U.S. patent application number 15/980160 was filed with the patent office on 2018-09-13 for metallic structures having porous regions from imaged bone at pre-defined anatomic locations.
The applicant listed for this patent is Biomet Manufacturing, LLC. Invention is credited to Gautam Gupta, Jason D. Meridew, Tom Vanasse.
Application Number | 20180256341 15/980160 |
Document ID | / |
Family ID | 48782613 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180256341 |
Kind Code |
A1 |
Vanasse; Tom ; et
al. |
September 13, 2018 |
METALLIC STRUCTURES HAVING POROUS REGIONS FROM IMAGED BONE AT
PRE-DEFINED ANATOMIC LOCATIONS
Abstract
An additively manufactured medical implant, comprising a
metallic body having at least one porous surface configured to
promote bony on-growth or in-growth of tissue, the porous surface
being replicated from a high resolution scan of bone, and a
biological surface coating configured to create a barrier to
particulate debris, the biological surface coating being produced
from a titanium porous plasma spray surface coating or a biomimetic
coating.
Inventors: |
Vanasse; Tom; (Gainesville,
FL) ; Gupta; Gautam; (Warsaw, IN) ; Meridew;
Jason D.; (Warsaw, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Biomet Manufacturing, LLC |
Warsaw |
IN |
US |
|
|
Family ID: |
48782613 |
Appl. No.: |
15/980160 |
Filed: |
May 15, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14475682 |
Sep 3, 2014 |
9993341 |
|
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15980160 |
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13554484 |
Jul 20, 2012 |
8843229 |
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14475682 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2002/30943
20130101; A61F 2002/30962 20130101; A61F 2/30942 20130101; A61F
2002/3097 20130101; A61F 2002/30011 20130101; A61F 2002/30968
20130101; A61F 2002/30948 20130101; A61F 2002/30971 20130101; A61F
2/28 20130101; A61F 2/4003 20130101; A61F 2002/3092 20130101; Y10T
29/49 20150115; A61F 2002/30985 20130101; A61F 2/30767 20130101;
B33Y 50/00 20141201; B33Y 80/00 20141201 |
International
Class: |
A61F 2/30 20060101
A61F002/30; B33Y 50/00 20060101 B33Y050/00; A61F 2/40 20060101
A61F002/40; B33Y 80/00 20060101 B33Y080/00; A61F 2/28 20060101
A61F002/28 |
Claims
1. A medical implant, comprising: a metallic body having at least
one surface replicated from a high resolution scan of bone and
configured to promote bony on-growth or in-growth of tissue;
wherein the implant is generated using an additive manufacturing
technique
2. The medical implant of claim 1, further comprising a biological
surface coating configured to create a barrier to particulate
debris.
3. The medical implant of claim 1, wherein the biological surface
coating is a titanium porous plasma spray surface coating or a
biomimetic coating.
4. The medical implant of claim 3, wherein the biological surface
coating is capable of exhibiting an enhanced biological performance
when subjected to at least one of grit blasting, hyaluronic acid
(HA), an RGD-containing glycoprotein or bend coating.
5. The medical implant of claim 1, wherein the at least one surface
is a porous surface.
6. The medical implant of claim 1, wherein the additive
manufacturing technique used to generate the implant is selected
from a Direct Metal Laser Sintering (DMLS) process or an Electron
Beam Melting (EBM) process, Selective Laser Sintering (SLS), Fused
Deposition Modeling (FDM), Stereolithography (SLA), Laminated
Object Manufacturing, Powder Bed and Inkjet Head 3D Printing and
Plaster-Based 3D Printing (PP).
7. The medical implant of claim 1, wherein the high resolution scan
of the bone comprises a scan that was imaged with a computed
tomography (CT) scanner.
8. The medical implant of claim 1, wherein the implant is
configured to be implanted into a hip, shoulder, knee, spine,
elbow, wrist, ankle, finger or toe.
9. An additively manufactured medical implant, comprising: a
metallic body having at least one porous surface configured to
promote bony on-growth or in-growth of tissue, the porous surface
being replicated from a high resolution scan of bone; and a
biological surface coating configured to create a barrier to
particulate debris, the biological surface coating being produced
from a titanium porous plasma spray surface coating or a biomimetic
coating; wherein the medical implant is produced from the steps of:
imaging bone with a high resolution digital scanner to generate a
three-dimensional design model of the bone; removing a
three-dimensional section from the design model; fabricating a
porous region on a digital representation of the implant by
replacing a solid portion of the digital implant with the section
removed from the design model; and using an additive manufacturing
technique to create a physical implant including the fabricated
porous region.
10. The additively manufactured medical implant of claim 9, wherein
the production step of imaging the bone with a high resolution
digital scanner comprises scanning the bone with a computed
tomography (CT) scanner.
11. The additively manufactured medical implant of claim 10,
wherein the production step of scanning the bone with a computed
tomography (CT) scanner comprises scanning the bone with a MicroCT
scanner.
12. The additively manufactured medical implant of claim 9, further
comprising the production step of modifying any artifacts from the
three-dimensional design model of the bone.
13. The additively manufactured medical implant of claim 12,
wherein the production step of modifying any artifacts from the
three-dimensional design model comprises removing defective regions
of the design model containing non-uniformities or discontinuities
by filling the defective regions with a selected and superimposed
region of the bone model that does not contain a non-uniformity or
a discontinuity.
14. The additively manufactured medical implant of claim 9, further
comprising the production step of converting the imaged bone to a
digital file format.
15. The additively manufactured medical implant of claim 9, wherein
the production step of fabricating a porous region on a digital
representation of the implant comprises utilizing a computer aided
design (CAD) program to fabricate a porous region that structurally
replicates the architecture of the bone, the porous region being
selected from one of a hip, shoulder, knee, spine, elbow, wrist,
ankle, finger and toe.
16. The additively manufactured medical implant of claim 9, wherein
the production step of using an additive manufacturing technique to
create a physical implant comprises using a Direct Metal Laser
Sintering (1)MLS) process or an Electron Beam Melting (EBM)
process, Selective Laser Sintering (SLS), Fused Deposition Modeling
(FDM), Stereolithography (SLA), Laminated Object Manufacturing,
Powder Bed and Inkjet Head 3D Printing and Plaster-Based 3D
Printing (PP).
17. The additively manufactured medical implant of claim 9, further
comprising the production step of performing an additional
manufacturing process on the physical implant to modify one or more
features, the manufacturing process being selected from at least
one of casting, molding, forming, machining, joining, polishing,
blasting and welding.
18. An additively manufactured medical implant, comprising: a
metallic body having at least one porous surface configured to
promote bony on-growth or in-growth of tissue, the porous surface
being replicated from a high resolution scan of bone; and a
biological surface coating configured to create a barrier to
particulate debris, the biological surface coating being produced
from a titanium porous plasma spray surface coating or a biomimetic
coating; wherein the medical implant is produced from the steps of:
creating a digital image of the bone with a microCT scanner;
removing any defective artifacts from the digital image; converting
the digital image to a three-dimensional design model of the bone;
removing a three-dimensional section that structurally replicates
the architecture of the bone from the design model; printing the
removed design model section on a digital representation of the
implant; and creating a physical implant from the printed digital
representation by using an additive manufacturing technique.
19. The additively manufactured medical implant of claim 18,
wherein the production step of printing the removed design model
section on a digital representation of the implant comprises using
a computer aided design (CAD) program to print the removed design
model section.
20. The additively manufactured medical implant of claim 18,
wherein the production step of removing any defective artifacts
comprises removing any defective regions containing a
non-uniformity or discontinuity from the image by filling the
defective regions with a selected and superimposed region of the
digital image that does not contain a non-uniformity or a
discontinuity.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 13/554,484, filed Jul. 20, 2012, and entitled "Metallic
Structures Having Porous Regions from Imaged Bone at Pre-Defined
Anatomic Locations," the disclosure of which is expressly
incorporated in its entirety herein by this reference.
TECHNICAL FIELD
[0002] The present invention generally relates to metallic
structures having porous or mesh regions that represent the
architecture of bone, and specifically to methods for imaging bone
at pre-defined anatomic locations to create implants having porous
regions that represent the bone's architecture at those imaged
anatomic locations.
BACKGROUND OF THE INVENTION
[0003] Devices used to replace various joints of the human body are
often implanted without the use of bone cement. To achieve and
maintain long-term fixation and stability, these implants generally
require some degree of bony on-growth or in-growth. The bony
on-growth or in-growth necessary to promote and encourage the
growth of surrounding bony and soft tissues, as well as to achieve
desirable long-term fixation and stability properties, is often
enhanced by fabricating porous coatings into one or more surfaces
of the implant. Depending on the various features of the fabricated
porous coatings (e.g., their pore size and roughness
characteristics), the resulting osteoconductive properties of the
implant can be improved in such a manner that the porous surfaces
are able to function as scaffolds exhibiting desirable load-bearing
strengths at the implantation site.
[0004] While several orthopedic device companies commercially offer
implants having porous surfaces, these products largely fail to
adequately replicate the trabecular structure of bone.
Additionally, when an implant is designed for a specific anatomic
site, its interaction with the bone is limited to the areas
immediately surrounding the implantation site. Bone architecture
consists of trabeculae that are oriented in certain patterns in
order to optimize the bone performance in that anatomic location.
Since the magnitude and mode of differential loading to which a
bone is subjected is influenced by the bone's anatomic location, by
Wolff's law, trabecular struts in bone can also be expected to have
anatomically site-specific architectures.
[0005] Over the past few years, additive manufacturing and
free-form fabrication processes have experienced some significant
advances in terms of fabricating articles directly from computer
controlled databases. For instance, rapid prototyping techniques
allow many articles (e.g., prototype parts and mold dies) to be
fabricated more quickly and cost effectively than conventional
machining processes that require blocks of material to be
specifically machined in accordance with engineering drawings.
[0006] Illustrative modern rapid prototyping technologies include
laser based additive manufacturing processes such as selective or
direct metal laser sintering processes. These processes utilize
digital electronic file formats (e.g., STL files) that can be
printed into three-dimensional (3D) CAD models, and then utilized
by a prototyping machine's software to construct various articles
based on the geometric orientation of the 3D model. The constructed
articles are produced additively in a layer-wise fashion by
dispensing a laser-fusible powder one layer at a time. The powder
is fused, re-melted or sintered, by the application of laser energy
that is directed in raster-scan fashion to portions of the powder
layer corresponding to a cross section of the article. After each
layer of the powder is fused, an additional layer of powder is
dispensed, and the process repeated, with fused portions or lateral
layers fusing so as to fuse portions of previous laid layers until
the article is complete.
[0007] Additive manufacturing processes allow for highly complex
geometries to be created directly (without tooling) from 3D CAD
data, thereby permitting the creation of articles exhibiting high
resolution surfaces. While these processes have been useful for
detailing various surface properties of produced articles, such
processes have struggled to replicate surfaces having reduced
three-dimensional structural densities. For instance, such
processes are unable to adequately replicate articles having
randomized porous or partially randomized porous metallic
structures, including metal porous structures having interconnected
porosity. As such, there is a need for an additive manufacturing
process that can replicate articles having reduced
three-dimensional structural densities, including porous and
partially porous metallic structures.
[0008] The present invention is intended to improve upon and
resolve some of these known deficiencies of the art.
SUMMARY OF THE INVENTION
[0009] In accordance with one aspect of the present invention, a
method of forming an implant having a porous region replicated from
scanned bone is provided. The method comprises the steps of imaging
bone with a high resolution digital scanner to generate a
three-dimensional design model of the bone, removing a
three-dimensional section from the design model, fabricating a
porous region on a digital representation of the implant by
replacing a solid portion of the digital implant with the section
removed from the design model, and using an additive manufacturing
technique to create a physical implant including the fabricated
porous region.
[0010] In accordance with another illustrative embodiment of the
present teachings, the method of forming an implant having a porous
region replicated from scanned hone comprises the steps of creating
a digital image of the bone with a microCT scanner, removing any
defective artifacts from the digital image, converting the digital
image to a three-dimensional design model of the bone, removing a
three-dimensional section that structurally replicates the
architecture of the bone from the design model, printing the
removed design model section on a digital representation of the
implant, and creating a physical implant from the printed digital
representation by using an additive manufacturing technique.
[0011] In still further embodiments, the present invention is
further directed to medical implants created in accordance with the
present teachings. One such illustrative medical implant includes a
metallic body having at least one surface replicated from a high
resolution scan of hone and configured to promote bony on-growth or
in-growth of tissue. The implant is generated, in accordance with
certain illustrative embodiments, using an additive manufacturing
technique, such as a Direct Metal Laser Sintering (DMLS) process,
an Electron Beam Melting (EBM) process, Selective Laser Sintering
(SLS), Fused Deposition Modeling (FDM). Stereolithography (SLA),
Laminated Object Manufacturing, Powder Bed and Inkjet Head 3D
Printing and Plaster-Based 3D Printing (PP).
[0012] in accordance with yet other embodiments of the present
invention, a method of forming an implant from scanned bone to fill
a bone void is provided. In accordance to this illustrative
embodiment, the method comprises the steps of imaging a voided bone
region with a high resolution digital scanner to generate a three
dimensional design model of the voided bone region, providing a
digital representation of a non-voided bone region, removing a
three dimensional section of the non-voided bone region, the
removed section having a size that substantially matches the size
of the voided bone region, and creating a physical implant from the
removed three dimensional section of the non-voided bone region by
using an additive manufacturing technique, the implant being
configured to be installed within the voided bone region.
[0013] In accordance with still another embodiment of the present
disclosure, a medical implant is generated from an additive
manufacturing technique and comprises a metallic body having at
least one surface replicated from a high resolution scan of bone
and configured to promote bony on-growth or in-growth of tissue.
According to certain aspects of the present embodiment, the medical
implant further comprises a biological surface coating configured
to create a barrier to particulate debris, wherein the biological
surface coating is produced from a titanium porous plasma spray
surface coating or a biomimetic coating.
[0014] According to yet another embodiment of the present
disclosure, an additively manufactured medical implant is provided
and comprises a metallic body having at least one porous-surface
configured to promote bony on-growth or in-growth of tissue,
wherein the porous surface is replicated from a high resolution
scan of bone, and a biological surface coating configured to create
a barrier to particulate debris, wherein the biological surface
coating is produced from a titanium porous plasma spray surface
coating or a biomimetic coating. According to certain aspects of
the present embodiment, the medical implant is produced from the
steps of imaging bone with a high resolution digital scanner to
generate a three-dimensional design model of the bone, removing a
three-dimensional section from the design model, fabricating a
porous region on a digital representation of the implant by
replacing a solid portion of the digital implant with the section
removed from the design model, and using an additive manufacturing
technique to create a physical implant including the fabricated
porous region.
[0015] In accordance with still another embodiment of the present
disclosure, an additively manufactured medical implant is provided
and comprises a metallic body having at least one porous surface
configured to promote bony on-growth or in-growth of tissue,
wherein the porous surface is replicated from a high resolution
scan of bone, and a biological surface coating configured to create
a barrier to particulate debris, wherein the biological surface
coating is produced from a titanium porous plasma spray surface
coating or a biomimetic coating. According to certain aspects of
the present embodiment, the medical implant is produced from the
steps of creating a digital image of the bone with a microCT
scanner, removing any defective artifacts from the digital image,
converting the digital image to a three-dimensional design model of
the bone, removing a three-dimensional section that structurally
replicates the architecture of the bone from the design model,
printing the removed design model section on a digital
representation of the implant, and creating a physical implant from
the printed digital representation by using an additive
manufacturing technique.
[0016] According to yet another embodiment of the present
disclosure, an additively manufactured medical implant to fill a
bone void is provided and comprises a metallic body having at least
one porous surface configured to promote bony on-growth or
in-growth of tissue, wherein the porous surface is replicated from
a high resolution scan of bone, and a biological surface coating
configured to create a barrier to particulate debris, wherein the
biological surface coating is produced from a titanium porous
plasma spray surface coating or a biomimetic coating. According to
certain aspects of the present embodiment, the medical implant is
produced from imaging a voided bone region with a high resolution
digital scanner to generate a three dimensional design model of the
voided bone region, providing a digital representation of a
non-voided bone region, removing a three dimensional section of the
non-voided bone region, the removed section having a size that
substantially matches the size of the voided bone region, and
creating a physical implant from the removed three dimensional
section of the non-voided bone region by using an additive
manufacturing technique, the implant being configured to be
installed within the voided bone region.
[0017] Other objects and benefits of the invention will become
apparent from the following written description along with the
accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above-mentioned aspects of the present invention and the
manner of obtaining them will become more apparent and the
invention itself will be better understood by reference to the
following description of the embodiments of the invention taken in
conjunction with the accompanying drawings, wherein:
[0019] FIG. 1 is a schematic flowchart of an illustrative process
for creating a porous region of an implant from a trabecular bone
in accordance with the teachings of the present invention;
[0020] FIGS. 2a and 2b are illustrative MicroCT scans of acetabular
bone sections from cadaver pelvises imaged in accordance with the
teachings of the present invention;
[0021] FIG. 3 is an illustrative 3D scan of a trabecular bone
obtained from a humeral head in accordance with the techniques of
the present invention;
[0022] FIG. 4 is a cross-sectional view of a mesh wing that was
created from a humeral head MicroCT scan in accordance with the
teachings of the present invention; and
[0023] FIG. 5 is a front, cross-sectional view of a stemless
shoulder prosthesis having a pair of mesh wings in accordance with
the teachings of the present invention.
[0024] Corresponding reference characters indicate corresponding
parts throughout the several views. Although the exemplification
set out herein illustrates embodiments of the invention, in several
forms, the embodiments disclosed below are not intended to be
exhaustive or to be construed as limiting the scope of the
invention to the precise forms disclosed.
DETAILED DESCRIPTION
[0025] In the following detailed description, reference is made to
the accompanying drawings, which form a part hereof. In the
drawings, similar symbols typically identify similar components,
unless context dictates otherwise. The illustrative embodiments
described in the detailed description, drawings, and claims are not
meant to be limiting. Other embodiments may be utilized, and other
changes may be made, without departing from the spirit or scope of
the subject matter presented herein. It will be readily understood
that the disclosed aspects of the invention, as generally described
herein, and illustrated in the Figures, may be arranged,
substituted, combined, and designed in a wide variety of different
configurations, all of which are explicitly contemplated and should
be construed as being incorporated into this disclosure.
[0026] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
any method and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, the specific methods and materials are now described.
Moreover, the techniques employed or contemplated herein are
standard methodologies well known to one of ordinary skill in the
art and the materials, methods and examples are illustrative only
and not intended to be limiting.
[0027] The present invention relates to methods of forming metallic
structures having porous or mesh regions that represent the
architecture of bone, and specifically methods for imaging bone at
pre-defined anatomic locations to create implants having porous
regions that represent the bone's architecture at those imaged
anatomic locations. Generally, the methods of the present invention
utilize laser technology by employing a variety of scanning
strategies. It should be understood and appreciated herein that
various different materials can be used to form the metallic
structures of the present invention; however, in accordance with
certain aspects of the present invention, the metal and metal
alloys employed include, but are not limited to, stainless steel,
cobalt chromium alloys, titanium and its alloys, tantalum and
niobium. It should also be understood and appreciated herein that
the present invention can be used for various different medical
device applications, including applications in which bone and soft
tissue interlock with a component or where a controlled structure
is required to more closely match the mechanical properties of the
device with surrounding tissue.
[0028] In accordance with certain aspects of the present invention,
an additive manufacturing process is utilized to create a porous
metal structure for an orthopedic device. According to one
illustrative embodiment, the porous metal structure is configured
to mimic the trabecular architecture of bone at the specific
anatomic site where the device is to be implanted. It should be
understood and appreciated herein that the teachings of the present
invention can be utilized with various different anatomic
applications, including, but not limited to, hip procedures, knee
procedures, spinal procedures, shoulder procedures, hand, finger,
wrist and elbow procedures and foot, toe and ankle procedures.
[0029] Moving now to FIG. 1, an illustrative process 10 for
creating a porous region of an implant from a trabecular bone is
now discussed. In accordance with this illustrative embodiment, a
bone sample is first obtained from a region of interest (e.g.,
humeral head) from a pre-defined and site-specific anatomic site of
a specimen (e.g., a cadaver specimen) (step 12). Once the bone
sample is obtained from the specimen, the sample is scanned using a
high resolution imaging technique (step 14). As those of skill in
the art will understand and appreciate, various methods can be
employed to quantitatively assess the microstructure of trabecular
bone in accordance with the teachings of the present invention.
Some of these imaging techniques include, but are not limited to,
high-resolution CT (hrCT) and microCT (.mu.CT) techniques and
high-resolution magnetic resonance (hrMR) and microMR (.mu.MR)
techniques.
[0030] In accordance with specific aspects of the present
invention, the obtained bone sample is scanned using a high
resolution microCT scanner. For instance, FIGS. 2a and depict
acetabular scans obtained from cadaver pelvises using
high-resolution microCT scanners. Depending on the selected
anatomic site that is used to obtain the bone sample, it is
possible that various non-uniformities or discontinuities may exist
in the bone structure of the scanned sample. When such artifacts
are present in the scanned bone sample image, it may be desirable
to clean up or remove these artifacts from the image, thereby
leaving only the desired trabecular structure (step 16). For
example, as the scanned image of FIG. 2a reveals, the bone in the
medial region at the apex has a discontinuity (shown by reference
numeral 202), while the remaining regions generally contain a
trabecular architecture that is uniform and continuous. While
various different known image processing techniques can be used to
remove the undesired artifacts from the image (step 16), in
accordance with certain aspects of the present invention, bone from
regions exhibiting desired trabecular structure can be selected and
superimposed to fill in the region or regions containing defects.
Alternatively, and in accordance with other embodiments of the
present invention, a region of the original bone sample scan
containing optimal trabecular architecture can be identified and
then used as a unit cell for the entire porous region of the
structure to be created.
[0031] Once the undesirable artifacts are removed, the scan having
the optimal or desired physical properties of the trabecular
structure is chosen and the scan converted to a digital file format
that is appropriate for printing the porous metal structure using
an additive manufacturing process (e.g., STL format, AMF format,
etc.) (step 18). In accordance with certain illustrative
embodiments of the present teachings, an STL file (i.e., the file
format native to the stereolithography CAD software created by 3D
Systems) representing the trabecular structure is produced from the
microCT scan. In accordance with this specific embodiment, the file
can be sliced and the data sent digitally to a scanning control to
permit the generation of a layer-by-layer facsimile replica (i.e.,
a 3D design model) of the scanned sample (step 20).
[0032] Once the 3D model is generated, one or more 3D sections of
the trabecular structure can be removed or cut from the model to
form the desired porous or mesh regions to be fabricated into the
implant (step 22). In accordance with certain aspects of the
present invention, bone can be selected based on intersection with
the model. Moreover, information can be taken from the porous
region where the implant would sit in the bone. It should be
understood and appreciated herein that the porous or mesh regions
of the final metal structures created in accordance with the
various embodiments of the present teachings contain the trabecular
architecture of natural bone, and as such, the porous structure
unit cells do not require the use of a mathematical model to be
created. Accordingly, the porous structure of the metallic device
created herein will mimic the trabecular architecture of the
natural bone from the specific targeted anatomic site.
[0033] After the desired mesh regions of the metallic structure are
formed, bone sections are then added to the solid portions of the
implant model using a software program, such as computer aided
design "CAD" software program or the like (step 24). It should be
understood and appreciated herein that care should be taken to
align the bone sections as they were originally aligned in the
native bone when applying the techniques of the present invention
as disclosed herein. More particularly, different regions of a
bone, such as the humerus, have different trabecular properties
(e.g., thickness, length, etc.) and orientation that should be
closely replicated in the implant mesh design.
[0034] After the implant is modeled, an additive manufacturing
process is then employed to manufacture the implant from the 3D
model data (step 26). Additive manufacturing processes are
generally known in the art and typically involve making objects
from 3D model data by joining materials together in a
layer-by-layer fashion. Some additive manufacturing processes that
can be utilized in accordance with the teachings of the present
invention include, but are not limited to, Direct Metal Laser
Sintering (DMLS) process, an Electron Beam Melting (EBM) process,
Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM),
Stereolithography (SLA), Laminated Object Manufacturing, Powder Bed
and Inkjet Head 3D Printing, Plaster-Based 3D Printing (PP) and the
like.
[0035] While not required herein, it should be understood and
appreciated that traditional manufacturing techniques (e.g.,
casting, molding, forming, machining, joining/welding, polishing,
blasting, etc.) can also be used in conjunction with the additive
manufacturing processes of the present invention if desired. For
instance, in accordance with certain aspects of the present
invention, it may be desirable to add tapers, grooves and/or
threads to the fabricated article. If such additional features are
desired, those of skill in the art can incorporate additional
manufacturing techniques into the various embodiments of the
present teachings without straying from the spirit or scope of the
present invention.
[0036] In accordance with further aspects of the present teachings,
the inventive techniques described herein can be used to form an
implant from scanned bone to fill a bone void. In accordance with
this illustrative embodiment, a voided bone region is imaged with a
high digital scanner (e.g., a microCT scanner) to generate a three
dimensional design model of the voided bone region. Once the three
dimensional design model of the voided bone region is provided, a
digital representation of a non-voided bone region (i.e., a section
or sample of bone that does not contain a non-uniformity or void)
is provided. As those of skill in the art will understand and
appreciate herein, the three dimensional representation of the
non-voided bone region can be generated from various different
sources, including either an autologous or a non-autologous source.
For instance, in accordance with certain aspects of the present
invention, the non-voided bone region can be obtained by scanning a
good section of the patient's bone--i.e., a section that is devoid
of any non-uniformities or discontinuities. Alternatively, in
accordance with further illustrative aspects of the present
invention, the non-voided bone region can be taken from a
computerized database of stock non-voided bone images. As such, it
should be understood that the present invention is not intended to
be limited herein.
[0037] Once the digital representation of the non-voided bone
region is provided, a three dimensional section of the non-voided
bone region is removed from the image. In accordance with this
aspect of the present invention, the removed three dimensional
section should have a size that substantially matches the size of
the voided bone region. The removed three dimensional section of
the scanned non-voided bone is then converted to a file format that
is appropriate for printing with an additive manufacturing process
(e.g., STL format, AMF format, etc.) (step 18). In accordance with
certain illustrative embodiments of the present teachings, an STL
file (i.e., the file format native to the stereolithography CAD
software created by 3D Systems) representing the removed non-voided
bone region is produced from the rnicroCT scan.
[0038] The removed three dimensional section of the non-voided bone
region is then subjected to an additive manufacturing process so
that a physical implant is manufactured from the 3D design model.
As explained in detail above, additive manufacturing processes are
generally known in the art and typically involve making objects
from 3D model data by joining materials together in a
layer-by-layer fashion. Some additive manufacturing processes that
can be utilized in accordance with the teachings of the present
invention include, but are not limited to, Direct Metal Laser
Sintering (DMLS) process, an Electron Beam Melting (EBM) process,
Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM),
Stereolithography (SLA), Laminated Object Manufacturing, Powder Bed
and Inkjet Head 3D Printing, Plaster-Based 3D Printing (PP) and the
like.
[0039] In accordance with this aspect of the present invention, the
manufactured physical implant of the non-voided bone region can
then be installed within the voided bone region.
[0040] Advantages and improvements of the processes, methods and
devices of the present invention are demonstrated in the following
example. This example is illustrative only and is not intended to
limit or preclude other embodiments of the present invention.
EXAMPLE 1
[0041] FIG. 3 depicts an illustrative 3D scan of a trabecular bone
obtained from a humeral head in accordance with the techniques of
the present invention. In accordance with this illustrative
embodiment, bone was selected from a cadaver, sectioned, placed in
a tube to scan, and then scanned at a resolution of 40 microns.
While this scan was taken at a resolution of 40 microns, those of
skill in the art will understand and appreciate that various other
scanning resolutions can be utilized if desired. For instance in
certain illustrative embodiments, a resolution of about 20 microns
can be used.
[0042] FIG. 4 shows cross-sectional view of a mesh wing that was
created from a humeral head MicroCT scan in accordance with the
teachings of the present invention, while FIG. 5 shows a front,
cross-sectional view of a stemless shoulder prosthesis 30 having a
pair of illustrative mesh wings 38 (such as the mesh wing shown in
FIG. 4) coupled thereto. More specifically, and with particular
reference to FIG. 5, a humeral head component 32 is configured to
be fined inside a top portion of an internal chamber 34 of the body
36 of the prosthesis. The wings 38 are connected to the body 36 and
can be partially or fully porous, as well as have a partial solid
section for increased strength if desired. It should be understood
and appreciated herein that fully porous wings would allow bone to
grow completely through the wings, thereby enhancing the stability
of the device. It should also be understood and appreciated herein
that in accordance with certain aspects of the present invention,
it may be desirable to utilize a biological surface coating (e.g.,
a titanium porous plasma spray (PPS.RTM.) surface coating or a
biomimetic coating (e.g., BoneMaster.RTM. coating), both of which
are commercially available from Biomet), with the porous or
nonporous surfaces to create a barrier to particulate debris
(metallic, polyethylene or PMMA) and/or to further promote and
increase the fixation or osseintegration of the bony in-growth
through the wings. In accordance with certain aspects of the
present invention, the biological surface coating can have its
associated biological performance further enhanced and modified if
the coating is subjected to one or more of the following: grit
blasting, hyaluronic acid (HA), an RGD-containing glycoprotein or
bend coating.
[0043] While this illustrative example shows the present teachings
utilized with stemless shoulder prosthesis, it should be understood
and appreciated herein that the present invention can be
incorporated into any implant design that utilizes a porous or mesh
structure for bony on-growth or in-growth.
[0044] While an exemplary embodiment incorporating the principles
of the present invention has been disclosed hereinabove, the
present invention is not limited to the disclosed embodiments.
Instead, this application is 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.
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