U.S. patent application number 14/204129 was filed with the patent office on 2014-09-18 for fixation of orthopaedic devices.
This patent application is currently assigned to SMED-TA/TD, LLC. The applicant listed for this patent is SMed-TA/TD, LLC. Invention is credited to Joseph W. Jurick, Troy D. Knapp, Paul S. Nebosky, Gregory C. Stalcup, Kreigh R. Williams.
Application Number | 20140277183 14/204129 |
Document ID | / |
Family ID | 51531152 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140277183 |
Kind Code |
A1 |
Stalcup; Gregory C. ; et
al. |
September 18, 2014 |
FIXATION OF ORTHOPAEDIC DEVICES
Abstract
The present invention provides an orthopaedic implant including
a base device having a device surface and a fixation material
attached to at least one portion of the device surface. The
fixation material is configured to provide a minimally sufficient
adhesive force to resist natural pull out caused by forces acting
on the base device after implantation and bone growth. Also
provided is a method of manufacturing an orthopaedic implant. A
base device with a device surface is provided and a minimally
sufficient adhesive force, that can resist natural pull out caused
by forces acting on the base device after implantation and bone
growth, is determined. A proper amount of fixation material
sufficient to provide an adhesive force equal to the minimally
sufficient adhesive force is determined and fixation material is
applied to the device. When the proper amount of fixation material
is applied to the device surface, application is stopped.
Inventors: |
Stalcup; Gregory C.;
(Columbia City, IN) ; Knapp; Troy D.; (Alachua,
FL) ; Jurick; Joseph W.; (Fort Wayne, IN) ;
Nebosky; Paul S.; (Fort Wayne, IN) ; Williams; Kreigh
R.; (Fort Wayne, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SMed-TA/TD, LLC |
Columbia City |
IN |
US |
|
|
Assignee: |
SMED-TA/TD, LLC
Columbia City
IN
|
Family ID: |
51531152 |
Appl. No.: |
14/204129 |
Filed: |
March 11, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61787507 |
Mar 15, 2013 |
|
|
|
Current U.S.
Class: |
606/298 ;
427/2.26; 606/301; 606/329; 606/60 |
Current CPC
Class: |
A61B 2017/8655 20130101;
A61L 31/022 20130101; A61L 31/16 20130101; A61L 31/06 20130101;
A61L 2300/41 20130101; A61L 2300/414 20130101; A61L 31/146
20130101; A61L 31/06 20130101; A61L 2400/18 20130101; A61B 17/8028
20130101; C08L 71/00 20130101; A61B 17/8625 20130101; A61L 2300/404
20130101; A61B 17/7098 20130101; A61B 17/846 20130101 |
Class at
Publication: |
606/298 ; 606/60;
606/329; 606/301; 427/2.26 |
International
Class: |
A61L 31/14 20060101
A61L031/14; A61L 31/04 20060101 A61L031/04; A61L 31/08 20060101
A61L031/08; A61L 31/16 20060101 A61L031/16 |
Claims
1. An orthopaedic implant, comprising: a base device having a
device surface; and a fixation material attached to at least one
portion of said device surface configured to provide a minimally
sufficient adhesive force to resist natural pull out caused by
forces acting on said base device after implantation and bone
ingrowth.
2. The orthopaedic implant of claim 1, wherein said base device is
one of a bone screw, a bone pin and a bone plate.
3. The orthopaedic implant of claim 2, wherein said fixation
material is a porous material having a plurality of pores and a
roughened outer surface.
4. The orthopaedic implant of claim 3, wherein said fixation
material is at least one of a metal and a polymer.
5. The orthopaedic implant of claim 4, wherein said fixation
material is at least one of titanium, cobalt-chrome and polyether
ether ketone (PEEK).
6. The orthopaedic implant of claim 5, wherein said base device
comprises at least one of a metal and a polymer.
7. The orthopaedic implant of claim 6, wherein said fixation
material has a biologically active substance provided within said
plurality of pores.
8. The orthopaedic implant of claim 7, wherein said biologically
active substance is at least one of a growth factor, an
antibacterial agent, an anti-inflammatory, a bone growth promoter
and a bone growth inhibitor.
9. The orthopaedic implant of claim 6, wherein said base device has
a plurality of openings formed on said device surface.
10. The orthopaedic implant of claim 9, wherein said base device
includes a reservoir in fluid communication with at least one of
said plurality of openings.
11. The orthopaedic implant of claim 10, wherein said reservoir is
at least partially filled with a treatment substance.
12. The orthopaedic implant of claim 11, wherein said treatment
substance is at least one of a growth factor, an antibacterial
agent, an anti-inflammatory, a bone growth promoter and a bone
growth inhibitor.
13. The orthopaedic implant of claim 6, wherein said base device is
composed of PEEK.
14. A method of manufacturing an orthopaedic implant, comprising
the steps of: providing a base device having a device surface;
determining a minimally sufficient adhesive force to resist natural
pull out caused by forces acting on said base device after
implantation and bone ingrowth; determining a proper amount of a
fixation material sufficient to provide an adhesive force equal to
said minimally sufficient adhesive force; applying said fixation
material to said device surface; and stopping application of said
fixation material to said device surface when said proper amount of
said fixation material is applied.
15. The method according to claim 14, further comprising the steps
of: determining a proper placement of said proper amount of said
fixation material to provide said adhesive force equal to said
minimally sufficient adhesive force; and distributing said proper
amount of said fixation material on said device surface in
accordance with said proper placement.
16. The method according to claim 15, wherein said base device and
said fixation material are composed of at least one of titanium,
cobalt-chromium, and polyether ether ketone (PEEK).
17. The method according to claim 16, wherein said fixation
material includes a roughened surface and a plurality of pores.
18. The method according to claim 15, wherein said proper placement
is affected by at least one of a size of said base device, said
device surface area, an intended implantation site, a diameter of
said base device, and how proud said fixation material will be
relative to said device surface.
19. A method of performing an orthopaedic surgery, comprising the
steps of: providing an orthopaedic implant having a device surface
and a fixation material attached to said device surface, said
fixation material configured to provide a minimally sufficient
adhesive force to resist natural pull out caused by forces acting
on said base device after implantation and bone ingrowth;
implanting said orthopaedic implant at an implantation site within
a patient; and revising the implantation of said orthopaedic
implant by applying a revisionary force to said orthopaedic implant
that is slightly greater than said minimally sufficient adhesive
force.
20. The method according to claim 19, wherein said revising step
creates minimal trauma to the implantation site and surrounding
anatomy structures of the patient.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional application based upon U.S.
provisional patent application Ser. No. 61/787,507, entitled
"FIXATION OF ORTHOPAEDIC DEVICES", filed Mar. 15, 2013, which is
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to orthopaedic devices, and
more particularly, to orthopaedic implants.
[0004] 2. Description of the Related Art
[0005] Orthopaedic implants are known that are implanted into the
body to achieve various surgical objectives. Such implants include
bone pins, bone screws and bone plates. The implantation period of
the implant can vary from a short period, such as a couple of days,
to the end of a patient's life. During the implantation period, the
implant will experience natural forces caused by surrounding
anatomy structures due to static and dynamic conditions of the
anatomy structures. These natural forces can cause the implant to
either loosen from the implantation site or, worse, ultimately
detach from the implant site.
[0006] To prevent the loosening and detachment of an orthopaedic
implant from its implantation site, the implant is usually fixated
to the implantation site by bone screws, which must be screwed into
the implantation site. The implant can also be bonded to the
implantation site with an adhesive, such as bone cement, or
materials can be attached to the implant that encourage natural
ingrowth of tissue onto or into the implant. Natural tissue
ingrowth will help to fixate the implant in place and can form a
strong bond with the implant.
[0007] One problem that arises with implanted devices is that there
is a risk that a revision surgery, to remove the implant, may be
required due to reasons such as an incorrect placement, an
unforeseen event or an infection causing the implant to prematurely
fail. In such cases, removing the implant can be a traumatic event
for anatomy structures around the site if a lot of force is
required to loosen the implant and remove it.
[0008] A similar problem can occur with devices that are meant to
be temporary, i.e., have a relatively short implantation period.
The device can become too integrated with the body and become very
difficult to remove, which can lead to trauma at the implantation
site during removal.
[0009] What is needed in the art is an orthopaedic implant that can
resist natural pull out but does not require excessive force to
remove.
SUMMARY OF THE INVENTION
[0010] The present invention provides an orthopaedic implant with a
fixation material attached to the implant that is configured to
provide a minimally sufficient adhesive force to resist natural
pull out of the implant caused by forces acting on the implant
during implantation and bone ingrowth.
[0011] The invention in one form is directed to an orthopaedic
implant including a base device with a device surface and a
fixation material attached to the base device. The fixation
material is attached to at least one portion of the device surface
and is configured to provide a minimally sufficient adhesive force
to resist natural pull out caused by forces acting on the base
device after implantation and bone ingrowth
[0012] The invention in another form is directed to a method of
manufacturing an orthopaedic implant. The method includes providing
a base device that has a surface area and determining a minimally
sufficient adhesive force to resist natural pull out caused by
forces acting on the base device after implantation and bone
ingrowth. A proper amount of a fixation material sufficient to
provide an adhesive force equal to the determined minimally
sufficient adhesive force is determined and the fixation material
is applied to the device surface. When the proper amount of the
fixation material is applied to the device surface, application of
the fixation material is stopped.
[0013] The invention in yet another form is directed to a method of
performing an orthopaedic surgery. The method includes providing an
orthopaedic implant having a device surface and a fixation material
attached to the device surface. The fixation material is configured
to provide a minimally sufficient adhesive force to resist natural
pull out caused by forces acting on the base device after
implantation and bone ingrowth. The orthopaedic implant is
implanted at an implantation site within a patient. The
implantation of the orthopaedic implant is revised by applying a
revisionary force to the orthopaedic implant that is slightly
greater than the minimally sufficient adhesive force.
[0014] An advantage of the present invention is that it provides an
orthopaedic implant that can withstand natural pull out forces when
implanted within a patient while not requiring excessive force to
remove, if necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above-mentioned and other features and advantages of
this invention, and the manner of attaining them, will become more
apparent and the invention will be better understood by reference
to the following description of embodiments of the invention taken
in conjunction with the accompanying drawings, wherein:
[0016] FIG. 1 is a perspective view of an embodiment of an
orthopaedic implant of the present invention;
[0017] FIG. 2 is another perspective view of the orthopaedic
implant shown in FIG. 1;
[0018] FIG. 3 is a cross-sectional view of the orthopaedic implant
shown in FIG. 2 along line A-A;
[0019] FIG. 4 is a perspective view of another embodiment of an
orthopaedic implant of the present invention;
[0020] FIG. 5 is a cross-sectional view of the orthopaedic implant
shown in FIG. 4 along line A-A;
[0021] FIG. 6 is a perspective view of yet another embodiment of an
orthopaedic implant of the present invention;
[0022] FIG. 7 is a sectional view of the orthopaedic implant shown
in FIG. 6;
[0023] FIG. 8 is a sectional view of yet another embodiment of an
orthopaedic implant of the present invention;
[0024] FIG. 9 is a perspective view of yet another embodiment of an
orthopaedic implant of the present invention;
[0025] FIG. 10 is a sectional view of the orthopaedic implant shown
in FIG. 9;
[0026] FIG. 11 is a perspective view of yet another embodiment of
an orthopaedic implant of the present invention;
[0027] FIG. 12 is a sectional view of the orthopaedic implant shown
in FIG. 11;
[0028] FIG. 13 is a perspective view of yet another embodiment of
an orthopaedic implant of the present invention;
[0029] FIG. 14 is a sectional view of the orthopaedic implant shown
in FIG. 13;
[0030] FIG. 15 is a perspective view of yet another embodiment of
an orthopaedic implant of the present invention;
[0031] FIG. 16 is a sectional view of the orthopaedic implant shown
in FIG. 15;
[0032] FIG. 17 is a before and after exploded view of forming yet
another embodiment of an orthopaedic implant of the present
invention;
[0033] FIG. 18 is another before and after exploded view of forming
yet another embodiment of an orthopaedic implant of the present
invention;
[0034] FIG. 19 is a perspective view of yet another embodiment of
an orthopaedic implant of the present invention;
[0035] FIG. 20 is another perspective view of the orthopaedic
implant shown in FIG. 19;
[0036] FIG. 21 is a perspective view of yet another embodiment of
an orthopaedic implant of the present invention;
[0037] FIG. 22 is a perspective view of yet another embodiment of
an orthopaedic implant of the present invention; and
[0038] FIG. 23 is a perspective view of yet another embodiment of
an orthopaedic implant of the present invention.
[0039] Corresponding reference characters indicate corresponding
parts throughout the several views. The exemplifications set out
herein illustrate embodiments of the invention and such
exemplification are not to be construed as limiting the scope of
the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0040] Referring now to the drawings, and more particularly to FIG.
1, there is shown an orthopaedic implant 30 which generally
includes a base device 32 and a fixation material 34 attached to
the base device 32. The base device 32 shown is a bone pin that can
reside within a patient for a short period of time. The base device
32 can be constructed of metals commonly used in orthopaedic
implants such as titanium, cobalt chrome and stainless steel.
Alternatively, the base device can be constructed of biocompatible
polymers such as polyether ether ketone (PEEK), polylactic acid
(PLA), polyglycolic acid (PGA), polyethylene (PE) and blends
thereof.
[0041] The fixation material 34 attached to the base device 32 is
shaped as a thin band wrapped around the circumference of the base
device 32. The fixation material 34 can be a porous polymer or
metal that has a roughened surface 36 to provide immediate fixation
of the device 30 due to frictional forces and to encourage quick
tissue ingrowth into the fixation material 34. The roughened
surface 36 can have customized surface properties for a specific
tissue type and desired tissue ingrowth amount or rate. Such
surface properties can include a surface energy density,
wettability and electrostatic charge. Polymers and metals that can
act as the fixation material 34 include PEEK, PLA, PGA, PE,
titanium, cobalt chrome and stainless steel. Pores 38 of the
fixation material 34 can be sized to allow or prevent ingrowth of
tissue into the fixation material 34. Additionally, biologically
active substances can be included in the pores 38 to encourage or
limit tissue ingrowth into the fixation material 34, as well as
provide other useful properties such as antimicrobial activity to
reduce the risk of infection.
[0042] As the orthopaedic implant 30 is a small diameter bone pin
that will likely be removed within a few weeks of implantation, a
strong interface between surrounding tissue and the orthopaedic
implant 30 is undesirable as it will cause removal of the
orthopaedic implant 30 to be unnecessarily difficult. As can be
seen in FIGS. 2 and 3, only a relatively small band of fixation
material 34 is necessary to provide a minimally sufficient adhesive
force that will resist pull out of the orthopaedic implant 30 while
it is implanted in a patient while not causing excessive adhesive
force that could make the device 30 difficult to remove. As shown
in FIG. 3, the fixation material 34 has a relatively low thickness
T (0.010'') and a width W ("0.050") significantly greater than the
thickness T. For the orthopaedic device 30 shown, a thickness T
range of about 0.005'' to 0.015'' and a width W range of about
0.020'' to 0.125'' can be appropriate dimensions for the fixation
material 34 shaped as a band to provide the minimally sufficient
adhesive force. It is also contemplated that there can be multiple
fixation materials attached to the base device 32, which would
alter the dimensions of each fixation material region. An
additional design consideration when shaping and placing the
fixation material 34 on a small diameter pin is that the pin won't
provide much leverage to apply torque and overcome the adhesive
force provided by the fixation material 34.
[0043] Referring now to FIGS. 4 and 5, an orthopaedic implant 40 is
shown which includes a base device 42, shown here as a large
diameter pin, with a fixation material 44 attached to the pin 42.
The fixation material 44 can be the same as the fixation material
34 described previously. When utilizing a large diameter pin 42,
the amount and geometry of the fixation material 44 will need to be
changed to provide a minimally sufficient adhesive force that will
resist natural pull out of the pin 42, due to increased size of the
pin 42. As shown in FIGS. 4 and 5, the fixation material 44 can be
shaped as a band around the circumference of the pin 42, similar to
the previously described small diameter pin 32. The band of
fixation material 44 can have a thickness T ranging from about
0.015'' to 0.050'' and a width W ranging from about 0.020'' to
0.125''. As can be seen in FIG. 5, the pin 42 can also have a
groove 46 formed on the outer surface 48 of the pin 42 where the
fixation material 44 attaches to the pin 42. The groove 46 can have
a varying depth that changes how proud an outer surface 50 of the
fixation material 44 is relative to the outer surface 48 of the pin
42. As seen in FIG. 5, the fixation material 44 has a thickness T
of 0.020'', but the outer surface 50 only elevates 0.010'' relative
to the outer surface 48 of the pin 42. Having the groove 46 in the
pin 42 allows for a thicker fixation material 44, which will
increase the potential bone ingrowth and adhesive force, with a
smaller increase in the overall diameter of the device 40. The
groove 46 also provides more surface area of the pin 42 to utilize
for attachment to the fixation material 44. As opposed to a small
diameter pin, a large diameter pin can have a larger minimally
sufficient adhesive force but still be easily removed because the
large diameter pin 42 provides more leverage to apply torque and
overcome the adhesive force provided by the fixation material
44.
[0044] Referring now to FIGS. 6 and 7, an orthopaedic implant 60 is
shown which includes a base device 62, shown as a bone screw, and a
fixation material 64 attached to the bone screw 62. The bone screw
62 can be constructed of biocompatible metals and polymers, similar
to previously described base devices, and the fixation material 64
can be made of a material similar to that of previously described
fixation materials. The bone screw 62 has a head end 66, a distal
end 68 and a plurality of threads 70 formed on a surface 72 of the
bone screw 62. The fixation material 64 forms a small patch on the
distal end 68 of the bone screw 62. The threads 70 of the bone
screw 62 will provide some adhesive force to keep the bone screw 62
in place during implantation, so the fixation material patch 64
acts to provide additional adhesive force at the distal end 68, if
necessary, to resist natural pull out of the bone screw 62.
[0045] Referring now to FIG. 8, an orthopaedic implant 80 is shown
which includes a bone screw 62 similar to that shown in FIGS. 6 and
7 having a fixation material 82 attached to the distal end 68 of
the bone screw 62. The fixation material 82 can be formed from any
fixation material previously described. In this embodiment, the
fixation material 82 is formed as a "dot" of material on the distal
end 68 of the bone screw 62 to provide additional adhesive force to
the bone screw 62.
[0046] Referring now to FIGS. 9 and 10, an orthopaedic implant 90
is shown which includes a bone screw 92 similar to that shown in
FIGS. 6, 7 and 8 having a fixation material 94 attached to a
surface 96 of the bone screw 92 between threads 98 formed on the
surface 96 of the bone screw 92. The fixation material 94 can be
formed from any fixation material previously described. As can be
seen, the fixation material 94 has a helical shape that wraps
around the circumference of the bone screw 92 between the threads
98. In this configuration, the fixation material 94 provides a
substantial amount of adhesive force to resist natural pull out of
the device 90. Such a configuration may be desirable for bone
screws that are intended to have a longer implantation period,
where additional fixation of the bone screw is desirable.
[0047] Referring now to FIGS. 11 and 12, an orthopaedic implant 100
is shown which includes a bone screw 101 similar to that shown in
FIGS. 6, 7, 8 and 9 having a fixation material 102 attached near a
distal end 103 of the bone screw 101 between the distal end 103 and
threads 104 and 106. The fixation material 102 can be formed from
any fixation material previously described. This configuration
allows for the fixation material 102 to provide less fixation force
than orthopaedic implant 90, previously described. Such a
configuration is better suited for bone screws that are intended to
have shorter implantation periods, where too much additional
fixation of the bone screw would make removal unnecessarily
difficult.
[0048] Referring now to FIGS. 13 and 14, an orthopaedic implant 110
is shown which includes a base device 112, shown as a bone screw,
with holes 114 formed through a surface 116 of the bone screw 112
between threads 118. The holes 114 are located axially in valleys
120 between the threads 118 and go through to the centerline of the
screw 112. The holes 114 can be placed along the full length of the
screw 112. The screw 112 is a cannulated screw having an inner
chamber 120 that has a fixation material 122 bonded inside the
inner chamber 120. By having holes 114 and the fixation material
122 inside the inner chamber 120, tissue will be chemoattracted to
the fixation material 122 and fill in the holes 114, forming a
strong interface with the orthopaedic implant 110. A wall thickness
(not shown) between the minor diameter of the bone screw 112 and
the inner wall of the inner chamber 120 should be in a range of
approximately 1 mm to 1.5 mm. Studies have shown that bone will
bridge a gap of approximately 1 mm to 1.5 mm to grow into a porous
material, such as the fixation material 122. FIGS. 15 and 16 show a
similar embodiment, with fewer holes 114 formed through the bone
screw 112 and the holes 114 being concentrated near a distal end
126 of the bone screw 112.
[0049] Referring now to FIG. 17, a base device 130 is shown before
and after being prepared into an orthopaedic implant 132 of the
present invention. As can be seen, the base device 130 is a screw
blank that has had elongated pockets 134 machined within. These
elongated pockets 134 are filled with a fixation material 136,
which can be any fixation material previously described. Following
filling of the elongated pockets 134 with the fixation material
136, threads 138 can be cut into the base device 130 and fixation
material 136 to form the completed orthopaedic implant 132. In this
configuration, the threads 138 will be composed of approximately
half fixation material 136 and half material of the base device
130, giving the orthopaedic implant 132 a substantial amount of
fixation material 136 to provide adhesive force during implantation
and also placing the fixation material 136 into intimate contact
with surrounding anatomy structures during implantation. Such a
configuration can be particularly useful when the orthopaedic
implant 132 is intended to be a long-term implant.
[0050] Referring now to FIG. 18, a base device 140 is shown before
and after being prepared into an orthopaedic implant 142. The base
device 140 is a screw blank with a minor diameter d1 between a head
end 144 and a distal end 146. A fixation material 148, which can be
any fixation material previously described, is bonded to a section
of the base device 140 having minor diameter d1 to create a
diameter d2 similar to that of the head end 146 and distal end 148.
Threads 150 are then formed into the fixation material 148 to
create the completed orthopaedic implant 142.
[0051] Referring now to FIGS. 19 and 20, an orthopaedic implant 160
is shown that includes a base device 162, shown as a bone plate,
and a fixation material 164 attached to the bone plate 162. The
bone plate 162 has a bare surface 166 and multiple openings 168
that are sized to allow bone screws (not shown) to be passed
through. The openings 168 are shaped so that when the bone screws
are driven into a bone, they will hold the bone plate 162 in place.
The bone plate 162 can be made of biocompatible metals such as
titanium, cobalt chrome and stainless steel, but can also be made
of a biocompatible polymer such as PEEK. A polymer bone plate 162
could offer advantages over more common metal bone plates, such as
higher compression and adjustable stiffening. The fixation material
164 is attached to a bottom surface (not shown) that is opposed to
the bare surface 166 and will be in contact with the bone during
implantation. The fixation material 164 can be any fixation
material previously described. In this embodiment, the fixation
material 164 forms a layer on the bottom surface of the bone plate
162. Since bone screws will be going through the openings 168, the
fixation material 164 does not cover the openings 168. If the bone
plate 162 had a bare bottom surface, the only fixation that the
bone plate 162 would have when implanted would be provided by
friction from the bone screws implanted in the bone. By attaching
the fixation material 164 to the bottom surface of the bone plate
162, the bone plate 162 is provided with adhesive force of its own:
initially from the roughness of the fixation material and later
from bone ingrowth into the fixation material 164. Although the
fixation material 164 is shown covering the entire bottom surface
of the bone plate 162, the amount of fixation material 164 could be
altered to provide a desired amount of adhesive force to the bone
plate.
[0052] Referring now to FIG. 21, an orthopaedic implant 170 is
shown that includes the bone plate 162 of FIGS. 19 and 20 with a
fixation material 172 attached at one end 174 of the bone plate
162. The fixation material 172 is shaped as a patch and can be any
fixation material previously described. By attaching the fixation
material 172 to only one end 174 of the bone plate 162, bone
ingrowth and fixation will only occur at the end 174 of the plate
with the fixation material 172, allowing an opposite end 176 to
float to whatever degree the attached bone screws allow. Such a
configuration allows for a dynamic bone plate 170.
[0053] Referring now to FIG. 22, an orthopaedic implant 180 is
shown that includes the bone plate 162 of FIGS. 19, 20 and 21 with
two regions of a fixation material 182 attached at both ends 184,
186 of the bone plate 162. The regions of fixation material 182 are
shaped as dots of material and can be any fixation material
previously described. Attaching the fixation material 182 to both
ends 184, 186 of the bone plate 162 provides bone ingrowth, and
therefore fixation, at both ends 184, 186 of the bone plate
162.
[0054] Referring now to FIG. 23, an orthopaedic implant 190 is
shown that includes the bone plate 162 of FIGS. 19, 20, 21 and 22
with three regions of a fixation material 192 surrounding the
openings 168 of the bone plate 162. The fixation material 192 can
be any fixation material previously described. Bone ingrowth into
the fixation material 192 around the openings 168 provide
additional fixation to the bone plate 162 in those regions. Such a
configuration could be desirable if the bone screws are to be
removed after implantation or do not provide enough fixation of the
bone plate 162 on their own.
[0055] While this invention has been described with respect to at
least one embodiment, the present invention can be further modified
within the spirit and scope of this disclosure. This application is
therefore intended to cover any variations, uses, or adaptations of
the invention using its general principles. Further, this
application is intended to cover such departures from the present
disclosure as come within known or customary practice in the art to
which this invention pertains and which fall within the limits of
the appended claims.
* * * * *