Note: Descriptions are shown in the official language in which they were submitted.
ELECTRIC MOTOR DRIVEN TOOL FOR ORTHOPEDIC IMPACTING
[0001]
FIELD OF THE DISCLOSURE
[0002] The
present disclosure relates to electric tools for impacting in orthopedic
applications, and, more particularly, to an electric motor driven tool for
orthopedic impacting
that is capable of providing controlled impacts to a broach or other end
effector.
BACKGROUND
[0003] In the
field of orthopedics, prosthetic devices, such as artificial joints, are
often implanted or seated in a patient' s body by seating the prosthetic
device in a cavity of a
bone of the patient. Typically, the cavity must be created before the
prosthesis is seated or
implanted, and traditionally, a physician removes and or compacts bone to form
this cavity.
1
CA 2872182 2019-10-04
CA 02872182 2014-10-30
WO 2013/169335
PCT/US2013/029962
A prosthesis usually includes a stem or other protrusion that serves as the
particular portion
of the prosthesis that is inserted into the cavity.
[0004] To
create such a cavity, a physician may use a broach, which broach conforms
to the shape of the stem of the prosthesis. Solutions known in the art include
providing a
handle with the broach, which handle the physician may grasp while hammering
the broach
into the implant area. Unfortunately, this approach is clumsy and
unpredictable as being
subject to the skill of the particular physician. "This approach almost will
always inevitably
result in inaccuracies in the location and configuration of the cavity.
Additionally, the
surgeon suffers from fatigue in this approach due to the constant hammering.
Finally, this
approach carries with it the risk that the physician will damage bone
structure in unintended
areas.
[0005] Another
technique for creating the prosthetic cavity is to drive the broach
pneumatically, that is, by compressed air. This approach is disadvantageous in
that it
prevents portability of an impacting tool, for instance, because of the
presence of a tethering
air line, air being exhausted from a tool into the sterile operating field and
fatigue of the
physician operating the tool. Further, this approach, as exemplified in U.S.
Patent No.
5,057,112, does not allow for precise control of the impact force or frequency
and instead
functions very much like a jackhammer when actuated. Again, this lack of any
measure of
precise control makes accurate broaching of the cavity more difficult.
[0006] A third technique relies on computer-controlled robotic arms for
creating the
cavity. While this approach overcomes the fatiguing and accuracy issues, it
suffers from
having a very high capital cost and additionally removes the tactile feedback
that a surgeon
can get from a manual approach.
[0007] A
fourth technique relies on the author's own prior disclosures to use a linear
compressor to compress air on a single stroke basis and then, after a
sufficient pressure is
created, to release the air through a valve and onto a striker. This then
forces the striker to
travel down a guide tube and impact an anvil, which holds the broach and or
other surgical
tool. This invention works quite well, but, in the process of testing it, does
not allow for a
simple method to reverse the broach should it become stuck in the soft tissue.
Further, the
pressure of the air results in large forces in the gear train and linear
motion converter
components, which large forces lead to premature wear on components.
2
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
[0008]
Consequently, there exists a need for an impacting tool that overcomes the
various disadvantages of the prior art.
SUMMARY OF THE INVENTION
[0009] In view
of the foregoing disadvantages of the prior art, an electric motor-
driven orthopedic impacting tool configured to include all the advantages of
the prior art and
to overcome the drawbacks inherent therein is provided. The tool may be used
by orthopedic
surgeons for orthopedic impacting in hips, knees, shoulders and the like. The
tool is capable
of holding a broach, chisel, or other end effector and gently tapping the
broach, chisel or
other end effector into the cavity with controlled percussive impacts,
resulting in a better fit
for the prosthesis or the implant. Further, the control afforded by such an
electrically
manipulated broach, chisel, or other end effector allows adjustment of the
impact settings
according to a particular bone type or other profile of a patient. The tool
additionally enables
proper seating or removal of the prosthesis or the implant into or out of an
implant cavity and
advantageously augments the existing surgeon's skill in guiding the
instrument.
[0010] In an
embodiment, an electric motor-driven orthopedic impacting tool
comprises a power source (such as a battery), a motor, a control means, a
housing, a method
for converting the rotary motion of the motor to a linear motion (hereafter
referred to as a
linear motion converter), at least one reducing gear, a striker, a detent and
an energy storage
means, which energy storage means can include either compressed air or a
vacuum. The tool
may further include an LED, a handle portion with at least one handgrip for
the comfortable
gripping of the tool, an adapter configured to accept a surgical tool, a
battery and at least one
sensor. At least some of the various components are preferably contained
within the housing.
The tool is capable of applying cyclic impact forces on a broach, chisel, or
other end effector,
or an implant and of finely tuning an impact force to a plurality of levels.
[0011] In a
further embodiment, the handle may be repositionable or foldable back to
the tool to present an inline tool wherein the surgeon pushes or pulls on the
tool co-linearly
with the direction of the broach. This has the advantage of limiting the
amount of torque the
surgeon may put on the tool while it is in operation. In a further refinement
of the hand grip,
there may be an additional hand grip for guiding the surgical instrument and
providing
increased stability during the impacting operation.
3
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
[0012] In a
further embodiment, the broach, chisel or other end effector can be rotated
to a number of positions while still maintaining axial alignment. This
facilitates the use of
the broach for various anatomical presentations during surgery.
[0013] In a
further embodiment, the energy storage means comprises a chamber,
which is under at least a partial vacuum during a portion of an impact cycle.
[0014] In a
further embodiment the linear motion converter uses one of a slider crank,
linkage mechanism, cam, screw, rack and pinion, friction drive or belt and
pulley.
[0015] In an
embodiment, the linear motion converter and rotary motor may be
replaced by a linear motor, solenoid or voice coil motor.
[0016] In an embodiment, the tool further comprises a control means, which
control
means includes an energy adjustment element, and which energy adjustment
element may
control the impact force of the tool and reduce or avoid damage caused by
uncontrolled
impacts. The energy may be regulated electronically or mechanically.
Furthermore, the
energy adjustment element may be analog or have fixed settings. This control
means allows
for the precise control of the broach machining operation.
[0017] In an
embodiment, an anvil of the tool includes at least one of two points of
impact and a guide that constrains the striker to move in a substantially
axial direction. In
operation, the movement of the striker along the guide continues in the
forward direction. A
reversing mechanism can be used to change the point of impact of the striker
and the
resulting force on the surgical tool. Use of such a reversing mechanism
results in either a
forward or a rearward force being exerted on the anvil and/or the broach or
other surgical
attachment. As used in this context, "forward direction" connotes movement of
the striker
toward a broach, chisel or patient, and "rearward direction" connotes movement
of the striker
away from the broach, chisel or patient. The selectivity of either
bidirectional or
unidirectional impacting provides flexibility to a surgeon in either cutting
or compressing
material within the implant cavity in that the choice of material removal or
material
compaction is often a critical decision in a surgical procedure. Furthermore,
it was
discovered in the use of the author's prior disclosure that the tool would
often get stuck
during the procedure and that the method of reversal in that tool was
insufficient to dislodge
the surgical implement. This new embodiment overcomes these limitations. In an
embodiment the impact points to communicate either a forward or rearward force
are at least
two separate and distinct points.
4
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
[0018] In an
embodiment the anvil and the adapter comprise a single element, or one
may be integral to the other.
[0019] In an
embodiment the tool is further capable of regulating the frequency of the
striker's impacting movement. By regulating the frequency of the striker, the
tool may, for
example, impart a greater total time-weighted percussive impact, while
maintaining the same
impact magnitude. This allows for the surgeon to control the cutting speed of
the broach or
chisel. For example, the surgeon may choose cutting at a faster rate (higher
frequency
impacting) during the bulk of the broach or chisel movement and then slow the
cutting rate as
the broach or chisel approaches a desired depth. In typical impactors, as
shown in U.S.
Patent No. 6,938,705, as used in demolition work, varying the speed varies the
impact force,
making it impossible to maintain constant (defined as +/- 20%) impact energy
in variable
speed operation.
[0020] In an
embodiment the direction of impacting is controlled by the biasing force
placed by a user on the tool. For example, biasing the tool in the forward
direction gives
forward impacting and biasing the tool in the rearward direction gives rear
impacting.
[0021] In an
embodiment the tool may have a lighting element to illuminate a work
area and accurately position the broach, chisel, or other end effector on a
desired location on
the prosthesis or the implant.
[0022] In an
embodiment the tool may also include a feedback system that warns the
user when a bending or off-line orientation beyond a certain magnitude is
detected at a
broach, chisel, or other end effector or implant interface.
[0023] In an
embodiment the tool may also include a detent that retains the striker and
which may be activated by a mechanical or electrical means such that the
energy per impact
from the tool to the surgical end effector is increased. In an embodiment, the
characteristics
of this detent are such that within 30% of striker movement, the retention
force exerted by the
detent on the striker is reduced by 50%.
[0024] These
together with other aspects of the present disclosure, along with the
various features of novelty that characterize the present disclosure, are
pointed out with
particularity in the claims annexed hereto and form a part of the present
disclosure. For a
better understanding of the present disclosure, its operating advantages, and
the specific
objects attained by its uses, reference should be made to the accompanying
drawings and
5
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
detailed description in which there are illustrated and described exemplary
embodiments of
the present disclosure.
DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better
understood
with reference to the following detailed description and claims taken in
conjunction with the
accompanying drawings, wherein like elements are identified with like symbols,
and in
which:
Figure 1 shows a perspective view of an orthopedic impacting tool in
accordance with
an exemplary embodiment of the present disclosure in which a motor, linear
motion
converter, and vacuum as energy storage means are used;
Figure 2 shows an exemplary position of the piston wherein the vacuum has been
created;
Figure 3 shows the striker being released and the striker moving towards
impacting
the anvil in a forward direction;
Figure 4 shows the striker being released and the striker moving such that the
anvil
will be impacted in a reverse direction;
Figure 5 shows the vacuum piston moving back towards a first position and
resetting
the striker;
Figure 6 shows an exemplary embodiment of a tool in which a compression
chamber
is used to create an impacting force;
Figure 7 shows an exemplary embodiment of a tool in which a valve is used to
adjust
the energy of the impact of the striker;
Figure 8 shows an exemplary embodiment of a tool in which the striker imparts
a
surface imparting a rearward force on the anvil;
Figure 9 shows an exemplary embodiment of a tool in which the striker imparts
a
forward acting force on the anvil; and
Figure 10 shows a comparison of the force vs. time curve between a sharp
impact and
a modified impact using a compliance mechanism in accordance with an exemplary
embodiment of the present disclosure.
6
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
DETAILED DESCRIPTION OF THE DISCLOSURE
[0025] The
best mode for carrying out the present disclosure is presented in terms of
its preferred embodiments, herein depicted in the accompanying figures. The
preferred
embodiments described herein detail for illustrative purposes are subject to
many variations.
It is understood that various omissions and substitutions of equivalents are
contemplated as
circumstances may suggest or render expedient, but are intended to cover the
application or
implementation without departing from the spirit or scope of the present
disclosure.
[0026] The terms "a" and "an" herein do not denote a limitation of
quantity, but
rather denote the presence of at least one of the referenced items.
[0027] The
present disclosure provides an electric motor-driven orthopedic impacting
tool with controlled percussive impacts. The tool includes the capability to
perform single
and multiple impacts as well as impacting of variable and varying directions,
forces and
frequencies. In an embodiment the impact force is adjustable. In another
embodiment a
detent may be provided, which detent facilitates the generation of a higher
energy impact. In
yet another embodiment the impact is transferred to a broach, chisel, or other
end effector
connected to the tool.
[0028] The
tool may further include a housing. The housing may securely cover and
hold at least one component of the tool. In an embodiment, the housing
contains a motor, at
least one reducing gear, a linear motion converter, a gas chamber, a striker,
a force adjuster, a
control means, an anvil, a forward impact surface and a different surface for
rearward impact.
[0029] The
tool further may include a handle portion with at least one hand grip for
comfortable and secure holding of the tool while in use, and an adapter, a
battery, a positional
sensor, a directional sensor, and a torsional sensor. The tool may further
comprise a lighting
element such as an LED to provide light in the work area in which a surgeon
employs the
tool. The anvil may be coupled to a broach, chisel or other end effector
through the use of an
adapter, which adapter may have a quick connect mechanism to facilitate rapid
change of
different broaching sizes. The anvil may further include a locking rotational
feature to allow
the broach to be presented to and configured at different anatomical
configurations without
changing the orientation of the tool in the surgeon's hands.
7
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
[0030]
Referring now to Figures 1 through 5, in an embodiment, the linear motion
converter 12 comprises a slider crank mechanism, which slider crank is
operatively coupled
to the motor 8 and reducing gears 7. The tool further comprises a vacuum
chamber 23 that
accepts a piston 24 which may be actuated by the linear motion converter 12.
It will be
apparent that the piston 24 may be actuated in more than one direction. The
vacuum is
created in the vacuum chamber 23 by the movement of piston 24 away from
striker 25. The
vacuum created in the vacuum chamber 23 is defined as a pressure of less than
9 psia for at
least a portion of the operational cycle.
[0031] In an
embodiment, the motor 8 of the tool causes the linear motion converter
12 to move, which pulls a vacuum on the face of the striker 25 and creates at
least a partial
vacuum in the vacuum chamber 23, as is shown in Figure 2. The piston 24
continues to move
increasing the size of the vacuum chamber 23 until it hits a forward portion
of the striker 25
(i.e., a portion of the strike that is proximate to the end effector or
patient), which dislodges
the striker 25 from its detent 10 and allows it to rapidly accelerate towards
the end of the tool
that is proximate to the end effector or patient. In an embodiment, the detent
may be
mechanical, electrical, or a combination thereof, with the preferred detent
shown in the
figures as a magnet. A characteristic of the detent 10 is that once the detent
10 is released or
overcome, the retention force of the detent 10 on the striker 25 reduces by at
least 50% within
the first 30% movement of the striker 25. The impact of the striker 25 on the
anvil 14
communicates a force to the adapter 1 and the broach, chisel or other
orthopedic instrument.
[0032] In an
embodiment, the direction of the force on the anvil is controlled by the
user's (such as a surgeon) force on the tool and a stroke limiter 13. It has
been determined
that prior art tools may occasionally get stuck in a cavity and the impact of
the striker in the
aforementioned paragraph may be insufficient to dislodge the tool. In this
present
embodiment, when the tool is being pulled away from the cavity, the striker 25
will not
impact the anvil 14, but will impact an alternate surface and thereby
communicate a rearward
force on the anvil 14. This impact surface is shown in an exemplary embodiment
as
actuation pin 27. Actuation pin 27 communicates a force to lever arm 17, which
communicates a rearward force on the anvil 14, and specifically on the anvil
retract impact
surface 26. This embodiment has the unexpected benefit of easily dislodging
tools and
instruments that have become stuck in a surgical cavity, while retaining all
the benefits of the
existing tool in temis of precision-controlled impacting. Thus, a further
advantage of this
8
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
tool was discovered as it can be seen that the surgeon can control the
direction of the
impacting by a bias that he or she may place on the tool and, in so doing, can
reduce the
likelihood of the broach, chisel or other end effector from getting stuck in a
patient or
surgical cavity.
[0033] In a further embodiment, an electromagnet may be incorporated as the
detent
and released at an appropriate point in the operation cycle to allow the
striker 25 to impact
the anvil 14. Once the striker 25 has been released from the detent 10, the
air pressure on the
rearward side of the striker 25, propels it forward to impact the anvil 14 or
other strike
surface. The resultant force may be communicated through an end of the anvil
14 that is
10 proximate to the anvil forward impact surface 16 and, optionally,
through the adapter 1 to
which a broach, chisel, or other end effector for seating or removing an
implant or prosthesis
may be attached.
[0034] The
striker guide 11 may also have striker guide vent holes 20, which allow
the air in front of the striker 25 to escape, thus increasing the impact force
of the striker 25 on
the anvil 14. The striker guide vent holes 20 may vent within the cavity of
the tool body,
thus creating a self-contained air cycle preventing air from escaping from the
tool and
allowing for better sealing of the tool. The position and the size of the
striker guide vent
holes 20 can also be used to regulate the impact force. Further, it was
unexpectedly found
that adding the striker guide vent holes 20 increases the impact force of the
striker 25 on the
anvil 14.
[0035] In an
embodiment, as the piston 24 continues through its stroke it moves
towards the rear direction, which movement brings it in contact with rear
striker face 28 of
striker 25 and moves it towards the rear of the tool. This allows the detent
10 to lock or
retain the striker 25 in position for the next impact. 'Me piston 24 completes
its rearward
stroke and preferably activates a sensor 22 that signals the motor 8 to stop
such that the piston
24 rests at or near bottom dead center of the vacuum chamber 23. The vacuum
chamber 23
preferably has a relief or check valve 9 or other small opening, which, in an
embodiment, is
part of the piston 24. The valve 9 may also be located at other points in the
vacuum chamber
23 and allows for any air which may have accumulated in the vacuum chamber 23
to be
purged out of the vacuum chamber 23 during each cycle. In a further embodiment
this valve
effect could be accomplished with a cup seal instead of an o-ring seal. This
ensures that
approximately atmospheric pressure is present in the vacuum chamber 23 at a
starting point
9
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
in the operational cycle, thus ensuring that each impact utilizes the same
amount of energy, as
is important in orthopedic impacting for at least the reason that it assures
of a substantially
consistent force and impact rate in multi-impact situations. Thus, in one
complete cycle, a
forward or a rearward impacting force may be applied on the broach, chisel, or
other end
effector, or on the implant or prosthesis.
[0036] In a
further embodiment, the motor 8 of the tool causes the linear motion
converter 12 to move the piston 24 until the piston 24 moves a sufficient
distance such that
the forward portion of the piston impacts a portion of the striker and
overcomes the detent 10
that retains the striker in the rear position. Once the striker has been
released from the detent
10, the vacuum in the vacuum chamber 23 exerts a force on the striker, which
accelerates the
striker, causing the striker to slide axially down a cavity internal to the
tool housing and strike
the anvil forward impact surface 16. In Figure 3, the anvil forward impact
surface 16 causes
a forward movement of the anvil 14 and/or tool holder, and, in Figure 4, the
anvil retract
impact surface 26 causes a rearward movement of the anvil 14 and/or tool
holder. The
resultant force is communicated through an end of the anvil 14 that is
proximate to the anvil
forward impact surface 16 and, optionally, through the adapter 1 to which a
broach, chisel, or
other end effector for seating or removing an implant or prosthesis may be
attached.
[0037] In
another embodiment, the impact force may be generated using a
compressed air chamber 5 in conjunction with a piston 6 and striker 4, as
shown in Figures 6
through 9. In this embodiment, the motor 8 of the tool causes the linear
motion converter 12
to move the piston 6 until sufficient pressure is built within the compressed
air chamber 5 that
is disposed between the distal end of the piston 6 and the proximate end of
the striker 4 to
overcome a detent 10 that otherwise retains the striker 4 in a rearward
position and or the
inertia and frictional force that holds the striker 4 in that rearward
position. Once this
sufficient pressure is reached, an air passageway 19 is opened and the air
pressure accelerates
the striker 4, which striker 4 slides axially down a cavity and strikes the
anvil 14. The air
passageway 19 has a cross sectional area of preferably less than 50% of the
cross sectional
area of the striker 4 so as to reduce the amount of retaining force required
from detent 10.
The resultant force is communicated through the end of the anvil 14 that is
proximate to the
anvil forward impact surface 16 and, optionally, through the adapter 1 to
which a broach,
chisel, or other device for seating or removing an implant or prosthesis may
be attached.
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
[0038] As the
piston 6 continues through its stroke, it moves towards the rear
direction, pulling a slight vacuum in compressed air chamber 5. This vacuum
may be
communicated through an air passageway 19 to the back side of the striker 4,
creating a
returning force on the striker 4, which returning force causes the striker 4
to move in a rear
direction, i.e., a direction away from the point of impact of the striker 4 on
the anvil forward
impact surface 16. In the event that an adapter 1 is attached to the anvil 14,
a force may be
communicated through the adapter 1 to which the broach, chisel, or other end
effector for
seating or removing an implant or prosthesis is attached.
[0039]
Further, when the tool is being pulled away from the cavity, the striker 4
will
not impact the anvil 14, but may instead impact an alternate surface and
thereby
communicate a rearward force on the anvil 14. This impact surface is shown in
an exemplary
embodiment as actuation pin 27. Actuation pin 27 communicates a force to lever
arm 17,
which communicates a rearward force on the anvil 14, and specifically on the
anvil retract
impact surface 26.
[0040] The tool may further facilitate controlled continuous impacting,
which
impacting is dependent on a position of a start switch (which start switch may
be operatively
coupled to the power source or motor, for example.) For such continuous
impacting, after the
start switch is activated, and depending on the position of the start switch,
the tool may go
through complete cycles at a rate proportional to the position of the start
switch, for example.
Thus, with either single impact or continuous impacting operational modes, the
creation or
shaping of the surgical area is easily controlled by the surgeon.
[0041] A
sensor 22 coupled operatively to the control means 21 may be provided to
assist in regulating a preferred cyclic operation of the linear motion
converter 12. For
example, the sensor 22 may communicate at least one position to the control
means 21,
allowing the linear motion converter 12 to stop at or near a position in which
at least 75% of
a full power stroke is available for the next cycle. This position is referred
to as a rest
position. This has been found to be advantageous over existing tools in that
it allows the user
to ensure that the tool impacts with the same amount of energy per cycle.
Without this level
of control, the repeatability of single cycle impacting is limited, reducing
the confidence the
surgeon has in the tool.
[0042] The
tool is further capable of tuning the amount of impact energy per cycle by
way of, for example, an energy control element 18. By controlling the impact
energy the tool
11
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
can avoid damage caused by uncontrolled impacts or impacts of excessive
energy. For
example, a surgeon may reduce the impact setting in the case of an elderly
patent with
osteoporosis, or may increase the impact setting for more resilient or intact
athletic bone
structures.
[0043] In an embodiment, the energy control element 18 preferably comprises
a
selectable release setting on the detent 10 that holds the striker 25. It will
be apparent that the
striker 25 will impact the anvil 14 with greater energy in the case where the
pressure needed
to dislodge the striker 25 from the detent 10 is increased. In another
embodiment, the detent
may comprise an electrically controlled element. The electrically controlled
element can
10 be released at different points in the cycle, thus limiting the size of
the vacuum chamber 23,
which is acting on the striker 25. In an embodiment, the electrically
controlled element is an
electromagnet.
[0044] In
another embodiment, the vacuum chamber 23 or compressed air chamber 5
may include an energy control element 18, which takes the form of an
adjustable leak, such
as an adjustable valve. The leakage reduces the amount of energy accelerating
the striker 4
or 25, thus reducing the impact energy on the anvil 14. In the case of the
adjustable leak,
adjusting the leak to maximum may give the lowest impact energy from the
striker 4 or 25,
and adjusting to shut the leak off (zero leak) may give the highest impact
energy from the
striker 4 or 25.
[0045] The tool may further comprise a compliance means inserted between
the
striker 4 or 25 and the surgical end effector, which purpose is to spread the
impact force out
over a longer time period, thus achieving the same total energy per impact,
but at a reduced
force. This can be seen clearly as a result of two load cell tests on the
instrument as shown in
Figure 10. Ibis type of compliance means can limit the peak force during
impact to preclude
such peaks from causing fractures in the patient's bone. In a further
embodiment, this
compliance means may be adjustable and in a still further embodiment the
compliance means
may be inserted between striker 4 or 25 and the anvil 14 or surgical tool. In
this manner and
otherwise, the tool facilitates consistent axial broaching and implant
seating. Preferably, the
compliance means increases the time of impact from the striker to at least 4
milliseconds and
preferable 10 milliseconds. This contrasts to impacting in which a very high
force is
generated due to the comparatively high strengths of the striker 4 or 25 and
the anvil 14 (both
steel, for example). Preferably, the compliance means comprises a resilient
material such as
12
CA 02872182 2014-10-30
WO 2013/169335
PCMJS2013/029962
urethane, rubber or other elastic material that recovers well from impact and
imparts minimal
damping on the total energy.
[0046] In a
further embodiment, the adapter 1 may comprise a linkage arrangement or
other adjustment means such that the position of the broach, chisel or other
end effector can
be modified without requiring the surgeon to rotate the tool. In an
embodiment, the adapter 1
may receive a broach for anterior or posterior joint replacement through
either an offset
mechanism or by a rotational or pivotal coupling between the tool and the
patient. The
adapter 1 may thereby maintain the broach or surgical end effector in an
orientation that is
parallel or co-linear to the body of the tool and the striker 25. The adapter
1 may also
comprise clamps, a vice, or any other fastener that may securely hold the
broach, chisel, or
other end effector during operation of the tool.
[0047] In use,
a surgeon firmly holds the tool by the handle grip or grips and utilizes
light emitted by the LED to illuminate a work area and accurately position a
broach, chisel or
other end effector that has been attached to the tool on a desired location on
the prosthesis or
implant. The reciprocating movement imparted by the tool upon the broach,
chisel or other
end effector allows for shaping a cavity and for seating or removal of a
prosthesis.
[0048] The
tool disclosed herein provides various advantages over the prior art. It
facilitates controlled impacting at a surgical site, which minimizes
unnecessary damage to a
patient's body and which allows precise shaping of an implant or prosthesis
seat. The tool
also allows the surgeon to modulate the direction, force and frequency of
impacts, which
improves the surgeon's ability to manipulate the tool. The force and
compliance control
adjustments of the impact settings allow a surgeon to set the force of impact
according to a
particular bone type or other profile of a patient. The improved efficiency
and reduced linear
motion converter loads allow use of smaller batteries and lower cost
components. 'Me tool
thereby enables proper seating or removal of the prosthesis or implant into or
out of an
implant cavity.
[0049] The
foregoing descriptions of specific embodiments of the present disclosure
have been presented for purposes of illustration and description. They are not
intended to be
exhaustive or to limit the present disclosure to the precise fomis disclosed,
and obviously
many modifications and variations are possible in light of the above teaching.
The exemplary
embodiment was chosen and described in order to best explain the principles of
the present
disclosure and its practical application, to thereby enable others skilled in
the art to best
13
CA 02872182 2014-10-30
WO 2013/169335
PCT/1JS2013/029962
utilize the disclosure and various embodiments with various modifications as
are suited to the
particular use contemplated.
14
