U.S. patent application number 14/012584 was filed with the patent office on 2014-06-26 for implant for osteotomy, tool for inserting the implant, and method of inserting the implant using the tool.
This patent application is currently assigned to Wright Medical Technology, Inc.. The applicant listed for this patent is Wright Medical Technology, Inc.. Invention is credited to Gary Lowery, Daniel McCormick, Wesley Reed, Brian Thoren.
Application Number | 20140180342 14/012584 |
Document ID | / |
Family ID | 50188518 |
Filed Date | 2014-06-26 |
United States Patent
Application |
20140180342 |
Kind Code |
A1 |
Lowery; Gary ; et
al. |
June 26, 2014 |
IMPLANT FOR OSTEOTOMY, TOOL FOR INSERTING THE IMPLANT, AND METHOD
OF INSERTING THE IMPLANT USING THE TOOL
Abstract
A tool comprises a first body shaped to detachably receive a
bone implant having a first portion with a first flat surface
adapted to be attached to a bone and a second portion with a second
flat surface oriented at a pre-determined angle relative to the
first flat surface, the bone implant having at least one fastener
hole penetrating each of the first and second portions. A second
body has a surface or member. The second body is adjustably
connected to the first body to selectably position the surface or
member relative to the bone implant.
Inventors: |
Lowery; Gary; (Eads, TN)
; Reed; Wesley; (Libertyville, IL) ; McCormick;
Daniel; (Bartlett, TN) ; Thoren; Brian;
(Memphis, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wright Medical Technology, Inc. |
Arlington |
TN |
US |
|
|
Assignee: |
Wright Medical Technology,
Inc.
Arlington
TN
|
Family ID: |
50188518 |
Appl. No.: |
14/012584 |
Filed: |
August 28, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61695162 |
Aug 30, 2012 |
|
|
|
Current U.S.
Class: |
606/281 ;
606/280; 606/87; 606/96 |
Current CPC
Class: |
A61B 17/8095 20130101;
A61B 17/1686 20130101; A61B 17/7291 20130101; A61B 17/8052
20130101; A61B 17/8061 20130101; A61B 17/809 20130101; A61B 17/1682
20130101; A61B 17/1728 20130101 |
Class at
Publication: |
606/281 ; 606/96;
606/87; 606/280 |
International
Class: |
A61B 17/17 20060101
A61B017/17 |
Claims
1. A tool, comprising: a first body shaped to detachably receive a
bone implant having a first portion with a first flat surface
adapted to be attached to a bone and a second portion with a second
flat surface oriented at a pre-determined angle relative to the
first flat surface, the bone implant having at least one fastener
hole penetrating each of the first and second portions; and a
second body having a surface or member, the second body adjustably
connected to the first body to selectably position the surface or
member relative to the bone implant.
2. The tool of claim 1, further comprising: a third body extending
through the first body, the third body detachably connectable to
the bone implant for retaining the bone implant against the first
body.
3. The tool of claim 2, wherein: the third body has a drill guide
configured for inserting a drill bit through the drill guide and
through a hole in the bone implant.
4. The tool of claim 3, wherein: the bone implant has a bottom
surface for abutting a bone, and the hole is oriented at an obtuse
angle relative to the bottom surface for receiving a fastener.
5. The tool of claim 3, wherein: the tool further comprises a cut
guide detachably connectable to the hole in the bone implant, the
cut guide having a planar surface defining a cutting plane through
a bone, when the bone implant is fastened to the bone and the cut
guide; and the third body has a threaded end for engaging the hole
in the bone implant when the bone implant is not fastened to the
cut guide.
6. The tool of claim 5, wherein the cut guide has a handle with a
distal end, the distal end having a connector for connecting the
shaft to a tool handle.
7. The tool of claim 1, further comprising a shaft rotatably
connected to the first body, the shaft having a threaded portion,
the second body having a threaded opening for receiving the
threaded portion of the shaft, such that rotation of the shaft
advances or retracts the second body relative to the bone
implant.
8. The tool of claim 7, wherein the shaft has an enlarged portion
positioned adjacent the threaded portion, so as to limit a range of
travel of the second body relative to the bone implant.
9. The tool of claim 7, wherein the shaft has an end distal from
the first body, with a connector for connecting the shaft to a tool
handle.
10. The tool of claim 1, wherein the member of the second body
comprises a shelf extending outward in a direction perpendicular to
a surface of the first body and parallel to a bottom surface of the
implant, the shelf having a ridge on a bottom surface thereof.
11. The tool of claim 1, further comprising: a third body extending
through the first body, the third body detachably connectable to
the bone implant for retaining the bone implant against the first
body, the third body having a drill guide configured for inserting
a drill bit through the drill guide and through a hole in the bone
implant, the bone implant having a bottom surface for abutting a
bone, wherein the hole is oriented at an obtuse angle relative to
the bottom surface for receiving a fastener, the third body having
a threaded end for engaging the hole in the bone implant; and a
shaft rotatably connected to the first body, the shaft having a
threaded portion, the second body having a threaded opening for
receiving the threaded portion of the shaft, such that rotation of
the shaft advances or retracts the second body relative to the bone
implant, wherein the shaft has an enlarged portion positioned
adjacent the threaded portion, so as to limit a range of travel of
the second body relative to the bone implant.
12. Apparatus comprising: a bone implant having a first portion
with a first flat surface adapted to be attached to a bone and a
second portion with a second flat surface oriented at a
pre-determined angle relative to the first flat surface, the bone
implant having at least one fastener hole penetrating each of the
first and second portions; and a cut guide attachable to the bone
implant using at least one of the fastener holes, the cut guide
having a guide surface that is coplanar with the second flat
surface when the cut guide is attached to the bone implant.
13. The apparatus of claim 12, wherein the fastener hole of the
second portion of the bone implant is oriented at a predetermined
angle relative to the second flat surface of about 30 degrees to
about 60 degrees, and the cut guide has a mounting member with a
mounting hole for attaching the cut guide to the bone implant, the
mounting hole being oriented at the predetermined angle relative to
the guide surface.
14. A method, comprising: (a) fastening a bone implant to a bone,
such that a first surface of the bone implant contacts a first
portion of the bone; (b) connecting a tool to the bone implant, the
tool having a movable contact member configured to engage a second
portion of the bone which has been severed from the first portion
of the bone; (c) adjusting the movable contact member until the
second portion of the bone has a predetermined offset relative to
the first surface of the bone implant; and (d) drilling a hole in
the second portion of the bone for fastening the bone implant
thereto, the drilling being performed using a drill guide in the
tool.
15. The method of claim 14, wherein step (b) includes rotating a
threaded body containing the drill guide, until threads of the
threaded body engage threads of the second portion of the bone
implant.
16. The method of claim 14, further comprising attaching the
movable contact member to the second portion of the bone
temporarily with a fastener.
17. The method of claim 14, wherein step (c) includes rotating a
shaft having a fixed displacement relative to the bone implant, the
movable contact member having a female thread engaging a male
thread of the shaft, whereby rotating the shaft adjusts a
displacement of the movable contact member relative to the bone
implant.
18. The method of claim 14, wherein the bone implant has a second
surface oriented at a predetermined angle relative to the first
surface, the method further comprising, before step (b): attaching
a cut guide to the bone implant, the cut guide having a guide
surface that is coplanar with the second surface when the cut guide
is attached to the bone implant; and cutting the bone along a plane
containing the guide surface.
19. The method of claim 18, wherein the step of attaching the cut
guide includes inserting a fastener through a first hole in the cut
guide and a second hole in a second portion of the bone implant,
the second portion of the bone implant having the second surface
thereon, wherein the hole drilled in step (d) is drilled through
the second hole.
20. The method of claim 14, further comprising: removing a portion
of the tool having the drill guide therein from an opening in the
tool; and inserting a fastener through a hole in the bone implant,
into the drilled hole in the second portion of the bone, so that
the bone implant is fastened in a corner between a perimeter of the
first portion of the bone and a cut face of the second portion of
the bone.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/695,149, filed Aug. 30, 2012, the entirety of
which is incorporated by reference herein.
FIELD
[0002] This disclosure relates to an implant for an osteotomy, and
tools for inserting an implant.
BACKGROUND
[0003] A calcaneal osteotomy is a form of surgery for correction of
severe hind foot misalignment. During the procedure, the heel bone
is cut and the tuberosity is moved medially toward the inside or
laterally towards the outside, depending on the direction of the
misalignment to be corrected. For example, if the patient has flat
feet, the heel may be offset medially to shift the hind foot toward
the inside to improve the weight distribution on the foot. On the
other hand, if the patient has a high arched foot the calcaneal
osteotomy may be performed to shift the hind foot laterally, to
improve stability and reduce risk of sprain.
[0004] This procedure has often been performed by driving screws
through the tuberosity into the anterior calcaneus. Some of the
primary challenges associated with this approach are determining
the amount of intra-operative offset that is achieved, the ability
for fluoroscopy for targeting and placing the screws, and screw
head prominence.
[0005] Implants have been developed for insertion during calcaneal
osteotomy. For example, the assignee of this patent application,
Wright Medical Technologies, has developed the DARCO.RTM. DPS
plate, which provides support. This plate includes an anterior
plate, a posterior plate, and an offset segment connecting the
anterior and posterior plates. The DARCO.RTM. DPS plate is
available with different amounts of offset between the anterior and
posterior plates.
SUMMARY
[0006] In some embodiments, a tool comprises a first body shaped to
detachably receive a bone implant having a first portion with a
first flat surface adapted to be attached to a bone and a second
portion with a second flat surface oriented at a pre-determined
angle relative to the first flat surface, the bone implant having
at least one fastener hole penetrating each of the first and second
portions. A second body has a surface or member, and is adjustably
connected to the first body to selectably position the surface or
member relative to the bone implant.
[0007] In some embodiments, an apparatus comprises a bone implant
having a first portion with a first flat surface adapted to be
attached to a bone and a second portion with a second flat surface
oriented at a pre-determined angle relative to the first flat
surface. The bone implant has at least one fastener hole
penetrating each of the first and second portions. A cut guide is
attachable to the bone implant using at least one of the fastener
holes. The cut guide has a guide surface that is coplanar with the
second flat surface when the cut guide is attached to the bone
implant.
[0008] In some other embodiments, a method is provided that
comprises: (a) fastening a bone implant to a bone, such that a
first surface of the bone implant contacts a first portion of the
bone; (b) connecting a tool to the bone implant, the tool having a
movable contact member configured to engage a second portion of the
bone which has been severed from the first portion of the bone; (c)
adjusting the movable contact member until the second portion of
the bone has a predetermined offset relative to the first surface
of the bone implant; and (d) drilling a hole in the second portion
of the bone for fastening the bone implant thereto, the drilling
being performed using a drill guide in the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an isometric view of a tool for inserting a
calcaneal implant.
[0010] FIG. 2 is an exploded view of the tool of FIG. 1.
[0011] FIG. 3 is a bottom isometric view of the tool of FIG. 1.
[0012] FIG. 4 is an isometric view of the tool of FIG. 1, with
implant attached.
[0013] FIGS. 5 and 6 show adjustment of the offset in the tool of
FIG. 1.
[0014] FIG. 7 shows the tool of FIG. 1 after screw insertion, prior
to removal of the tool.
[0015] FIGS. 8A and 8B are rear and front isometric views of a cut
guide.
[0016] FIG. 8C is an exploded view of the cut guide illustrated in
FIGS. 8A and 8B.
[0017] FIG. 9 is a front isometric view of the cut guide, with
implant attached, in position on the bone.
[0018] FIG. 10 shows the implant of FIG. 7, after removal of the
insertion tool.
[0019] FIG. 11 is a side cross-sectional view showing a detail of
the tool of FIG. 7, before removal of the tool.
[0020] FIG. 12 is a flow chart of a method for performing a
calcaneal osteotomy, using the cut guide and insertion tool.
[0021] FIG. 13 is a flow chart of a method for performing a
calcaneal osteotomy, using the insertion tool.
[0022] FIG. 14 is a flow chart of a method for performing a
calcaneal osteotomy, using the insertion tool.
DETAILED DESCRIPTION
[0023] This description of the exemplary embodiments is intended to
be read in connection with the accompanying drawings, which are to
be considered part of the entire written description. In the
description, relative terms such as "lower," "upper," "horizontal,"
"vertical,", "above," "below," "up," "down," "top" and "bottom" as
well as derivative thereof (e.g., "horizontally," "downwardly,"
"upwardly," etc.) should be construed to refer to the orientation
as then described or as shown in the drawing under discussion.
These relative terms are for convenience of description and do not
require that the apparatus be constructed or operated in a
particular orientation. Terms concerning attachments, coupling and
the like, such as "connected" and "interconnected," refer to a
relationship wherein structures are secured or attached to one
another either directly or indirectly through intervening
structures, as well as both movable or rigid attachments or
relationships, unless expressly described otherwise.
[0024] This disclosure provides an implant 150 (FIG. 10), an
insertion tool 100 (FIGS. 1-7) for positioning the implant 150 and
drilling aligned holes, and optionally, a cut guide 200 (FIGS. 8-9)
for making an aligned cut through the bone 170 during a calcaneal
osteotomy. The implant 150 is suitable for shifting the tuberosity
171 of the calcaneus 170, either medially or laterally, relative to
the anterior calcaneus 172, and provides rigid fixation during the
bone healing process.
[0025] In some embodiments, the implant 150 has a "door stop" or
"L" bracket configuration, as best seen in FIG. 10. The implant has
a bottom surface 151 adapted to engage the lateral or medial
surface of the tuberosity 171. The implant also has an anterior
surface 152 (FIG. 6) which abuts the cut surface of the anterior
calcaneus, as shown in FIG. 10. In some embodiments, the anterior
surface 152 is normal to the bottom surface 151. As shown in FIG.
10, the anterior holes 153 in the implant 150 are oriented at an
angle .theta..sub.1 with respect to the posterior holes. The angle
.theta..sub.1 can be in a range from 30 to 60 degrees. In some
embodiments, the angle .theta..sub.1 is about 45 degrees. In some
embodiments, the posterior holes in the implant are angled about 10
(e.g., from 7 to 13) degrees away from the cut made in the
calcaneous. This, when used with a drill guide, forces screw
placement posteriorly to optimize bony purchase.
[0026] The anterior hole 153 is oriented at an obtuse angle
.theta..sub.2 relative to the bottom surface 151 for receiving a
fastener 162. In some embodiments, the implant 150 is a plate
having four holes 153; the posterior holes accept two (2) screws
161 inserted into the tuberosity 171, and the anterior holes accept
two screws 162 placed into the cut surface 173 of the anterior
calcaneus 172. Other embodiments (not shown) include one hole 153
for receiving one screw 161 inserted into the tuberosity and one
hole for receiving one screw 162 inserted into the anterior
calcaneus.
[0027] The plate 150 is positioned below the distal (anterior)
portion 172 of the calcaneus 170 and therefore is not felt by the
patient. Seating the implant 150 below the surface of the anterior
calcaneus 172 also allows the surgeon to tamp down the edge or
shelf created by the osteotomy, and smooth the transition. The
configuration of the implant 150 does not dictate a specific offset
amount between the tuberosity and the anterior calcaneus. One size
of implant 150 as described herein can be used to provide a variety
of offsets. Although the configuration of the implant 150 does not
dictate the offset increments, in some embodiments, the inserter
instrument sized to install the implant 150 may provide for
discrete offset increments (e.g., 1 mm increments). In other
embodiments, the inserter tool permits continuous control of the
offset throughout a range (e.g., 6 mm to 12 mm).
[0028] FIGS. 1-7 show an embodiment of an insertion tool 100, which
can be used during the calcaneal osteotomy. The insertion tool 100
has a first (core) body 110 shaped to detachably receive a bone
implant 150. The anterior and bottom surfaces of the first (core)
body 110 abut the top surface of the implant 150 during insertion.
A second body (track groove body) 120 comprises a shelf 121
extending outward in a direction perpendicular to a surface of the
core body 110 and parallel to a bottom surface 151 of the implant
150. The shelf 121 has a surface or member, such as the stop 122
(FIGS. 2 and 3). The surface or the stop member 122 is adapted to
provide a stable point of contact with the bone 170 regardless of
the exact shape of the bone. Because a bone is not perfectly flat,
member 122 is configured to provide two points of fixation against
the bone. This allows the tool 100 to seat stably without rocking.
This also provides a self-centering capability when applying the
screws 162.
[0029] The second (track groove) body 120 is adjustably connected
to the core body 110 to selectably position the surface or member
122 relative to the bone implant 150. For example, as shown in
FIGS. 2 and 3, the core body 110 has a track 112 on its anterior
side, and the track/groove body 120 has a groove 123 on its
posterior surface configured to receive and slide along the track.
FIGS. 2 and 3 show one example, but a variety of track and groove
configurations may be used in alternative embodiments.
[0030] As shown in FIG. 7, the shelf 121 of track/groove body 120
has a slot or hole 123, through which a temporary fixation pin 160
is optionally placed during implant insertion. The fixation pin 160
has a thread 163 for insertion into the anterior calcaneus 172. The
fixation pin 160 has a flange 164, head or ridge, for engaging the
top surface of the shelf 121, and fixing the track/groove body
against the anterior calcaneus 172. When the tread 163 of the
fixation pin 160 engages the bone, adjustment of the position of
the track/groove body 120 relative to the core body 110 causes
relative movement between the tuberosity 171 and the anterior
calcaneus 172. Thus, the insertion tool can be used to smoothly and
precisely move the anterior calcaneus 172 relative to the
tuberosity 171 during the osteotomy.
[0031] A third (drill-through thumb screw) body 130 extends through
the first (core) body 110. The third body 130 is detachably
connectable to the bone implant 150 for retaining the bone implant
against the core body 110, as shown in FIGS. 4-6. In some
embodiments, the drill-through thumb screw 130 has a drill guide
131 configured for inserting a drill bit 139 (FIG. 5) through the
drill guide 131 and through a hole 153 in the bone implant 150. For
example, in some embodiments, drill-through thumb screw 130 has a
male thread 132 which is the same size as the anterior hole 153 of
the implant 150. Thus, the drill-through thumb screw 130
simultaneously connects the insertion tool 100 to the implant 150
and provides the drill guide 131 for drilling a properly aligned
hole into the cut surface 173 of the anterior calcaneus 172, into
which an anterior screw 162 is to be inserted. Although FIG. 2
shows thread 132 as a straight thread, in other embodiments, thread
132 may be tapered.
[0032] The drill-through thumb screw 130 also has a ridge 133 for
retaining the drill-through thumb screw 130 in the core body 110.
During assembly of the tool 100, the drill-through thumb screw 130
is inserted into the core body 110, and two of the dowel pins 111
are inserted to retain the drill-through thumb screw 130. The
drill-through thumb screw 130 of FIGS. 1-7 has a rounded
cylindrical outer surface for easy gripping, but the configuration
of the outer surface can be configured differently for convenience.
For example, the outer surface can have a square or hexagonal
cross-section, or other suitable grip configuration.
[0033] The tool 100 further comprises a shaft 140 rotatably
connected to the first (core) body 110. The shaft 110 has a male
threaded portion 141 (FIGS. 5 and 6). The second (track/groove)
body 120 has a female threaded opening for receiving the threaded
portion 141 of the shaft 140, such that rotation of the shaft 140
advances the second (track/groove) body 120 relative to the bone
implant 150, as shown in FIG. 5, or retracts the track/groove body
120 relative to the bone implant 150, as shown in FIG. 6. This
permits the surgeon to vary the offset between the member 122 and
the bottom surface 151 of the implant 150, in a range from D1 (FIG.
5) to D2 (FIG. 6).
[0034] During insertion, the stop 122 of track/groove 120 abuts the
cortex of the anterior calcaneus 172; and the bottom surface 151 of
the implant 150 abuts the tuberosity 171 of the calcaneus. Thus,
the offset distance between the tuberosity 171 and the anterior
calcaneus 172 is directly controlled by rotating the shaft 140.
This offset distance is equal to the vertical component of the
distance between the member 122 of the groove/track body 120 and
the bottom surface 151 of the implant 150. In some embodiments, the
range of offsets is from D1=6 mm to D2=12 mm. The surgeon selects
the appropriate offset for the individual patient, and rotates the
shaft 140 to achieve the selected offset. In some embodiments, the
shaft 140 has an enlarged portion 142 positioned adjacent the
threaded portion 141, so as to limit a range of travel of the
groove/track body 120 relative to the bone implant 150. For
example, in some embodiments the stop 142 limits the maximum offset
to 12 mm. This can prevent the surgeon from inadvertently
offsetting the anterior calcaneus 172 beyond 12 mm relative to the
tuberosity at any time during the osteotomy. In other embodiments
(not shown), the track/groove body 120 is advanced using a ratchet,
detents or other mechanism
[0035] In some embodiments, the shaft 140 has an end distal from
the core body 110, with a connector 144 for connecting the shaft
140 to a tool handle (not shown). For example, the connector 144
may be an "AO QUICK CONNECT" connector. In some embodiments, the
shaft 140 has a prescribed thread 141 to facilitate selection of a
desired offset by the surgeon. For example, in some embodiments,
the thread 141 provides one mm advance/retraction of the
groove/track body 120 per full turn of the shaft. The handle
facilitates turning of shaft 140, and clear identification of when
the shaft 140 has turned through a complete 360 degree rotation. In
other embodiments, the shaft 140 has a groove 145. During assembly
of the tool 100, the shaft 140 is inserted through the threaded
hole in the groove/track body 120 and into the core body 110. One
of the pins 111 is then inserted into the core body 110 to retain
the shaft in place.
[0036] FIG. 11 is a side cross sectional view showing the tool 100
and implant 150 in place prior to removal of the tool 100. The
implant has a bottom surface 151 abutting a lateral or medial
surface of the tuberosity 171 and an anterior surface 152 abutting
the cut surface of the anterior calcaneus 172. The anterior surface
152 is normal to the bottom surface 151, and is oriented at the
same angle as the cut face 173 of the anterior calcaneus 172, which
it abuts. The thread 132 of the drill-through thumb screw 130 fits
into the anterior hole 153 of the implant 150, and is oriented at
an angle of 45 degrees relative to the vertical surface. In this
position, the drill-through thumb screw 130 provides the drill
guide 131 for drilling one of the holes into the bone, into which
one of the anterior screws 162 is inserted. In some embodiments,
the core body 110, groove/track body 120, drill-through thumb screw
130 and shaft are all made of grade 630 stainless steel, and the
dowel pins 111 are made of grade 818 stainless steel. Other
suitably hard and strong alloys can be used.
[0037] FIGS. 8A, 8B, 8C and 9 show a cut guide 200, which can
optionally be used to cut the bone 170 in alignment with the
implant 150. The cut guide 200 is detachably connectable to the
anterior hole 153 in the bone implant 150. The cut guide 200 has a
planar saw guide surface 201 defining a cutting plane through the
bone 170, when the bone implant 150 is fastened to the bone and the
cut guide. The cut guide 200 comprises the planar saw guide surface
201, a mounting member 202, a set screw 204. and optionally, a
handle 205. The cut guide 200 may be formed from a single piece of
material, or a plurality of components. A "C" clip 207 (FIG. 8B)
holds the set screw 204 in mounting member 202 so that the screw is
retained in the cut guide 200. The set screw 204 is used to attach
the cut guide 200 to the implant plate 150. The combination of the
cut guide 200 and implant plate 150 can be used to guide the
cutting for the calcaneal osteotomy. The cut guide 200 is adapted
for use during installation of a bone implant 150 of a type
described above, having a first (posterior) portion with a first
flat surface 151 adapted to be attached to a bone 172 and a second
(anterior) portion with a second flat surface 152 oriented at a
pre-determined angle (e.g., 90 degrees) relative to the first flat
surface 151.
[0038] The planar saw guide surface 201 of the cut guide 200 is
coplanar with, or parallel to the plane containing the front
surface 152 of the implant 150, when the cut guide 200 is attached
to the implant. In some embodiments, the planar saw guide surface
201 of the cut guide 200 has a built in 0.127 to 0.381 mm offset
from the front surface 152 of the implant 150 (when the cut guide
is attached to the implant 150). The cut guide 200 is configured to
form a cut from about 0.127 to 0.381 mm anterior of the front
surface 152 of the implant 150, so that the anterior surface 152 of
the installed implant 150 is about 0.127 to 0.381 mm away from the
cut surface of the tuberosity. Subsequently, when the implant plate
150 is fastened to the anterior calcaneus 172 and the fasteners 162
are tightened, there is a 0.127 to 0.381 mm compression of the
calcaneus against the tuberosity. In other embodiments, the planar
saw guide surface 201 is coplanar with the second flat surface 152
of the bone implant 150, when the cut guide 200 is attached to the
implant. The bone implant 150 has at least one fastener hole 153
penetrating each of the first and second portions. In some
embodiments the implant has one anterior hole 153 and one posterior
hole. In other embodiments, the implant 150 has two anterior holes
153 and two posterior holes. The cut guide 200 is attachable to the
bone implant 150 using at least one of the same fastener holes 153
through which the anterior screws 162 (which fasten the implant 150
to the cut surface 173 of the anterior calcaneus 172).
[0039] The cut guide 200 has a mounting member 202 with a mounting
hole for attaching the cut guide to the bone implant 150. The
mounting hole receives the screw 204. The mounting hole is oriented
at a predetermined angle relative to the guide surface, matching
the orientation of the anterior hole(s) 153 of the implant 150. The
predetermined angle relative to the second flat surface can be from
about 30 degrees to about 60 degrees. In one embodiment, the
predetermined angle is 45 degrees, matching the orientation of the
anterior holes 153 in the implant 150. The cut guide 200 has a
handle 205 comprising a shaft with a distal end fixed to cut guide
200 by dowel 203. In some embodiments, the distal end has a
connector 206 for connecting the shaft to a tool handle (not
shown). In other embodiments, the handle shaft contains a AO quick
connection so an additional handle can be placed onto the shaft if
desired.
[0040] FIG. 12 is a flow chart of a method of installing a bone
implant. At step 1202, a cut guide 200 is attached to the bone
implant 150. The cut guide 200 has a guide surface 201 that is
coplanar with or parallel to the plane containing the second
surface 152 of the implant 150 when the cut guide is attached to
the bone implant. The step of attaching the cut guide 200 includes
inserting a fastener 204 through a first hole in the cut guide 200
and a second (anterior) hole 153 in a second portion of the bone
implant 150. The second portion of the bone implant has a second
surface 152 thereon, with a second (anterior) hole 153, where the
anterior screw 162 is to be inserted through the second (anterior)
hole.
[0041] At step 1204, the implant 150 with attached cut guide 200 is
positioned on the calcaneus 170. At step 1206, the bone implant 150
is fastened to the bone 170, such that a first surface 151 of the
bone implant 150 contacts a first portion 171 of the bone 170. In
some embodiments, the implant 150 has two posterior holes, and this
fastening step includes inserting two posterior screws 161 through
the posterior hole(s) 153 in the implant and into the first portion
171 of the bone 170. In other embodiments, the implant has one
posterior hole, and this step inserts one screw into that posterior
hole. At step 1208, the bone is cut along a plane containing the
guide surface 201 of the cut guide 200. At step 1210, the screw 204
is removed and the cut guide 200 is removed from the implant 150.
The implant 150 remains attached to the tuberosity.
[0042] At step 1212, an insertion tool 100 is connected to the bone
implant 150. The tool 100 has a track/groove body 120 with a
movable contact member 122 configured to engage a second portion
172 of the bone 170 which has been severed from the first portion
171 of the bone. In some embodiments, the connection between the
tool 100 and the implant 150 is made by inserting the threaded male
end 132 of the drill-through thumb screw 130 into female threads of
one of the anterior holes 153 of the implant 150. At step 1214, a
(temporary) insertion pin 160 is optionally inserted through an
opening 123 in the shelf 121 of the track/groove body 120 having
the movable contact member 122, so that the threaded end 163 of the
pin engages the bone 170 through the opening 123. In some
embodiments, the pin 160 has a flange 164, and the pin 160 is
inserted until the flange abuts the shelf 121.
[0043] At step 1216, the shaft 140 of the insertion tool is
rotated, so as to adjust the movable contact member 122 until the
second portion 172 of the bone 170 has a predetermined offset
relative to the first surface 151 of the bone implant 150. In some
embodiments, a shaft 140 having a fixed displacement relative to
the bone implant 150 is rotated. The groove/track body 120 having
the movable contact member 122 includes a female thread engaging
the male thread 141 of the shaft 140. Rotating the shaft 140
adjusts the displacement of the movable contact member 122 relative
to the bone implant 150. With the fixation pin 160 screwed into the
bone, the rotation of shaft 140 and advancement/retraction of the
track/groove body 120 changes the offset of the anterior calcaneus
172 relative to the tuberosity 171. At step 1218, in embodiments
having two anterior holes 153, a drill guide (not shown) which is
not engaged by the tool from the tool 100 is inserted in the open
hole 153 of the implant 150 not covered by the tool 100. A hole is
drilled in the second portion 172 of the bone 170 for fastening the
bone implant 150 thereto. At step 1220, the drill guide is removed
from the open hole and one of the anterior screws 162 is inserted
through the anterior hole 153 and into the anterior calcaneus 172.
In some embodiments, if compression is desired, non-locking screws
are used. In other embodiments, locking screws are used. Also, in
embodiments where the implant has only a single anterior hole 153
and a single posterior hole 153, steps 1218 and 1220 are skipped.
At step 1222, the remaining anterior hole is drilled into the
anterior calcaneus, through the drill guide 131 of the
drill-through thumb screw 130. In some embodiments, instead of
performing step 1222 while the tool 100 is attached, the tool 100
is removed, and steps 1218 and 1220 are repeated to form the
remaining anterior screw hole.
[0044] At step 1224, drill-through thumb screw 130 containing the
drill guide 131 is rotated, until threads 132 of the threaded body
130 disengage from the threads of the second (anterior) portion of
the bone implant 150. The insertion tool 100 is removed. At step
1226, the final anterior fastener (e.g., a screw) 162 is inserted
through the anterior hole 153 and into the anterior calcaneus 172.
The screw 162 is inserted into the drilled hole in the second
portion of the bone, so that the bone implant is fastened in a
corner between a perimeter of the first portion of the bone and a
cut face of the second portion of the bone.
[0045] FIG. 13 is a flow chart of a variation of the method, which
is performed free-hand, without the cut guide 200. At step 1304,
the implant 150 (without cut guide 200) is positioned on the
calcaneus 170. At step 1306, the bone implant 150 is fastened to
the bone 170, such that a first surface 151 of the bone implant 150
contacts a first portion 171 of the bone 170. In some embodiments,
the implant 150 has two posterior holes, and this fastening step
includes inserting two posterior screws 161 through the posterior
hole(s) 153 in the implant and into the first portion 171 of the
bone 170. In other embodiments, the implant has one posterior hole,
and this step inserts one screw into that posterior hole. At step
1308, the bone is cut along the implant that was positioned in step
1306. At step 1312, an insertion tool 100 is connected to the bone
implant 150. In some embodiments, the connection between the tool
100 and the implant 150 is made by inserting the threaded male end
132 of the drill-through thumb screw 130 into female threads of one
of the anterior holes 153 of the implant 150.
[0046] At step 1314, a (temporary) insertion pin 160 is optionally
inserted through an opening 123 in the shelf 121 of the
track/groove body 120 having the movable contact member 122, so
that the threaded end 163 of the pin engages the bone 170 through
the opening 123. In some embodiments, the pin 160 has a flange 164,
and the pin 160 is inserted until the flange abuts the shelf 121.
At step 1316, the shaft 140 of the insertion tool is rotated, so as
to adjust the movable contact member 122 until the second portion
172 of the bone 170 has a predetermined offset relative to the
first surface 151 of the bone implant 150. At step 1318, in
embodiments having two anterior holes 153, a drill guide (not
shown) which is not engaged by the tool from the tool 100 is
inserted in the open hole 153 of the implant 150 not covered by the
tool 100. A hole is drilled in the second portion 172 of the bone
170 for fastening the bone implant 150 thereto. At step 1320, the
drill guide is removed from the open hole and one of the anterior
screws 162 is inserted through the anterior hole 153 and into the
anterior calcaneus 172. In some embodiments, if compression is
desired, non-locking screws are used. In other embodiments, locking
screws are used. Also, in embodiments where the implant has only a
single anterior hole 153 and a single posterior hole 153, steps
1318 and 1320 are skipped.
[0047] At step 1322, an anterior hole 153 is drilled into the
anterior calcaneus, through the drill guide 131 of the
drill-through thumb screw 130. At step 1324, drill-through thumb
screw 130 containing the drill guide 131 is rotated, until threads
132 of the threaded body 130 disengage from the threads of the
second (anterior) portion of the bone implant 150. The insertion
tool 100 is removed. At step 1326, the final anterior screw 162 is
inserted through the anterior hole 153 and into the anterior
calcaneus 172.
[0048] FIG. 14 is a flow chart of another variation of the method,
which is performed free-hand, without the cut guide 200. At step
1404, the implant 150 (without cut guide 200) is positioned on the
calcaneus 170.
[0049] At step 1406, the implant 150 is positioned, such that a
first surface 151 of the bone implant 150 contacts a first portion
171 of the bone 170, and the implant is used to make a line across
the bone using a skin marker. At step 1408, the bone is cut,
following the line made at step 1406. At step 1412, an insertion
tool 100 is connected to the bone implant 150. In some embodiments,
the connection between the tool 100 and the implant 150 is made by
inserting the threaded male end 132 of the drill-through thumb
screw 130 into female threads of one of the anterior holes 153 of
the implant 150. At step 1414, a (temporary) insertion pin 160 is
optionally inserted through an opening 123 in the shelf 121 of the
track/groove body 120 having the movable contact member 122, so
that the threaded end 163 of the pin engages the bone 170 through
the opening 123. In some embodiments, the pin 160 has a flange 164,
and the pin 160 is inserted until the flange abuts the shelf 121.
At step 1416, the shaft 140 of the insertion tool is rotated, so as
to adjust the movable contact member 122 until the second portion
172 of the bone 170 has a predetermined offset relative to the
first surface 151 of the bone implant 150. At step 1418, in
embodiments having two anterior holes 153, a drill guide (not
shown) which is not engaged by the tool 100 is inserted in the open
hole 153 of the implant 150 not covered by the tool 100. A hole is
drilled in the second portion 172 of the bone 170 for fastening the
bone implant 150 thereto. At step 1420, the drill guide is removed
from the open hole and one of the anterior screws 162 is inserted
through the anterior hole 153 and into the anterior calcaneus 172.
Steps 1418 and 1420 are then repeated for placement of the open
posterior screw 161 after the anterior screw 162 is placed into the
anterior calcaneus 172, as indicated by the dashed arrow in FIG.
14.
[0050] In embodiments where the implant has only a single anterior
hole 153 and a single posterior hole 153, steps 1418 and 1420 are
skipped. At step 1422, an anterior hole 153 is drilled into the
anterior calcaneus, through the drill guide 131 of the
drill-through thumb screw 130. At step 1424, drill-through thumb
screw 130 containing the drill guide 131 is rotated, until threads
132 of the threaded body 130 disengage from the threads of the
second (anterior) portion of the bone implant 150. The insertion
tool 100 is removed. At step 1426, the final anterior screws 162
are inserted through the anterior holes 153 and into the anterior
calcaneus 172. the drill guide is used to drill and the final
posterior screw is placed.
[0051] The insertion tool 100 can be used in other ways. For
example, the surgeon can preset the position of the groove/track
body 200 to provide a desired offset between the anterior calcaneus
172 and the tuberosity 171. Then the surgeon can move the bone
portions 171, 172 into position on the tool 100. When the bone
portions 171, 172 abut the tool, they have been moved into the
desired spatial relationship.
[0052] Although a particular example is described above in which
the implant is used for a calcaneal osteotomy, one of ordinary
skill in the art can readily apply the teachings herein to implants
and insertion tools for osteotomies related to other bones besides
the calcaneus.
[0053] Although the subject matter has been described in terms of
exemplary embodiments, it is not limited thereto. Rather, the
appended claims should be construed broadly, to include other
variants and embodiments, which may be made by those skilled in the
art.
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