U.S. patent application number 14/643881 was filed with the patent office on 2016-08-11 for locking device for fixation mechanism of medical implant.
This patent application is currently assigned to Alliance Partners, LLC. The applicant listed for this patent is Alliance Partners, LLC. Invention is credited to Mike Faraj, Frankie Morris, Justin Rice.
Application Number | 20160228156 14/643881 |
Document ID | / |
Family ID | 56566394 |
Filed Date | 2016-08-11 |
United States Patent
Application |
20160228156 |
Kind Code |
A1 |
Morris; Frankie ; et
al. |
August 11, 2016 |
LOCKING DEVICE FOR FIXATION MECHANISM OF MEDICAL IMPLANT
Abstract
A device for locking a bone fastening or fixation mechanism in a
receiving member of a medical implant. The locking mechanism is
kept in place (both in its locked and unlocked positions) using a
retaining mechanism. The retaining mechanism also provides
predetermined locked and unlocked positions that are readily moved
to by the practitioner and maintained in position once placed
there.
Inventors: |
Morris; Frankie; (Austin,
TX) ; Faraj; Mike; (San Antonio, TX) ; Rice;
Justin; (San Antonio, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Alliance Partners, LLC |
San Antonio |
TX |
US |
|
|
Assignee: |
Alliance Partners, LLC
San Antonio
TX
|
Family ID: |
56566394 |
Appl. No.: |
14/643881 |
Filed: |
March 10, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14617367 |
Feb 9, 2015 |
|
|
|
14643881 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2560/0443 20130101;
A61F 2002/30787 20130101; A61B 17/8061 20130101; A61F 2002/30481
20130101; A61F 2002/30604 20130101; A61B 17/7059 20130101; A61B
17/8042 20130101; A61F 2002/30904 20130101; A61F 2002/30331
20130101; A61F 2002/30784 20130101; A61F 2002/30136 20130101; A61F
2/44 20130101; A61F 2220/0016 20130101; A61F 2/4455 20130101; A61F
2002/30593 20130101 |
International
Class: |
A61B 17/70 20060101
A61B017/70; A61B 17/80 20060101 A61B017/80 |
Claims
1. A medical implant comprising: (a) a receiving member body that
comprises a first fastener opening, wherein the first fastener
opening is operable for allowing a first fastener to be inserted
through the first fastener opening for fixing the medical implant
to bone; (b) a locking mechanism located near the first fastener
opening, wherein (i) the locking mechanism comprises a rotating
block cover operable to move between an unlocked position and a
locked position, (ii) when the rotating block cover is in the
unlocked position, the first fastener can be inserted through the
first fastening opening, (iii) when the rotating block cover is in
the locked position, a portion of the rotating block cover is
covering the first fastener opening to prevent the first fastener
for moving through the first fastener opening and which locks the
first fastener in place; and (c) a retaining mechanism that
comprises an engagement body rotatably coupled to at least two
retaining levers, wherein (i) the engagement body is attached to
the rotating block cover, (ii) the engagement body is operable for
moving rotatably relative to the retaining levers while maintaining
contact with the retaining levers throughout movement of the
engagement body between a first position and a second position,
(iii) the engagement body is operable for moving in a first
direction to the first position, wherein (A) when the engagement
body is in the first position, the locking mechanism is in the
unlocked position, (B) the engagement body is blocked from rotating
past the first position when moved in the first direction, and (C)
the engagement body is retained in the first position by the
application of opposing rotational forces by the retaining levers
such that the engagement body cannot move without the application
of a force in a second direction that is opposite to the first
direction, and (iv) the engagement body is operable for moving in
the second direction to the second position, wherein (A) when the
engagement body is in the second position, the locking mechanism is
in the locked position, (B) the engagement body is blocked from
rotating past the second position when moved in the second
direction, and (C) the engagement body is retained in the second
position by the application of opposing rotational forces by the
retaining levers such that the engagement body cannot move without
the application of a force in the first direction.
2. The medical implant of claim 1, wherein the medical implant is a
bone fixating plating system.
3. The medical implant of claim 2, wherein the bone fixating
plating system comprises a cervical plate.
4. The medical implant of claim 3, wherein (a) the cervical plate
further comprises a second fastener opening, (b) the second
fastener opening is operable for allowing a second fastener to be
inserted through the second fastener opening for fixing the medical
implant to bone, (c) the locking mechanism is further located near
the second fastener opening, (d) when the rotating block cover is
in the unlocked position, the second fastener can be inserted
through the second fastening opening, and (e) when the rotating
block cover is in the locked position, a portion of the rotating
block cover is covering the second fastener opening to prevent the
second fastener for moving through the second fastener opening and
which locks the second fastener in place.
5. The medical implant of claim 2, wherein the first fastener
comprises a bone screw.
6. The medical implant of claim 2, wherein the retaining mechanism
comprises exactly two retaining levers.
7. A medical implant comprising: (a) a receiving member body that
comprises a first fastener opening, wherein the first fastener
opening is operable for allowing a first fastener to be inserted
through the first fastener opening for fixing the medical implant
to bone; (b) a locking mechanism located near the first fastener
opening, wherein (i) the locking mechanism comprises a rotating
block cover operable to move between an unlocked position and a
locked position, (ii) when the rotating block cover is in the
unlocked position, the first fastener can be inserted through the
first fastening opening, (iii) when the rotating block cover is in
the locked position, a portion of the rotating block cover is
covering the first fastener opening to prevent the first fastener
for moving through the first fastener opening and which locks the
first fastener in place; and (c) a retaining mechanism that
comprises an engagement body rotatably coupled to at least two
retaining levers, wherein (i) the engagement body is attached to
the rotating block cover, (ii) the engagement body is operable for
moving rotatably through the retaining levers, (iii) the engagement
body is operable for moving in a first direction to a first
position, wherein (A) when the engagement body is in the first
position, the locking mechanism is in the unlocked position, (B)
the engagement body is blocked from rotating past the first
position when moved in the first direction, and (C) the engagement
body is retained in the first position by the retaining levers such
that the engagement body cannot move without the application of a
force in a second direction that is opposite to the first
direction, (iv) the engagement body is operable for moving in the
second direction to a second position, wherein (A) when the
engagement body is in the second position, the locking mechanism is
in the locked position, (B) the engagement body is blocked from
rotating past the second position when moved in the second
direction, and (C) the engagement body is retained in the second
position by the retaining levers such that the engagement body
cannot move without the application of a force in the first
direction, (v) the medical implant is a bone fixating plating
system, and (vi) each of the retaining levers has an indent that
retains the engagement body in the first position and the second
position.
8. The medical implant of claim 2, wherein the rotating block cover
has a hole operable for receiving a rotatable tool, wherein the
rotating block cover is rotatable in the first direction and the
second direction using the rotating tool.
9. The medical implant of claim 2, wherein (a) the receiving member
body comprises a plurality of fastener openings and plurality of
locking mechanisms, and (b) each of the locking mechanisms is
operable for locking fasteners positioned in at most two of the
fastener openings.
10. The medical implant of claim 9, wherein each of the locking
mechanisms is operable for locking fasteners positioned in at most
one of the fastener openings.
11. A method comprising: (a) selecting a medical implant having a
receiving body that comprises a first fastener opening, a locking
mechanism, and a retaining mechanism, wherein (i) the locking
mechanism comprises a rotating block cover operable to move between
an unlocked position and a locked position, (ii) the locking
mechanism is in the unlocked position, (iii) the retaining
mechanism comprises an engagement body rotatably coupled to at
least two retaining levers, (iv) the engagement body is attached to
the rotating block cover, and (v) the retaining mechanism retains
the engagement body at a first position to maintain the rotating
block cover in the unlocked position, wherein the at least two
retaining levers apply opposing rotational forces to maintain the
rotating block cover in the unlocked position; (b) inserting a
first fastener into the first fastener opening; (c) securing the
first fastener to a bone; (d) rotating the locking mechanism from
the unlocked position to the locked position while the retaining
levers maintain contact with the engagement body throughout the
step of rotating, wherein (i) a portion of the rotating block cover
is covering the first fastener opening to prevent the first
fastener for moving through the first fastener opening and which
locks the first fastener in place, (ii) the engagement body is
blocked from rotating to prevent the rotating lock cover from
rotating past the locked position, and (iii) the retaining
mechanism retains the engagement body at a second position to
maintain the rotating block cover in the locked position wherein
the at least two retaining levers apply opposing rotational forces
to maintain the rotating block cover in the locked position.
12. The method of claim 11, wherein the medical implant is a bone
fixating plating system.
13. The method of claim 12, wherein the bone fixating plating
system comprises a cervical plate.
14. The method of claim 13, wherein (a) the cervical plate further
comprises a second fastener opening, (b) the method further
comprises (i) inserting a second fastener into the second fastener
opening and (ii) securing the second fastener to the bone while the
locking mechanism is in the unlocked position, and (c) the step of
rotating the locking mechanism further comprises that a portion of
the rotating block cover is covering the second fastener opening to
prevent the second fastener for moving through the second fastener
opening and which locks the second fastener in place.
15. The method of claim 12, wherein the first fastener comprises a
bone screw.
16. The method of claim 12, wherein the retaining mechanism
comprises exactly two retaining levers.
17. A method comprising: (a) selecting a medical implant having a
receiving body that comprises a first fastener opening, a locking
mechanism, and a retaining mechanism, wherein (i) the locking
mechanism comprises a rotating block cover operable to move between
an unlocked position and a locked position, (ii) the locking
mechanism is in the unlocked position, (iii) the retaining
mechanism comprises an engagement body rotatably coupled to at
least two retaining levers, (iv) the engagement body is attached to
the rotating block cover, and (v) the retaining mechanism retains
the engagement body at a first position to maintain the rotating
block cover in the unlocked position; (b) inserting a first
fastener into the first fastener opening; (c) securing the first
fastener to a bone; (d) rotating the locking mechanism from the
unlocked position to the locked position, wherein (i) a portion of
the rotating block cover is covering the first fastener opening to
prevent the first fastener for moving through the first fastener
opening and which locks the first fastener in place, (ii) the
engagement body is blocked from rotating to prevent the rotating
lock cover from rotating past the locked position, (iii) the
retaining mechanism retains the engagement body at a second
position to maintain the rotating block cover in the locked
position, (iv) the medical implant is a bone fixating plating
system, and (v) each of the retaining levers has an indent that
retains the engagement body in the first position and the second
position.
18. The method claim 12, wherein the step of rotating the locking
mechanism comprises inserting a rotating tool into a hole in the
rotating block cover and rotating the rotating tool.
19. The method of claim 12, wherein (a) the receiving member body
comprises a plurality of fastener openings and plurality of locking
mechanisms, (b) the method comprises moving each of the locking
mechanisms in the plurality of locking mechanism to lock at most
two fasteners positioned in at most two fastener openings.
20. The method of claim 19, wherein the method comprises moving
each of the locking mechanisms in the plurality of locking
mechanism to lock at most one fastener.
21. The method of claim 12 further comprising rotating the locking
mechanism from the locked position to the unlocked position,
wherein (a) no portion of the rotating block cover is covering the
first fastener opening which unlocks the first fastener, (b) the
engagement body is blocked from rotating to prevent the rotating
lock cover from rotating past the unlocked position, and (c) the
retaining mechanism retains the engagement body at the first
position to maintain the rotating block cover in the unlocked
position.
Description
RELATED APPLICATIONS
[0001] This application is related to U.S. patent application Ser.
No. ______, (Attorney Docket No. 156238.000201), filed concurrent
herewith, entitled "Locking Device For Fixation Mechanism Of
Medical Implant." This application is commonly assigned to the
Assignee of the present invention and is hereby incorporated herein
by reference in their entirety for all purposes.
FIELD OF INVENTION
[0002] A device for locking a bone fastening or fixation mechanism
in a receiving member of a medical implant.
BACKGROUND OF INVENTION
[0003] The spine is the axis of the skeleton on which all of the
body parts hang. In humans, the normal spine has seven cervical,
twelve thoracic and five lumbar segments. The lumbar spine sits
upon the sacrum, which then attaches to the pelvis, and in turn is
supported by the hip and leg bones. The bony vertebral bodies of
the spine are separated by intervertebral discs, which act as
joints but allow known degrees of flexion, extension, lateral
bending, and axial rotation and translation.
[0004] Typical vertebra has a thick anterior bone mass called the
vertebral body, with a neural (vertebral) arch that arises from the
posterior surface of the vertebral body. The central of adjacent
vertebrae are supported by intervertebral discs. The spinal disc
and/or vertebral bodies may be displaced or damaged due to trauma,
disease, degenerative defects, or wear over an extended period of
time. One result of this displacement or damage to a spinal disc or
vertebral body may be chronic back pain. In many cases, to
alleviate back pain from degenerated of herniated discs, the disc
is removed along with all or part of at least one neighboring
vertebrae and is replaced by an implant that promotes fusion of the
remaining bony anatomy.
[0005] The success or failure of spinal fusion may depend upon
several factors. For instance the spacer or implant or cage used to
fill the space left by the removed disc and bony anatomy must be
sufficiently strong to support the spine under a wide range of
loading conditions. The spacer should also be configured so that it
likely to remain in place once it has been positioned in the spine
by the surgeon. Additionally the material used for the spacer
should be biocompatible material and should have a configured that
promotes bony ingrowth.
[0006] In combination with spacers or cages, a plating system is
used to further stabilize the spine during the fusion process.
These devices, commonly referred to as bone fixation plating
systems (i.e., cervical plate), typically include one or more
plates and fasteners (typically screws) for aligning and holding
vertebrae in a fixed position with respect to one another. Plating
systems independent of the spacers provide additional complications
such as loosening and failure of the hardware. Two common failures
are the breakage of the plates, and the backing out of screws into
soft tissues of the patient's body. The backing out of the screws
is typically a result of the screws failure to achieve a sufficient
purchase in the bone, although the stripping of the screws has also
been known to cause this problem. Another common problem is that
plating systems require "carpentry" work to match fit aspects of
the vertebral bodies.
[0007] Thus, it is important that the medical implant is properly
held in place by the fastener. To keep the fastener from backing
out, a locking device is typically utilized. The locking device
physically impedes the top of the screw from rising, which prevents
the fastener from rotating (as this would cause the fastener to
rise). Once the locking device is in the "locked" position, the
fixation mechanism is held in place.
[0008] It is further important that the locking device be properly
positionable both in the unlocked position (so that the medical
practitioner can have access to properly position and implant the
fastener) and the locked position (so that the locking device can
properly function). Accordingly, there is a need for an improved
locking device for plating systems.
SUMMARY OF INVENTION
[0009] The present invention is a medical implant (cervical plate)
that is held in place by a fixation mechanism, that is, typically,
a screw. To keep the screw from backing out, a locking device is
utilized. The locking device physically impedes the top of the
screw from rising, which prevents the screw from rotating (as this
would cause the screw to rise). The locking device has a retention
device that controllably maintains the locking device in the
unlocked and locked positions as the case may be. The retention
device provides for hard stops for the locking device in its
unlocked and locked positions, while maintaining a low profile.
[0010] In general, in one aspect, the invention features a medical
implant that includes a receiving member body that has a first
fastener opening. The first fastener opening is operable for
allowing a first fastener to be inserted through the first fastener
opening for fixing the medical implant to bone. The medical implant
further has a locking mechanism located near the first fastener
opening. The locking mechanism includes a rotating block cover
operable to move between an unlocked position and a locked
position. When the rotating block cover is in the unlocked
position, the first fastener can be inserted through the first
fastening opening. When the rotating block cover is in the locked
position, a portion of the rotating block cover is covering the
first fastener opening to prevent the first fastener for moving
through the first fastener opening and which locks the first
fastener in place. The medical implant further includes a retaining
mechanism that has an engagement body rotatably coupled to at least
two retaining levers. The engagement body is attached to the
rotating block cover. The engagement body is operable for moving
rotatably through the retaining levers. The engagement body is
operable for moving in a first direction to a first position. When
the engagement body is in the first position, the locking mechanism
is in the unlocked position. The engagement body is blocked from
rotating past the first position when moved in the first direction.
The engagement body is retained in the first position by the
retaining levers such that the engagement body cannot move without
the application of a force in a second direction that is opposite
to the first direction. The engagement body is operable for moving
in a second direction to a second position. When the engagement
body is in the second position, the locking mechanism is in the
locked position. The engagement body is blocked from rotating past
the second position when moved in the second direction. The
engagement body is retained in the second position by the retaining
levers such that the engagement body cannot move without the
application of a force in the first direction.
[0011] Implementations of the invention can include one or more of
the following features:
[0012] The medical implant can be a bone fixating plating
system.
[0013] The bone fixating plating system can include a cervical
plate.
[0014] The cervical plate can further include a second fastener
opening. The second fastener opening can be operable for allowing a
second fastener to be inserted through the second fastener opening
for fixing the medical implant to bone. The locking mechanism can
further be located near the second fastener opening. When the
rotating block cover is in the unlocked position, the second
fastener can be inserted through the second fastening opening. When
the rotating block cover is in the locked position, a portion of
the rotating block cover can be covering the second fastener
opening to prevent the second fastener for moving through the
second fastener opening and which locks the second fastener in
place.
[0015] The first fastener can include a bone screw.
[0016] The retaining mechanism can include exactly two retaining
levers.
[0017] Each of the retaining levels can have an indent that retains
the engagement body in the first position and the second
position.
[0018] The rotating block cover can have a hole operable for
receiving a rotatable tool. The rotating block cover can be
rotatable in the first direction and the second direction using the
rotating tool.
[0019] The receiving member body can include a plurality of
fastener openings and plurality of locking mechanisms. Each of the
locking mechanisms can be operable for locking fasteners positioned
in at most two of the fastener openings.
[0020] Each of the locking mechanisms can be operable for locking
fasteners positioned in at most one of the fastener openings.
[0021] In general, in another aspect, the invention features a
method that includes selecting a medical implant having a receiving
body that includes a first fastener opening, a locking mechanism,
and a retaining mechanism. The locking mechanism includes a
rotating block cover operable to move between an unlocked position
and a locked position. The locking mechanism is in the unlocked
position. The retaining mechanism includes an engagement body
rotatably coupled to at least two retaining levers. The engagement
body is attached to the rotating block cover. The retaining
mechanism retains the engagement body at a first position to
maintain the rotating block cover in the unlocked position. The
method further includes inserting a first fastener into the first
fastener opening. The method further includes securing the first
fastener to a bone. The method further includes rotating the
locking mechanism from the unlocked position to the locked
position. A portion of the rotating block cover is covering the
first fastener opening to prevent the first fastener for moving
through the first fastener opening and which locks the first
fastener in place. The engagement body is blocked from rotating to
prevent the rotating lock cover from rotating past the locked
position. The retaining mechanism retains the engagement body at
second position to maintain the rotating block cover in the locked
position.
[0022] Implementations of the invention can include one or more of
the following features:
[0023] The medical implant can be a bone fixating plating
system.
[0024] The bone fixating plating system can include a cervical
plate.
[0025] The cervical plate can further include a second fastener
opening. The method can further include inserting a second fastener
into the second fastener opening. The method can further include
securing the second fastener to the bone while the locking
mechanism is in the unlocked position. The step of rotating the
locking mechanism can further include that a portion of the
rotating block cover is covering the second fastener opening to
prevent the second fastener for moving through the second fastener
opening and which locks the second fastener in place.
[0026] The first fastener can include a bone screw.
[0027] The retaining mechanism can include exactly two retaining
levers.
[0028] Each of the retaining levels can have an indent that retains
the engagement body in the first position and the second
position.
[0029] The step of rotating the locking mechanism can include
inserting a rotating tool into a hole in the rotating block cover
and rotating the rotating tool.
[0030] The receiving member body can include a plurality of
fastener openings and plurality of locking mechanisms. The method
can further include moving each of the locking mechanisms in the
plurality of locking mechanism to lock at most two fasteners
positioned in at most two fastener openings.
[0031] The method can further include moving each of the locking
mechanisms in the plurality of locking mechanism to lock at most
one fastener.
[0032] The method can further include rotating the locking
mechanism from the locked position to the unlocked position. No
portion of the rotating block cover can be covering the first
fastener opening which unlocks the first fastener. The engagement
body can be blocked from rotating to prevent the rotating lock
cover from rotating past the unlocked position. The retaining
mechanism can retain the engagement body at the first position to
maintain the rotating block cover in the unlocked position.
[0033] The foregoing has outlined rather broadly the features and
technical advantages of the invention in order that the detailed
description of the invention that follows may be better understood.
Additional features and advantages of the invention will be
described hereinafter that form the subject of the claims of the
invention. It should be appreciated by those skilled in the art
that the conception and the specific embodiments disclosed may be
readily utilized as a basis for modifying or designing other
structures for carrying out the same purposes of the invention. It
should also be realized by those skilled in the art that such
equivalent constructions do not depart from the spirit and scope of
the invention as set forth in the appended claims.
[0034] It is also to be understood that the invention is not
limited in its application to the details of construction and to
the arrangements of the components set forth in the following
description or illustrated in the drawings. The invention is
capable of other embodiments and of being practiced and carried out
in various ways. Also, it is to be understood that the phraseology
and terminology employed herein are for the purpose of the
description and should not be regarded as limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] For a more complete understanding of the present invention,
and the advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawings,
in which:
[0036] FIG. 1A is a top view of an embodiment of the present
invention showing a cervical plate with the locking mechanism in
the unlocked position.
[0037] FIG. 1B is a perspective view of the embodiment of FIG.
1A.
[0038] FIG. 2 is a bottom view of the embodiment of FIG. 1A.
[0039] FIG. 3A is a top view of the embodiment of FIG. 1A with
fasteners (screws) inserted within. The locking mechanism is in the
unlocked position.
[0040] FIG. 3B is a top view of the embodiment of FIG. 3A with the
locking mechanism in the locked position.
[0041] FIG. 3C is a perspective view of the embodiment of FIG.
3B.
[0042] FIG. 4 is a bottom view of the embodiment of FIG. 3A.
[0043] FIG. 5 is an exploded view of the embodiment of FIG. 1B.
[0044] FIG. 6A is a top view of the embodiment of FIG. 1A with the
locking mechanism removed to show the retaining mechanism.
[0045] FIG. 6B is an enlarged top view of the retaining mechanism
shown in FIG. 6A.
[0046] FIG. 6C is an enlarge perspective view of the retaining
mechanism shown in FIG. 6A.
[0047] FIG. 7A is a top view of a locking mechanism used in
embodiments of the invention.
[0048] FIG. 7B is a bottom view of the locking mechanism shown in
FIG. 7A.
[0049] FIGS. 7C-7D are perspective views of the locking mechanism
shown in FIG. 7A.
[0050] FIG. 8A is an enlarged top view of locking mechanism shown
in FIG. 3A.
[0051] FIG. 8B is the enlarged top view of the locking mechanism
shown in FIG. 8A without the cover piece of the locking
mechanism.
[0052] FIG. 8C is a cut-out side view of locking mechanism shown in
FIG. 8A.
[0053] FIG. 9A is an enlarged top view of locking mechanism shown
in FIG. 3B.
[0054] FIG. 9B is the enlarged top view of the locking mechanism
shown in FIG. 9A without the cover piece of the locking
mechanism.
[0055] FIG. 9C is a cut-out side view of locking mechanism shown in
FIG. 9A.
DETAILED DESCRIPTION
[0056] The technology relates to a device for locking a bone
fastening or fixation mechanism in a receiving member of a medical
implant. The bone fastening or fixation mechanism is used to mount
the receiving member to a bone structure in the medical implant.
The locking mechanism prevents the bone fastening mechanism for
backing out of the receiving member. A retention mechanism is used
to controllable move and retain the locking mechanism in the locked
(closed) or unlocked (open) position.
[0057] Referring to the figures, FIG. 1A is a top view of an
embodiment of the present invention showing a cervical plate 100
with the locking mechanism 101 in the unlocked position. The
locking mechanism 101 has a rotating blocker cover 701 (shown in
more detail in FIGS. 7A-7D discussed below) that can be rotated to
partially cover holes (bone screw holes) 102 and 103. (The holes
are also referred to as "fastener openings") As shown in FIG. 1A,
the locking mechanism 101 is in the unlocked (otherwise known as
open) position in that fasteners (screws) can be fit through holes
102 and 103 for implantation to fasten the cervical plate 100. FIG.
1B is a perspective view of the cervical plate 100. FIG. 2 is a
bottom view of cervical plate 100.
[0058] FIG. 3A is a top view of cervical plate 100 with fasteners
201 (bone screws) inserted within holes 102 and 103. FIG. 4 is a
bottom view of cervical plate 100 with the fasteners 201 inserted.
Such insertion of fasteners 201 can incur into holes 102 and 103
because rotating blocker cover 701 of locking mechanism 101 is in
the open position. Locking mechanism 101 is rotatably connected to
cervical plate 100. Locking mechanism 101 can be rotated using the
star-shaped hole 104 that can be engaged with a rotatable tool. As
shown in FIGS. 3A-3B, rotating locking mechanism 101 in the
clockwise direction moves locking mechanism to the locked
(otherwise known as closed) position. FIG. 3B is a top view of the
embodiment of cervical plate 100 with the locking mechanism 101 in
the locked position. FIG. 3C is a perspective view of the
embodiment of FIG. 3B.
[0059] When locking mechanism 101 is in the locked position, the
fastener 201 is blocked for moving upwards and out through holes
102 and 103. Because fastener 201 cannot move upward and out, the
fastener 201 cannot itself rotate (as rotating would cause it to
move upward and out). Such blocking occurs due to the shape of
rotating blocker cover 701 which, when the locking mechanism 101 is
rotated such that a portion of rotating blocker cover 701 overlays
holes 102 and 103. Examples of locking mechanisms known in the art
are shown in U.S. Pat. No. 8,702,766, issued Apr. 22, 2014 to
Mueller and U.S. Pat. No. 8,641,768, issued Feb. 4, 2014, to
Duffield et al.
[0060] FIG. 5 is an exploded view of cervical plate 100 in which
locking mechanism 101 has been separated from the cervical plate
100 to show the retaining mechanism that lies beneath. FIG. 6A is a
top view of cervical plate 100 with the locking mechanism 101
removed to show the retaining mechanism 600. FIG. 6B is an enlarged
top view of the retaining mechanism shown in FIG. 6A.
[0061] The retaining mechanism 600 has a pair of retaining levers
(or arms) 601 and 602. Hole 605 is positioned within the retaining
mechanism 600 and is where locking mechanism 101 (not shown) is
rotatably connected to cervical plate 100. Each of retaining levers
601 and 602 has an indent 603 and 604, respectively, which is
utilized in the retaining of the locking mechanism.
[0062] The retaining levers 601 and 602 oppose one another to apply
a force to the locking mechanism 101 when retaining it in either
the locked or unlocked position. The retaining levers 601 and 602
also control the rotational movement of the locking mechanism 101
such that it cannot be over rotated when moving from one position
to the other.
[0063] FIGS. 7A-7D are illustrations of locking mechanism 101.
FIGS. 7A-7B are top and bottom views of locking mechanism 101.
FIGS. 7C-7D are perspective view of locking mechanism 101. The
locking mechanism 101 includes a rotating blocker cover 701, which
is the portion of the locking mechanism 101 that, when rotated,
will partially cover holes 102 and 103 when the locking mechanism
is in the locked position.
[0064] Locking mechanism 101 has a post 703 that is rotatably
connected within hole 605 (shown in FIG. 6B). Locking mechanism 101
further has an engagement body 702 that is engagable with retaining
levers 601 and 602 to retain locking mechanism 101 in its locked
and unlocked position, as the case may be. As shown in FIGS. 7B and
7D, engagement body 702 can be geometric shaped, such as the
multisided shaped body shown in those figures. Engagement body 702
includes sides 704-709, which, when the locking mechanism 101 is in
place, are positioned to engage with retaining levers 601 and 602
(and their respective indents 603 and 604).
[0065] FIGS. 8A-8C and 9A-9C illustrate the operability of the
retaining mechanism 600 with respect to locking mechanism 101. FIG.
8A shows locking mechanism 101 in cervical plate 100 in the
unlocked position. FIG. 8C is a cut-out side view of the cervical
plate 101 shown in FIG. 8A. FIG. 8B is the same view as FIG. 8A,
except without showing rotating blocker cover 701. This allows the
underworking to be more readily viewed and described. As shown in
FIG. 8B, engagement body 702 is positioned within retaining levers
601 and 602, such that sides 704 and 705 are nestled in place in
retaining lever 601. As shown in FIG. 8B, indent 603 is to the
immediate right of side 704, which maintains engagement body in
this position and keeps engagement body 702 from rotating in the
clockwise direction. Likewise, sides 706 and 708 are nestled in
place in retaining lever 602, with indent 604 to the immediate left
of side 707, and which likewise maintains engagement body in this
position and keeps engagement body 702 from rotating in the
clockwise direction. Thus, the engagement between the engagement
body 702 and retaining levers 601 and 602 prevents engagement body
702 (and thus locking mechanism 101) from rotating clockwise into
the locked position.
[0066] Furthermore, walls 801 and 802 block engagement body 702
from being able to rotate counter-clockwise (i.e., to rotate in the
backwards direction). If that were not the case, then locking
mechanism could rotate counter-clockwise into a locked
position.
[0067] Accordingly, the engagement between the engagement body 702
and retaining levers 601 and 602 will maintain the locking
mechanism in the unlocked position once positioned there. Moreover,
as over-rotation is not possible, the practitioner using the
cervical plate 100 will know that it has been properly
positioned.
[0068] FIG. 9A is shows locking mechanism 101 in cervical plate 100
in the locked position. FIG. 9C is a cut-out side view of the
cervical plate 101 shown in FIG. 9A. Because retaining levers 601
and 602 have some limited flexibility, rotation of the engagement
body 702 in the clockwise direction with the application of a
force, will allow the retaining levers 601 and 602 to move radially
outward to allow engagement body 702 to rotate from the position
shown in FIG. 8B to the position shown in FIG. 9B. During such
clockwise rotation, sides 704-706 rotate past indent 603 of
retaining lever 601, such that side 706 is now to the immediate
right of indent 603. This then precludes engagement body 702 from
being able to rotate back counter-clockwise to the position shown
in FIG. 8B. Likewise, sides 707-709 rotate past indent 604 of
retaining lever 602, such that side 709 is now to the immediate
left of indent 604. This then also precludes engagement body 702
from being able to rotate back counter-clockwise to the position
shown in FIG. 8B. Thus, the engagement between the engagement body
702 and retaining levers 601 and 602 prevents engagement body 702
(and thus locking mechanism 101) from rotating clockwise into the
locked position.
[0069] Furthermore, walls 801 and 802 are positioned such that this
stops engagement body from turning further clockwise, i.e., walls
801 and 802 prevent over-rotation of engagement body 702.
Accordingly, the practitioner cannot over-rotate when moving from
the unlocked to the locked position.
[0070] When the locking mechanism is in the locked position, an
application of force in the counter-clockwise direction will allow
retaining levers 601 and 602 to expand radially, which then permits
the engagement body 702 (and thus the locking mechanism 101) to
return to the unlocked position shown in FIG. 8A-8C. Again, this
cannot be over-rotated due to the walls 801 and 802.
[0071] The locking mechanism used in combination with the retaining
mechanism has significant advantageous. It provides for hard stops
when moving between the open and closed positions. It also
precludes over-rotation by the practitioner when implanting the
cervical plate. Moreover, once the locking mechanism is set in
place, locked or unlocked, it will be maintained in that position.
The locking mechanism maintains its low profile because the
retaining mechanism is able to fit in the space beneath it.
[0072] The disclosures of all patents, patent applications, and
publications cited herein are hereby incorporated herein by
reference in their entirety, to the extent that they provide
exemplary, procedural, or other details supplementary to those set
forth herein. It will be understood that certain of the
above-described structures, functions, and operations of the
above-described embodiments are not necessary to practice the
present invention and are included in the description simply for
completeness of an exemplary embodiment or embodiments. In
addition, it will be understood that specific structures,
functions, and operations set forth in the above-described
referenced patents and publications can be practiced in conjunction
with the present invention, but they are not essential to its
practice. It is therefore to be understood that the invention may
be practiced otherwise than as specifically described without
actually departing from the spirit and scope of the present
invention.
[0073] While embodiments of the invention have been shown and
described, modifications thereof can be made by one skilled in the
art without departing from the spirit and teachings of the
invention. The embodiments described and the examples provided
herein are exemplary only, and are not intended to be limiting.
Many variations and modifications of the invention disclosed herein
are possible and are within the scope of the invention.
Accordingly, the scope of protection is not limited by the
description set out above.
* * * * *