U.S. patent application number 13/369824 was filed with the patent office on 2012-06-07 for bone fixation tensioning tool and method.
This patent application is currently assigned to Zimmer Spine S.A.S.. Invention is credited to Karl Pierre Belliard, Marion Jeanne Sophie Delclaud, Jean-Luc Albert Paul Jouve, Gilles Larroque-Lahitette.
Application Number | 20120143207 13/369824 |
Document ID | / |
Family ID | 40564220 |
Filed Date | 2012-06-07 |
United States Patent
Application |
20120143207 |
Kind Code |
A1 |
Belliard; Karl Pierre ; et
al. |
June 7, 2012 |
BONE FIXATION TENSIONING TOOL AND METHOD
Abstract
A tensioning tool and method for tensioning a conformable
ligature of a bone fixing system are disclosed. The ends of a
conformable ligature can be passed around bones, bone grafts,
tendons, plates, rods, fasteners, or other anatomical or implanted
structures, and the like to form a loop. Another portion of the
conformable ligature can be coupled to a tensioning tool. The
tensioning tool can include a first portion and a second portion in
threaded engagement with each other. Rotation of one portion
relative to the other can cause tensioning of the conformable
ligature through translation of a tensioning member.
Inventors: |
Belliard; Karl Pierre; (La
Membrolle, FR) ; Larroque-Lahitette; Gilles; (Lagor,
FR) ; Delclaud; Marion Jeanne Sophie; (Pau, FR)
; Jouve; Jean-Luc Albert Paul; (Marseille, FR) |
Assignee: |
Zimmer Spine S.A.S.
Bordeaux
FR
|
Family ID: |
40564220 |
Appl. No.: |
13/369824 |
Filed: |
February 9, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11877160 |
Oct 23, 2007 |
8128635 |
|
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13369824 |
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Current U.S.
Class: |
606/103 |
Current CPC
Class: |
A61B 17/7053 20130101;
A61B 17/8869 20130101; A61B 17/7001 20130101; A61B 17/707
20130101 |
Class at
Publication: |
606/103 |
International
Class: |
A61B 17/56 20060101
A61B017/56 |
Claims
1. A tensioning tool providing continuous control of conformable
ligature tension, comprising: a tool body defining a slot; a
connection portion shaped to at least abut a ligature capturing
element; a threaded drive shaft running through at least a portion
of the tool body; a carriage movable along the slot, the carriage
defining a drive shaft passage having at least one thread engaging
portion to engage threads on the drive shaft and wherein the drive
shaft passes through the drive shaft passage; and a tensioning
member coupled to the carriage; wherein the carriage is configured
to be rotated from a first position in which the at least one
thread engaging portion is engaged with threads on the drive shaft
to a second, slidable position, in which the at least one thread
engaging portion is not engaged with the threads of the drive
shaft; wherein rotation of the drive shaft causes the carriage to
move towards or away from the connection portion.
2. The tensioning tool of claim 1, further comprising: a drive
shaft seat in which a first end of the drive shaft is seated; a
spring that compresses between the drive shaft seat and the tool
body, wherein the first end is an end proximate the connection
portion.
3. The tensioning tool of claim 2, further comprising: one or more
markings on the tool body that indicate an amount of compression of
the spring.
4. The tensioning tool of claim 1, further comprising: a detachable
handle connected to the drive shaft proximate to a second end that
is distal from the first end.
5. The tensioning tool of claim 1, wherein the drive shaft passage
includes a first thread engaging portion at a first end of the
drive shaft passage, a second thread engaging portion at a second
end of the drive shaft passage, and a non-threaded portion
positioned between the first thread engaging portion and the second
thread engaging portion.
6. The tensioning tool of claim 5, wherein the first thread
engaging portion and the second thread engaging portion are located
on opposing sides of the drive shaft passage.
7. The tensioning tool of claim 1, wherein the tensioning member is
a post extending from the carriage.
8. The tensioning tool of claim 7, wherein the post is configured
to receive a loop of a conformable ligature therearound.
9. The tensioning tool of claim 1, wherein the tool body extends
through the carriage with a portion of the carriage including the
drive shaft passage extending into the slot for receiving the drive
shaft therethrough.
10. A tensioning tool for applying tension to a conformable
ligature of a bone fixing system, the tension tool comprising: an
elongate tool body having a first end and a second end; a threaded
drive shaft extending along at least a portion of the tool body; a
connection portion positioned at the second end of the elongate
tool body shaped to engage a ligature capturing element of the bone
fixing system; and a carriage movable along the elongate tool body
to selectively apply tension to the conformable ligature via
movement of the carriage; the carriage defining a drive shaft
passage through which the drive shaft extends through, the drive
shaft passage having at least one thread engaging portion
configured to engage threads on the drive shaft; wherein the
carriage is configured to be actuated between a first position and
a second position; and wherein in the first position the at least
one thread engaging portion is engaged with threads on the drive
shaft such that rotation of the drive shaft causes the carriage to
move along the elongate tool body, and in the second position the
at least one thread engaging portion is not engaged with the
threads of the drive shaft such that the carriage is freely movable
along the elongate tool body without rotation of drive shaft.
11. The tensioning tool of claim 10, wherein the drive shaft
passage includes a first thread engaging portion at a first end of
the drive shaft passage, a second thread engaging portion at a
second end of the drive shaft passage, and a non-threaded portion
positioned between the first thread engaging portion and the second
thread engaging portion.
12. The tensioning tool of claim 11, wherein the first thread
engaging portion and the second thread engaging portion are located
on opposing sides of the drive shaft passage.
13. The tensioning tool of claim 10, further comprising a
tensioning member extending from the carriage configured to receive
a loop of a conformable ligature therearound.
14. The tensioning tool of claim 10, wherein the carriage is
actuated between the first position and the second position by
rotating the carriage about an axis generally perpendicular to a
longitudinal axis of the drive shaft.
15. The tensioning tool of claim 14, wherein the at least one
thread engaging portion is moved into engagement with threads of
the drive shaft as the carriage is rotated to the first
position.
16. The tensioning tool of claim 15, wherein the at least one
thread engaging portion is moved out of engagement with threads of
the drive shaft as the carriage is rotated to the second
position.
17. The tensioning tool of claim 10, wherein the drive shaft
extends through at least a portion of the elongate tool body.
18. The tensioning tool of claim 17, wherein the elongate tool body
includes an elongate slot along which the carriage travels.
19. The tensioning tool of claim 18, wherein the elongate tool body
extends through the carriage with a portion of the carriage
including the drive shaft passage extending into the slot for
receiving the drive shaft therethrough.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/877,160, filed on Oct. 23, 2007, the entire
disclosure of which is incorporated herein by reference.
TECHNICAL FIELD OF THE DISCLOSURE
[0002] This disclosure relates generally to systems and method for
fixing bone. In particular, embodiments of the disclosure may be
helpful for holding bones, rods, or other structures in a desired
configuration or in particular relative position. Even more
particularly, the disclosure relates to instruments and methods for
installing bone fixing systems.
BACKGROUND OF THE DISCLOSURE
[0003] The spine is formed of superposed vertebrae, normally
aligned along a vertebral axis, from the lumbar vertebrae to the
cervical vertebrae, each having a posterior wall from which
projects a spinous process and two lateral edges from the walls of
which there project ribs and/or transverse processes. If the spine
of a person has abnormal curvature, the vertebrae are typically
inclined relative to one another and relative to said vertebral
axis. The lateral edges of the vertebrae on one side are therefore
closer together and form a concave shape while the lateral edges on
the other side are farther apart and form a convex shape.
[0004] In order to straighten the vertebral column as a remedy for
this situation, the lateral edges of the vertebrae on the concave
side can be moved away from one another and supported at distances
from one another substantially equivalent to the distances between
the lateral edges on the other side. Devices known in the art to
hold the vertebrae relative to one another include screws that are
inserted into the vertebrae or hooks that are inserted along the
internal wall of the spinal canal and rods adapted to connect the
screws or hooks.
[0005] When using a hook and rod system, pairs of hooks are
generally inserted into each vertebra, one on each side, near the
pedicle. The hooks typically have heads that project from the
posterior wall of the vertebra, one on each side of the spinous
process. The heads can be tulip-shaped and adapted to receive a rod
that is immobilized by a nut screwed onto the head and contacting
the rod. The heads of the hooks situated on either side of the
spinous process can then be connected together and fixed in
position by two rods approximately parallel to one another and to
the axis of the spine.
[0006] However, using such hooks can be difficult because their use
increases the risk that the physician (or other operative) might
contact and potentially damage the spinal cord that extends along
the center of the spinal canal (which can result in paralysis of
the patient).
[0007] Using a screw and rod system reduces this risk, but has
other drawbacks. The screws typically have tulip-shaped heads and
are inserted in pairs into the pedicles on each side of the spinous
process on the posterior wall of the vertebrae. The screws
therefore constitute fixing points on the vertebrae for holding the
vertebrae in a fixed position relative to one another. However, the
screws are inserted into the pedicles of the vertebrae, which in
some cases are small or have deteriorated and can be damaged or do
not provide sufficient purchase to permanently hold the screw.
SUMMARY OF THE DISCLOSURE
[0008] According to various embodiments described herein, a
surgical procedure can be performed using a tensioning tool that
provides continuous control over tensioning the ligature. A user
can form a loop about one or more structures in a patient's body
with a conformable ligature and a ligature capturing implant. The
ligature capturing implant can be a ligature capturing implant that
include rods, compression members or can be another type of
ligature capturing implant. The structures can include, for
example, a bone, a bone fastener, a tendon, a bone graft, a plate,
a rod or other structure in the body. The user can attach a portion
of the conformable ligature to a tensioning member of a tensioning
tool that provides a continuous range of control. The tensioning
tool can comprise a first portion in threaded engagement with a
second portion. For example, the tensioning tool can comprise a
drive shaft that engages with a carriage, a column that engages
with a threaded shaft, a threaded shaft that engages with another
shaft or other threaded portions that engage with each other to
translate rotational motion of the portions relative to each other
into linear motion of the tensioning member. The user can rotate
the first portion relative to the second portion to move the
tensioning member to tension the loop. For example, a user can
rotate a drive shaft to move a carriage carrying the tensioning
member. In some embodiments, the user can disengage the carriage
from the drive shaft and slide the carriage along the drive shaft
to a selected position. As another example, the user can rotate one
portion of the tool to move a shaft that is coupled to the
tensioning member. The first portion can also be rotated relative
to the second portion in an opposite direction to release tension
from the loop.
[0009] According to one embodiment, a spinal reduction can be
performed using tensioning tools. A method of progressive spinal
reduction can comprise forming multiple loops about structures in a
patient's body with multiple conformable ligatures and ligature
capturing implants and partially tensioning each conformable
ligature in turn with a corresponding tensioning tool until each
conformable ligature is at a desired tension to perform spinal
reduction procedure. Tensioning each conformable ligature may
comprise attaching a portion of that conformable ligature to a
tensioning member of the corresponding tensioning tool, the
corresponding tensioning tool comprising a first portion in
threaded engagement with a second portion and rotating the first
portion relative to the second portion to move the tensioning
member away from a corresponding ligature capturing implant to
tension that conformable ligature about at least a portion of a
vertebra. The first portion is rotated relative to the second
portion about an axis that is substantially parallel to a primary
direction of movement of the tensioning member.
[0010] Another embodiment of a method comprises providing a
tensioning tool comprising, a tool body defining a slot, a threaded
drive shaft running through at least a portion of the tool body, a
tensioning member and a carriage coupled to the tensioning member.
The carriage defines a drive shaft passage having at least one
thread engaging portion to engage threads on the drive shaft. The
drive shaft passes through the drive shaft passage. The method
further comprises forming a loop about one or more structures in a
patient's body with a conformable ligature and a ligature capturing
implant and coupling a portion of the conformable ligature to the
tensioning member. The method can further include rotating the
drive shaft to move the carriage away from the ligature capturing
implant to tension the conformable ligature. Embodiments can also
include rotating the drive shaft the opposite direction to release
tension from the loop. The structures about which the loop is
formed can include, for example, a bone, a bone fastener, a tendon,
a bone graft, a plate, a rod or other structure in the body.
[0011] According to one embodiment, the drive shaft passage
includes one or more additional unthreaded portions. The method can
further comprise rotating the carriage to disengage the at least
one thread engaging portion from the threaded drive shaft and
sliding the carriage along the drive shaft to a desired
position.
[0012] Another embodiment of a method for holding a bone in a
position, the method comprises passing a conformable ligature
around one or more structures in a body, passing first and second
ends of the conformable ligature through a loop passage in a
ligature capturing implant to form a loop, adjusting the ligature
capturing implant to increase to resistance on the movement of the
conformable ligature to a selected amount that allows the
conformable ligature to move through the ligature capturing implant
when a force is applied to the conformable ligature, attaching a
portion of the conformable ligature to a tensioning member of a
tensioning tool, rotating a threaded drive shaft of the tensioning
tool to move the tensioning member to apply tension to the
conformable ligature and adjusting the ligature tensioning implant
to prevent the loop from loosening. According to one embodiment,
rotating a threaded drive shaft of the tensioning tool to move the
tensioning member comprises rotating the threaded drive shaft to
move a carriage coupled to the tensioning member. The carriage can
define a drive shaft passage having at least one thread engaging
portion to engage threads on the drive shaft and wherein the drive
shaft passes through the drive shaft passage. The method can
further comprise positioning the tensioning tool so that a
connecting portion of the tensioning tool abuts the ligature
capturing implant. According to one embodiment the drive shaft can
be rotated in an opposite direction to release tension from the
conformable ligature.
[0013] According to one embodiment a drive shaft passage can
include one or more additional unthreaded portions. The method can
further include rotating the carriage to disengage the at least one
thread engaging portion from the threaded drive shaft and sliding
the carriage along the drive shaft to a desired position.
[0014] Another embodiment comprises a tensioning tool providing
continuous control of conformable ligature tension, the tensioning
tool comprising a tool body defining a slot, a connection portion
shaped to at least abut a ligature capturing implant, a threaded
drive shaft running through at least a portion of the tool body, a
tensioning member and a carriage coupled to the tensioning member,
the carriage defining a drive shaft passage having at least one
thread engaging portion to engage threads on the drive shaft and
wherein the drive shaft passes through the drive shaft passage,
wherein rotation of the drive shaft causes the carriage to move
towards or away from the connection portion. According to one
embodiment, the carriage is configured to be rotated from a first
position in which the at least one thread engaging portion is
engaged with threads on the drive shaft to a second, slidable
position, in which the at least one thread engaging portions is not
engaged with the threads of the drive shaft.
[0015] The tensioning tool can further comprise a drive shaft seat
in which a first end of the drive shaft is seated, a spring that
compresses between the drive shaft seat of and the tool body, and a
removable handle connected to a second end of the drive shaft
distal from the first end.
[0016] Embodiments of the disclosed systems and methods can provide
the advantage of providing progressive and continuous tensioning of
a ligature used in bone fixing procedures.
[0017] Embodiments of the disclosed systems and methods can provide
the advantage of allowing tension of the ligature to be
progressively reduced in an easily controlled manner.
[0018] Embodiments of the disclosed systems and methods provide
another advantage by allowing a tensioning tool used to tension one
ligature to be left in place while the other ligatures are
tightened.
BRIEF DESCRIPTION OF THE FIGURES
[0019] FIG. 1 is a fragmentary diagrammatic perspective view
showing a vertebral fixing system of the disclosure and a rod.
[0020] FIG. 2 is a diagrammatic view in vertical section of the
subject matter of the disclosure mounted on a rod.
[0021] FIG. 3 is a diagrammatic perspective view in section of the
subject matter of the disclosure.
[0022] FIG. 4 is a diagrammatic view in elevation of the subject
matter of the disclosure mounted on a vertebra.
[0023] FIG. 5 is a perspective view of a first embodiment of a
vertebral fixing system.
[0024] FIGS. 6A, 6B, and 6C are vertical section views of the
fixing system showing the use of said system as shown in FIG.
5.
[0025] FIG. 7 is a face view showing the FIG. 5 fixing system put
into place on a vertebra.
[0026] FIG. 8 is a perspective view of a second embodiment of the
fixing system, the ligature not being shown.
[0027] FIG. 9 is an exploded view of the connection device of FIG.
8.
[0028] FIG. 10 is a plan view of a portion of the FIG. 9 connection
device.
[0029] FIG. 11 is a section view on line AA of FIG. 10.
[0030] FIG. 12 is a face view of the fixing system of the second
embodiment.
[0031] FIGS. 13A and 13B are section views on line VII-VII of FIG.
12 showing two ways in which the flexible ligature can be put into
place.
[0032] FIG. 14 depicts a cross-sectional end view of one embodiment
of a bone fixing system.
[0033] FIG. 15 depicts an exploded perspective view of one
embodiment of a blocking body.
[0034] FIG. 16 depicts a perspective view of one embodiment of a
compression member.
[0035] FIG. 17 depicts a cross-sectional end view of one embodiment
of a bone fixing system.
[0036] FIG. 18 depicts a side view of one embodiment of a bone
fixing system.
[0037] FIG. 19 depicts an exploded view of one embodiment of a
blocking body.
[0038] FIG. 20 depicts an exploded view of one embodiment of a bone
fixing system.
[0039] FIG. 21 depicts a side view of one embodiment of a blocking
body.
[0040] FIG. 22 depicts an exploded view of a portion of a blocking
body.
[0041] FIG. 23 depicts a cross-sectional end view of one embodiment
of a bone fixing system.
[0042] FIG. 24 depicts a side view of one embodiment of a blocking
body.
[0043] FIG. 25 depicts an exploded view of one embodiment of a
blocking body.
[0044] FIG. 26 depicts a perspective view of one embodiment of a
blocking body.
[0045] FIG. 27 depicts a cross-sectional side view of one
embodiment of a bone fixing system.
[0046] FIG. 28 depicts a perspective view of one embodiment of a
bone fixing system.
[0047] FIG. 29 depicts a perspective view of one embodiment of a
bone fixing system attached to a portion of bone.
[0048] FIG. 30 depicts a posterior view of one embodiment of a bone
fixing system attached to a portion of a bone.
[0049] FIG. 31 depicts a sagittal view of one embodiment attached
to a portion of a spine, illustrating a method for repairing a
spine.
[0050] FIGS. 32-38 depict views of a bone fixing system implanted
on a spine.
[0051] FIG. 39 depicts a side view of one embodiment of a
tensioning tool for a bone fixing system.
[0052] FIG. 40 is a diagrammatic representation of another
embodiment of tensioning tool.
[0053] FIG. 41 is a cross sectional view of one embodiment of a
tensioning tool.
[0054] FIGS. 42A-42B are diagrammatic representations of another
embodiment of a tensioning tool.
[0055] FIGS. 43A-43B are diagrammatic representations of a portion
of a tensioning tool.
[0056] FIG. 44 is a diagrammatic representation of yet another
embodiment of a tensioning tool.
DETAILED DESCRIPTION
[0057] The disclosure and the various features and advantageous
details thereof are explained more fully with reference to the
non-limiting embodiments that are illustrated in the accompanying
drawings and detailed in the following description. Descriptions of
well known starting materials, processing techniques, components
and equipment are omitted so as not to unnecessarily obscure the
disclosure in detail. Skilled artisans should understand, however,
that the detailed description and the specific examples, while
disclosing preferred embodiments of the disclosure, are given by
way of illustration only and not by way of limitation. Various
substitutions, modifications, additions or rearrangements within
the scope of the underlying inventive concept(s) will be apparent
to those skilled in the art after reading this disclosure.
[0058] A bone fixing system may be installed in a patient to hold
or fix one structure in a selected relation with one or more other
structures. As used herein, the term structure may refer to bones,
portions of bones, or bone implants, as well as rods, elongated
members, plates, or other implanted man-made devices. Among other
methods, a bone fixing system as described herein may be installed
using a minimally invasive surgery (MIS) procedure. In one
embodiment, the bone fixing system and method of use may include
instruments and bone fixing components for maintaining one or more
structures in a selected alignment.
[0059] Components of bone fixing systems in accordance with the
disclosure may be made of materials including, but not limited to,
titanium, titanium alloys, stainless steel, ceramics, and/or
polymers. Some components of a bone fixing system may be autoclaved
and/or chemically sterilized. Components that may not be autoclaved
and/or chemically sterilized may be made of sterile materials.
Components made of sterile materials can be used with other sterile
components during assembly of a bone fixing system.
[0060] Embodiments of bone fixing systems disclosed herein are
useful in repairing broken bones, correcting curvatures of the
spine and for other surgical procedures that hold structures (e.g.,
bones) in a fixed relative position. Embodiments of the bone fixing
system and method of use disclosed herein can be particularly
useful for minimally invasive surgery (MIS) procedures, which can
reduce trauma to soft tissue due to the relatively small incision
made in a patient. For example, a surgical procedure may be
performed through a 2 cm to 4 cm incision formed in the skin of the
patient. Dilators, a targeting needle, and/or a tissue wedge may be
used to provide access to structures without the need to form a
larger incision with a scalpel through muscle and other tissue. A
minimally invasive surgery (MIS) procedure may reduce an amount of
post-operative pain felt by a patient as compared to invasive
procedures. A minimally invasive procedure may also reduce recovery
time for the patient as compared to invasive procedures. In some
embodiments, the natural flexibility of skin and soft tissue may be
used to limit the length and/or depth of an incision or incisions
needed during the procedure. Minimally invasive procedures may
provide limited direct visibility in vivo.
[0061] Bone fixing systems may be used to correct problems due to
spinal injury, deformity, or disease. For example, various
embodiments of a bone fixing system may be used from the C1
vertebra to the sacrum to correct spinal problems. For example, a
bone fixing system may be implanted posterior to the spine to
maintain distraction between adjacent vertebral bodies in a lumbar
portion of the spine. Various embodiments of a bone fixing system
may be used to correct orthopedic deficiencies. Embodiments of the
disclosure may be useful for holding tendons, bones, or muscles
during the healing process and may be implanted using MIS
procedures and thus it is in this context that embodiments of the
disclosure may be described. It will be appreciated, however, that
embodiments of the systems and methods of the present disclosure
may be applicable for stabilizing other areas of the body.
[0062] In general, a flexible ligature can be used to secure bones
or other structures. The ligature comprises an elongate flexible
member capable of conforming to the contour of the parts that it
connects. The ligature can be passed through a ligature capturing
implant to form a loop that is looped about the structures to fixed
relative to each. The ligature capturing implant can be any body
through which the ligature passes to form a loop and that allows
the loop to be tightened and left in a patient's body in a
tightened state. According to one embodiment, force is applied to
the ligature to tension the loop. The instrument used to tighten
the ligature can include a first shaft, a second shaft drivably
engaged with the first shaft and a tensioning member. The
tensioning member can be coupled to the first shaft or the second
shaft or can be drivably engaged with one or both of the first
shaft and the second shaft. A portion of the ligature couples to
the tensioning member such that movement of tensioning member can
increase the tension in the ligature. For example, a portion of the
ligature can be formed into a loop that is looped around the
tensioning member. Movement of the tensioning member can be driven
by rotational movement of the first shaft relative to the second
shaft. Embodiments of an instrument tensioning the ligature are
discussed below in conjunction with FIGS. 40-44.
[0063] By way of context, FIG. 1 shows one embodiment of a bone
fixing system, specifically a vertebral fixing system 10 of the
disclosure mounted on a rod 18. The vertebral fixing system
comprises a connecting part 12 having two longitudinal members, of
which a first longitudinal member 22 extends between a first end
22a and a second end 22b and a second longitudinal member 20
extends between a first end 20a and a second end 20b. The two
longitudinal members 22 and 20 are pivoted together at their first
ends 20a and 22a for the purposes of mounting the system. The first
end 22a of the longitudinal member 22 has a notch 26 with two
opposite edges 28 and 30 and between which the first end 20a of the
other longitudinal member 20 may be inserted. A pivot pin 24 passes
through the two first ends 20a and 22a and is free to rotate in at
least one of said ends 20a and/or 22a. The second end 22b of the
first longitudinal member 22 includes a bore 28 into which a screw
26 may be inserted. The second end 20b of the second longitudinal
member 20 comprises a thread 38 which is aligned with said bore 28
when the two longitudinal members are disposed facing each other,
with the result that the screw 26 may be screwed into said thread
38 in order to drive the second ends 20b and 22b of the two
longitudinal members 20 and 22 towards each other. The consequences
of screwing said screw 26 into the thread 38, thereby forming the
adjustable locking means, are explained in more detail hereinafter
FIG. 1 also shows a first orifice 40 through which a ligature may
be stretched. The method of connecting said ligature to said
connecting part is described with reference to FIG. 2.
[0064] FIG. 2 shows the connecting part 12 comprising of the first
longitudinal member 22 and the second longitudinal member 20, said
longitudinal members 22 and 20 pivoting about the pin 24 that joins
them. The adjustable locking means comprising of said screws 26
passing through the bore 28 and screwed into the thread 38 to
immobilize said connecting part 12 relative to the rod 18 and fix
in position a portion of a ligature 14 shown in part in FIG. 2.
[0065] The ligature 14 consists of an elongate flexible member
capable of conforming to the contour of the parts that it must
connect.
[0066] The ligature 14 has a first end 44 that is ligated around
the pin 24 and a free second end 42 that is inserted into a passage
48 between the rod 18 and the internal walls 50 and 52 of the
longitudinal members 22 and 20 and the external wall of the rod 18.
As shown in FIG. 2, the second longitudinal end 20a includes a
second orifice 54 through which said ligature 14 passes. Moreover,
as shown in FIG. 4, the ligature 14 may be formed into a loop 56 in
which the transverse process is trapped. In some embodiments, the
ligature 14 may also trap the rib.
[0067] As shown in FIG. 3, which shows the second longitudinal
member 20, the middle part has a first portion through which said
ligature 14 passes and a second portion 58 adapted to bear directly
on the rod 18. In some embodiments, the passage 48, which is
symmetrical inside the first longitudinal member 14, is produced by
a groove formed in each of the two facing faces of the middle parts
of the longitudinal members 22 and 20.
[0068] In some embodiments, the first portion of the middle part
forms an edge with cylindrical symmetry and that the corresponding
second portion of the middle part 58 of the first longitudinal
member 22 forms a substantially cylindrical space 60 into which
said rod 18 is inserted.
[0069] FIG. 2 shows that the second portion 58 of the middle part
comes into contact with the rod 18 and is adapted to bear on top of
it and the first portion presses the free second end of said
ligature 14 against the rod 18. The adjustable locking means
therefore drive the longitudinal members 22 and 20 forcibly against
the rod 18 and simultaneously against the ligature 14, which is
also forcibly pressed against the rod 18.
[0070] In some embodiments, as shown in FIG. 2, the passage 48 has
a section S1 in the vicinity of the orifice 54 greater than the
section S2 in the vicinity of the first orifice 40, the section of
said passage 48 decreasing progressively in the direction from the
second orifice 54 to the first orifice 40. The ligature 14 is
therefore progressively compressed around a portion of the rod 18
with a pressure that increases in the direction from the second
orifice 54 towards the first orifice 40.
[0071] FIG. 4 shows a vertebral fixing system of the disclosure
mounted on a vertebra having a transverse process. This figure
shows again the rod 18 and the two longitudinal members 22 and 20
that grip it and press a portion of the ligature 14 against said
rod 18.
[0072] In FIG. 4, the flexible ligature 14 consists of a flexible
strip of substantially constant width and thickness whose first end
is ligated to the pin 24, the ligature 14 surrounding the
transverse process of the vertebra being inserted through the
connecting part 12. The section of the flexible strip 14 is
substantially rectangular so that, the pin 24 and the rod 18 being
substantially perpendicular to the transverse process, the ligature
14 has to be partly twisted in order to insert it into the passage
48 and between the pin 24 and the point at which it contacts the
transverse process. The connecting part 12 is fixed in position
against the posterior wall of the vertebra despite these partially
twisted portions, the ligature 14 being forcibly tensioned by
stretching the free second end 14.
[0073] The ligature 14 is advantageously made from a flexible
material such as polyester that may be lightly crushed locally to
immobilize it with a clamping effect.
[0074] One aspect of the disclosure relates to a spine
straightening assembly comprising a plurality of vertebral fixing
systems conforming to the present disclosure and mounted on a
plurality of successive vertebrae, on all the transverse processes
of one lateral wall thereof, and connected to a single rod that is
disposed substantially parallel to said spine. The transverse
processes of a portion of the spine can therefore be connected
together by a single longitudinal rod, to fix them in position
relative to each other, by means of the above vertebral fixing
system.
[0075] In some embodiments, flexible ligature 14 may not be ligated
around pin 24 or otherwise fixed to connecting part 12. As shown in
FIG. 5, in one embodiment, a vertebral fixing system comprises a
connecting part 12, a flexible ligature 14, and adjustable locking
means 16. The flexible ligature 14 is of elongate shape and is
capable of matching the outline of the parts it is to connect
together. In this figure, there can also be seen the rod 18 that is
to be secured to the vertebra by means of the vertebral fixing
system. In the first embodiment, the connecting part 12 is
constituted by two longitudinal elements given respective
references 22 and 20, each having a first end 22a, 20a and a second
end 22b, 20b.
[0076] In FIG. 6A, the longitudinal elements 22 and 20 are hinged
to each other at their second ends 22b, 20b about a pivot pin
24.
[0077] In the embodiment described, the locking means are
constituted by a screw 26 having a head 26a that is engaged in a
bore 28 formed in the first end 22a of the longitudinal element 22.
The first end 20a of the longitudinal element 20 is pierced by a
tapped bore 38 for co-operating with the threaded shank 26b of the
screw 26. Each longitudinal element 20, 22 has an outside face 20c,
22c and an inside face 20d, 22d. The longitudinal elements 20 and
22 are mounted in such a manner that the inside faces 20d, 22d of
the longitudinal elements face each other. The inside faces 20d,
22d of the longitudinal elements 20 and 22 have respective
mutually-facing recesses 30 and 32, each of substantially
semicylindrical shape. The recesses 30 and 32 define walls 34 and
36 which are ruled surfaces having generator lines parallel to the
pivot axis 24. Finally, slots 54 and 40 cause the bottoms of the
recesses 30 and 32 to communicate with the outside faces 20c and
22c of the longitudinal elements 20 and 22. As explained below, the
recesses 30 and 32 are for receiving the rod 18 together with a
strand of the ligature 14, the slots 54 and 40 serving to pass the
ligature 14.
[0078] With reference to FIGS. 6A, 6B and 6C, there follows an
explanation of how the fixing system is used.
[0079] In FIG. 6A, there can be seen the longitudinal elements 20
and 22 in the spaced-apart position, a position in which the
locking means 16 are not active, the threaded shank 26b of the
screw 26 not being engaged in the bore 38. The ligature 14 is
engaged in the slots 54 and 40 of the longitudinal elements against
one portion of the inside wall 34, 36 of the recesses 30 and 32.
The rod 18 is then introduced into the recess 30 of the
longitudinal element 20 so that the two strands 42 and 44 of the
ligature 14 are disposed between the inside wall of the recesses 30
and 32 and the side face 18a of the rod 18. These two surfaces
define a passageway 48 for passing the ligature 14 and having
portions 42 and 44 of the ligature 14 placed therein.
[0080] As shown in FIG. 6B, the portions 42 and 44 of the ligature
14 define a portion of the ligature 14 that forms a loop that
extends beyond the outside face 20c of the longitudinal element 20,
and also two free portions 42 and 44 that extend beyond the outside
face 22c of the longitudinal element 22. When the longitudinal
elements 20 and 22 are spaced apart as shown in FIG. 6B, the
ligature 14 can slide freely along the passageway 48. Once the
ligature 14 is placed around the transverse process or a rib or
indeed a portion of the posterior arc of a vertebra, the surgeon
engages the threaded shank 26b of the screw 26 in the tapped bore
38, causing the longitudinal element 22 to come progressively
closer to the longitudinal element 20. This approach simultaneously
reduces the section of the passageway 48 in which the portions 42
and 44 of the ligature 14 are engaged and simultaneously introduces
a certain coefficient of friction between the ligature and
respectively the rod 18 and the walls of the recesses 30 and 32.
Nevertheless, it is still possible for the surgeon to extract
traction on the free ends 42 and 44 of the ligature 14 until
sufficient tension is obtained in the ligature around the vertebral
process. Once the tension in the ligature is sufficient for
providing appropriate fastening, the surgeon finishes off
tightening the screw 26 in the tapped bore 38, thus locking the
longitudinal elements 20 and 22 together. Advantageously, the
portions 42 and 44 of the ligature 14 are pinched between the rod
18 and the wall of the recesses 30 and 32.
[0081] In this locking position, the rod 18 is thus secured to the
ligature 14 via the connecting part 12.
[0082] Advantageously, because the surgeon exerts traction only on
the free ends 42 and 44 of the ligature 14, there is no risk of
jamming between the ligature 14 and the bottom face of the
transverse process or of the rib, thus guaranteeing that effective
fastening is provided with the transverse process or the rib or
indeed a portion of the posterior arc of a vertebra. FIG. 7 depicts
a face view where reference AT identifies the transverse
process.
[0083] In the above description, both of the portions 42 and 44 of
the ligature 14 are disposed in the recesses 30 and 32 on the same
side of the rod 18. In some embodiments, the portions 42 and 44 of
the ligature 14 may be placed on opposite sides of the rod 18.
Under such circumstances, it should be considered that the outside
face 18a of the rod 18 and the inside walls of the recesses 30 and
32 define two passageways, respectively for passing each of the
portions 42 and 44 of the ligature 14.
[0084] FIGS. 8 to 13B depict various view of one embodiment of the
fixing system. In these figures, there can be seen the rod 18, the
connecting part 12, and the flexible ligature 14.
[0085] In this embodiment, the connecting part 12 is constituted by
a part 55 that is generally U-shaped. The inside wall of this part
55 is constituted by a bottom 57 of substantially semicylindrical
shape and by two substantially plane portions 53 and 54 that
correspond to the two limbs of the part 55. The width of the recess
58 formed in the part 55 is substantially equal to the diameter of
the rod 18. On its outside face 59 which is circularly symmetrical
about a longitudinal axis of the part 55, there is provided a
thread 60 occupying its upper portion. The thread 60 is located
entirely above the rod 18 when it is put into place in the recess
58. The thread 60 is designed to co-operate with a clamping ring 62
that constitutes the adjustable locking means. This ring has a
slightly frustoconical bore 64 with an inside face 66 that carries
tapping 68.
[0086] In some embodiments, when the ring 62 is screwed tight on
the threaded portion 60 of the part 55, it deforms the limbs of the
part 55 elastically, thereby pinching and clamping strands of the
ligature 14 between the rod 18 and the inside wall(s) of the recess
58, in a manner explained below.
[0087] As shown in FIGS. 10 and 11, the part 55 includes in its
bottom 70 a passage 72 for passing the ligature 14 in a manner
explained below.
[0088] With references to FIGS. 12, 13A, and 13B, there follows a
description of two different ways of putting the flexible ligature
14 into place inside the connecting part 12 in the second
embodiment. The side wall of the rod 18 and the inside wall of the
recess 58 of the part 55 potentially define two passageways 74 and
76 for passing the middle strands of the flexible ligature 14. In
the configuration shown in FIG. 13A, only the passageway 74 is
used. Thus, both intermediate portions 42 and 44 of the flexible
ligature 14 are disposed in the passage 74.
[0089] In the configuration shown in FIG. 13B, the middle portions
42 and 44 of the flexible ligature 14 are disposed respectively one
in each of the passageways 74 and 76, i.e. on either side of the
rod 18. Advantageously, the free ends of the ligature 14 are
accessible for exerting the desired traction in order to obtain
suitable clamping on the spinous process prior to locking the
clamping ring 62 on the part 55.
[0090] One advantage to this type of embodiment may be the ability
to avoid making two longitudinal parts constituting a kind of clamp
hinged on the pin 24. In some embodiments, the locking means are
constituted by an element that is distinct from the connecting part
and that is removable therefrom. In some embodiments, the locking
means co-operate with the connecting part by screw engagement. It
is thus possible to adjust accurately the dimensions of the
ligature-passing passageway(s) as defined by the connecting part
and the rod. In an initial stage, the coefficient of friction
between the coefficient of the ligature and secondly the rod and
the connecting part can be adjusted. In the final stage, very
effective clamping of the ligature is obtained between the rod and
the locking part.
[0091] In some embodiments, including for example the embodiments
shown in FIGS. 14-39, rod 18 may not be needed in order for the
bone fixing system to effectively hold a bone in a relative
position. The embodiments of the bone fixing system 100 shown in
FIGS. 14-39 can include conformable ligature 14 and blocking body
120, which may include compression member 140. In these embodiments
that do not require the use of rod 18, the conformable ligature 14
may be passed around one or more bones, tendons, muscles, rods,
plates, screws, or other structures in a body and passed through
loop passage 126 in blocking body 120 to form a loop extending from
a first portion of blocking body 120 and a first end and a second
end of conformable ligature 14 may be passed out one or more exit
passages 128 in blocking body 120 to extend in a free configuration
from a second portion of blocking body 120. Thus, although
conformable ligature 14 may, in some uses, pass around rod 18 to
capture rod 18 in a loop portion, rod 18 is not necessary for bone
fixing system 100 to hold a bone in a secure position.
[0092] With reference to FIGS. 14-38, in embodiments that do not
require the use of rod 18 to hold a structure in a relative
position, bone fixing system 100 may include compression member 140
having a first surface 146 for contact with conformable ligature 14
and for cooperating with inside surface 125 of blocking body 120 to
form a passageway for one or more ends of conformable ligature 14.
Compression member 140 may be inserted into blocking body 120
before conformable ligature 14 is passed through blocking body 120.
In some embodiments, closure member 130 may engage with engagement
portion 123 of blocking body 120 before inserting compression
member 140 and/or passing conformable ligature 14 through blocking
body 120.
[0093] In other embodiments that do not require the use of rod 18
to hold a structure in a relative position, bone fixing system 100
may include closure member 130 for engagement with engagement
portion 123 of blocking body 120 and for contact with compression
member 140 so that advancing closure member 130 into blocking body
120 biases compression member 140 onto conformable ligature 14.
Closure member 130 may be advanced into blocking body 120 for
biasing compression member 140 against conformable ligature 14 to
create a friction force between conformable ligature 14 and
blocking body 120. A friction force between conformable ligature 14
and blocking body 120 may hold conformable ligature 14 in place
without significant movement relative to blocking body 120. In some
embodiments, closure member 130 may be advanced into blocking body
120 for impinging conformable ligature 14 between compression
member 140 and blocking body 120 to prevent any relative
movement.
[0094] Advantageously, the use of compression member 140 in these
embodiments enable bone fixing system 100 to be used in
circumstances in which rod 18 may be undesirable or unnecessary.
Another advantage of the embodiments illustrate in FIGS. 14-38 is
the ability for the surgeon to more easily see conformable ligature
14 as it is passed through various passages in the bone fixing
system. Another advantage to this embodiment is the reduced size of
blocking body 120 over prior art devices that couple to a rod. In
particular, the use of compression member 140, particularly having
a hemispherical profile, can reduce the height and overall profile
of blocking body 120.
[0095] FIG. 14 depicts a cross-sectional view of a portion of one
embodiment of bone fixing system 100 useful for holding a bone in a
position without requiring rod 18. Bone fixing system 100 of FIG.
14 includes blocking body 120 with compression member 140 and
closure member 130, ligature 14, and tensioning tool 250. Blocking
body 120 of FIG. 14 includes closure member passage 123 for
receiving closure member 130 and loop passage 126 and exit passages
128 for receiving ligature 14 through blocking body 120 (e.g., as
shown). As shown in FIG. 14, ligature 14 has been passed through
blocking body 120 such that each end 14 of ligature 14 extends out
of one of exit passage 128 and ligature 14 passes through loop
passage 126 to form ligature loop portion 14. In some embodiments,
ligature 14 may have a round profile, which can often provide the
highest strength per unit of cross-sectional area of ligature 14,
enable passing ligature through small openings, and/or reduce the
area of contact with a structure. As shown in FIG. 14, ligature 14
may have a wide, flat (or approximately flat) profile which may
distribute forces over a larger area, provide higher strength,
and/or prevent rolling (e.g. as compare to a round profile).
Compression member 140 includes first surface 146 for cooperating
with inner surface 125 of blocking body 120 to form a passageway
between loop passage 126 and exit passages 128. As shown in FIG.
14, closure member 130 includes threads 132 for engaging threads
122 in engagement portion 123 of blocking body 120 and bottom
surface 135 for contact with compression member 140. As shown in
FIG. 14, closure member 130 has been engaged with threads 122 in
blocking body 120 and bottom surface 135 contacts compression
member 140 such that ligature 14 is held in place relative to
blocking body 120 due to compression in the passageways formed by
first surface 146 and inner surface 125 between loop passage 126
and exit passages 128. As shown in FIG. 14, bone fixing system 100
includes tensioning tool 250 having central passage 152 for passage
of ends 14 of ligature 14 and distal end 154 for contact with
blocking body 120.
[0096] As shown in FIG. 14 (and FIG. 15), blocking body 120 may be
manufactured with inner surface 125 for cooperating with first
surface 146 of compression member 140 to form a space through which
conformable ligature 14 passes and for contacting with a portion of
conformable ligature 14 to hold conformable ligature 14 in
position. In some embodiments, inner surface 125 may be
manufactured with a grooved, knurled, or otherwise textured surface
to aid in holding conformable ligature 14 in place. Inner surface
125 of blocking body 120 may be coated, layered, or otherwise
treated to aid in holding conformable ligature 14 in place. In some
embodiments, inner surface 125 may allow one-way passage of
conformable ligature 14 through blocking body 120, for example, by
manufacturing inner surface 125 with an asymmetric saw-tooth
profile to allow passage of conformable ligature 14 through
blocking body 120 in a first direction but to resist movement in
the opposite direction.
[0097] As shown in FIG. 14, loop passage 126 is located along the
arclength opposite (i.e., facing) first surface 146 of compression
member 140 positioned in blocking body 120, but it should be
understood that loop passage 126 could be positioned at other
places around blocking body 120. As shown in the embodiment of FIG.
14, exit passages 128 are located on opposing portions of blocking
body 120 and each is located higher than the uppermost portion of
compression member 140 when positioned in blocking body 120.
However it should be understood that exit passages 128 can be
located at other positions around blocking body 120. In various
embodiments, loop passage 126 and exit passages 128 may be
circular, oval, elliptical, or other shape, may be symmetric or
asymmetric, and may be oriented such that conformable ligature 14
may enter or exit blocking body 120 at an angle, normal, or
substantially tangential to a portion of blocking body 120. In
alternative embodiments, there may only be a single exit passage
128 through which both ends 14 of ligature 14 pass.
[0098] As shown in FIG. 14, tensioning tool 250 (discussed in
further detail below) has distal end 154 for detachable engagement
with a portion of blocking body 120. In some embodiments, distal
end 154 of longitudinal member 260 may have passage 152 for
accessing closure member 130. As shown in FIG. 14, distal end 154
may be curved for engagement with a portion of blocking body 120
having a generally curved profile.
[0099] In some uses, ligature 14 may have one or both ends passed
around a structure in the body. Both ends of ligature 14 may be
inserted in loop passage 126 to form a loop around the structures.
Compression member 140 may be inserted in compression member
opening 124. Ligature 14 may be passed through the passageway
formed between first surface 146 of compression member 140 and
inner surface 125 of blocking body 120. Ends of ligature 14 may be
passed out one or more exit passages 128. Closure member 130 may be
inserted in engagement portion 123 to engage threads 122. Ends of
ligature 14 may be connected to tensioning tool 250, such as
tensioning tool 250 shown in FIG. 39, Ligature 14 may be tightened,
and closure member 130 may be inserted in engagement portion 123
and advanced until closure member 130 contacts compression member
140. Advancing compression member 140 creates a friction force
between ligature 14 and blocking body 120. The friction force may
be great enough to impinge ligature 14 relative to blocking body
120 or may be enough to resist movement of ligature 14 relative to
blocking body 120.
[0100] FIG. 15 depicts an exploded perspective view of the
embodiment of blocking body 120 shown in FIG. 14, including
compression member 140 and closure member 130. As shown in FIG. 15,
blocking body 120 includes engagement portion 123 having threads
122 for receiving closure member 130, and compression member
opening 124 through which compression member 140 may be inserted to
"side-load" compression member 140 within blocking body 120. As
shown in the embodiment of FIG. 15, closure member 130 includes
tool portion 134 and thread 132 and compression member 140 includes
first surface 146, second surface 145, and flanges 142.
[0101] As shown in FIG. 15, blocking body 120 can include
compression member openings 124 on either side of blocking body 120
for insertion of compression member 140. In the embodiment of FIG.
15, compression member opening 124 has a constant diameter, while
in alternative embodiments opening 124 may have a first diameter
large enough to accommodate flanges 142 and a second diameter
smaller than flange 142 but large enough to seat compression member
140. Compression member 140 can be inserted, positioned, and/or
removed from blocking body 120. In various embodiments, compression
member 140 may be short enough to fit inside blocking body 120,
compression member 140 may be substantially the same length as
blocking body 120, or compression member 140 may extend some
distance beyond blocking body 120. Advantageously, compression
member 140 enables embodiments of the bone fixing system 100 to
operate in areas of the body or in situations in which a rod may be
difficult or undesirable. An advantage to blocking body 120 having
compression member opening 124 oriented for side-loading
compression member 140 is the ability to adjust the positioning of
compression member 140 after closure member 130 has engaged
engagement portion 122.
[0102] Extensions 142 (such as flanges 142) of compression member
140 can operate to prevent compression member 140 from shifting or
moving out of position once closure member 130 has engaged
engagement portion 123 of blocking body 120. In operation, closure
member 130 will contact compression member 140 to hold ligature 14
substantially in place when ligature 14 has been positioned to hold
a bone or other structure in a relative position. In some
embodiments, extensions 142 may extend around the entire arclength
of first surface 146 of compression member 140, such as flanges 142
depicted in FIG. 15, while in other embodiments, extensions 142 may
extend around a portion of the arclength of first surface 146. In
some embodiments, a radius of extension 142 may allow insertion or
removal of compression member 140 in a first orientation and may
prevent removal or insertion in a second orientation. For example,
in some embodiments, extensions 142 may have a radius to enable
compression member 140 to be inserted into blocking body 120 when
compression member 140 is rotated to a first angle, while
preventing compression member 140 from being removed when
compression member 140 is rotated (e.g., 90 degrees) from the first
angle. In some embodiments, compression member 140 may have a
variable radius.
[0103] As shown in the embodiment of FIG. 15, first surface 146 of
compression member 140 can form a passageway in cooperation with
inner surface 125 of blocking body 120 for passing ligature 14 and
for contacting conformable ligature 14. In some embodiments, first
surface 146 may be knurled, grooved, or otherwise machined, may be
coated, layered, or otherwise treated for contact with conformable
ligature 14, and/or may allow one-way passage of conformable
ligature 14 through compression member 140 (e.g., having an
asymmetric saw-tooth profile for allowing passage of conformable
ligature 14 past compression member 140 in a first direction but
resisting passage in an opposite direction).
[0104] Various mechanisms can be used to allow closure member 130
to engage engagement portion 123 of blocking body 120. In some
embodiments, closure member 130 has helically wound thread 132 and
can be advanced in blocking body 120 through engagement passage 123
by rotating closure member 130 to engage threads of engagement
portion 123 of blocking body 120. In some embodiments, tool portion
134 on closure member 130 can be a hex shaped receiving are that
would allow a surgeon to use a hex tool to engage and rotate
closure member 130 so that threads 132 engage with the threads of
engagement portion 123. In some embodiments, closure member 130 may
have a sawtooth profile or other profile for ratcheting closure
member 130 into blocking body 120. Those of ordinary skill in the
art will recognize a variety of other mechanisms (some of which
will be described herein) for engaging closure member 130 with
engagement portion 123 in order to enable closure member 130 to
contact compression member 140 and secure in place ligature 14.
[0105] Advantages to embodiments of bone fixing systems 100 such as
the one depicted in FIGS. 14 and 15 include the curved profile of
blocking body 120, which can result in an overall lower profile
and/or in less stress on surrounding tissue based on friction
contact.
[0106] FIG. 16 depicts a perspective view of an alternative
embodiment of compression member 140 of FIGS. 14 and 15 having
longitudinal slot 144 and stress reducer 148. In some embodiments,
compression member 140 may have a length and width such that when
compression member 140 is positioned inside blocking body 120,
first surface 146 is in contact with inner surface 125 of blocking
body 120 (or first surface 146 is in contact with conformable
ligature 14 which is in contact with inner surface 125 of blocking
body 120, for example as shown in FIG. 14). In various embodiments,
compressing on second surface 145 may bias first surface 146
against inner surface 125 and the radius of curvature of first
surface 146 may effectively change some amount, based at least in
part on the length and depth of longitudinal slot 144. One
advantage to compression member 140 having longitudinal slot 144 is
the capability to adjust the compressive force exerted by
compression member 140 on ligature 14. In addition to the length
and depth of longitudinal slot 144, the amount that the radius of
curvature can change can depend on the compression force applied to
second surface 147, the shape of inner surface 125, the
deformability of any coating, layer, a machined feature of inner
surface 125 or first surface 146, the thickness of conformable
ligature 14, or the original shape of first surface 146. As shown
in the embodiment of FIG. 16, longitudinal slot 144 can include
stress reducer 148, which can advantageously prevent or reduce the
likelihood of compression member 140 cracking or other material
failure due to a change in curvature of first surface 146. While
other shapes can be employed, stress reducer 148 may be generally
circular or other non-angular shape to prevent the build-up of
stresses associated with bending forces. The radius and position of
stress reducer 148 may be based on the material used for
compression member 140, the radius of curvature of first surface
146, the depth and width of longitudinal slot 144, the anticipated
compression force applied to second surface 147, or the length of
compression member 140.
[0107] FIGS. 17-19 illustrate another embodiment of the bone fixing
system 100. FIG. 19 is a perspective view of this embodiment of
blocking body 120, in which compression member 140 and closure
member 130 may be top-loaded or side-loaded into blocking body 120
via U-shaped channel 127. In this embodiment, blocking body 120 is
shown to include two upwardly extending walls forming a generally
U-shaped channel 127. Compression member 140 is shown with a
similar "dual cylinder" shape as the compression member 140 of FIG.
16 (in fact, the compression member of FIG. 16 can be used in the
FIG. 17 embodiment) with first surface 146 and flanges 142. As
shown in FIG. 18, compression member 140 may extend some distance
beyond blocking body 120 with extensions 142 on compression member
140 designed to prevent compression member 140 from moving
laterally once compression member 140 is positioned in blocking
body 120. As shown in the FIG. 18 embodiment, extensions 142 may be
located exterior to blocking body 120 (while in alternative
embodiments, extensions 142 may be located interior to blocking
body 120).
[0108] Compression member 140 can be placed within channel 127 with
surface 146 contacting inner wall 125 at the bottom of channel 127.
Closure member 130 may be inserted into channel 127 (e.g., by
engaging the exterior threads on the body of closure member 130
with the interior threads of channel 127) for engaging engagement
portion 122. Advancing closure member 130 down channel 127 (e.g.,
rotating closure member 130) can force compression member 140
against ligature 14 to hold ligature 14 in place without
significant movement (or with complete impingement) relative to
blocking body 120.
[0109] FIG. 17 shows a cross-sectional view of this embodiment of
bone fixing system 100 using the blocking body 120 of FIG. 19 in
which compression member 140 is either side or top-loaded into
blocking body 120. As shown in FIG. 17, conformable ligature 14 may
be passed through loop passage 126 in blocking body 120 to form a
loop extending from blocking body 120 and first and second ends may
be passed out one or more exit passages 128 to extend from a second
portion of blocking body 120. In order to use the bone fixing
system 100 to hold a bone in position, compression member 140 may
be inserted in blocking body 120 after conformable ligature 14 has
been passed through blocking body 120. Closure member 130 may be
engaged to engagement portion 122 of blocking body 120 after
conformable ligature 14 has been passed through blocking body 120
and after compression member 140 has been positioned in blocking
body 120.
[0110] Engaging closure member 130 in engagement portion 122 of
blocking body 120 prevents all or significant movement of
conformable ligature 14 relative to blocking body 120.
[0111] As shown in FIG. 17, exit passages 128 can be positioned
higher than first surface 146 of compression member 140 in order to
provide a longer passage between first surface 146 of compression
member 140 and inner surface 125 of blocking body 120 to provide a
higher friction coefficient or reduced point stresses on
conformable ligature 14, blocking body 120, and/or compression
member 140. In alternative embodiments, exit passages 128 may be
positioned near engagement portion 122 such that closure member 130
may contact conformable ligature 14. In various embodiments,
closure member 130 may impinge a portion of conformable ligature
14. As shown in FIG. 17, exit passages 128 may be located on
blocking body 120 such that when distal end 154 of tensioning tool
250 engages blocking body 120, first and second ends of ligature 14
are external of distal end 154. However, it should be understood
that exit passages 128 may be located at a number of locations on
the blocking body 120 and relative to tensioning tool 250. Distal
end 154 of tensioning tool 250 may engage a portion of blocking
body 120 to enable a surgeon to tension conformable ligature 14 in
order to hold a bone or structure in position. In various
embodiments, distal end 154 of tensioning tool 250 may be flanged
for engaging blocking body 120. Tensioning tool 250 may include
passage 152 along the entire length of tensioning tool 250 for
accessing closure member 130 or passage 152 may extend a selected
length of tensioning tool 250.
[0112] FIG. 18 depicts a side view of this embodiment of bone
fixing system 100 where conformable ligature 14 passes through loop
passage 126 to form a loop extending from a first portion of
blocking body 120, and further passes through a passage formed by
compression member 140 and blocking body 120, and passes out both
exit passages 128 (though ligature 14 could in various embodiments
pass both ends through a single exit passage 128). FIG. 18
illustrates the flanges 142 extending outside of blocking body
120.
[0113] As described, closure member 130 may be top-loaded into
blocking body 120 for the embodiments of FIGS. 17-19. One advantage
to top-loading closure member 130 and compression member 140 is
that closure member 130 may be integrated with compression member
140 to form a unitary piece, which reduces the number of components
that the surgeon has to implant during surgery. In various
embodiments, closure member 130 may be connected to compression
member 140 by a pin (not shown) to form a unitary piece. In some
embodiments, closure member 130 may rotate while compression member
140 does not rotate. One advantage to this unitary closure
member/compression member embodiment is that compression member 140
may apply only compression forces to ligature 14. In contrast, if
compression member 140 rotates inside blocking body 120, torsion
may be applied to ligature 14.
[0114] FIGS. 20-22 depict yet another embodiment of bone fixing
system 100 in which conformable ligature may be passed around one
or more bones, tendons, muscles, rods, plates, screws, or other
structures in the body, and then passed through loop passage 126 in
blocking body 120 to form a loop extending from a first portion of
blocking body 120. Ligature 14 can then be passed through a
passageway formed by first surface 146 of compression member 140
and inner surface 125 of blocking body 120, and passed out through
the center of blocking body 120 to extend out of blocking body 120
so that ends 14 of ligature 14 can be in a free configuration.
Tensioning tool 250 may have a central passage 152 to allow first
end and second end of ligature 14 to pass through.
[0115] FIG. 21 depicts a side view of a portion of one embodiment
of blocking body 120, in which compression member 140 may be
side-loaded through compression member opening 124 into blocking
body 120. As shown, blocking body 120 of FIG. 21 has a similar
shape to the blocking body 120 of FIG. 19, except that the FIG. 21
embodiment of blocking body 120 encloses compression member 140 (as
opposed to the "open" top of the blocking body 120 of FIG. 19).
Thus, in the FIG. 21 embodiment, compression member 140 may be
pre-loaded into blocking body 120 or even manufactured to be
permanently enclosed within blocking body 120. In an alternative
embodiment, compression member 140 and/or extensions 142 may be
manufactured with dimensions such that once compression member 140
is inserted in blocking body 120, the position of compression
member 140 may be altered but compression member 140 may not be
removed from blocking body 120. In other words, in the embodiment
shown in FIG. 21, compression member 140 may be moved around inside
blocking body 120, but may not be removed. In various embodiments,
blocking body 120 may be manufactured with compression member
opening 124 having a first set of dimensions and after compression
member 140 is inserted into blocking body 120 through opening 124,
the size of opening 124 may be altered (e.g., by adding material or
altering the shape of blocking body 120 at opening 124) to reduce
opening 124 dimension to prevent removal of compression member 140.
Alternatively, compression member 140 may be manufactured having a
first set of dimensions, inserted into opening 124 of blocking body
120, and then altered, such as by adding material, to increase the
dimensions of compression member 140 to prevent removal of
compression member 140. In various embodiments, compression member
140 may be compression fit or sweat-locked through opening 124 into
blocking body 120. In another embodiment, blocking body 120 may be
manufactured with two upwardly extending walls, compression member
140 may be inserted in a channel formed by the two walls, and
material may be added to convert the channel into opening 124.
[0116] FIG. 22 depicts an exploded perspective view of the
embodiment of blocking body 120 of FIGS. 20 and 21 in which
compression member 140 may be side-loaded into blocking body 120
and closure member 130 may threadably engage engagement portion 122
of blocking body 120. A tool may engage with tool portion 134 for
rotating closure member 130 to engage external threads 132 on
closure member 130 with internal threads 122 in blocking body 120.
Tool portion 134 of closure 130 can be hollow to enable one or more
ends of conformable ligature 14 to pass through and extend out exit
passage 128.
[0117] FIGS. 23-25 show another embodiment of a bone fixing system
100 having an alternate closure mechanism and exit passage. FIG. 23
depicts a cross sectional end view of bone fixing system 100 in
which conformable ligature 14 may be passed through loop passage
126 in blocking body 120 to form a loop extending from a first
portion of blocking body 120, through a passage formed by first
surface 146 of compression member 140 and inner surface 125 of
blocking body 120, and extend out through exit passage 128. As
shown in FIGS. 23 and 25, in this embodiment, ring-style closure
member 130 may have internal threads 132 for engaging external
threads 122 on blocking body 120. This type of embodiment will
provide the advantage of allowing the surgeon to see conformable
ligature 14 as it passes through loop passage 126 in blocking body
120 and to see compression member 140 as it is positioned in
blocking body 120.
[0118] FIG. 24 depicts a side view of the FIG. 23 embodiment in
which bottom surface 135 of closure member 130 is in contact with
second surface 145 of compression member external to blocking body
120, and in this embodiment bottom surface 135 of closure member
130 contacts second surface 145 at extensions 142 of compression
member 140. An advantage to this type of embodiment is the ability
for the surgeon to see the engagement between threads 132 on
closure member 130 with threads 122 on blocking body 120. As shown
in FIG. 24, tool portions 134 of closure member 130 may be
positioned on an exterior portion of closure member 130. An
advantage to this type of embodiment is the ability for a tool (not
shown) to engage tool portions 134 exterior to distal end 154 (not
shown) engaged with a portion of blocking body 120. This exterior
engagement can provide a superior tightening mechanism to engage
closure member 130 with blocking body 120 in certain
embodiments.
[0119] FIG. 25 depicts an exploded perspective view of the FIG. 24
view with the various portions of blocking body 120 separated prior
to engagement of closure member 130 onto blocking body 120. An
advantage to this embodiment is the reduced number of passages,
which may reduce the time needed to implant the system.
[0120] FIGS. 26-28 illustrate an alternative embodiment of bone
fixing system 100 that provides a hinged closing mechanism offset
from ligature 14 that also does not require a rod, and which can
provide certain advantages over other embodiments. FIG. 26 shows
blocking body 120 with first portion 170 hingedly connected via
hinge pin 178 to second portion 180. Conformable ligature 14 can
pass through loop passage 126 in first portion 180 of blocking body
120 to form a loop extending from first portion 180 of blocking
body 120, further passed through a passage formed between first
surface 146 of compression member 140 and inner surface 125 of
blocking body 120, and then passed through exit passage 128 in
second portion 170. As with every embodiment described, ligature 14
may get to this desired configuration (with a loop portion
extending from blocking body 120) in a variety of ways. An
advantage to this embodiment is the low profile possible due to the
configuration of closure member 130 offset from compression member
140.
[0121] In various embodiments, hinge pin 178 connects first portion
170 to second portion 180 in either a permanent manner or
alternatively the hinged connection may be disconnectable. The
hinged connection can be formed so as to allow two-way hinged
motion for engaging or disengaging first portion 170 from second
portion 180. In an alternative embodiment, the hinged connection
may allow one-way hinged motion for engaging first portion 170 from
second portion 180 but may subsequently prevent first portion 170
from disengaging second portion 180. In various embodiments, first
portion 170 and/or second portion 180 may allow hinged motion
between a selected arclength, for example, first portion 170 and
second portion 180 may move through an arc of approximately 180
degrees.
[0122] As further shown in FIGS. 26-28, closure member 130 will be
used to close the hinged bone fixing system 100 in a manner to hold
ligature 14 in a relatively or completely stable position relative
to blocking body 120. Closure member 130 of FIG. 27 is shown having
external threads 132 for engaging internal threads 122 in
engagement portion 123 of blocking body 120. Second portion 180 may
include engagement portion 122 for engagement by threads 132 on
closure member 130. In one embodiment, closure member 130 may be
positioned within first portion 170 such that closure member 130 is
free to rotate in first portion 170 to join first portion 170 with
second portion 180, but may not be removed from first portion 170
after such engagement. In other words, in some embodiments, closure
member 130 may be rotated to engage threads on closure member 130
with engagement portion 122 to collapse first portion 170 and
second portion 180, and the direction of rotation may be reversed
to disengage closure member 130 from engagement portion 122, but
closure member 130 may not be removed from first portion 170. In
the embodiment shown in FIG. 26, closure member 130 can be
rotatably positioned in second portion 180 such that closure member
130 is free to rotate in second portion 180 but may not be removed
from second portion 180, which can provide the advantage of
reducing the risk of having loose hardware (which can be lost
inside a patient during surgery) associated with bone fixing system
100.
[0123] FIG. 27 depicts a cross-sectional side view of a portion of
the embodiment of bone fixing system 100 depicted in FIG. 26, in
which conformable ligature 14 may be passed through loop passage
126 in first portion 170 to form a loop extending from first
portion 170 of blocking body 120, passed through a passage formed
by first surface 146 of compression member 140 and inner surface
125 of blocking body 120, and extend from exit passage 128 in
second portion 180. As shown in FIG. 27, first portion 170 and
second portion 180 rotate about hinge pin 178 to open or close
blocking body 120. Tool portion 134 on closure member 130 may be
rotated so threads 132 on closure member 130 engage threads 122 in
engagement portion 123. Once bottom surface 135 of closure member
130 reaches a selected point, first portion 170 and second portion
180 compress to impinge movement of ligature 14 relative to
blocking body 120.
[0124] First surface 146 of compression member 140 and inner
surface 125 of blocking body 120 provide a passageway through
blocking body 120. In some embodiments, inner surface 125 may be
located on first surface 170 and first surface 146 of compression
member 140 may be located on second portion 180 as depicted in FIG.
27. In some embodiments, inner surface 125 may be located on second
surface 180 and first surface 146 of compression member 140 may be
located on first portion 170.
[0125] Closure member 130 may be offset from compression member 140
such that threaded engagement of threads 132 of closure member 130
with engagement portion 122 of blocking body 120 may indirectly
apply compression to compression member 130. In other words,
compression member 140 may be positioned some distance L.sub.b from
hinge pin 178 and closure member 130 may be positioned some
distance L.sub.s from hinge pin 178. Compression of compression
member 140 onto conformable ligature 14 may not be accomplished by
directly contacting bottom surface 135 of closure member 130, but
may instead be accomplished by rotatably engaging threads 132 with
threads 122 to advance closure member 130 in blocking body 120 such
that second portion 180 may be leveraged around the fulcrum created
by hinge pin 178. An advantage to one embodiment uses the
mechanical advantage of L.sub.s/L.sub.b to apply compression forces
on conformable ligature 14. Another advantage to one embodiment is
the ability for the surgeon to apply large compression forces to
conformable ligature 14 due to the mechanical advantage based on
the position of hinge pin 178, compression member 140, and closure
member 130. The compression forces available may also be based on
the radius of curvature of compression member 140, the size or
pitch of threads 132 and 122, and/or the size of hinge pin 178.
Another advantage may be the precision in which a friction
coefficient may be selected between conformable ligature 14 and
blocking body 120. In some embodiments, the pitch, shank diameter,
or other dimensions of closure member 130 may enable control of the
application of compression. For example, a large number of threads
per inch may allow more compression due to the mechanical advantage
of threads 122 engaging with threads 132, and the application may
be more controlled due to the greater angular rotation needed to
advance closure member 130 the same distance as closure members 130
having lower numbers of threads per inch. Another advantage to this
embodiment relates to the outer surface of first portion 170 and/or
second portion 180. Because blocking body 120 can achieve a
mechanical advantage through the use of hinge pin 178, closure
member 130 may be made smaller than prior art approaches, which
allows blocking body 120 to have a smaller opening 123. As shown in
FIG. 27, second portion 180 has an outer surface that is curved,
which may reduce pain, discomfort, or other undesirable effects
that result from using an angular implant.
[0126] FIG. 28 depicts a perspective view of the embodiment of
FIGS. 26 and 27 shown in a closed configuration, where ligature 14
is held completely or substantially in place relative to blocking
body 120. One advantage to this type of embodiment may be the
ability to pass conformable ligature 14 around one or more bones,
tendons, muscles, rods, plates, screws, or other structures in the
body, pass conformable ligature 14 through blocking body 120 out a
single exit passage 128, and engage closure member 130 on blocking
body 120, but offset from conformable ligature 14 and/or
compression member 140. One advantage may be that tensioning tool
250 may not need passage 152 in distal end 154 because closure
member 130 (e.g., tool portions 134) may be accessed outside
tensioning tool 250.
[0127] It should be understood that the various closure mechanisms,
closure members, exit passages, and blocking bodies, and other
design features shown in the various embodiments of bone fixing
system 100 of FIGS. 14-28 may potentially be used in the other
embodiments of FIGS. 14-28. For example, the ring-style closure
member 130 of the FIG. 25 embodiment can be used on the embodiment
of FIG. 22 by modifying the blocking body of FIG. 22 to have
external threads onto which the internal threads of the ring-style
closure member 130 would engage.
[0128] FIGS. 29-38 depict embodiments of bone fixing system 100 in
various configurations, arrangements and orientations. In FIGS.
29-38, the embodiment of blocking body 120 is the embodiment
depicted in FIGS. 26-28. However, any of the embodiments depicted
in FIGS. 14-28 and variations may be used without departing in
scope from the present disclosure.
[0129] FIG. 29 depicts a perspective view of one embodiment of bone
fixing system 100 for holding a bone in a position. Bone fixing
system 100 may be useful for orthopedic applications, such as
holding a bone near a tendon or muscle. Portions 214 of conformable
ligature 14 may be passed through or around a portion of a muscle
and through or around a portion of a femur to provide support while
a tear or cut in the muscle heals. Advantageously, blocking body
120 may be positioned at various locations near the muscle, tendon,
or bone based on the type or extent of the injury, trauma, or
illness, surgical preferences such as MIS access, or patient health
such as age or weight, or the like Advantageously, embodiments of
bone fixing system 100 may be implanted near other surgical
implants without affecting their placement or function. In various
embodiments, bone fixing system 100 may include blocking body 120
indirectly applying tension to conformable ligature 14. For
example, in the embodiment depicted in FIG. 29, bone fixing system
100 may be implanted to maintain bone 219 in a position with muscle
209 while wound 211 heals. In this embodiment, conformable ligature
14 may be passed around bone 219 and through muscle 209, and
through blocking body 120 located on portion 112 of conformable
ligature 14 such that substantially all tension between muscle 209
and bone 219 may be supported by portion 111 of conformable
ligature 14.
[0130] Bone fixing systems 100 may be implanted without affecting
plates, rods, or other implanted structures. Bone fixing systems
may be implanted without affecting bone screws, hooks, bolts, or
other implanted hardware. FIG. 30 depicts one embodiment of
conformable ligature 14 passed around a part of bone 219, muscle
209 and/or tendon 213 and through blocking body 120, and further
depicts bone screw 212 and plate 210 implanted on a portion of bone
219. In this type of embodiment, bone fixing system 100 including
blocking body 120 may be positioned on portion 111 of conformable
ligature 14 such that some of the tension between muscle 209 and
bone 219 may be supported by blocking body 120.
[0131] Bone fixing system 100 may be advantageous for correcting
alignment of one or more bones. Conformable ligatures 14 and
blocking bodies 120 may be useful for correcting alignment of a
portion of the spine. FIGS. 31 and 32 depict posterior and sagittal
views of a portion of the spine in which bone fixing system 100 may
be useful for aligning vertebra L5 with adjacent vertebrae L4 and
sacrum S. In some embodiments, bone fastener assemblies 212 may be
implanted in lumbar vertebra L4 and sacrum S. In some embodiments,
bone fastener assemblies 212 may be inserted through an incision in
the skin and implanted using Minimally Invasive Surgery (MIS)
techniques, and ligature 14 may be passed around one or more
structures.
[0132] In some embodiments, passing may include going into,
through, or out of a structure. In some embodiments, passing may
include going over, under, or around a structure. In some
embodiments, passing may include crossing over other ligatures 14
or portions of ligatures 14. In some embodiments, passing may
include multiple passes along the same path FIGS. 33-38 depict
various embodiments of bone fixing systems in place on a portion of
a spine. In FIGS. 33-38, bone fixing system 100 is shown holding
bone graft 230, which may be useful for supporting a portion of the
spine. However, embodiments of bone fixing system 100 may be used
to correct problems with the spine without rods, bone grafts,
plates, or other implants. Conformable ligature 14 may be passed
around a portion of a bone, such as spinous process SP Conformable
ligature 14 may be passed around a portion of bone graft 230.
Passing conformable ligature 14 around a portion of bone graft 230
may include passing a portion of conformable ligature 14 through a
portion of bone graft 230. One end of conformable ligature 14 may
be inserted and passed through blocking body 120 from one side and
the other end of conformable ligature 14 may be inserted and passed
through blocking body 120 from another side, as depicted in FIG.
33.
[0133] Advantageously, conformable ligature 14 may be selectively
passed around structures such as bones and bone grafts. Conformable
ligature 14 may be passed around a bone, bone graft, tendon, or
other tissue due to disease, injury, tumor, degenerative effects or
the like. For example, FIG. 33 depicts a posterior view of one
embodiment in which conformable ligature 14 may be passed around a
portion of spinous process SP on lower vertebra L5. FIG. 33 further
depicts one embodiment in which conformable ligature may be passed
through bone, such as the pedicle of lower vertebra L5. As another
example, FIG. 34 depicts a sagittal view of one embodiment in which
conformable ligature 14 may be passed around the posterior portion
of spinous process SP. As another example, FIG. 35 depicts a
posterior view of one embodiment in which conformable ligature 14
may be passed around a portion of the pedicle portion of lower
vertebra L5. As another example, FIG. 36 depicts a sagittal view of
one embodiment in which conformable ligature 14 may be passed
around the pedicle portion and the posterior portion of spinous
process SP. In some embodiments, ligature 14 may not be passed
around a structure FIG. 37 depicts a posterior view of one
embodiment in which conformable ligature 14 may be passed around a
portion of the pedicle portion of lower vertebra L5 and the
transverse process of upper vertebra L4 but not the spinous process
for either vertebra FIG. 38 depicts a sagittal view of one
embodiment in which conformable ligature 14 may be passed around
the pedicle portion and through the posterior portion of spinous
process SP on lower vertebra L5.
[0134] In some embodiments, the surgeon may pass conformable
ligature 14 alternative ways due to disease, injury, tumor,
degenerative effects or the like. For example, FIG. 33 depicts a
posterior view of one embodiment in which conformable ligature 14
may be passed through a portion of the pedicle of lower vertebra
L5, which may allow system 100 to apply direct tension on lower
vertebra L5. As another example, FIG. 34 depicts a sagittal view of
one embodiment in which conformable ligature 14 may be passed
around bone graft 230 and spinous process SP on lower vertebra L5
such that the lower portion of bone graft 230 may be prevented from
moving posterior to the spine but may move anterior to the spine
FIG. 35 depicts a posterior view of one embodiment in which
conformable ligature 14 may be passed around a portion of the
pedicle portion of lower vertebra L5, which may allow system 100 to
indirectly apply tension on lower vertebra L5. FIG. 36 depicts a
sagittal view of one embodiment in which conformable ligature 14
may be passed around bone graft 230 and spinous process SP on lower
vertebra L5 such that the lower portion of bone graft 230 may be
prevented from moving posterior or anterior to the spine. FIG. 37
depicts a posterior view of one embodiment in which first and
second conformable ligatures 110 may be passed around a portion of
the pedicle portion of lower vertebra L5. Advantageously, the
system 100 may be able to selectively apply tension to either side
of the spine. Furthermore, system 100 may be able to control
movement between vertebrae L4 and L5 similarly to the embodiments
depicted in FIGS. 33 and 34, but without contacting the spinous
process SP of lower vertebra L5. FIG. 38 depicts a sagittal view of
one embodiment in which conformable ligature 14 may be passed
around the pedicle portion and through the posterior portion of
spinous process SP on lower vertebra L5. Advantageously, vertebrae
L4 and L5 may be able to move relative to each other but bone graft
230 may be held in place.
[0135] An advantage to bone fixing system 100 is that the position
of blocking body 120 may be based on disease, injury, tumor,
degenerative effects or the like. For example, FIG. 33 depicts one
embodiment in which a single blocking body 120 may be positioned
off-center of the spine. As another example, FIG. 34 depicts one
embodiment in which blocking body 120 may be positioned abutting a
bone such as spinous process SP. FIG. 35 depicts one embodiment in
which blocking body 120 may be positioned centered on the midline
of the spine. FIG. 36 depicts one embodiment in which blocking body
120 may be positioned some distance away from spinous process SP.
FIG. 37 depicts one embodiment in which two blocking bodies 120 may
be positioned lateral to bone graft 230 FIG. 38 depicts one
embodiment in which blocking body 120 may be positioned centered
between spinous processes SP.
[0136] Two or more conformable ligatures 14 and/or two or more
blocking bodies 120 may be used to hold a bone, bone graft, tendon,
rod, shaft, or other structure in a body. FIG. 36 depicts a
posterior view and FIG. 37 depicts a sagittal view of one
embodiment of a bone fixing system having two blocking bodies 120
and 120' and two conformable ligatures 14 and 14'. In some
embodiments, bone fixing system 100 may include a first conformable
ligature 14 passed around a bone such as transverse process TP on
lumbar vertebra L4 and transverse process TP on lumbar vertebra L5,
and a second conformable ligature 14' passed around a bone such as
transverse process TP on lumbar vertebra L4 and transverse process
TP on lumbar vertebra L5. Bone fixing system 100 with a first
blocking body 120 on a first side of the spine and a second
blocking body 120' on the second side of the spine may be used to
straighten a spine. For example, tensioning one conformable
ligature 14 greater than conformable ligature 14' may bias
vertebrae to help straighten a curved spine.
[0137] FIG. 39 depicts a side view of a portion of one embodiment
of tensioning tool 250, which may be used to apply tension to
conformable ligature 14. As shown in FIG. 39, tensioning tool 250
includes tool body 266 for engaging conformable ligature 14,
longitudinal member 260 for advancement in tool body 266, and
distal end (such as distal end 154 depicted in FIGS. 14, 17, and
20) for engagement with blocking body 120. As shown in FIG. 39,
tool body 266 includes attachment point 274 (with flange 258) for
connection to ligature 14, fixed handle 254, movable handle 252 for
rotation about axis 256, return spring 262, catch mechanism 264,
return spring adjustment member 270, and spring adjustment member
268.
[0138] Attachment point 274 can attach first and second ends of
conformable ligature 14 to tensioning tool 250. In some
embodiments, attachment point 274 may include flange 258 for
preventing first and second ends of conformable ligature 14 from
detaching from tensioning tool 250. Distal end 154 (such as the
embodiments shown in FIGS. 14, 17, and 20) of tensioning tool 250
may engage to a portion of blocking body 120. Fixed handle 254 may
be gripped by a surgeon, movable handle 252 may be rotated about
axis 256, such as by squeezing movable handle 252, to longitudinal
member 260 through tool body 266 a selected distance. Advancing
longitudinal member 260 to move blocking body 120 away from tool
body 266 while maintaining first and second ends of conformable
ligature 14 on attachment point 274 applies tension to conformable
ligature 14. In some embodiments, the selected distance
longitudinal member 260 advances through tool body 266 may be
proportional to the tension applied to conformable member 110.
[0139] In some embodiments, tool body 266 may include return spring
262, catch mechanism 264, and return spring adjustment member 270
for controlling the distance that longitudinal member 260 is
allowed to return when movable handle 252 is released. In some
embodiments, return spring 262 may bias catch mechanism 264 such
that movement is permitted in one direction only. In some
embodiments, return spring 262 may bias catch mechanism 264 such
that longitudinal member 260 may only move forward through tool
body 266. Advantageously, return spring 262 may ensure that a
surgeon does not inadvertently relieve tension from conformable
ligature 14. In other words, tensioning tool 250 may have a default
configuration for tensioning conformable ligature 14. In some
embodiments, actuating catch mechanism 264 (such as a surgeon
pressing on catch mechanism 264 with a thumb) may change the
positioning of catch mechanism 264 such that movement of
longitudinal member 260 is permitted in a reverse direction as
well. In some embodiments, movement of longitudinal member 260 in a
reverse direction may include changing the positioning of catch
mechanism 264 in relation to longitudinal member 260 as well as
pulling in a reverse direction on grasping member 272.
[0140] In some embodiments, tensioning tool 250 may include spring
adjustment member 268 for adjusting the compression on a spring
(not shown) in body 266. In some embodiments, rotating spring
adjustment member 268 one direction, spring adjustment member 268
may be advanced some distance into body 266 such that a spring may
be compressed. In some embodiments, rotating spring adjustment
member 268 in the other direction, spring adjustment member 268 may
be advanced some distance out of body 266 such that compression
forces on the spring may be relieved. By changing the compression
forces on the spring, the spring may exert more or less force on
longitudinal member 260, which may affect how much tension can be
applied to the ends of conformable ligature 14.
[0141] In some embodiments, ligature 14 may be passed around
elongate members 210, bone fastener assemblies 212, vertebrae (such
as L5), and other tendons, muscles, plates or other anatomical or
implanted structures and the ends of ligature 14 may be passed into
a portion of blocking body 120, such that a loop is formed
extending from a first portion of blocking body 120. In some
embodiments, first and second ends of ligature 14 may be passed
through a passage in blocking body 120. In some embodiments, a
passage may be formed by inner surface 125 of blocking body 120 and
first surface 146 of compression member 140. In some embodiments,
first and second ends of ligature 14 may exit by passing out of one
or more exit passages 128 in blocking body 120.
[0142] Distal end 154 of tensioning tool 250 engages blocking body
120. In some embodiments, distal end 154 of longitudinal member 260
may conform to the shape or profile of blocking body 120. In some
embodiments, distal end 154 of longitudinal member 260 may be
configured with features for engaging one or more features on
blocking body 120. In some embodiments, first and/or second ends of
ligature 14 may be attached to tensioning tool 250. In some
embodiments, first and/or second ends of ligature 14 may be
attached to attachment point 274 located on tool body 266. In some
embodiments, movable handle 252 of tensioning tool 250 may be
rotated about axis 256 to advance longitudinal member 260 through
tool body 266. The advancement of longitudinal member 260 through
tensioning tool 250 moves attachment point 274 away from blocking
body 120, pulling ends of ligature 14 to decrease the size of the
loop, and further advancement tensions ligature 14. In some
embodiments, the tension applied to ligature 14 may be sufficient
to hold one or more structures in a desired position. In some
embodiments, the tension applied to ligature 14 may be sufficient
to hold a bone in a position. In some embodiments, the tension
applied to ligature 14 may be sufficient to pull one or more bones
or structures into alignment. For example, tensioning tool 250 may
provide sufficient tension to one or more ends of ligatures 14
(depicted in FIG. 31) to pull vertebra L5 (depicted in FIG. 32) in
alignment with the natural curvature of the spine.
[0143] In some embodiments, once an appropriate tension has been
applied to ligature 14, closure member 130 may be actuated to
create a friction force to restrict movement of ligature 14
relative to blocking body 120, or to impinge ligature 14 in
blocking body 120. In some embodiments, closure member 130 may be
pre-installed in blocking body 120. In some embodiments, closure
member 130 may be inserted in blocking body 120 after engagement of
blocking body 120 by tensioning tool 250. In some embodiments,
closure member 130 may be inserted through distal end 154 of
longitudinal member 260 into blocking body 120.
[0144] In some embodiments, once closure member 130 has engaged
threads 122 in blocking body 120 to provide a desired friction
force to impinge ligature 14 in blocking body 120, first and second
ends of ligature 14 may be disconnected from tensioning tool 250.
Once ligature 14 has been disconnected from tensioning tool 250,
tensioning tool 250 may be disengaged from blocking body 120.
[0145] The tensioning tool of FIG. 39 can use a ratcheting motion
to advance longitudinal member 260. Each time the surgeon squeezes
handles 252 and 254 together, longitudinal member 260 advances a
predefined distance, typically greater than 10 mm. While tensioning
tool 250 works well in surgical procedures, it has several
shortcomings. Because longitudinal member 260 advances the same
amount with each pull of handle 252, the surgeon must tension
ligature 14 in relatively large increments, but cannot tension
ligature 14 to a position between the increments. In other words,
tensioning tool 250 does not offer a full range of tensioning
control as the attachment point can only be positioned at the
increments determined by the ratcheting mechanism (e.g., every 10
mm or so). A corollary of this problem is that tension is applied
in a pulsed manner to ligature 14 as the surgeon squeezes and
releases the handles.
[0146] Another issue with tensioning tool 250 is that it is
difficult for a surgeon to release a selected amount of tension in
ligature 14. If a surgeon believes that ligature 14 has been over
tensioned, the surgeon must typically release all or a large amount
of tension in ligature 14 and begin tensioning ligature 14
again.
[0147] Moreover, tensioning tool 250 is relatively bulky. This
makes it difficult to have multiple tensioning tools in place at
the same time during a procedures. Consequently, tensioning
multiple ligatures can be take a significant amount of time as the
tensioning tool 250 may have to be removed from a surgical site
each time a surgeon wishes to tension a new ligature. This
especially inefficient in procedures in which a surgeon may wish to
tension each ligature a little at a time rather than tensioning one
ligature completely, then moving to the next ligature.
[0148] FIG. 40 is a diagrammatic representation of another
embodiment of a tensioning tool 300 for tensioning a conformable
ligature that overcomes the shortcomings of tensioning tool 250.
Tensioning tool 300 comprises a tool body 305, a threaded drive
shaft 310 and a movable carriage 315 engaged with the threads of
drive shaft 310. The threads of drive shaft 310 can include any
suitable thread shape including a symmetric v-thread, square
thread, British acme thread, worm thread, buttress thread, metric
acme thread or other suitable thread. Preferably, drive shaft 310
has a thread pitch of between 1-5 mm. Movable carriage 315 is
engaged with the threads of drive shaft 310 and moves along slot
320 in tool body 305 when drive shaft 310 rotates, Slot 320 can
partially overlap carriage 315 to capture carriage 315 in slot 320.
In other embodiments, carriage 315 can be held in place by drive
shaft 310. Carriage 315 carries tensioning member 325 that acts as
an attachment point for a conformable ligature. Tensioning tool 300
further includes a handle that provides an ergonomic user control
to rotate drive shaft 310. According to one embodiment, the handle
can connect to drive shaft 310 using a quick connect 330. In other
embodiments, the handle may be fixed. Preferably, all portions of
tensioning tool are formed of biocompatible material such as
stainless steel, titanium, a strong plastic or other material.
[0149] Tensioning tool 300 also includes a connector 335 shaped to
interface with a ligature capturing implant (e.g., such as the
connection parts shown in FIGS. 1-13 and blocking bodies shown in
FIGS. 14-38). Connector 335 can be shaped to abut a variety of
ligature capturing implants or connector 335 can be interchangeable
such that a surgeon can select the appropriate interface member
based on the type(s) of ligature capturing implants used in a
particular procedure. According to one embodiment, connector 335
can simply abut the ligature capturing implant (including abutting
a rod if the ligature capturing implant uses a rod) or, according
to other embodiments, may attach to the ligature capturing implant.
Connector 330 can include tangs 340 that define an open area 345
through which the ends of the conformable ligature can pass so that
a portion of conformable ligature can be looped around tensioning
member 325.
[0150] FIG. 41 is a diagrammatic representation of a cross section
of one embodiment of tensioning tool 300 showing tool body 305,
drive shaft 310, carriage 315, tensioning member 325, quick connect
330 and connector 335. While various components such as body 305
and drive shaft 310 are each shown as being single pieces, they may
comprise multiple parts. For example, drive shaft 310 can include a
threaded portion that connects to a non-threaded portion. As
another example, tool body 305 may comprise multiple pieces.
[0151] As illustrated in FIG. 41, carriage 315 defines a threaded
passage 355 that engages the threads of drive shaft 310. As drive
shaft 310 rotates, carriage 315 will move either towards or away
from connector 335 along slot 320 depending on the direction of
rotation of drive shaft 310. In the embodiment of FIG. 41, rotation
occurs about an axis that is substantially parallel to the primary
direction of movement of tensioning member 325. The tension in a
conformable ligature looped about or otherwise attached to
tensioning member 325 will increase or decrease depending on the
direction of rotation. Tensioning member 325 may include flange 360
for preventing the conformable ligature from detaching from
tensioning tool 300.
[0152] Tensioning tool 300 further includes a handle that provides
an ergonomic user control to rotate drive shaft 310. According to
one embodiment, the handle can connect to drive shaft 310 at quick
connect 330. At the other end, drive shaft 310 can rest in a drive
shaft seat 364 that is movable in tool body 305. A spring 365
between drive shaft seat 364 and tool body 305 allows drive shaft
310 to be pushed towards connector 335. This can dampen forces
applied to the drive shaft towards connector 335 (e.g., by the
surgeon inadvertently pushing on then handle). Furthermore, since
spring 365 will have a known displacement per unit force applied, a
measure of displacement of spring 365 indicates how much tension is
applied to the ligature (i.e., the force from the tensioned
ligature is transferred through carriage 315 to drive shaft 310 to
compress spring 365 a known displacement). According to one
embodiment, tensioning tool 300 can include features (such as
extensions 366) that are coupled to the drive shaft. Extensions 366
move forward as drive shaft 310 moves forward when spring 365
compresses. The position of extensions 366 can be compared to
markings on body 305 to determine the force applied to the
ligature. Preferably, spring 365 is selected so that spring 365 is
fully compressed at between 500 Newtons and 1500 Newtons.
[0153] In operation, a surgeon can form a loop about one or more
structures with a conformable ligature and a ligature capturing
implant Examples of ligature capturing implants are shown in FIGS.
1-28, though any ligature capturing implant known or developed in
the art can be used, Examples of a conformable ligature looped
about one or more structures are shown in FIGS. 29-38. The
structures can include bones, rods and other structures in a
patient's body. Initially, the surgeon can configure the ligature
capturing implant to allow tightening of the ligature. Another
portion of the ligature can be coupled to tensioning tool 300 at
tensioning member 325. According to one embodiment, the conformable
ligature is attached by creating a loop with the free ends of the
ligature (e.g., such as ends 42 and 44 of FIG. 6C). This can be
done using pins, brackets, metal attachments, sewing, a knot, a
clamp or other mechanism for forming the free ends into a loop. In
other embodiments, the conformable ligature may be clamped to a
portion of tool 300 or otherwise attached to tool 300.
[0154] Before or after attaching the ligature to tensioning member
325, the surgeon can bring connector 335 into contact with the
ligature capturing body so that connector 335 pushes against the
ligature capturing body as the ligature is tensioned. Rotating
drive shaft 310 causes carriage 315 to move along slot 320. As
carriage 315 moves, a portion of the conformable ligature is pulled
causing the loop about the various structures to tighten. When the
surgeon determines that the ligature is sufficiently tightened
about the structures to be fixed, the surgeon can tighten the
ligature capturing implant so that the ligature does not move
within the ligature capturing implant thereby securing the loop
about the structures. In other embodiments, the ligature capturing
implant may be configured to allow the ligature to be tightened but
not loosened. Consequently, once the surgeon is satisfied with the
tension in the loop, the surgeon does not have to further adjust
the ligature capturing implant to prevent loosening of the loop.
Preferably, tensioning tool 300 can apply a tensioning force of at
least between 300 and 1500 Newtons to the conformable ligature.
[0155] When the loop about the structures is secure, the surgeon
can rotate drive shaft 310 in the opposite direction to move
carriage 315 towards connector 335. This will release the tension
from the portion of the ligature between tensioning member 325 and
the ligature capturing implant to allow the surgeon to remove the
tensioning tool 300.
[0156] The embodiment of FIGS. 40 and 41 provides several
advantages over the embodiment of FIG. 39. First, the movement
speed and placement of carriage 315 can be finely controlled by
controlling rotation of drive shaft 310. This allows the surgeon to
have continuous control over the tensioning process and greater
control over the final tension of the ligature when compared to the
pulsed tensioning provided by the embodiment of FIG. 39.
Furthermore, the surgeon can easily reduce the tension in the
ligature by small, controllable amounts simply by rotating drive
shaft 310 in the opposite direction. Consequently, if the surgeon
deems that the ligature is too tight, the surgeon can rotate drive
shaft 310 in the appropriate direction until the ligature is at the
appropriate lower tension. This is a simpler process than having to
release a relatively large amount of tension and then retention the
ligature to the desired tension.
[0157] Another advantage is provided in procedures in which
multiple ligatures are being installed. In some cases, surgeons
find it desirable or necessary to use multiple ligatures. In such
procedures, the surgeon will often want to tension each ligature a
little at a time. For example, if there are three ligatures, the
surgeon will tension the first ligature a small amount, then
tension the second ligature a small amount, then tension the third
ligature a small amount, then return to the first ligature and
tension it some more and so on until all the ligatures are
tensioned the appropriate amount. The embodiments of FIGS. 40 and
41 provide an advantage for this type of procedure because they are
less bulky. This allows tensioning tool 300 to be left in place
during a procedure so that the surgeon can tension other ligatures
with other similar tensioning tools without removing tensioning
tool 300. Consequently, multiple tensioning tools can be during a
procedure to progressively tension a number of ligatures. Thus,
efforts can be divided along the spine during a reduction procedure
so that reduction is continuous.
[0158] FIGS. 42A and 42B illustrate another embodiment of a
tensioning tool 300. Tensioning tool 300 comprises a tool body 305
and a threaded drive shaft 310. A movable carriage 315 is engaged
with the threads of drive shaft 310 and moves along slot 320 in
tool body 305. Slot 320 can partially overlap carriage 315 to
capture carriage 315 in slot 320. In other embodiments, carriage
315 can be held in place by drive shaft 310. Carriage 315 carries
tensioning member 325 that acts as an attachment point for a
conformable ligature. Tensioning tool 300 further includes a handle
that provides an ergonomic user control to rotate drive shaft 310.
According to one embodiment, the handle can connect to drive shaft
310 using a quick connect 330.
[0159] Tensioning tool 300 also includes a connector 335 shaped to
interface with a ligature capturing implant (e.g., such as the
connection parts shown in FIGS. 1-13 and blocking bodies shown in
FIGS. 14-38). Connector 335 can be shaped to abut a variety of
ligature capturing implants or connector 335 can be interchangeable
such that a surgeon can select the appropriate interface member
based on the type(s) of ligature capturing implants used in a
particular procedure. According to one embodiment, connector 335
can simply abut the ligature capturing implant or, according to
other embodiments, may attach to the ligature capturing implant
Connector 330 can include tangs 340 that define an open area 345
through which the ends of the conformable ligature can pass so that
a portion of conformable ligature can be looped around tensioning
member 325.
[0160] FIGS. 42A and 42B further show extensions 366 that can move
in slot 420 as drive shaft 310 moves (e.g., due to compression of
spring 365 shown in the embodiment of FIG. 40). The position of
extensions 366 can be used to determine the amount of force applied
to the spring and hence the ligature.
[0161] In the embodiment of FIG. 42A, carriage 315 includes a
portion 370 that is exterior to tool body 305. This portion can
allow a surgeon to more easily grasp carriage 315 with fingers or a
tool to allow the surgeon to manipulate carriage 315. This can be
advantageous in embodiments such as shown in FIGS. 43A and 43B in
which the orientation of the carriage can be changed to engage or
disengage carriage 315 from drive shaft 310.
[0162] FIG. 42B is a diagrammatic representation of tensioning tool
300 with handle 375 attached Handle 375 provides an ergonomic
interface for a surgeon to rotate drive shaft 310 and may be
detachable or fixed. If the handle is detachable, a kit for
tensioning tool 300 can include a variety of handles to allow a
surgeon to select a preferred handle 375. In other embodiments, a
motor may attach to drive shaft 310 to allow for motorized rotation
of drive shaft 310.
[0163] FIGS. 43A and 43B are diagrammatic representations of a view
of carriage 315 carrying tensioning member 325 in a first
orientation (FIG. 43A) and a second orientation (FIG. 43B) relative
to drive shaft 310. Carriage 315 includes a drive shaft passage 355
through which drive shaft 310. Drive shaft passage can completely
or partially encircle drive shaft 310. In the embodiments of FIGS.
43A and 43B, drive shaft passage 355 includes thread engaging
portions 380 and unthreaded portions 385. Drive shaft passage 355
can be shaped and sized such that carriage 315 can rock slightly to
selectively engage or disengaged thread engaging portions 380 with
threads on drive shaft 310. According to one embodiment, the center
of mass of carriage 315 can be positioned so that carriage 325
naturally rests in the orientation of FIG. 43A with thread engaging
portions 380. In any case, when force is applied to tensioning
member 325 by a tensioned ligature, carriage 315 will tend to
rotate to engage thread engaging portions 380. Carriage 315 can be
rotated slightly to disengage thread engaging portions 380. This
can allow a user to easily slide carriage 315 to a desired
position. For example, a user can apply force by hand or with a
tool to portion 370 to rotate carriage 315 from the position shown
in FIG. 43A to the position shown in FIG. 43B to slide carriage 315
in either direction along drive shaft 310.
[0164] The ability to selectively disengage thread engaging
portions 380 so that the user can slide carriage 315 may make the
various portions of the tensioning procedure more efficient. Rather
than having to rotate drive shaft 310 to move carriage 315 to a
position in which the conformable ligature begins to tension, a
user can slide carriage 315 to that position (or other desired
position) and then rotate drive shaft 310 to further tension the
conformable ligature. Additionally, once the tension of the loop
about the various structures in the body has been set by fully
closing the ligature capturing implant to prevent loosening of the
loop, the user can simply slide carriage 315 along drive shaft 310
to remove tension from the portion of the conformable ligature
attached to tensioning member 325. Additionally, if for some reason
a user determines that tension must be released from the
conformable ligature quickly, the user can do so by sliding
carriage 315 rather than rotating drive shaft 310.
[0165] In the embodiment of FIGS. 43A and 43B, drive shaft passage
355 includes thread engaging portions 380 on the top portion of one
end and the bottom portion of the other end. In other embodiments,
drive shaft passage 355 may include a thread engaging portion 380
at just one end or at any suitable point along drive shaft passage
355.
[0166] In the previous embodiments, tensioning member 325 is
carried by carriage 315 that moves along drive shaft 310 as drive
shaft 310 rotates. In other embodiments, the tensioning member is
located at the end of a movable shaft. FIG. 44 is a diagrammatic
representation of another embodiment of a tensioning tool. In the
embodiment of FIG. 44, a tensioning tool 400 can include a tool
body 405, a tensioning member shaft 410 and a rotatable column 415.
Tensioning member shaft 410 carries a tensioning member 412 in the
form of a hook. Tensioning member shaft 410 can include threads
that engage with rotatable column 415. Rotation of column 415 can
cause shaft 410 to actuate to move tensioning member 412 towards or
away from ligature capturing implant 420. In the embodiment of FIG.
44, a user can loop a portion of the conformable ligature 418 about
tensioning member 425 and rotate column 415 to actuate shaft 410 to
increase or release tension in the conformable ligature.
[0167] Tensioning tool 400 can include an end 425 that contacts
ligature capturing implant 420. According to one embodiment, the
end of tensioning tool 400 can act as a tool portion to tighten a
rotatable ring or other portion of ligature capturing implant 420
to capture the conformable ligature in ligature capturing implant
420. As one example, end 425 can be adapted to engage with tool
portions 134 of the ligature capturing implant shown in FIG.
25.
[0168] Thus, like the embodiments of FIGS. 40-42B, the embodiment
of FIG. 44 includes a first portion in threaded engagement with a
second portion. Rotation of the portions relative to each other
causes translation of tensioning member 412. The position of
tensioning member 412 can be continuously controlled, avoiding the
shortcomings of pulsed tensioning. Additionally, the tension can be
easily released by rotating the portions of tensioning tool 400 in
an opposite direction to move tensioning member 412 closer to
ligature capturing implant 420.
[0169] In the above embodiments, a portion of the tensioning tool
is rotated to translate a tensioning member. While specific
embodiments are shown, other embodiments of translating a
tensioning member can be used. For example, the tensioning member
can be coupled to the tool body. As a shaft advances due to
rotation either of the shaft or another portion of the tensioning
tool in threaded engagement with the shaft, the tool body and
consequently, the tensioning member can be pushed away from the
ligature capturing implant causing tension in the ligature to
increase. The tension can be reduced by rotating the portions of
the tensioning tool in threaded engagement in the opposite
direction relative to each other.
[0170] According to various embodiments, a surgical procedure can
be performed using a tensioning tool that provides continuous
control over tensioning the ligature. A user can form a loop about
one or more structures in a patient's body with a conformable
ligature and a ligature capturing implant. The ligature capturing
implant can include ligature capturing comprising rods, compression
members or other ligature capturing implant. The structures can
include, for example, a bone, a bone fastener, a tendon, a bone
graft, a plate, a rod or other structure in the body. For example,
the loop can be placed about a portion of a vertebra. The user can
attach a portion of the conformable ligature to a tensioning member
of a tensioning tool that provides a continuous range of control.
The tensioning tool can comprise a first portion in threaded
engagement with a second portion. The user can rotate the first
portion relative to the second portion to move the tensioning
member to tension the loop. For example, a user can rotate a drive
shaft to move a carriage carrying the tensioning member. In some
embodiments, the user can disengage the carriage from the drive
shaft and slide the carriage along the drive shaft to a selected
position. As another example, the user can rotate a portion of a
tool engaged with a threaded shaft to cause the cause the shaft to
move. The first portion can also be rotated relative to the second
portion in an opposite direction to release tension from the loop.
The method can further comprise positioning the tensioning tool so
that a connecting portion of the tensioning tool abuts the ligature
capturing implant.
[0171] According to one embodiment, a spinal reduction can be
performed using tensioning tools. A method of progressive spinal
reduction can comprise forming multiple loops about structures in a
patient's body with multiple conformable ligatures and ligature
capturing implants and partially tensioning each conformable
ligature in turn with a corresponding tensioning tool until each
conformable ligature is at a desired tension to perform spinal
reduction procedure. Tensioning each conformable ligature may
comprise attaching a portion of that conformable ligature to a
tensioning member of the corresponding tensioning tool, the
corresponding tensioning tool comprising a first portion in
threaded engagement with a second portion and rotating the first
portion relative to the second portion to move the tensioning
member away from a corresponding ligature capturing implant to
tension that conformable ligature about at least a portion of a
vertebra. The first portion is rotated relative to the second
portion about an axis that is substantially parallel to a primary
direction of movement of the tensioning member.
[0172] Another embodiment of a method comprises providing a
tensioning tool comprising, a tool body defining a slot, a threaded
drive shaft running through at least a portion of the tool body, a
tensioning member and a carriage coupled to the tensioning member.
The carriage defines a drive shaft passage having at least one
thread engaging portion to engage threads on the drive shaft. The
drive shaft passes through the drive shaft passage. The method
further comprises forming a loop about one or more structures in a
patient's body with a conformable ligature and a ligature capturing
implant, coupling a portion of the conformable ligature to the
tensioning member and rotating the drive shaft to move the carriage
away from the ligature capturing implant to tension the conformable
ligature. Embodiments can also include rotating the drive shaft the
opposite direction to release tension from the loop. The structures
about which the loop is formed can include, for example, a bone, a
bone fastener, a tendon, a bone graft, a plate, a rod or other
structure in the body. For example, the loop can be located about
at least a portion of a vertebra for a spinal reduction
procedure.
[0173] According to one embodiment, the drive shaft passage of the
carriage includes one or more additional unthreaded portions. The
method can further comprise rotating the carriage to disengage the
at least one thread engaging portion from the threaded drive shaft
and sliding the carriage along the drive shaft to a desired
position.
[0174] Another embodiment of a method comprises passing a
conformable ligature around one or more structures in a body,
passing first and second ends of the conformable ligature through a
loop passage in a ligature capturing implant to form a loop,
adjusting the ligature capturing implant to increase to resistance
on the movement of the conformable ligature to a selected amount
that allows the conformable ligature to move through the ligature
capturing implant when a force is applied to the conformable
ligature, attaching a portion of the conformable ligature to a
tensioning member of a tensioning tool, rotating a threaded drive
shaft of the tensioning tool to move the tensioning member to apply
tension to the conformable ligature and adjusting the ligature
tensioning implant to prevent the loop from loosening. According to
one embodiment, rotating a threaded drive shaft of the tensioning
tool to move the tensioning member comprises rotating the threaded
drive shaft to move a carriage coupled to the tensioning member.
The carriage can define a drive shaft passage having at least one
thread engaging portion to engage threads on the drive shaft and
wherein the drive shaft passes through the drive shaft passage. The
method can further comprise positioning the tensioning tool so that
a connecting portion of the tensioning tool abuts the ligature
capturing implant. According to one embodiment the drive shaft can
be rotated in an opposite direction to release tension from the
conformable ligature.
[0175] According to one embodiment a drive shaft passage can
include one or more additional unthreaded portions. The method can
further include rotating the carriage to disengage the at least one
thread engaging portion from the threaded drive shaft and sliding
the carriage along the drive shaft to a desired position.
[0176] Another embodiment comprises a tensioning tool providing
continuous control of conformable ligature tension, comprising a
tool body defining a slot, a connection portion shaped to at least
abut a ligature capturing implant, a threaded drive shaft running
through at least a portion of the tool body, a tensioning member
and a carriage coupled to the tensioning member, the carriage
defining a drive shaft passage having at least one thread engaging
portion to engage threads on the drive shaft and wherein the drive
shaft passes through the drive shaft passage, wherein rotation of
the drive shaft causes the carriage to move towards or away from
the connection portion. According to one embodiment, the carriage
is configured to be rotated from a first position in which the at
least one thread engaging portions are engaged with threads on the
drive shaft to a second, slidable position, in which the at least
one thread engaging portions are not engaged with the threads of
the drive shaft. The tensioning tool can further comprise a drive
shaft seat in which a first end of the drive shaft is seated, a
spring that compresses between the drive shaft seat of and the tool
body, and a removable handle connected to a second end of the drive
shaft distal from the first end.
[0177] The foregoing specification and accompanying figures are for
the purpose of teaching those skilled in the art the manner of
carrying out the disclosure and should be regarded in an
illustrative rather than a restrictive sense. As one skilled in the
art can appreciate, embodiments disclosed herein can be modified or
otherwise implemented in many ways without departing from the
spirit and scope of the disclosure and all such modifications and
implementations are intended to be included within the scope of the
disclosure as set forth in the claims below.
* * * * *