Note: Descriptions are shown in the official language in which they were submitted.
CA 02375352 2001-11-27
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BONE SUTURING DEVICE
RELATED APPLICATIONS
This application is a continuation-in-part of US patent application number
09/476,682,
filed December 30, 1999, the disclosure of which is incorporated herein by
reference.
FIELD OF THE INVENTION
The present invention relates to forming channels through bones.
BACKGROUND OF THE INVENTION
Attaching a suture to a bone is a task that is well known in the art of
surgery. A
common solution is to screw a threaded screw into the bone. However,
screwdrivers used to
to perform this task are often complex and/or expensive. Another solution
described for example
in US. Patent 5,520,700 to Beyar et al., the disclosure of which is
incorporated herein by
reference, is to insert a threaded bone anchor into the bone. A possible
disadvantage of both
this and the previous techniques is that a hard foreign body is left implanted
in the body. In
general, it is desirable to leave as small an amount as possible of foreign
material in the human
bone. Additionally, screws and bone anchors typically cause a considerable
amount of trauma
to the bone, which trauma is undesirable.
PCT publication WO 97/47246, the disclosure of which is incorporated herein by
reference, describes a suture insertion device that purports to form channels
in a bone for the
suture to be tied through the channel. The needles suggested in this PCT
publication for
2o forming a curved channel are either curved or are super-elastic needles
that are supposed to
curve inside the bone. In general, these needles are inserted into the bone at
a perpendicular
thereto by pushing them along a suitable bore. An alternative method suggested
is drilling
using a rotary drill, along a curved path. However, it is noted that such
drills usually damage a
large amount of bone.
Biolectron, Inc. provides a device ("CurvTek") which drills along a curved
path in a
bone, from two ends of the path, using air-pressure powered rotary drill bits.
SUMMARY OF THE INVENTION
An object of some embodiments of the invention is to provide a method of
fixing a
suture to a bone, while causing a minimum of damage to the bone and/or a
minimum of
3o implanted foreign objects, especially a minimum of implanted hard objects.
An aspect of some embodiments of the invention relates to mounting a bone-
boring
needle on a rotary hinge. One desirable result of this structure is that
transfer of power to the
tip of the needle is more efficient. Another desirable result is a simpler
construction. Another
desirable result is obtaining a more controllable and/or known path inside the
bone. It should
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be noted that some or all of these desirable results (and others described
herein) might not be
achieved in some embodiments of the invention.
An aspect of some embodiments of the invention relates to boring a channel
through a
bone using two opposing needles. One desirable result is that more of the
force applied to the
needles is utilized to bore into the bone, rather than for pushing the needle
away from the
bone. In some embodiments, the needles are in a same plane. Optionally, the
needles are
curved. Alternatively, the needles are straight. In some embodiments, an anvil
which does not
enter the bone, but which provides a contra-force to the other needle replaces
one of the
needles.
to An aspect of some embodiments of the invention relates to a cross-section
of needles
used for boring in bone. Optionally the needles are smooth. Alternatively, the
needles are
grooved. Optionally the cross-section is circular, however, other cross-
sections, such as flat-
rectangular, triangular and ellipsoid may also be provided. Optionally, the
cross-sectional
shape varies along the length of the needle, for example providing a spiraling
cross-section.
An aspect of some embodiments of the invention relates to inserting a bone-
boring
needle into a bone at an angle substantially different from a perpendicular.
Optionally, two or
more needles are provided, facing each other and applying force to the bone at
the same time,
in opposite directions and having a main force vector pointed towards a common
point.
An additional result of entering the bone at the non-perpendicular angle is
that, even in
2o a flat or concave bone, the resulting path is not a full half circle, but
only an arc of a circle. In
some cases, as described herein, a path which is more than a half circle may
be bored.
Although an arc path is preferred, in some embodiments of the invention other
curves may be
formed. Further, although the curves Iare optionally planar, in some
embodiments of the
invention, the curves are non-planar, for example being bi-planar (each of two
halves of the
curve in a different plane).
An aspect of some embodiments of the invention relates to a method of boring a
hole
in a bone in which a cortex of a bone is penetrated using a drill and a
medulla of the bone is
bored using one or two needles. In an embodiment of the invention, the drills
are straight and
the needles are curved, so the needles meet inside the bone. Optionally, the
drills do not move
other than rotating around their axes. Alternatively, the drills travel along
a curved path, for
example one defined by the needles. Alternatively or additionally to the
needles being curved,
the needles are straight. In an embodiment of the invention, the needles (and,
optionally, the
thread) pass through the drill bits. In some embodiments of the invention, the
needles do not
travel on a hinge, if the cortex is pierced by a drill. In an alternative
embodiment of the
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invention, the drill bits drill through all or most of the medulla, meeting
inside the bone. The
drill bits may be curved in some embodiments. The needles may be curved or
straight and may
complete a small part of boring not performed by the drill bits.
In one embodiment of the invention, only one needle is provided, which extends
from
one drill bit to the other one. Optionally, the needle has a removable tip at
its end, which tip
engages the other drill bit. In one embodiment, the bit, once engaged by the
drill bit, rotates so
that it is not dislodged by the bone when the drill and tip are retracted. In
some embodiments
of the invention, the needle travels through a lumen defined in the drill bit.
In others, the
needle travels along a groove defined in the drill bit.
l0 An aspect of some embodiments of the invention relates to a drill bit for
drilling in
bone that includes an aperture for the extension of a needle through the
aperture in the drill bit.
Optionally, the aperture is in the side of the drill bit. In an embodiment of
the invention, the
drill bit is mounted in a drill head that mechanically synchronizes the
angular position of the
drill bit and the extension of the needle. Alternatively, when the needles
advance, the drill bits
are released to rotate freely, so that the advance of a needle can rotate the
drill bit to a desired
angular position. Alternatively, an electrical synchronization method is used,
for rotating the
drill bits a complete number of rotations so that they are properly aligned
when they stop.
Alternatively, the needle exits through the tip of the drill bit. Optionally,
the needle forms a
hole in the drill bit when it extends. Alternatively or additionally, the
drill bits reciprocate,
instead of rotating.
An aspect of some embodiments of the invention relates to a method of
transferring
power from a power source to a tip of a bone-boring needle. Optionally, the
power is applied
using a lever. In an embodiment of the invention, a main leverage point is
provided at or about
the needle. Optionally, a second leverage point is provided further away from
the needle and
remote from the power source. In an embodiment of the invention, the power
source is a
human hand that moves a lever relative to a handle. The movement of this
handle-lever is
transferred, optionally using a cable or a bar to a second lever near the bone-
boring needle.
One desirable result of providing the leverage near the needle is that a less
rugged construction
is possible. Possibly, the bone-boring device is flexible rather than rigid.
An aspect of some embodiments of the invention relates to a method of
threading a
bore. In an embodiment of the invention, two needles are inserted -from either
side of the bore.
The needles meet and when one needle is retracted, it pulls the other needle
and a thread
attached thereto along with it. In an embodiment of the invention, the needles
form the bore
when they are inserted. Alternatively, first the bore is formed and then the
needles are inserted.
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An aspect of some embodiments of the invention relates to a tip exchange
mechanism,
in which a sharp tip attached to a thread is exchanged between two needles
that meet inside a
bone. In an embodiment of the invention, the tip is mounted at the end of a
needle and forms a
boring tip. When the two needles meet, the tip is captured by the other needle
and retracts with
it, pulling a thread along with it. Alternatively, the tip includes a long
flexible extension, to
which extension the thread is attached. Optionally, the extension is a super-
elastic wire. Thus,
the thread is not required to be inside the bone while the needles are in the
bone and is less
likely to be damaged. Also, such an extension is less likely to tear when the
tip is pulled
through the formed bore. Also, in some embodiments contact shearing forces may
be applied
1o to the thread. A flexible metallic extension is expected to resist such
forces. Thus, a flexible
extension may be provided, for example, also for a needle retraction mechanism
as above, and
not only for tip exchange mechanisms.
An aspect of some embodiments of the invention relates to apertured needle
tips for
engaging a sharp tip of an opposing needle. In an embodiment of the invention,
the apertured
tip comprises a bore through the needle, optionally formed when the needle is
straight.
Alternatively or additionally, the tip is slotted, optionally so that it
elastically (or plastically)
distorts to engage the opposing tip. In an embodiment of the invention, the
bore is not along
the axis of the needle, so that bone material that enters the bore at one end,
exists at the other
end. Optionally, the bone material exits within the bone volume, however, in
some
2o embodiments it exists inside the device that holds the needle or outside
the bone.
Alternatively, instead of a through bore, a blind bore is provided. Possibly,
a hole is provided
on the side of the needle, to allow bone matter which enters the aperture to
exit through the
hole.
An aspect of some embodiments of the invention relates to a retractable tip of
a tip
receiving needle. In an embodiment of the invention, a sharp mandrel is placed
within the bore
of the receiving needle. When the needle is advancing through the bone, the
mandrel is
optionally advanced, to function as a boring tip for the needle. When the two
needles meet, the
mandrel is optionally retracted, leaving an aperture at the tip of the
receiving needle, to receive
the thread carrying tip of the other needle and/or for engaging the other
needle.
An aspect of some embodiments of the invention relates to a method of forming
a path
for a thread in a pair of needles. In an embodiment of the invention, two
needles are inserted
into a bore and when the needles meet a path is formed, along and/or through
the needles from
one side of the bore to the other side thereof. A thread is then threaded
through or along this
path. In an embodiment of the invention, the needles meet end to end.
Alternatively or
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additionally, the needles meet side to side. One needle may be closer to the
bone surface than
the other at their meeting point or they both might be the same distance from
the bone surface
but laterally displaced with respect to the surface.
An aspect of some embodiments of the invention relates to providing a bone-
boring
geometry that is not adversely affected by small errors in the placement of a
bone-boring head
against a bone. In an embodiment of the invention, this is achieved by
providing a needle
which rotates on a hinge and providing a resting point of said bone boring
head near a center
of rotation of the needle. Alternatively or additionally, the invariance is
achieved by providing
a self leveling bone-boring head that mechanically aligns itself relative to a
bony area against
which it is placed. Alternatively or additionally, the invariance is provided
by an entire bone
boring device being held by a hinged holder, so that the entire device rotates
around the hinge
to achieve an optimal placement against the bone.
An aspect of some embodiments of the invention relates to a safety mechanism
that
shelters a sharp tip of a bone boring device, until said tip is to be inserted
into a bone. In an
embodiment of the invention, the mechanism is controlled from a handle of the
device so that
the tip is not exposed inadvertently. In an embodiment of the invention, the
safety mechanism
is a shield that is retracted by applying pressure on the handle of the
device. Optionally the
applied pressure is also used to activate the device. Alternatively or
additionally, the shield is
further protected by a safety latch which prevents the pressure from being
transferred to the
2o shield unless the latch is in an "armed" state. Alternatively or
additionally to a retracting
shield, it is the sharp tip which is selectively retracted and advanced,
relative to a shield, so
that it does not engage tissue unless a desired sequence has been performed.
In an embodiment of the invention, the device is designed to support the
following
sequence: first the needles are urged towards the bone, so that they compress
any soft tissue
between them and the bone and then the needles are advanced through the soft
tissue (if
necessary) to bore a hole through the bone.
An aspect of some embodiments of the invention relates to a safety feature for
preventing damage to or from, circular needles that are inserted in a bone. In
an embodiment of
the invention, when a device coupled to said needles is released, the
releasing action first
3o retracts the needles and only then allows the device to be moved.
An aspect of some embodiments of the invention relates to sensing and remotely
indicating when certain spatial configurations of a bone borer are achieved.
In an embodiment
of the invention, when these configurations sensed, a visual and/or audible
indication is
displayed to a surgeon. Alternatively or additionally, when these
configurations are sensed, a
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function of the borer is locked and/or unlocked. One example of a sensed
spatial configuration
is an angle of the borer head relative to the bone. Another example is
determining if two
boring needles meet in the bone in a desired manner.
There is thus provided in accordance with an exemplary embodiment of the
invention,
a bone boring device, comprising:
a needle base;
a pivot;
at least one curved needle having a tip at one end thereof and rotatably
mounted on the
needle base, said needle and pivot arranged and adapted so that when said tip
is placed against
to bone tissue and said needle is rotated around said pivot, said needle is
urged into said bone.
Optionally, said pivot comprises a rotary hinge coupled to said needle base.
Alternatively or
additionally, the device comprises a resting point adjacent said pivot and on
an outside of said
device, which resting point is adapted to be placed against said bone.
In an exemplary embodiment of the invention, said curved needle has a radius
of
curvature matching a distance of said needle from said pivot. Alternatively or
additionally,
said device comprises at least one drill bit for drilling into said bone and
defining a channel
formed therethrough and an aperture from the outside of said bit to said
channel, wherein said
at least one needle is adapted to fit through said aperture. Optionally, said
drill comprises a
bone drill, adapted to drill through a cortex portion of said bone.
Alternatively, said at least
one needle is not suitable for boring through a cortex portion of said bone.
In an exemplary embodiment of the invention, said at least one drill bit
comprises two
drill bits. Alternatively, said at least one drill bit comprises a single
drill bit.
In an exemplary embodiment of the invention, said drill bits are positioned
substantially parallel to each other. Optionally, said drill bits rotate in a
same direction.
Alternatively, said drill bits rotate in opposite directions.
In an exemplary embodiment of the invention, said at least one needle
comprises at
least two needles. Alternatively, said at least one needle comprises a single
needle. Optionally,
said at least one needle, said channel, said aperture and said drill bits are
arranged and adapted
such that said at least one needle can pass through said channel in said at
least one of said two
3o drill bits, exit through said aperture and meet a second one of said two
drill bits. Optionally,
said second drill bit defines a receiving aperture in its side and wherein
said needle meets said
second drill bit at said receiving aperture. Optionally, said at least one
needle comprises a
detachable tip and wherein said receiving aperture is adapted to engage said
detachable tip.
Optionally, said receiving aperture comprises a narrowing of said aperture
radially inside of a
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volume defined by said second drill bit. Optionally, said detachable tip is
adapted to rotate
inside said drill bit after said engagement, to lie within said volume.
In an exemplary embodiment of the invention, said second drill bit defines an
axial
groove adjacent a drilling tip thereof, of a size sufficient for receiving a
thread attached to said
detachable tip.
In an exemplary embodiment of the invention, said aperture is formed in a side
of said
drill bit.
In an exemplary embodiment of the invention, said device comprises a motor for
rotating said drill bits. Optionally, said motor is a stepper motor adjusted
to rotate said drill
1o bits only whole numbers of rotations. Alternatively, said device comprises
a mechanical stop
for stopping said drill bits so that they are angularly aligned.
In an exemplary embodiment of the invention, said device comprises a sensor
for
detecting an angular position of at least one of said drill bits and
comprising a controller for
controlling said motor responsive to input from said sensor.
In an exemplary embodiment of the invention, said at least one needle
comprises a first
needle and a second needle.
In an exemplary embodiment of the invention, said needles rotate about a same
pivot
for urging into said bone. Alternatively, said needles do not share a common
hinge.
In an exemplary embodiment of the invention, said needles are adapted to meet
at their
2o ends, when said needles are rotated around said pivot. Optionally, said
needles meet tip-to-tip.
Alternatively, said needles meet side-to-side, at their ends.
In an exemplary embodiment of the invention, said needles are formed with a
conduit
and wherein, when said needles meet, a continuous conduit is formed along the
needles.
In an exemplary embodiment of the invention, said first needle is adapted to
engage a
tip of said second needle. Optionally, said second needle is hollow, defining
a conduit
therethrough. Alternatively, said second needle has a groove defined along
most of its length,
describing a conduit.
In an exemplary embodiment of the invention, said device comprises a channel
substantially contiguous with said conduit and adapted for advancing a thread
through said
3o channel and along said conduit. Optionally, said device comprises a thread
pusher for
advancing thread through said conduit and said channel. Optionally, said
thread pusher is long
enough to extend through said channel and said conduit to outside said device.
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In an exemplary embodiment of the invention, said tip comprises a detachable
tip to
which the thread is attached. Optionally, said detachable tip comprises an
extension to which a
thread is attached, which extension is substantially longer than said second
needle.
In an exemplary embodiment of the invention, said second needle is detachable
from
said needle base. Optionally, said needles meeting causes said second needle
to detach.
Optionally, said second needle is adapted for attaching a thread thereto.
In an exemplary embodiment of the invention, said first needle defines an
aperture at
its tip, which aperture is adapted to engage said tip of said second needle.
Optionally, said
aperture is an opening to a blind hole. Alternatively, said aperture is an
opening to a through
1o hole which exists through a side in said needle. Alternatively, said
aperture connects to a
hollow volume along an axis of said needle. Optionally, said device comprises
a sharp-tip
mandrel that fills said hollow volume, for at least part of a rotation of said
needle around said
pivot. Optionally, said mandrel is retracted when said needles meet.
In an exemplary embodiment of the invention, said aperture connects to a
hollow
volume having an axis oblique to an axis of said needle. Alternatively, said
aperture is an
opening to a volume extending into said needle and having a substantially
constant inner
diameter. Alternatively, said aperture is an opening to a volume extending
into said needle and
having an inner diameter that increases away from the aperture. Alternatively,
said aperture is
an opening to a slotted volume.
2o In an exemplary embodiment of the invention, said device comprises a
handle.
Optionally, said needles and said hinge are comprised in a disposable
cartridge, separable from
said handle.
There is also provided in accordance with an exemplary embodiment of the
invention,
a bone boring device, comprising:
at least one needle adapted for boring into bone;
a force providing element, remote from said needle, for advancing said needle;
and
a force amplifier, coupled to said needle and adjacent to said needle which
amplifies
force provided from said force providing element and supplies it to said
needle. Optionally,
said at least one needle comprises two needles. Alternatively, said needle is
mounted on a
3o hinge and wherein said needle is rotated around said hinge by force
provided by said force
amplifier. Alternatively, said force amplifier comprises a lever.
There is also provided in accordance with an exemplary embodiment of the
invention,
a bone-boring device, comprising:
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at least one curved needle adapted for extending to bore a hole in a bone;
a base holding said needle and including a portion on an outside of said
device, which
portion is adapted for being placed against a bone;
a handle coupled to the base; and
a needle retractor, which retracts said needle when a force on said handle in
a particular
direction is lower than a predetermined amount, prior to said base retreating
from said bone in
response to a lowering of the force.
There is also provided in accordance with an exemplary embodiment of the
invention,
a bone-boring device, comprising:
at least one curved needle adapted for extending to bore a hole in a bone;
a base holding said needle and adapted for being placed against a bone
a handle coupled to the base; and
a needle advancer, which advances said needle only when a force on said handle
in a
particular direction is higher than a predetermined amount, said predetermined
force assuring
1s that said base is urged against said bone.
There is also provided in accordance with an exemplary embodiment of the
invention,
a detachable tip for a needle, comprising:
a tip having a sharp end and adapted for boring through a bone; and
a flexible extension of said tip, opposite of said sharp end and substantially
longer than
said sharp tip, attached to a thread. Optionally, said tip is adapted for
being grasped by a non-
solid needle, at a side of the extension. Alternatively, said sharp end is
adapted for being
grasped by a hollow needle, at a side of the sharp tip opposite of the
extension.
There is also provided in accordance with an exemplary embodiment of the
invention,
a self aligning device for boring into bone, comprising:
a boring head having at least two boring tips;
a body; and
a hinge coupling said head to said body at a location substantially
equidistant from said
boring tips. Optionally, said boring tips comprise drill bits. Alternatively
or additionally, said
boring tips comprise boring needles.
In an exemplary embodiment of the invention, said head includes a power source
for
activating said boring tips. Alternatively or additionally, said boring tips
face said handle.
There is also provided in accordance with an exemplary embodiment of the
invention,
a method for forming a channel in a bone, especially an in vitro bone,
comprising:
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drilling two holes in a cortex of the bone; and
advancing at least one needle through said drilled holes through a medulla of
said bone.
Optionally, said holes are perpendicular to a surface of said bone.
Alternatively, said at least
one needle comprises two needles that meet inside the bone.
There is also provided in accordance with an exemplary embodiment of the
invention,
a bone boring device, comprising:
at least one bone-drilling drill bit defining a needle path therein; and
at least one needle adapted to travel along said needle path. Optionally, said
needle
path comprises a lumen. Alternatively or additionally, said device comprises a
needle base and
1o a pivot, wherein said at least one needle has a tip at one end thereof and
is rotatably mounted
on the needle base, said needle and pivot arranged and adapted so that when
said tip is placed
against bone tissue and said needle is rotated around said pivot, said needle
is urged into said
bone. Alternatively or additionally, said at least one needle comprises at
least two needles.
Alternatively or additionally, said at least one drill bit comprises at least
two drill bits.
BRIEF DESCRIPTION OF THE DRAWINGS
Some embodiments of the invention will now be described with reference to the
following description of some embodiments thereof in conjunction with the
figures, wherein
identical structures, elements or parts which appear in more than one figure
are optionally
labeled with a same or similar numeral in all the figures in which they
appear, in which:
2o Figs. 1A and 1B are schematic illustrations of a bone-boring device, in un-
activated
and an activated configuration, respectively, in accordance with an exemplary
embodiment of
the invention;
Fig. 2 is a schematic illustration of a hinged dual-needle boring-head, in
accordance
with an exemplary embodiment of the invention;
Figs. 3A and 3B illustrate the action of a leveraged hinged dual needle boring
head, in
accordance with an exemplary embodiment of the invention;
Fig. 3C illustrates a replaceable needle-boring head, with needles retracted,
in
accordance with an exemplary embodiment of the invention;
Figs. 4A and 4B schematically illustrate a bone-boring device having a needle
3o extension/retraction mechanism that matches a particular activation logic,
in accordance with
an exemplary embodiment of the invention;
Fig. 5A illustrates an end to end needle configuration, in accordance with an
exemplary
embodiment of the invention;
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Fig. 5B illustrates various needle cross-sections for the configuration of
Fig. 5A;
Figs. 6A and 6B are a side and a top view, respectively of a side-by-side
needle
configuration, in accordance with an exemplary embodiment of the invention;
Fig. 7A illustrates a top-bottom needle configuration, in accordance with an
exemplary
embodiment of the invention;
Fig. 7B is a cross-sectional view along line B-B in Fig. 7A, showing a detail
of the
needle configuration;
Figs. 8A-8C illustrate a detachable needle configuration, and its use in
boring and
threading a bone, in accordance with an exemplary embodiment of the invention;
to Figs. 8D-8F illustrate a safety latch which releases the detachable needle
of Figs. 8A-
8C only if the rivo needles meet, in accordance with an exemplary embodiment
of the
invention;
Figs. 9A and 9B schematically illustrate a hinged single needle boring head,
in
accordance with an exemplary embodiment of the invention;
Fig. 10A illustrates an angle independence of a boring head, in accordance
with an
exemplary embodiment of the invention;
Fig. lOB illustrates a self aligning boring head, in accordance with an
exemplary
embodiment of the invention;
Figs. 11A and 11B illustrate a self aligning boring device in accordance with
an
2o exemplary embodiment of the invention;
Fig. 11 C illustrates an alternative self aligning boring device, in
accordance with an
exemplary embodiment of the invention;
Figs. 12A and 12B illustrate a thread pusher, in accordance with an exemplary
embodiment of the invention in an open configuration and in a closed
configuration;
Figs. 13A and 13B illustrate a method of passing a thread through the bores of
the
needles of Figs. 5A and 5B, in accordance with an exemplary embodiment of the
invention;
Figs. 14A-14D illustrate various stages in a usage of a thread-exchanging
needle
assembly, in accordance with an exemplary embodiment of the invention;
Figs. 14E-14H illustrate needle-receiving tips in accordance with various
embodiments
of the invention;
Figs. 15A-15D illustrates the operation of a hollow needle boring mechanism,
in
accordance with an exemplary embodiment of the invention, in which a bore in
one of the
needles is filled by a retractable mandrel;
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Figs. 16A and 16B illustrate a combined drilling and needle boring head, in
accordance
with an exemplary embodiment of the invention;
Figs. 17A-17E illustrate a method of using the combined head of Figs. 16A-B;
Fig. 18 illustrates a variant of the combined boring head of Figs. 16A-B
Figs. 19A-19E illustrate the use of an alternative combined drilling and
boring head, in
which only one needle is used for two drill bits, in accordance with an
exemplary embodiment
of the invention;
Figs. 20A-20C show a blowup of the drill bits and the needle of Figs. 19A-19E,
illustrating an engagement of the needle tip by an aperture in a drill bit, in
accordance with one
embodiment of the invention;
Figs. 21A and 21B illustrate, in perspective view, the drill bits of Figs. 20A-
20C, in
accordance with one embodiment of the invention;
Figs. 22A-22E illustrate a method of threading the device of Figs. 19A-19E, in
accordance with one embodiment of the invention;
Fig. 23A shows a sling pre-mounted on a device 600, in accordance with one
embodiment of the invention;
Fig. 23B shows a sling ready for suturing to a bone, in accordance with one
embodiment of the invention;
Fig. 24 illustrates a bone-boring head mounted at an end of an endoscope,
catheter or
trocar, in accordance with an exemplary embodiment of the invention;
Fig. 25 illustrates a bone-boring head mounted at a side of an endoscope,
catheter or
trocar, in accordance with an exemplary embodiment of the invention;
Fig. 26 illustrates a method of treating a fractured bone, in accordance with
an
exemplary embodiment of the invention; and
Figs. 27A-27C illustrate an alternative method of attaching a thread to a
bone, in
accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF SOME EMBODIMENTS
Figs. 1A and 1B are schematic illustrations of a bone-boring device 100, in un-
activated and activated configurations, respectively, in accordance with an
exemplary
3o embodiment of the invention. Device 100 generally comprises a base 102
including a bone-
boring head 104, a handle 106, possibly including a lever 108 and a shaft 110
interconnecting
the handle and the base. In Fig. 1A, a pair of needles 112 of bone-boring head
104 are
retracted. In Fig. 1B, when lever 108 is moved towards handle 106, needles 112
rotate and
extend, boring a hole in adjacent bone.
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The device shown in Figure 1A and 1B is suitable for attaching sutures to an
inside
face of a pubic bone. Thus, needles 112 extend towards the handle. In use,
boring-head 104 is
placed against the pubic bone, upwards pressure being applied to handle 106 to
assure good
contact between the boring head and the bone, and then lever 108 is depressed
to advance
needles 112 and bore the hole. In devices for other uses, bone-boring head 104
may extend
away from handle 106 or at a different orientation thereto and may even be
adjustable between
several orientations.
Fig. 2 is a schematic illustration of a hinged dual-needle boring-head 120, in
accordance with an exemplary embodiment of the invention. Optionally, head 120
comprises a
1o needle 122 and a needle 124 that share a common hinge 126. When the needles
rotate around
the hinge, they form a channel 128 in the bone.
In an exemplary embodiment of the invention, the needles are arranged to enter
the
bone at a non-perpendicular angle thereto. Thus, forces applied by the two
needles to the bone
cooperate for drilling a bore. In the figure, rotation of needle 124 around
its hinge applies a
force vector FV1, which can be represented by its components FX1 and FYl.
Similarly, needle
122 applies a force vector FV2, represented by components FX2 and FY2. An
additional force
FC is applied by the needles (or by a resting point 134, Fig. 3A below) as a
result of a
physician urging boring-head 120 against the bone. Force FC is also found in a
needle that is
directed perpendicular to the bone. FC urges the needle into the bone.
However, as the bone
has a large resistance to penetration by the needle, a large FC is required to
effect that entry,
which force is applied from outside the body. In addition, the force
applicator is not stable,
allowing the needle to slip and/or penetrate at an undesirable angle and/or
form an undesirable
channel.
In the embodiment shown, forces FX1 and FX2 are in opposing directions, thus
stabilizing head 120 from moving. Also, it is noted that the channel is not
perpendicular to the
bone surface but also includes a significant X component, already at its
start. Thus, once the
needles enter the bone, or if the bone is not smooth, the FX forces can start
boring in the
desired direction immediately. Further, if the FX forces engage the surface,
the FY forces can
start boring, even without an FC force (or with a reduced one) to hold the
needles against the
3o bone, since the bone, overlying the needles, holds them in place. Further,
if the needles are
forced through soft tissue, once the soft tissue is pierced, the soft tissue
assists in holding the
needles against the bone.
Additionally, forces FY1 and FY2 are generated at the boring-head and are
typically,
but not necessarily, smaller than force FC. The application of forces FY1 and
FY2 is at least
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somewhat decoupled from the FC force, making them easier to control, so that
increasing
these forces or decreasing them (for example by a sudden give of the bone) do
not necessarily
affect the application of force FC to the handle. Thus, the bone boring head
is more stable.
Figs. 3A and 3B illustrate the action of a leveraged hinged dual needle boring
head
130, in accordance with an exemplary embodiment of the invention. In this
embodiment, not
only are the bone-penetration forces generated near the head, but also any
force amplification
necessary for generating these forces is also performed near the head, so that
there is less
variation in the force that is transferred along the device. Thus, a more
stable and/or easy to
use device is provided.
In head 130, force amplification and/or transduction is provided by
translating
substantially linear motion of a lever 136 and a lever 138 into rotation of
needles 122 and 124.
In an embodiment of the invention, lever 136 and needle 122 are formed of a
single piece of
material, possibly increasing reliability and/or reducing cost. In an
embodiment of the
invention, the linear force is applied to levers 136 and 138 using anchors 140
and 142, for
example holes. A shield 132 optionally prevents the needle tips from engaging
tissue when the
needles are retracted. Alternatively (and as shown), the tips of the needles
may peek out
beyond the shield, but possibly not beyond the resting point 134 (described
below).
As can be appreciated from Figs. 2 and 3A-3B, different needle tip force
geometries
will have different mechanical properties with respect to entering a bone.
Different medical
2o situations, bone types, bone surfaces and/or other considerations may
require different bore
head configurations. Parameters that can varied may include one or more of the
following:
(a) the attack angle of the needles, and especially of the tip thereof, which
can affect
the force vectors at the tip (i) when the needle enters the bone and (ii) when
the needle travels
through the bone; the effect of the attack angle being, for example, neutral,
urging the needle
towards the hinge, urging the needle away from the hinge or urging the needle
in a plane
perpendicular to the needle;
(b) penetration depth, i.e., a distance between where the needles meet inside
the bone
and a resting point 134 of the bore-head against the bone surface (shown
slightly separated
from the surface, for clarity of presentation);
(c) distance between the entry holes;
(d) leverage (affected by the lengths of both the levers and the needles);
(e) cross-section of the needle tip and the needle as a whole (will be
described in
greater detail below);
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(f) threading behavior of the needles (described in greater detail below);
(g) radius of rotation; and
(h) a degree of asymmetry between the parameters of the two needles, for
example
causing one needle to bore easier than the other.
In an embodiment of the invention, a plurality of replaceable boring-heads is
provided,
each head having different parameter values. Fig. 3C illustrates a replaceable
needle-boring
head 150, in accordance with an embodiment of the invention. A plurality of
matching
protrusions and depressions 154 and 152 are optionally provided on the boring
head and on the
base of the device, to align the head and the device. In an embodiment of the
invention, a
1o coupler 156 and a coupler 158 are provided at the ends of force
transmission bars (described in
Figs. 4A and 4B) which engage anchors 140 and 142. Optionally the coupler is a
snap coupler
which can be separated by the application of sufficient force.
Alternatively, the boring head includes means for adjusting one or more of the
above
parameters. In one example, the penetration depth can be adjusted by
increasing a distance
between resting point 134 and hinge 126, for example using a screw mechanism.
This also
affects the distance between the entry holes of the needles.
It should be noted that the two needles may have different cross-sections,
different radii
of rotation, different leverage, different angles of attack (penetration of
the tip) and/or other
characteristics in which they differ. In some embodiments of the invention,
however, the
needles are substantially the same. In addition, although the two needles can
use different
hinges, possibly with a controllable distance (in the X and/or Y axes) between
the hinges, in an
embodiment of the invention, a single hinge is shared by the two needles, as
shown.
Figs. 4A and 4B schematically illustrate a bone boring device 200, in
accordance with
an alternative embodiment of the invention. Device 200 comprises a base 202
having a boring
head such as boring head 130, mounted thereon. Base 202 is connected to a
shank 210, having
a lever 206 coupled thereto. A contra-force spring 214 couples lever 206 to
shank 210. In use,
head 130 (actually resting point 134) is placed against a pubic bone (not
shown). Lever 206 is
pulled away from the boring head against the resistance of spring 214. At this
stage, the
motion of lever 206 only urges resting point 134 against the pubic bone (the
force being
transmitted by spring 214), compressing intermediate tissue. Optionally the
motion of lever
206 does not extend the needles. After a short travel distance, handle 206
engages an engager,
such as a protrusion 216 provided on a force-transferring element 212. Once
engaged, further
motion of lever 206 causes force to be transmitted to element 212 and hence to
boring head
130, causing the needles to extend. In an embodiment of the invention, a peg
(or other type of
CA 02375352 2001-11-27
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latch) 218 further couples lever 206 to force transferring element 212 via an
indentation 219 in
element 212.
Element 212 rotates one, possibly two levers 220 and 222 around their
respective
hinges 224 and 226, thereby causing a bar 230 and a bar 232, coupled to the
levers, to move
along the base and transfer force to the levers of the boring-head (which move
as described
above with reference to Figs. 3A and 3B). As shown, the configuration of the
two levers
reduces the transferred force. However, in other embodiments of the invention,
the levers
increase the transmitted force, while reducing the travel distance.
When lever 206 is released, peg 218 forces the needles to be retracted, before
reducing
to the pressure of head 130 against the pubic bone. Thus, there is less
likelihood of the needles
damaging the bone after the bone boring is completed. In an embodiment of the
invention,
once the needles are retracted, peg 218 is disengaged (for example by an
inclined portion 221
of the peg when it is urged against a protrusion 223) and device 200 can be
removed from the
pubic bone. Alternatively, peg 218 does not disengage, so that device 200 is
substantially a
one-use device. Alternatively, peg 218 is disengaged by a specially provided
control, such as a
button, to prevent inadvertent reuse of the device before the physician is
ready for another
bone-boring process.
Alternatively or additionally to the specially provided control, a safety
latch may be
provided which does not allow lever 206 to travel far enough along shank 210
to extend the
2o needles, unless the latch is released. Thus, inadvertent damage to tissue
by the needles is less
likely. Alternatively or additionally to the safety latch, a pin (not shown)
may be provided at or
about resting point 134, which pin, if depressed with sufficient force, causes
the needles or
their levers to engage the bars 230 and 232. If an insufficient force is
presented, the needles are
not coupled to the bars and cannot be extended. Possibly, a spring is provided
at the needles,
which spring retracts the needles from the bone if no opposite force is
provided by the bars.
Thus, if there is insufficient pressure on the pin, the needles are retracted.
Such a pin may act
in a purely mechanical fashion or may include an electrical circuit to alert
the operator and/or
actively retract the needles.
It should be noted that a designated resting point 134 is not required.
However, in
3o many cases it is desirable that the needles be completely retracted and
some element is
generally required for compressing intermediate soft tissue and/or for
stabilizing the boring
head.
In devices not meant for the pubic area, or in devices in which boring head
130 can
point away from lever 206, spring 214, protrusion 216 and peg 218 may need to
be replaced
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WO 00/74578 PCT/IL00/00320
and/or augmented by suitably located elements which perform their functions,
in a reverse
direction. Additionally, various designs of handles, for example, axial or
perpendicular to the
device body may be provided.
Element 212 is shown as a bar. However, it is noted that most of the force is
applied
when extending the needles. Thus, element 212 may have its function served by
a wire,
optionally with a retraction spring for retracting the needles when lever 206
is released.
Alternatively or additionally, bars 230 and 232 may be replaced by wires.
Possibly, a
coaxial wire pair is used, in which the inner wire is attached to one lever
and the outer one to
the other lever. Thus, boring head 130 can be more easily twisted around base
202 and/or
to otherwise moved. Optionally, a spring is provided to retract the needles
once they are
extended.
As can be appreciated, the resistance of spring 214 is related to the total
force applied
against the pubic bone. In an embodiment of the invention, the tension in
spring 214 can be
adjusted to require a physician to apply a desirable minimum pressure against
the pubic bone.
Alternatively or additionally, the linearity of the spring and/or the force
constant of the spring
may be varied to match a desired profile of applying force to the needles
and/or to provide
better controllability of the force. In one example, a large force is required
to enter the bone,
but, once the bone is entered, possibly less additional force is required to
continue the boring.
In general, it is possible to control the amount of compression force applied
to the soft tissue
2o before and after the needles advance, by suitable varying the parameters of
the spring, motion
of the lever 206 and the force amplification of the power train to the
needles.
In some cases it is desirable that the physician be provided with a tactile
indication of
the extension of the needles. This may be achieved by putting a protrusion on
shank 210,
under spring 214 at a point corresponding to the extension of the needles.
Thus, as the lever is
pulled a "bump" is felt at that point. Additional such protrusions may be
provided at other
points on the shank, for example at a point where the needles are fully
extended and no further
force is required. Alternatively or additionally, to these bumps transmitting
feed-back to the
physician, the bumps may be used to control the device, for example as a
safety mechanism
that allows the needles to extend or as a control which "fires" the thread (as
described below).
3o Alternatively or additionally, a large protrusion 217 is provided
underlying spring 214 and
frictionally engaging lever 206, so that compressing the soft tissue will be
more difficult than
advancing the needles. Possibly, the protrusion applies more friction when the
lever is pulled
than when the lever is released, for example by suitable machining of its
surface. In an
exemplary device the various parameters, such as spring constant, amount of
motion and
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needle leverage are adapted so that a 100N force is required to compress the
soft tissue prior to
the extension of the needles. An additional force of 40N is optionally
required for extension of
the needle through a typical pubic bone. The total motion of the lever is 10
mm for
compressing the tissue and 4 mm for extending the needles.
Although this embodiment is shown with a single lever 206, a non-movable
handle
may also be provided, for example for co-gripping with lever 206. Also,
instead of manual
forces used to power the needle head, air-pressure, electric or other types of
power sources
may be used.
Once the needles meet, a channel is created in the bone and a thread can be
passed
to through the channel. In an embodiment of the invention, the thread is
passed through a channel
forming in and/or along the body of the needles. The thread may be inserted
with the needles,
while they bore, or after the boring is completed. Alternatively, the device
is used only to bore
a hole in the channel and not to pass a thread, which may be passed manually,
for example, if
so desired, optionally after the needles are removed.
Fig. 5A illustrates an end to end needle configuration, in accordance with an
embodiment of the invention. A needle 240 and a needle 242 meet end to end. It
should be
appreciated that, in accordance with some embodiments of the invention, better
control over
the final location of the needles is possible if the needles are rigidly
attached to a single hinge
than if they do not use hinges or are attached to separate hinges.
2o Needles 240 and 242 optionally comprise an inner bore, such that when they
meet end
to end, a path 241 is formed therethrough.
Fig. 5B illustrates various suitable cross-sections for needles 240 and 242.
Cross-
sections 248 and 246 are triangular cross-sections, having a circular inner
bore. Cross-section
250 is circular, with a circular inner bore. Cross-section 252 is an example
of an open-bore
needle, having a "U" shaped cross-section, with the bore on the inside of the
"U". In some
embodiments, a groove on the side of a substantially solid needle is used
instead of a deeply
grooved cross-section such as a "U". It is noted that the cross-section of the
needle may vary
along the needle, for example, there being a groove for the thread along most
of the needle and
an inner bore only at the needle tip. Alternatively or additionally, the tip
of one needle may be
narrow enough to enter the tip of the other needle, forming an inside-outside
matching. In an
alternative embodiment described below, one needle has a removable tip, to
which the thread
is attached, which tip is captured by the other needle. The attachment method
can be, for
example, using a knot, in a crevice in the tip or using other methods of
attaching a thread to a
metal object, as known, for example, in the art of bone anchors.
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Optionally, the bore of the needles is cleaned out, for example using suction,
forward
flow of a saline solution or an advancing mandrel, to remove bone debris that
accumulates in
the bore. An opening at the side of the needle may be provided for the exit of
such material, or
such a hole may be defined when the two needles meet. Alternatively, a
somewhat rigid thread
pusher is provided, which can push the bone debris ahead of itself or form a
channel in the
debris.
Figs. 6A and 6B are a side and a top view of a side-by-side needle
configuration, in
accordance with an embodiment of the invention. In the embodiment shown in
Fig. 6A, a
needle 254 and a needle 252 overlap at an area 256 thereof. A bore 258 is
formed from the
bores of the individual needles. In an embodiment of the invention, the bore
of the individual
needles do not reach the tip of the needle but exit the needle at its side,
near the tip, so the tip
can be solid. When the two needles overlap properly, the bore exits meet and
bore 258 is
formed.
In some embodiments, when the two needles are retracted, the retracting solid
tips may
shear the thread between them. One possible solution is that the tip has a
smaller cross-section
than the rest of the needle. Another possible solution is providing a metallic
or otherwise
tougher thread pusher or thread, which is less likely to be sheared.
Alternatively or
additionally, the inside faces of the tips are inclined, so the shear forces
on the thread are
gradual and smaller. Alternatively or additionally, the two needles have
different radiuses or
2o rotation and/or the hinge is not at their center of curvature, so that when
they retract, they
move apart. Such moving apart can also be achieved by using needle tips that
are not
symmetrical, so that when they are advanced and/or retracted through bone, a
force is
generated perpendicular to the line of motion of the needle.
In one embodiment, the bores of the needles point backwards. Thus, for the
bores to
meet, the needle tips must pass each other. One method of forming such needles
is to fold the
needle tip while providing a mandrel in the needle bore, to prevent the bore
from collapsing.
Another method is to remove the portion of the needle surface inside the bend
of the needle, to
provide an alternative bore for the collapsed bore. The part of the needle
near the bore is
optionally inclined away from the needle tip, to assist in locking the needles
together, while
3o still allowing them to be disengaged by applying sufficient retraction
force on the needles.
Fig. 7A illustrates a top-bottom needle configuration, in accordance with an
embodiment of the invention. Instead of or in addition to the needles being
side-by-side in a
plane perpendicular to the needle plane, the needles are one on top of the
other (or inside the
other, with respect to the view from the hinge), effectively being side-to-
side in the plane of
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the needles. In the embodiment shown, a needle 264 is inside a radius of
needle 262, and the
two needles overlap at an overlap area 266. Fig. 7B illustrates various
possible bores for the
overlap area, for example two opposing "U"-shaped bores (268) or two opposing
"V" shaped
bores (270). This bore may be open for the entire length of the needle or only
at the overlap
area.
In an embodiment of the invention, the radius of needle 264 is smaller than
the radius
of needle 262, when measured from the hinge. Alternatively or additionally,
the needles are
not perfect arcs and/or the radius of the needles does not match the radius of
rotation. Properly
configured, such construction will cause the needles to engage each other when
they meet at
to overlap 266, instead of sliding over each other. A similar result can be
achieved with side-by-
side needles, where the needles do not travel in exactly parallel planes, so
once they meet,
further movement is difficult or impossible.
Figs. 8A-8C illustrate a detachable needle configuration 280, and its use in
boring and
threading a bone, in accordance with an embodiment of the invention.
Configuration 280
includes a non-detachable needle 284, and a detachable needle 282, mounted on
a base 286.
Needle 284 includes a tip 288 and needle 282 includes a tip 290; these tips
are designed to
engage, once they meet. Although a particular engagement design is shown,
others may be
used, for example tip 288 enters into a bore in tip 290 and one or both tips
are elastically or
plastically deformed so that the tips engage.
2o As shown in Fig. 8B, once the needles are inserted into the bone, they bore
a path and
then meet, locking. When the needles are retracted, needle 282 stays latched
to needle 284 and
is pulled out along the path of needle 284, rather than back along its path.
Optionally, a thread
292 is attached to needle 282, such that the thread is pulled along by needle
282 when it
advances. Many methods are known in the art for attaching a thread to a
needle.
Fig. 8C shows the result of the process, which is a path threaded by a thread
292.
It should be noted that not all of needle 282 needs to be detachable. Rather,
it is enough
that any part to which the thread is attached is detachable. Thus, in some
embodiment, only the
tip of needle 282 is detached. Optionally, a groove or a bore is defined in
needle 282, so that
the boring in the bone does not damage the thread. Also, although needle 284
is pornayed as
3o non-detachable, in some embodiments, it may be desirable to allow needle
284 to be
detachable, for example outside the body, for replacement thereof.
In an embodiment of the invention, needle 282 includes a safety latch that
releases the
needle only if the needle is actually engaged by needle 284, so that needle
282 is not
inadvertently left in the bone.
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Figs. 8D-8F illustrate a safety latch which releases the detachable needle of
Figs. 8A-
8C only if the two needles 282 and 284 meet, in accordance with an embodiment
of the
invention. In the exemplary latch shown, a pin 294 is arranged in a slot 295
in base 286. The
base of pin 294 is possibly urged against an incline 296, for example using a
spring (not
shown). Alternatively to an incline, a flexible pin may be provided which is
attached to a fixed
location. As needle 282 is advanced, pin 294, urged by the incline, slides in
slot 295. At a
certain point, the motion of pin 294 releases needle 282. Fig. 8E shown a
method in which pin
294 has an aperture 298 formed therein. When the pin is moved, shown in Fig.
8F, the needle
is disengaged from the pin and can be extracted by needle 284 that engages it.
1o Alternatively or additionally, to a mechanical latch, an electrical sensor
may be used.
This sensor senses when the needles meet, for example from the amount of
motion of the
needles. Alternatively, the sensor directly senses the contact between the
needles, for example
by measuring a reduced electrical resistance when the needles meet. The signal
generated by
this sensor can have one or more uses, including indicating to a physician
that contact was
made (optionally using a light or a sound), freeing the detachable needle or
"firing" a thread
(described below).
In an embodiment of the invention, the needles described above are pushed into
the
bone and they form a channel by forcing through the bone, rather than by
removing bone
material. Alternatively, in some cases, the needle cross-section may be
selected so that the
2o needle removes and/or pulverizes bone when the needle advances. Optionally,
the needle's
cross-section, especially at the tip, matches the direction of fibers in the
bone, so that it can
better enter the bone without cutting across fibers. Optionally, one or both
needles are smooth.
Alternatively, a needle may be grooved, especially at its tip. Possibly, a
spiral is defined on the
outside of a needle. It is noted that the finishing and geometry of the
outside surface of the
needle can affect the direction of advancing of the needle in the bone. In a
typical
implementation, the needles have a radius of curvature of about 6mm, a cross-
section diameter
of between l and 1.5 mm and are formed of surgical tool grade stainless steel
or implant grade
stainless steel. However, smaller sizes are possible, for example a radius of
4 or 3 mm and a
diameter or 0.75 or 0.5 mm.
In an embodiment of the invention, the needles are simply pushed into the
bone.
Alternatively, the needles may be vibrated (axially, trans-axially and/or
rotationally, optionally
in a reciprocating manner), for example using a piezoelectric motor coupled to
them, to aid
their advancement into the bone.
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In an embodiment of the invention, the needles are advanced and retracted by
the
action of lever 106 or 206, allowing the boring and threading process to be
paced by a
physician. Alternatively or additionally, the needles may include a self
retracting mechanism,
in which, once the needles bore the hole, they are automatically retracted.
This may be
achieved using a mechanism similar to that of Figs. 8D-8F, which is used to
couple the needles
to their levers. Optionally, the automatic retraction occurs after the thread
is threaded through
the needles.
In an embodiment of the invention, one of the two needles can be a non-
penetrating
needle, for example a flat (possibly angled) anvil. Optionally, the anvil
includes a hole to
receive the other needle. Alternatively or additionally, the anvil also
advances when the needle
advances. Alternatively, the anvil is fixed. Optionally, the anvil includes
small spikes or other
gripping elements for engaging the bone so the anvil does not slip and/or to
assist in applying
a contra-force to stabilize the needle.
Figs. 9A and 9B schematically illustrate a hinged single needle boring head
300,
without an anvil, in accordance with an embodiment of the invention. Head 300
comprises a
needle 302 connected to a hinge 304 via a needle arm 304. In an embodiment of
the invention,
needle arm 304 also serves as a needle stop to stop the advance of the needle
once it completes
its path. Fig. 9B shows the single needle when it completes boring through the
bone. If needle
302 (or a tip thereof) is detachable from needle arm 304 and is attached to a
thread, the tip of
2o needle 302 can be captured by a capture device (not shown), for example by
friction, once it
exits the bone.
In an alternative embodiment of the invention, the mechanism of Figs. 9 is
used for a
pair of needles, to avoid the need for the needle tips to interlock. In an
embodiment of the
invention, the hole is bored by two needles that meet in the bone. Once the
needles meet, their
rotation mechanism locks, rather than the needles. Then the rotation of one of
the needle is
continued over more than 90° (as shown in Fig. 9B for a single needle,
for example). Since the
mechanism is locked, the other needle is retracted along its bore. Once the
advancing needle's
tip is outside the bone, it can be engaged by the bone boring device and
detached at its base
(like needle 282 in Fig. 8D), so that when the bone boring device is
retracted, a thread attached
3o to the advancing needle is threaded through the bore in the bone.
Optionally, only one of the
needles rotates more than 90°, however, based on the geometry, it might
be required for both
needles to travel at least an angle of 110°, for example. The needle
that travels a longer path
may be grasped in its middle, at least during the bone boring step, to prevent
its distortion.
However, this is not essential.
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A feature of some embodiments of the invention is an invariance to the angle
of
incidence between the boring head and the bone. This invariance has several
aspects, one or
more of which are provided by some embodiments of the invention:
(a) depth of penetration invariance;
(b) slippage invariance; and
(c) bone penetration ability invariance.
Fig. 10A illustrates an angle independence of boring head 130, in accordance
with an
embodiment of the invention. Due to there being only a small distance between
resting point
134 and hinge 126, the penetration depth is unaffected by small, and even some
large angles
between the resting point and the bone, since, in some embodiments of the
invention, rotation
around the resting point does not substantially affect the distance between
the resting point and
the meeting point of the needles. In an embodiment of the invention, the small
distance is less
than 60%, 40%, 20% or 10% of a radius of curvature of a path along which said
needles travel.
Due to the simultaneous gripping of the bone by two opposing needles, slippage
is prevented.
Alternatively, resting point 134 allows the needles to penetrate the bone at
many different
attack angles, even if the needles are not in contact with the bone at a
beginning of extension,
since resting point is. In some embodiments, the resting points may be
roughened or include
barbs, to assist in its engaging the bone and/or intervening soft tissue.
Alternatively or
additionally, the gain for each needle may be different, so they rotate at
different speeds and
2o different entry angles are provided.
Fig. lOB illustrates a self aligning boring head 320, in accordance with an
embodiment
of the invention. In this embodiment, head 320 is gimbaled on one or more
hinges 326, so that
head 320 is always facing to the bone, such that both the needles can enter
the bone at
substantially the same angle and time. In an embodiment of the invention, a
pair of stabilizers
322 and 324 contact the bone and straighten head 320. Alternatively to an
axial hinge, as
shown, an integral hinge may be used, for example one formed of silicon
rubber. Possibly,
three or more stabilizers are provided, to provide stability also in the plane
perpendicular to the
needle path. Possibly, the tips of the stabilizers are soft, to prevent
inadvertent damage to soft
tissue. In an alternative embodiment of the invention, head 320 is self
aligning even without
3o such stabilizers, by the unequal forces against the needles causing the
head to gimbal.
Alternatively, the mechanism for rotating the needles may only rotate one
needle relative to
the other. The absolute angular position of the needles is determined by the
relative resistance
each needle feels.
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Alternatively or additionally, to being self aligning, head 320 can include
one or more
sensors for determining that the head is in a correct configuration. In one
example, a force
sensor is provided at each of the stabilizers, to determine a contact force,
which should be
approximately the same for all the stabilizers. Alternatively or additionally,
force sensors are
connected to the needles, both of which should measure about equal forces.
Possibly, the result
of the sensor measurement is portrayed to a user, for example as a go/no-go
signal.
Alternatively or additionally, the signal from the sensor is used to free a
pin, which freeing
will allow the extension of the needles. Alternatively, a mechanical
construction may be
provided, which allows motion of the needles and/or force to be transferred to
the needles only
if the pressure on the stabilizers and/or their alignment is about the same.
Although the above description of angles has been mainly with respect to an
angle in
the plane of the needles, similar considerations, measurements and apparatus
can be utilized
for controlling the angle between the needle plane and the surface of the
bone.
Further, the above description has been mainly directed to needles that share
a plane or
that travel in parallel planes. In some embodiments of the invention, the
needles may travel in
two oblique planes. An extreme example is cork-screw needles which twist
around their own
axis (and may be coaxial). Another example is a boring-head comprising three
needles, which
meet at a point inside the bone. It is noted that the hinge does not need to
be at the center of
rotation of the needles (if they have one).
Figs. 11A and 11B illustrate a self aligning boring device 400 in accordance
with an
embodiment of the invention. Device 400 comprises generally of a holder 402
and a boring
mechanism 404 and a boring head 412 which is held against a bone by force
applied by a user
to a handle 406. In an exemplary embodiment, mechanism 404 includes a power
source such
as a motor and head 412 includes drill bits powered by the motor. A hinge 410
is optionally
provided between holder 402 and mechanism 404, optionally near boring head
412, to allow
boring head 412 to align itself with the surface of the bone to be bored into,
substantially
independently of the force vector applied to handle 406. A second hinge 408,
optionally with a
positional freedom of motion, may be provided to maintain the relative
positions of holder 402
and mechanism 404 and/or as a safety feature to prevent warping of head 412 by
undue forces.
3o Alternatively or additionally, reference 408 may represent a safety catch
which prevents the
extension of the needles until released.
Fig. 11B is a different view of device 400 and showing a relative rotation of
holder 402
and mechanism 404 around hinge 410.
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In an embodiment of the invention, the hinge is substantially equidistant from
the tips
of the drill bit, so that a substantially equal force is applied to them. The
hinge may be
positioned not equidistant, for example, if an unequal force on the two drill
bits is desired.
Alternatively or additionally, such an unequal force can be provided using a
spring which
resist the gimbaling of the head. The hinge may be in the head or in the body,
for example.
In some embodiments, holder 402 is used as an outer skeleton for an existing
mechanism 404, which mechanism can also be used without holder 402.
Alternatively or
additionally, a holder-type device may be used for other uses than boring
holes in bones, for
example for stapling and/or tacking in the vagina or the throat.
Fig. 11 C illustrates an alternative self aligning boring device 420, in
accordance with
an embodiment of the invention. In device 420, a boring head 422 rotates
around a hinge 428
which is between a handle 426 and boring head 422. In some embodiments, the
angular
freedom of hinge 428 is small, for example 5°, 10° or
20°.
In various embodiments of the invention, the path bored in the bone can be
threaded in
different ways. In a first way, a thread is pulled through the path by one of
the needles. In
another way, the thread is pushed through the path. In yet another way, a
separate threaded
needle is brought through the path. Once the path is threaded, the ends of the
suture are tied
together, optionally manually. Alternatively, a clip is attached to the two
ends of the thread
and performs the functions of a knot. In the case where the device performs
the threading,
2o when the device is retracted from the one, the thread remains in the bone.
The suture may be
tied immediately. In some cases, some or all the required bone bores are
formed first and the
threaded and/or tying of sutures is performed later.
A general process of bone suturing, in accordance with some embodiments of the
invention thus comprises:
(a) compressing soft tissue against the bone (optional);
(b) advancing needles through the soft tissue and the bone, to bore a path
through the
bone;
(c) advancing a thread along the path, optionally while the needles are still
in the hole
(or by the advance of the needles);
(d) removing the device (generally first retracting the needles); and
(e) tying the ends of the thread.
In various embodiments of the invention, selected ones of these steps may be
performed sequentially or simultaneously. Even in cases when sequential steps
are performed,
the transition between the steps may be automatic, for example advancing a
thread one the
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needles are fully extended, or manual, for example requiring a user action
(manually
advancing a thread) or allowance (releasing a safety latch). In one example of
sequential
action, the two needles are advanced sequentially, rather than simultaneously.
In some
embodiments, this sequential motion may be used to assist one needle in
cleaning out a groove
(or thread) in the other needle.
As indicated above, a thread may be pushed through the bores of the needles,
after they
meet. Generally, pushing a thread will require the thread itself to be stiff
or to be attached to a
stiff thread pusher, which is pushed and carries the ductile thread along with
it. The stiffness of
the thread/thread pusher depends, inter alia, on the radius of the bore, the
amount of bone
to material in the bore and the type of mechanism used to advance the thread.
Figs. 12A and 12B illustrate a thread pusher 330, in accordance with an
embodiment of
the invention in an open configuration and in a closed configuration. In an
embodiment of the
invention, pusher 330 is formed of an elastic or super elastic material and
has an eye 332
formed at one end thereof. A thread is threaded through the eye and then the
thread pusher is
inserted into a channel (or the needle bore). The dimensions of the channel
compress the eye,
so that it grips the thread. Alternatively, a double thread may be used, so
that both ends of the
thread are far away from the eye.
Figs. 13A and 13B illustrate a method of passing a thread through the bores of
the
needles of Figs. 5A and SB, in accordance with an embodiment of the invention.
A channel
334 contains thread pusher 330. A lever 338 is coupled to thread pusher 330,
such that moving
the lever advances the thread pusher. Depending on the configuration used,
reference number
336 may indicate an extension of thread pusher 330 or a thread attached to
thread pusher 330.
In Fig. 13A, the needles meet, but lever 338 maintains the thread outside the
needle
bore. In Fig. 13B, the lever is depressed and the thread is advanced through
the needle bore.
2s Optionally, an engager 340, possibly a friction element, engages thread
pusher 330 and/or the
thread, so that it does not retract when the needles are retracted and/or when
the device is
removed from the bone. In embodiments where the needles retract automatically
when the
bore is threaded, engager 340 may also release a catch on a spring that
retracts the needles.
In one embodiment of the invention, thread pusher 330 is urged forward by a
spring
342 (shown schematically). However, advance of pusher 330 is prevented by
lever 338. In
other embodiments, a pin, such as shown in Figs. 8D-8F, prevents the thread
pusher from
entering the needle bore, even if it is urged forward by a spring. Optionally,
the tip of thread
pusher 330 is preloaded into the tip of needle 242, so that it travels with
the needle.
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Alternatively, channel 334 is arranged so that it has a clear view of the bore
only when the
needle is fully extended.
In some embodiments, bar 232 and/or bar 230 (shown in Fig. 4), when they
completely
extend the needles, continue their travel (optionally sliding along anchors
140 and 142) and are
used to retract the thread pusher and/or to advance it.
Figs. 14A-14D illustrate various stages in usage of a thread-exchanging needle
assembly 350, in accordance with an embodiment of the invention. Assembly 350
optionally
comprises a needle 352, a needle 354, a tip 356 mounted on needle 350 and
attached to a
thread 358. The tips of needles 352 and 354 are formed to engage tip 356 in
the following
to manner. Tip 356 is optionally fractionally engaged by needle 352 so that it
does not fall off
(Fig. 14A). When the two needles are brought together, the point of tip 356 is
engaged by an
inner bore (or other spatial configuration) of needle 354 (Fig. 14B). When the
needles are
retracted (Fig. 14C), the engagement of the tip by needle 354 is stronger than
was the
engagement by needle 356, so that the tip travels with needle 354. When the
device is
removed, thread 358 remains in the bore (Fig. 14D). In some embodiments of the
invention,
needle 354 is replaced by an anvil (which does not enter the bone) or by a tip-
engager that is
distanced from the bone, but is within the needle track.
Figs. 14E-14H illustrate needle- (or needle-tip) receiving tips in accordance
with
various embodiments of the invention. For clarity of presentation, all these
figures include a
perspective view and a corresponding perspective axial cross-sectional view.
Fig. 14E
illustrates a needle 430, having an aperture 432 formed at its tip. An inner
volume 438 is
hollowed out in the needle. Optionally, but not necessarily, an outer lip 436
of the aperture has
a smaller diameter than that of volume 438. Lip 436 is optionally smooth,
however, this is not
essential and lip 436 may be, for example, jagged. Optionally, an incline 434
is defined
adjacent aperture 432, to bridge the outer diameters of needle 430 and lip
436.
Optionally, volume 438 is longer than shown and exits the side of needle 438
at a
location marked 439. Thus, any bone material that enters volume 438 can be
pressed out by
the received tip of the opposite needle.
Fig. 14F illustrates an aperture 442 for a needle 440, similar to the design
shown in
3o Fig. 14E, except that one or more slots 447 are formed between a volume 448
defined in the
needle and an incline 444 on the outside of the needle. Slot 447 can server to
exhaust debris
from volume 448 and/or for adding elasticity to aperture 442, for assisting in
engaging the tip
of the opposite needle.
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Fig. 14G illustrates a needle tip design similar to that of Fig. 14F, except
that two slots
457 are defined between a volume 458 in a needle 450 and an incline portion
454 of the
needle. The two slots are nearby, defining a flexible tab 455 between them.
Tab 455 can, for
example, provided an elasticity or plasticity in an aperture 452, to engage
the other needle tip.
Fig. 14H illustrates a variant of the design of Fig. 14G, in which a pair of
slots 467 do
not extend to a lip 462 of an aperture 466 defined in a needle 460. Rather, a
small slot 463
bridges between the ends of slots 467, so that a tab 465 is formed. Lip 462 is
thus whole and
tab 465 is less likely to be distorted by the travel in the bone than is the
design of Fig. 14G.
Figs. 15A-15D illustrates a hollow needle boring mechanism, in accordance with
an
to embodiment of the invention, in which a bore in one of the needles is
filled by a retracting
mandrel.
Fig. 15A illustrates a needle-boring head 470, having two opposing hollow
needles, a
needle 472 which carries a tip 482 and a tip-receiving needle 474. In some
embodiments,
needle 472 is not hollow, for example as described above. The two needles
optionally rotate
around a hinge 476. Tip 482 is optionally attached to a thread 484, which can
be carried past a
bore 486 of needle 472, to a conduit 488, optionally an elastic conduit, for
example an axially
flexible conduit. A mandrel 490 is optionally provided in a bore 475 of needle
474. Mandrel
490 is optionally maintained in an axial position relative to needle 474 for
example by a stop-
clip 492. Stop clip 492 optionally includes a base 493 against which mandrel
490 is placed, an
2o arm 494 which engages a protrusion 496 of needle 474, so that stop-clip 492
holds mandrel
490 in place. Stop clip 492 optionally also includes an extension 491, adapted
to match a
protrusion 498 in head 470, for releasing stop-clip 492.
Fig. 15A shows mandrel 490 and tip 482 forced into or against a cortex layer
478 of a
bone and overlaying a medulla 480 of the bone. The tissue may be removed or is
not shown
for clarity of presentation.
In Fig. 15B the needles are rotated around hinge 476, so they create a bore
499 through
cortex 478 and medulla 480. During the advance of needle 474, extension 491 is
stopped by
protrusion 498, causing stop-clip 492 to disengage from needle 474 and
allowing mandrel 490
to retract. Thus, an aperture appears in the tip of needle 474, into which tip
482 can enter and
3o by which it can be engaged. Optionally, the tip of needle 474 is slotted,
for example as
described with reference to Figs. 14F-14G. In an embodiment of the invention,
bore 475 is
filled with debris from medulla 480, as mandrel 490 retracts, preventing the
formed aperture
from being blocked.
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In Fig. 15C, the needles are retracted, so thread 484 enters bore 499.
In Fig. 15D, boring head 470 is separated from the bone, leaving thread 484
threaded
through bore 499.
In some embodiments of the invention, what is shown as a thread 484 is
actually a
metallic extension of tip 482, for example made of Nitinol, to which a thread
may be
connected. Thus, the thread is far away from tip 482 and is not near the bone
during the boring
procedure. It is noted that a hollow needle with a mandrel may also be used
for a single needle
device, such as shown in Figs. 9, for example to assist in engaging the needle
when it finishes
its travel.
to Figs. 16A and 16B illustrate a combination drilling and needle boring head,
in
accordance with an embodiment of the invention. A combined drilling and boring
device 500
optionally comprises a combination drilling and boring head 502 attached to a
handle 501. Fig.
16A shows device 500 with the needles retracted and Fig. 16B shows the device
with the
needles extended. As shown in Fig. 16A, two drill bits 504 are provided, each
with one or
more openings 506 in its side for passage of one of a needle 508 and a needle
510. The needles
may share a single hinge, or as shown in the Figure, a hinge 512 may be
provided for each
needle, coupling the respective needles to a casing 514 of head 502. Various
lever types may
be used for leveraging the extension of the needles. A power train 516 is
shown for advancing
the needles. A power train 518 is shown for rotating the drill bits.
2o Fig. 16B shows head 502 with the boring needles extended, and also affords
a better
view of the drive mechanism for rotating the drill bits. Although an exemplary
drive
mechanism is shown, many other mechanisms can be used within the scope of the
invention.
The rotation of drive train 518 is optionally transferred to a flat gear 520,
which rotates a gear
522 that has a drill bit at its center. A second gear 524 transfers power from
gear 522 to a gear
526 that also has a drill bit at its center. In some embodiments, only one
drill is used, possibly
with a single needle extending through that drill bit. An optional peg 528 is
shown which
allows some rotational freedom of the drill bits, so that the needles can be
more easily aligned
with openings 506.
In an alternative embodiment, the position of peg 528 is detected using a
sensor (not
shown), which sensor electrically or mechanically stops the rotation of the
drill bits, so they
will be correctly aligned. Exemplary suitable sensors are optical and magnetic
sensors.
Alternatively or additionally, a rotational encoder is used to detect the
drill bit position. The
rotation may be stopped at any point between the motor and the drill bit,
depending on the
implementation. Alternatively, the motor may be controlled to generate
complete rotations, so
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that the end-position of the drill-bit can be as desired. Alternatively or
additionally, a stepper
motor may be provided. Alternatively or additionally, an impulse type motor
controller may be
provided, that provides power impulses to the motor, causing the drill bits to
rotate complete
rotations in response to a known number of impulses. Alternatively or
additionally, a
mechanical stop may be provided that stops the drill bits at a certain
position if no external
power is provided, such that the drill bits coast to their desired rotational
position.
In an embodiment of the invention, the two drill bits rotate in a same
direction and at a
same speed. Alternatively, they may rotate in opposite directions and/or at
different speeds.
Alternatively, they may have reciprocating motion, rather than pure rotational
motion. In some
l0 cases, axial or transaxial vibration may also be provided. Optionally, a
spike is provided
between the drill bits, for maintaining the bits in place before they
penetrate the bone. This
spike is optionally retracted as the bits advance.
Figs. 17A-17E illustrate a method of using device 500. Some of the elements of
head
502 are not shown, for clarity of presentation.
In Fig. 17A, drill bits 504 are against a cortex 478 of a bone. The needles
used in this
exemplary embodiment are a bored needle 508 having a detachable tip 530
threaded with a
thread 534 and a solid needle 520 with a through aperture 532 defined in its
tip, for receiving
detachable tip 530. Other needle types, for example as described above, may be
used instead.
In Fig. 17B, pressure is applied to a handle (not shown) forcing drill bits
504 against
2o cortex 478, forming a pair of cortex-bores 540, after they have rotated a
sufficient amount. In
an embodiment of the invention, the drill bits are prevented from rotation
unless a minimum
pressure is applied to them, for example using a mechanical clutch.
Alternatively or
additionally, the number of rotations of the drill-bits is predetermined and
once the number is
reached the drilling stops. Once bores 540 are formed, drill bits 504 are
prevented from
advancing by the base of head 502, which contacts the bone or by a suitable
protrusion from
head 502 (not shown). The drilling depth may be set, for example by moving the
protrusion
axially relative to the drill bits.
In Fig. 17C the needles are advanced so that a bore 542 is formed in medulla
480 and
detachable tip 530 is engaged by aperture 532.
In Fig. 17D, the needles are retracted, leaving thread 534, which is attached
to
detachable tip 530, in bore 542.
In Fig. 17E, head 502 is retracted, leaving thread 534 (or an extension of tip
530)
threading the bone.
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Fig. 18 illustrates a variant 550 of device 500, which can adapt to the local
bone
geometry. A boring head 554 is mounted on a body 552, by a hinge 556. When
head 554 is
pressed against the bone, the head aligns so that both drill bits 504 contact
the bone.
Figs. 19A-19E illustrate the use of an alternative combined drilling and
boring head
602, in which only one needle 608 is used for two drill bits 604 and 605. Fig.
19A shows a
device 600 having boring head 602 mounted on a handle 601, similar to the
configuration of
device 500. However, other mounting methods may be used as well, for example
as shown in
Fig. l, for attaching a boring head to a handle. Head 602 is shown comprising
two drill bits
604 and 605. Drill bit 604 includes a path for a needle 608, optionally
curved, to be extended
to therethrough and meet drill bit 605. Unlike device 500, no needle extends
from drill bit 605.
Optionally, however, the distance between the drill bits may be smaller, to
compensate.
Various methods of passing a thread between needle 608 and drill bit 605 may
be used, for
example as described above, including both tip exchanging an thread pushing
through a
hollow conduit formed between the needle and the drill bit it meets. In the
particular
embodiment shown in Figs. 19A-19E, needle 608 has a detachable tip 630 to
which thread 634
is attached. Tip 630 is engaged by an aperture 636 in drill bit 605, when tip
630 meets drill bit
605.
Fig. 19B shows device 600 after drill bits 604 and 605 have drilled through
cortex 478
of the bone.
Fig. 19C shows the advancing of needle 608. In this exemplary embodiment,
needle
power train 616 is activated by retracting an inner element 620 of handle 601.
However, other
mechanisms for activating or powering the needle retraction can be used as
well, for example
as described with reference to the embodiments in Figs. 1-18. As a result,
needle 608 rotates
around a hinge 610, to which it can be connected, for example connected by an
arm, such as
shown in the details of Fig. 17, thereby passing through medulla 480, so that
tip 630 engages
aperture 636 of drill bit 605. It should be noted that needle 608 may also be
a straight needle,
which, for example, can enter drill bit 604 from the bit's side, rather than
along its axis.
In Fig. 19D, needle 608 is retracted, leaving tip 630 engaged by drill bit
605. The
details, in one embodiment of this engagement and an optional rotation of tip
630 are shown in
3o Figs.20A-20C.
In Fig. 19E, head 602 is removed from the bone, leaving thread 634 in the
lumen
formed by drill bits 604 and 605 and needle 608.
Figs. 20A-20C show a blowup of the drill bits and the needle, illustrating the
engagement of tip 630 by aperture 636 in drill bit 605.
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Fig. 20A corresponds to Fig. 19C, showing tip 630 being engaged by aperture
636. In
one embodiment, as shown, bit 605 comprises an outer sheath 622 and an inner
tube 624. In
this embodiment a slot is formed in outer sheath 622 and a narrower slot is
formed in inner
tube 624. Alternatively, tip 630 may puncture, in its advance, one or both of
sheath 622 and
tube 624. Alternatively, other grasping mechanisms can be provided, for
example tube 624
may comprise an elastic or a plastic material, for example an elastomer. In
the mechanism
shown, tip 630 comprises a conical head 632 and a rear tubular portion 633,
which, for
example, holds thread 634.
When needle 608 is retracted, as shown in Fig. 20B, head 632 is held in place
by the
to lips of the slot in inner tube 624.
In some implementations, tube 633 may extend beyond slot 636. Then when bit
605 is
retracted, tube 633 will hit against the bone and may dislodge. One solution
is for tube 633 to
be relatively short. An alternative solution is shown in Fig. 20C, which
corresponds to Fig.
19E. In Fig. 20C, tip 630 rotates inside slot 636, so that tube 633 is within
the confines of bit
605. Alternatively or additionally, a slot 626 is formed along bit 605, to
provide a space for
thread 636 and prevent the thread being cut between bit 605 and the bone.
Alternatively or
additionally, drill bit 605 may have a tapering diameter, to provide clearance
for tube 633.
One potential advantage of using only one needle, is also shown in Figs. 20A-
20C. A
gear 612 of bit 604 directly engages a gear 614 of bit, 605, since they can be
closer together
2o than in the embodiments of Fig 16, where two opposing needles meet.
Figs. 19 and 20 show an exemplary embodiment where needle 608 has a center of
rotation between the needle and the boring head, and tip 630 meets bit 605 at
substantially a
perpendicular angle. Alternatively, tip 630 may meet bit 605 at an oblique
angle, towards or
away from head 602. Alternatively, as noted, needle 608 may be straight.
Further alternatively,
needle 608 may be curved away from the head. Optionally, needle 608 is formed
of a super-
elastic, elastic or shape memory material, that is allowed to curve once it
leaves head 602.
Figs. 21A and 21B illustrate, in perspective view, drill bits 604 and 605
respectively, in
accordance with a particular embodiment of the invention. Fig. 21A shows an
aperture 607 in
drill bit 604 through which needle 608 is extended and retracted. Fig. 21B
illustrates aperture
636 for engaging tip 630 and slot 626 for thread 634.
Figs. 22A-22E illustrate a method of threading tip 630 and thread 636 into
device 600.
However, it should be noted that a substantially same method may be used for
threading
device 500 of Figs. 17.
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A thread 636 with a tip 630 attached thereto are inserted into aperture 607 of
drill bit
604 and through needle 608, until tip 630 reaches needle 608. Optionally, the
side of thread
636 distal from tip 630 is attached to a guide, such as a Nitinol wire, to
assist in pushing the
thread through device 600.
In one embodiment of the invention, a device 640 is provided to assist
threading needle
608. Device 640 as shown in Fig. 22A, comprises a base 642 having openings 643
and 645
defined therein for receiving drill bits 604 and 605 respectively. An tube 646
with a lumen 648
is provided, such that lumen 648 can be aligned with aperture 607 and
optionally advanced
into aperture 607, for example to contact needle 608. Alternatively, needle
608 may be
1o extended out of aperture 607. Lumen 646 may also be provided with a widened
opening 650,
to aid in inserting thread 636 into lumen 648.
In this embodiment of device 640, an extension 644 of base 642 folds around
and holds
tube 646. The fold in extension 644 is optionally elastic, so that tube 646
can be selectively
advanced or retracted by pressing extension 644 towards base 642.
In Fig. 22B, tube 646 is in contact with needle 608 and thread 636 is being
pushed
through lumen 648, needle 608 and device 600. Once the thread exits device
600, it can be
pulled, for example by hand or using forceps, rather than pushed.
In Fig. 22C, tip 630 is pulled all the way so that it is stopped by needle
608.
In Fig. 22D, tube 646 is retracted from aperture 607.
In Fig. 22E, device 640 is removed from device 600.
Alternatively to threading each tip 630 into device 600, a magazine of one or
more tips
630, is provided inside head 602. In an exemplary embodiment, the tips 630 are
positioned so
that when needle 608 is advanced, it carries along one tip 630 with it. The
next tip may spring
into position when needle 608 is retracted. In this embodiment, needle 608 may
include a
groove on its outside for the thread attached to tip 630. Each such tip may be
attached to a
separate, possible coiled up thread or a plurality may be attached, loosely or
fixedly to a same
thread. In one embodiment, the thread is looped and doubled though tip 630. In
another, its
end is engaged by the tip.
One type of procedure for which device 600 (or 500) may be used is a modified
sling
3o procedure in which a urethra or bladder neck are suspended or supported by
a sling of material,
such as a mesh or an allograft.
Fig. 23A shows a sling 650 pre-mounted on a device 600, in accordance with one
embodiment of the invention. Drill bits 604 and 605 are shown inserted in
holes formed in
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sling 650. Such holes may be pre-formed or they may be punched or cut in sling
650 when
needed. Alternatively, sling 650 may be placed against the bone and drilled
through.
Device 600 with sling 650 mounted thereon may be threaded and/or used to drill
in a
bone, as described above.
Fig. 23B shows sling 650 on the surface of cortex 478 and threaded with thread
634.
Sling 650 may be fixed to the bone by knotting the threads. Optionally, the
knot may be
pushed into the bone channel formed by the drilling.
The other end of sling 650 may be fixed in various ways. For example, it may
be
attached directly to sling 650, for example using adhesive, it may be sutured
using thread 636,
to or it may be attached to the bone in the same way as the first side of the
sling, for example
being mounted on device 600 or device 600 drilling through it, possibly via a
reinforced
section or through pre-punched holes of the sling. It is noted that in
general, drilling is less
likely to puncture fingers than staple tips or needles.
In many of the above figures, the thread has been shown traveling from a left
needle to
a right needle. It should be appreciated that this convention, as well as
other conventions
related to mirroring and relative placement of device elements have been
adopted for
simplicity of description and should not be construed to limit the embodiments
to those shown,
for example, a thread may travel from the needle on the side of the shank to
the needle on the
outside of the device (unlike shown in Fig. 13A).
2o In an embodiment of the invention, the device or parts thereof are made for
one time or
limited time used. Thus, sterilization of the device can better be achieved.
Further, issues of
wear and maintainability are solved, allowing a less expensive device to be
manufactured. In
one embodiment, the device is a one-patient device and the needles are one-
time use.
Alternatively or additionally, the needles are one-patient use and the sutures
and/or thread
pusher (if provided) are one-time use. Alternatively, the device is a mufti-
use device and the
boring head is disposable. In the example of Fig. 12A, the thread and its
channel may comprise
a disposable cartridge. In the example where lever 338 is not needed or is
replaced by a latch
pin and/or spring 342, a cartridge may comprises a plurality of pre-threaded
thread pushers,
which are advanced one at a time, out of a cartridge (schematically shown as
343 in Fig. 13B)
3o into the needle bore. As one needle pusher is advanced, the next one
becomes available for
advancing and comes into contact with spring 342. Optionally, but not
necessarily, the
disposable needle pusher is provided as an extension of needle pusher 330. The
size of
cartridge 343 can be larger, of course, for example if a long disposable
thread pusher is used.
In the embodiment shown, the retraction of the needles optionally cocks spring
342.
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WO 00/74578 PCT/IL00/00320
In an embodiment of the invention, even in a disposable device, the device is
tested,
optionally on a piece of test material (possibly a live or dead bone removed
from the body),
after it is manufactured or prior to its being used by the physician, to
ensure that the device is
operating properly.
The above description has focused on forming holes in a pubic bone, especially
for
attaching a thread through the hole for a bladder sling or a bladder or
bladder neck suspension.
However, a similar device may be used for other applications. In one broad
class of uses, the
channel is used for attaching soft tissue to a bone, using a thread that grips
the bone and is
engaged by the channel. Examples of attaching soft tissue include correction a
dislocating
to shoulder (e.g., Bankard procedure), hyoid suspension, and cosmetic
applications, such as
tightening flabby flesh, by suturing it to a bone.
Fig. 24 illustrates a bone-boring head 360 mounted at an end of an endoscope,
catheter
or trocar 362, in accordance with an embodiment of the invention. Fig. 25
illustrates bone-
boring head 360 mounted at a side of endoscope, catheter or trocar 362, in
accordance with an
embodiment of the invention. It is expected that only a small pressure is
needed to maintain
head 360 against a bone prior to the needles engaging the bone. In a trocar,
which is
substantially rigid, the pressure may be achieved by pushing against the
trocar. In an
endoscope, which is usually somewhat rigid, the pressure may be applied
through the
endoscope. In flexible endoscopes and/or flexible catheters, the pressure may
be applied by
2o advancing the endoscope and using the surrounding body tissues to apply a
contra force. In
some of these small-diameter devices, levers may not be suitable, due to space
constraints,
however, other ways of rotating the needles) around the hinge may be used, for
example,
using a screw mechanism or a motor. In some cases, a clamp or a suction nozzle
(not shown)
may be provided to hold head 360 against the bone. The clamp may engage bone
or it may
engage nearby soft tissue.
In an embodiment of the invention, especially when an endoscope or trocar is
used for
cosmetic surgery, a minimal diameter hole is formed in the body, optionally in
an
inconspicuous location and a boring head 360 is brought to a location where
soft tissue is to be
attached to bone. The suture is applied, as described herein and the thread is
tied through the
3o hole. Thereafter, the hole is sealed. This type of procedure may be
especially useful for surgery
of the face when implantation of staples or screws or long incisions may not
be viable options.
Another class of uses is attaching implants, either using a suture, as
described above or
by inserting a projection of the implant into a channel formed in the bone.
CA 02375352 2001-11-27
WO 00/74578 PCT/IL00/00320
Another class of uses is treating fractures of bones. In one example, small
bones, such
as wrist bones may be immobilized or prevented form moving apart by threading
them
together. Optionally, first a channel is formed in each bone and then the
bones are sutured to
each other (or to soft tissue, such as ligaments). Further, in cases where
there are many bone
fragments, such as in skull injuries or in cases of shattered jaw bones, the
fragments may be
stitched together. In some cases it is advantageous for the needles to oppose
each other (180
degrees), possibly traveling in straight lines towards each other. Optionally,
a large radius of
rotation around the hinge approximates such straight lines.
In an embodiment of the invention, bone fragments are attached to a structural
element
to that maintains them in place. Fig. 26 illustrates a plate 374 that is
sutured to a fractured bone
370, using a plurality of sutures 372. Optionally, holes are pre-formed in the
structural element
for receiving the needles. Alternatively, holes in the structural element may
be bored in a
single step with boring the holes in the bone. Possibly, a biodegradable
structural element is
used, so that there is no need to remove it after the bone heals.
Alternatively or additionally,
the needles may be biodegradable. Another relevant procedure is sternal
suturing in which a
cut-open rig cage is sutured shut. In a variation of the above embodiment,
plate 374 may be an
intramedullar nail (possibly not filling the entire cross-section but
functioning like plate 374)
which is inside the bone.
The above description has focused on boring holes through bones. However, it
should
be noted that various aspects of the invention may be applied towards other,
similar medical
applications. In one example, it is noted that the self aligning feature and
the various safety
mechanisms may be useful separately or in combination for screw driving
devices and for
staplers, for example, to prevent slippage, incorrect penetration and/or
inadvertent damaging of
soft tissue.
With regard to staplers, the above described force transduction mechanism
(e.g., Fig. 1)
that advance a needle may be used for advancing staples, noting, that unlike
needles, the
staples remain in the body. Possibly, the staples are inserted side by side
with a pair of needles,
each of which needles includes a groove for receiving an arm of the staple and
which needle
does the actual boring. Thus, the staple itself can contain less material
and/or otherwise be
3o mechanically weaker.
Additionally, the above device may be used for tacking, which is a method
where a
suture or other object is attached to a bone by its being pressed between a
tack and the bone. A
more complete description of tacking can be found in a PCT patent application
number
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CA 02375352 2001-11-27
WO 00/74578 PCT/IL00/00320
PCT/IL00/00012, filed January 8, 2000, by applicant Influence Medical Systems
Ltd., and
titled "Tack Device", the disclosure of which is incorporated herein by
reference.
Additionally, the above device can be used for implanting a bone anchor,
noting that
since the hole is bored by a needle, the bone anchor can be made with less
material, weaker
material and/or from bio-absorbable material.
Figs. 27A-27C illustrate an alternative method of fixing a thread 634 to a
bone. As in
some of the previous embodiments, the thread is held by the bone itself.
However, in the
embodiment of Figs. 27, only one hole is formed in the bone.
In Fig. 27A, a V shaped hole 660 is formed in cortex 478, for example using a
tool 668
1o with a tip cross-section 670, as shown. The hole formed has a larger
aperture 662, for example
at the center of the "V" and two thinner arms 664.
Fig. 27B shows a thread 634 with a knot 672 formed therein. The knot is
inserted
through the larger aperture 662 and is prevented from escaping the bone, by
sliding the knot to
be under the thinner portions 664. In some cases, no knot is required, for
example, thread 634
can be engaged directly by the bone, for example by arms 664 defining a slot
that is thinner
than thread 634. Alternatively or additionally to a knot 672, a fixed element,
such as a bead,
may be provided at the end of thread 634. Alternatively or additionally, an
expanding element,
such as a plastic or metal element may be provided at the end of thread 634,
such that once
they expand, they cannot slip out of aperture 662 and/or 664 (depending on the
embodiment).
2o Depending on the initial diameter of the suture (or elements fixed thereto)
and/or the fixation
method, the size and/or shape of apertures 662 and 64 may vary.
Fig. 27C shows an exemplary completed secured thread.
Other hole forms can be used as well. For example, a C shaped hole can be used
to
hold a thread in the bone in a manner similar to that described above in Figs.
1-26. The thread
is looped and mounted over two arms of the c at the same time. As each end of
the thread
gravitates to a different tip of the C, it will not slip off. Alternatively ,
a simpler horizontal peg
may be formed in the bone using tool 668, to which peg the thread is attached.
Alternatively to forming hole 660 using a tool 668, an advancing needle having
a
suitable cross-section, may be used. The needle may also deposit a thread in
the hole, for
3o example using a same mechanism as used to deposit a tip in a drill bit
(Figs. 19) or exchange
tips between needles. Optionally, the removable tip of the needle defines a
groove to engage
the bone cortex when the needle is retracted, so the tip remains inside the
bone.
In some embodiments of the invention, the above-described mechanisms for
forming a
hole in a bone are used for inserting objects, such as anchors, into a bone at
a non
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CA 02375352 2001-11-27
WO 00/74578 PCT/IL00/00320
perpendicular angle thereto. It is not required that any part of the inserted
object project from
the bone.
It will be appreciated that the above described methods of forming a channel
through
bone and threading the channel and devices therefore may be varied in many
ways, while
remaining within the scope of the present invention. In addition, a
multiplicity of various
features, both of methods and of devices has been described. It should be
appreciated that
different features may be combined in different ways. In particular, not all
the features shown
above in a particular embodiment are necessary in every similar embodiment of
the invention.
Further, combinations of the above features are also considered to be within
the scope of some
1o embodiments of the invention. Also within the scope of the invention are
surgical kits that
include sets of bone-boring devices, bone-boring heads, needles and/or sutures
and methods
for using the devices and/or such surgical kits. When used in the following
claims, the terms
"comprises", "includes", "have " and their conjugates mean, "including but not
limited to".
A person skilled in the art will appreciate that the present invention is not
limited by
1S what has thus far been described. Rather, the scope of the present
invention is limited only by
the following claims.
38
