configuration of screw head 102a and the dimension of
bore 110'' allows for the screw ball or head 102a'' to protrude
through the bore 110''. The lower portion 102c'' has been further
truncated or indented to allow for maximal exposure of the
screw-ball.
[0133] As mentioned earlier herein, the receiver 20'' may have
generally straight channels 32'' and 34'' of the type illustrated
in FIGS. 18-32 or channels of varying dimensions of the type
illustrated in FIGS. 49-57, in which case the rod 24'' would be
positioned in the receiver 20' as illustrated in FIGS. 49 and 55.
For ease of discussion, it will be assumed that receiver 20''
comprises the channels 32'' and 34'' of the type illustrated in
FIGS. 37-42.
[0134] After the screw(s) 102'' are screwed into the bone a desired
distance and the guide or sleeve 104'' is inserted into the
receiver 20'', the surgeon aligns the rod 102'' in the receiver
20'' to the desired position relative to the spine, vertebrae or
bone and also relative to one or more other receivers 20'', if any,
that are being used during the procedure. It should be understood
that the screws 102'' and the position of the vertebrae 14''-18'',
relative to each other may be adjusted by the surgeon. Once the
bones 14''-18'' are adjusted and the angular or polyaxial position
of the receiver 20'' is adjusted, the rod 102'' is adjusted within
the receiver 20'' and in the guide sleeve 104''. The surgeon or
technician may then lock the receiver 20'' to the rod 24'' by
rotating or turning the receiver 20'' with the tool, such as a
flat-head screw driver (not shown), placed in the slot 26''. This
causes the rod 24'' to directly engage at least a portion of the
screw head 102a'', such as surfaces or portions 120a'', 150'',
152'', 154'' or 156'', thereby causing the rod 24'' to become
locked or fixed onto the screw 102''. This causes the receiver 20''
to become affixed to its respective bone, such as spinal bones
14-18 (FIG. 1).
[0135] As illustrated in FIGS. 37-42 and 49-57, notice that as the
receiver 20'' is rotated, the rod 24'' is cammed, forced or urged
downward (as viewed in FIGS. 43-46) and in a direction parallel to
the axis SA (FIG. 43) until the rod 24'' comes into direct
engagement with the at least a portion of the head 102a''. In the
illustration being described, notice in FIGS. 45 and 46 that the
rod 24'' comes into direct contact and engagement with the portion
in 120'' of the head 102a''.
[0136] FIGS. 39 and 40 illustrate the rod 24'' situated in the
receiver 20'' after it is rotated between unlocked and locked
positions. FIGS. 50 and 56 also illustrate an intermediate position
after the receiver 20'' has been rotated slightly and the rod 24''
is captured in the channels 32'' and 34'' and upon rotation of
receiver 20'', being urged downward toward the head 102a'' of the
screw 102''. Finally, the FIGS. 41, 42, 45 and 46 illustrate the
assembly 100'' after the receiver 20'' has been rotated clockwise
in the illustration, showing the rod 24 directly engaging at least
portion, such as portion 120a'', of the head 102a'' of the screw
102''. As best illustrated in FIGS. 37-42, after the receiver 20''
is rotated from the unlocked position (shown in FIGS. 37, 38, 43
and 44) to the locked position (shown in FIGS. 41, 42, 45 and 46),
the rod 24'' engages, compresses and becomes locked against at
least a portion, such as portion 120a'', of the head 102a'' of the
screw 102''.
[0137] If the receiver 20'' comprises the channels 32'' and 34''
having the configurations of the type illustrated in FIGS. 18-34,
then the operation is similar. In this regard, the screw 102'' is
received in the bore 110'' and the guide or sleeve 104'' is
situated in the bore 110'' after which the screw 102 is driven by a
tool, such as tool 125'' in FIG. 36I, into bone, such as vertebrae
14''. In other words, as with the embodiment described earlier
herein relative to FIGS. 18-34, the rod 24'' is loosely captured in
the channel 32'' and 34'' as illustrated. In FIGS. 49 and 55 recall
that the channels 32'' and 34'' each have the introducing area
60a'', the intermediate holding area 60b'' and the locking area
60c''. As illustrated in FIGS. 49, 52 and 55, the guide sleeve
104'' and receiver 20'' are aligned such that their respective
channels 121'' and 26'', respectively, become generally aligned so
that the rod 24'' may be inserted therein. As illustrated in FIGS.
50, 53 and 56, as the receiver 20'' is rotated about its axis RA
(FIG. 56), the rod 24'' becomes captured in the intermediate
holding or receiving area 60b'' as illustrated in FIGS. 50 and 56.
The intermediate holding area 60b'' in the channels 32' and 34'
enable the intermediate step between the initial rod 24'' insertion
and final rod 102'' locking.
[0138] As with the embodiment described earlier herein, relative to
FIGS. 18-34, the rod 24'' capturing step during which the rod 24''
is loosely captured in the receiver 20'', but is not yet rigidly
locked in place against at least a portion 120a'' of screw head
102a''. This allows the surgeon greater ease and flexibility when
he adjusts the relative position of the rod relative to the screw
head 102a''. For example, and as mentioned earlier herein, the
surgeon may cause or move the screws 102'' closer together
(compression) or further apart and then rotate the receiver 20''
using the tool, such as a screwdriver placed in the slot 26'', to
lock the rod 24'' in direct engagement with the screw head
102a''.
[0139] Notice in FIGS. 51, 54 and 57, the receiver 20'' has been
rotated to the locked position, thereby locking the rod 24''
directly to at least a portion, such as portion 120a'', of the
screw head 102''.
[0140] It should be understood, however, that as with prior
embodiments, the receiver 20'' may be situated such that its axis
RA is not coaxial with the screw axis SA (FIG. 43) of screw 102''.
The relative position of the receiver 20'' and the head 102''
enables the polyaxial position of the receiver 20'' and the
corresponding position of the rod 24'' relative to the head 102a''
to be adjusted by the surgeon during use. For example, notice the
receiver 20'' may be tilted or pivoted as shown in FIGS. 47 and 48,
after the rod 24'' is positioned in the desired position, the
receiver 24'' is rotated from, for example, the unlocked position
and intermediate positions, illustrated in FIGS. 49 and 50, to the
locked position illustrated in FIGS. 51 and 57, whereupon the rod
24'' engages and compresses against at least a portion of the head
102a'' as described herein. Notice that after the receiver 20'' has
been moved or rotated to the locked position, the rod 24'' engages,
compresses and becomes locked against the at least a portion of the
screw head 102a'', such as portions or surfaces 120a'', 150'',
152'', 154'' and 156'' (FIG. 36A). The receiver 20'' remains in the
tilted position relative to the head 102a''.
[0141] Advantageously, the screw head 102a'' is configured and
adapted to have a desired shape, such as a curved, arcuate or
spherical shape or other desired shape, so that the receiver 20''
can be positioned in a desired polyaxial position, even if its axis
RA (FIG. 56) is not coaxial with the axis SA (FIG. 43) of the screw
102''. This permits the polyaxial position of the rod 24'' relative
to the screw head 102a'' to be changed. In this regard, note in
FIGS. 35A, 35B, 45 and 46 that the screw 102'' has a truncated or
indented area 102c'' to permit or allow for maximal exposure of the
screw ball or head 102a'', which in turn facilitates a wide range
of polyaxial movement
[0142] It should be appreciated that the recesses 122'', 124'',
126'' and 128'' (FIG. 36B) could also comprise more or fewer
recesses or apertures and could comprise other configurations or
shapes. FIGS. 36C-36D, 36E-36F and 36G-36H illustrate other
representative or illustrative configurations of the head 102a'' of
the screw 102'' that also permit polyaxial movement and locking of
the receiver 20'' to the rod 24''. Notice, for example, a screw
170'' (FIG. 36C) has a head 172 having a shape or surface that is
also curved, arcuate or spherical. However, the recessed areas
174'' and 176'' provide at least one or a plurality of female
openings that receive elongated engagement members 180'', 182'' of
a tool 184'' (FIG. 36J) used to rotate the screw 102''.
[0143] FIGS. 36E and 36F Illustrate a screw head 188'' having a
square aperture 189'' in the curved or spherical head 188a'' (FIG.
36E) for receiving a tool 178'' (FIG. 36K) having a square hollow
tip 178a''. Similarly, a screw head 190'' (FIGS. 36G and 36H)
having a hexagonal aperture 192'' for receiving a hollow male
hexagonal tip 194'' (FIG. 36L) of a tool 196'' (FIG. 36L) for
rotating the head 190a'' and the screw 190''. Notice that the heads
188'' and 190'' in the embodiments illustrated in FIGS. 36E-36H
each have surfaces 188a1'' and 190a1'', respectively, that are
arcuate, curved or spherical and also provide a plurality of areas,
portions, surfaces or surface area contact points against which the
rod 24'' may be compressed or engaged after the receiver 20'' has
been rotated to the locked position mentioned herein.
[0144] Advantageously, this system and method provides apparatus,
method and means for providing a capless and polyaxial positionable
and moveable receiver 20'' which reduces or eliminates the need for
a compression member, such as the compression member 40'' of the
type described earlier herein relative to the embodiments shown in
FIGS. 1-34. In this embodiment, the guide sleeve 104'' provides
means for receiving the rod 24'' and guiding it into the receiver
20'' and also for guiding the rod 24'' toward the head 102'' as the
receiver 20'' is moved or rotated from the unlocked or intermediate
positions shown, for example, 43 and 44 to the locked position 45
and 46, respectively. Thus, in the illustration being described,
the rod 24'' directly engages the head 102a'' and becomes locked
there against.
[0145] Advantageously, this system and method provide a capless
multiaxial screw which eliminates the need for caps or screws or
threads of the type used in the prior art. This system and method
combine a very simplified yet effective means for locking an
elongated member or rod to a screw and bones, such as spinal bones
or other human bones, in the manner described and shown herein.
[0146] While the apparatus, system and method herein described, and
the form of apparatus for carrying this method into effect,
constitute several illustrative embodiments of this invention, it
is to be understood that the invention is not limited to this
precise method and form of apparatus, and that changes may be made
in either without departing from the scope of the inventions, which
is defined in the appended claims.
* * * * *