U.S. patent application number 10/607664 was filed with the patent office on 2004-02-05 for bone cell covered arthroplasty devices.
Invention is credited to Ferree, Bret A..
Application Number | 20040024471 10/607664 |
Document ID | / |
Family ID | 31191159 |
Filed Date | 2004-02-05 |
United States Patent
Application |
20040024471 |
Kind Code |
A1 |
Ferree, Bret A. |
February 5, 2004 |
Bone cell covered arthroplasty devices
Abstract
Arthroplasty devices having improved bone in growth to provide a
more secure connection within the body. Different embodiments
disclosed include devices having threaded intramedullary
components, devices configured to receive bone growth promoting
substances, devices with resorbable components, and devices
configured to reduce shear stress.
Inventors: |
Ferree, Bret A.;
(Cincinnati, OH) |
Correspondence
Address: |
JERROLD J. LITZINGER
2134 MADISON ROAD
CINCINNATI
OH
45208
US
|
Family ID: |
31191159 |
Appl. No.: |
10/607664 |
Filed: |
June 27, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60392234 |
Jun 27, 2002 |
|
|
|
Current U.S.
Class: |
623/23.63 ;
623/23.15; 623/23.76 |
Current CPC
Class: |
A61F 2/3676 20130101;
A61F 2002/2817 20130101; A61F 2002/3631 20130101; A61F 2002/30289
20130101; A61F 2002/30433 20130101; A61F 2002/30158 20130101; A61F
2002/30624 20130101; A61F 2002/30789 20130101; A61B 17/1671
20130101; A61F 2002/30205 20130101; A61F 2/4425 20130101; A61F
2002/30235 20130101; A61F 2002/3085 20130101; A61F 2002/3611
20130101; A61F 2230/0069 20130101; A61B 17/164 20130101; A61B
2090/036 20160201; A61F 2002/30112 20130101; A61F 2002/30123
20130101; A61F 2002/30365 20130101; A61F 2/36 20130101; A61F
2002/30354 20130101; A61F 2002/30738 20130101; A61B 17/1655
20130101; A61F 2/30734 20130101; A61F 2250/0058 20130101; A61F 2/34
20130101; A61F 2/447 20130101; A61F 2002/30795 20130101; A61F
2002/3079 20130101; A61F 2/442 20130101; A61F 2002/30032 20130101;
A61F 2002/30233 20130101; A61F 2002/30507 20130101; A61F 2002/30604
20130101; A61F 2002/30733 20130101; A61F 2230/0082 20130101; A61F
2310/00029 20130101; A61F 2/389 20130101; A61F 2002/30004 20130101;
A61F 2002/30535 20130101; A61F 2002/3625 20130101; A61F 2002/30154
20130101; A61F 2002/4631 20130101; A61F 2210/0004 20130101; A61F
2310/00059 20130101; A61F 2230/0006 20130101; A61F 2250/0014
20130101; A61F 2310/00976 20130101; A61F 2002/30261 20130101; A61F
2002/30884 20130101; A61F 2250/001 20130101; A61B 17/1668 20130101;
A61F 2/30771 20130101; A61F 2002/30556 20130101; A61F 2002/368
20130101; A61F 2002/30062 20130101; A61F 2002/365 20130101; A61F
2220/0025 20130101; A61F 2002/30367 20130101; A61F 2002/4638
20130101; A61F 2220/0041 20130101; A61F 2230/0091 20130101; A61F
2002/30787 20130101; A61F 2002/30975 20130101; A61F 2002/30224
20130101; A61F 2230/0004 20130101; A61F 2/30724 20130101; A61F 2/32
20130101; A61F 2230/0021 20130101; A61F 2250/0009 20130101; A61F
2002/30579 20130101; A61F 2002/30827 20130101; A61F 2002/30909
20130101; A61F 2002/3401 20130101; A61F 2/30723 20130101; A61F
2/30767 20130101; A61F 2/3662 20130101; A61F 2230/0026 20130101;
A61F 2250/0031 20130101; A61F 2/367 20130101; A61F 2002/3055
20130101; A61F 2310/00982 20130101; A61F 2/4601 20130101; A61F
2002/30474 20130101; A61F 2230/0067 20130101; A61B 17/744 20130101;
A61F 2/4607 20130101; A61F 2002/30784 20130101; A61F 2002/30797
20130101; A61F 2002/3694 20130101; A61F 2310/00023 20130101; A61F
2310/00365 20130101; A61B 17/86 20130101; A61F 2220/0033 20130101;
A61F 2002/30545 20130101; A61F 2002/3469 20130101; A61F 2310/00293
20130101 |
Class at
Publication: |
623/23.63 ;
623/23.76; 623/23.15 |
International
Class: |
A61F 002/28; A61F
002/36; A61F 002/02 |
Claims
What is claimed is:
1. A prosthetic device for implanting into a bone, comprising: a
body having an outer surface, including a first section which
contacts the bone upon implantation; and a coating, covering at
least said first section, containing living bone cells, wherein
when said device is implanted into bone, said living bone cells
contact said bone to promote bone ingrowth between said device and
said bone.
2. The device of claim 1, wherein said body is composed of
titanium.
3. The device of claim 1, wherein said outer surface of said body
is porous.
4. The device of claim 1, wherein said body is composed of a
ceramic material.
5. The device of claim 1, wherein said body is composed of a
hydroxyapatite-covered metal.
6. The device of claim 1, wherein at least said first section
contains a textured surface.
7. The device of claim 6, wherein said textured surface comprises
an array of beads.
8. The device of claim 6, wherein said textured surface comprises
an array of fibrullar wires.
9. The device of claim 1, wherein said bone cells contain
osteoblasts.
10. The device of claim 1, wherein said bone cells contain
osteocytes.
11. The device of claim 1, wherein said coating contains a bone
growth promoting substance.
12. The device of claim 11, wherein said bone growth promoting
substance comprises at least one of the following substances:
TGF-.alpha., .beta.1,-2; EGF, IGF-I; PDGF; FGF; BMP-1 and VEGF.
13. A method of implanting a prosthetic device into a bone of a
patient, comprising the steps of: a. harvesting bone cells from a
patient; b. culturing the bone cells within a lab; c. growing the
bone cells onto a prosthetic device; d. implanting the prosthetic
device into the bone of the patient.
14. This method of claim 13, wherein the harvesting step further
includes removing a piece of iliac crest bone from the patient.
15. The method of claim 14, wherein the harvesting step further
includes treating the iliac crest bone to remove the cells.
16. The method of claim 13, wherein said cells may be osteoblasts,
osteocytes, and stem cells.
17. The method of claim 13, wherein the culturing step includes
adding a bone growth promoting substance to the culture medium.
18. A method of implanting a prosthetic device into the bone of a
patient, comprising the steps of: a. harvesting bone cells from a
patient; b. culturing the bone cells within a lab; c. coating a
prosthetic device with the bone cell culture; and d. implanting the
prosthetic device into the patient immediately after coating.
19. The method of claim 18, wherein the culturing step includes
adding a bone growth promoting substance to the culture medium.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit from U.S. Provisional Patent
Application Serial No. 60/392,274, filed Jun. 27, 2002 which
application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed in general to arthroplasty
devices and, in particular, to arthroplasty devices which improve
bone growth into said devices.
[0004] 2. Description of the Related Art
[0005] The use of arthroplasty devices to replace damaged or
defective joints within the body is commonplace in the medical
field. The prosthetic replacement of joints has evolved over the
years from early relatively crude models to current prostheses
which closely replicate functions and motions of a natural joint.
Prosthetic arthroplasty devices have been used as replacements for
the shoulder, hips, knee, ankle and invertebral disc.
[0006] One problem encountered with prosthetic joints includes
movement of the implant with respect to the patient's bones. This
motion often compromises fixation. Another problem that occurs is
an abnormal stress transference from the implant to the bone.
[0007] The most common method of holding the implant in the bones
is "press-fitting" the device into the intramedullary cavity of the
bone. This often causes abnormal stress distribution, leading to
premature failure.
[0008] These devices also rely on the ingrowth of the patient's
bone to hold these devices in place. The difficulty of achieving
true growth of a patient's bone into a metal prosthesis is a well
known problem in the surgical field.
SUMMARY OF THE INVENTION
[0009] It is, therefore, an object of the present invention to
provide an arthroplasty device which has improved bone ingrowth
capabilities.
[0010] It is a further object of the present invention to provide
an arthroplasty device configured to reduce shear stress.
[0011] It is a still further object of the present invention to
provide an arthroplasty device having a resorbable component which
restricts motion in a joint for a period of time to allow for
improved bone ingrowth.
[0012] It is a still further object of the present invention to
provide an arthroplasty device configured to receive bone growth
promoting substances.
[0013] These and other objects and advantages of the present
invention will be readily apparent in the description the
follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a lateral view, partly in cross section, of a
femur and a prior art impacted femoral component of a hip
replacement;
[0015] FIG. 2 is a lateral view, partly in cross section, of a
femur and an embodiment of the present invention showing a femoral
hip replacement device having a threaded component;
[0016] FIG. 3 is a cross-sectional view of the embodiment of the
present invention shown in FIG. 2;
[0017] FIG. 4 is an exploded view of the device of FIG. 2;
[0018] FIGS. 5A-D, taken together, show the sequence of
installation of the device of FIG. 2;
[0019] FIG. 6 is a lateral view, partly in cross section, of the
device of FIG. 2 which includes a collared rod component;
[0020] FIG. 7 is a cross-sectional view of the device of FIG. 2
which includes an anti-rotation feature;
[0021] FIG. 8A is a cross-sectional view of the femur and another
embodiment of the device of the present invention having an
expandable component shown in the contracted position;
[0022] FIG. 8B is a cross-sectional view of the device of FIG. 8A
showing the expandable component in the extended position;
[0023] FIG. 9A is a lateral view of another embodiment of the
present invention;
[0024] FIG. 9B is a cross-sectional view of the device of FIG.
9A;
[0025] FIG. 9C is a cross-sectional view of another version of the
device of FIG. 9A;
[0026] FIG. 10A is a lateral view of another embodiment of the
present invention;
[0027] FIG. 10B is a cross-sectional view of the device of FIG.
10A;
[0028] FIG. 10C is a different cross-sectional view of the device
of FIG. 10A;
[0029] FIG. 11A is a lateral view, partly in cross section, of
another embodiment of the present invention;
[0030] FIG. 11B is a lateral view, partly in cross section, of the
device of FIG. 11A after a period of time;
[0031] FIG. 11C is a lateral view of another embodiment of the
present invention;
[0032] FIG. 11D is a cross-sectional view of the device of FIG.
11C;
[0033] FIG. 11E is a lateral view of another embodiment of the
present invention;
[0034] FIG. 12A is a lateral view of an alternative device
according to the present invention for use in prosthetic disc
replacement shown in the unassembled position;
[0035] FIG. 12B is a lateral view of the device of FIG. 12A in the
assembled position;
[0036] FIG. 13 is a lateral view of a femoral component according
to the present invention;
[0037] FIG. 14 is a perspective view of another embodiment of the
present invention;
[0038] FIG. 15A is a perspective view of the device of FIG. 14 with
a portion of the device removed and a syringe shown for injecting a
bone growth promoting substance into the device;
[0039] FIG. 15B is a perspective view of FIG. 15A showing the
device of FIG. 14 partially filled;
[0040] FIG. 16A is a lateral view of a section of the spine showing
the device of FIG. 14 installed in position between the
vertebrae;
[0041] FIG. 16B is a lateral view of a drill bit which may be used
to create a hole in the device of FIG. 14;
[0042] FIG. 17 is a perspective view of an alternative embodiment
of the device of FIG. 14;
[0043] FIG. 18A is an end view of an alternative artificial disc
replacement device for use in the present invention;
[0044] FIG. 18B is a sectional view of the device of FIG. 18A
positioned between vertebrae of the spine;
[0045] FIG. 19 is a perspective view of an acetabular component for
use in an embodiment of the present invention;
[0046] FIG. 20 is a perspective view of a femoral component for use
in an embodiment of the present invention;
[0047] FIG. 21 is a perspective view of an alternative acetabular
component similar to the device of FIG. 19;
[0048] FIG. 22A is a perspective view of an alternative femoral
component similar to the device of FIG. 20;
[0049] FIG. 22B is a perspective view of another alternative
femoral component similar to the devices of FIG. 20 and FIG.
22A;
[0050] FIG. 23A is a lateral view of an alternative embodiment of
the device of FIG. 12A;
[0051] FIG. 23B is a lateral view of the device of FIG. 23A shown
in the deployed position;
[0052] FIG. 23C is a lateral view of an alternative embodiment of
the device shown in FIG. 23A;
[0053] FIG. 23D is a sectional view of the device of FIG. 23C;
[0054] FIG. 24A is an exploded view of an alternative embodiment of
a device according to the present invention;
[0055] FIG. 24B is a cross-sectional view of the device of FIG. 24A
in the assembled position;
[0056] FIG. 24C is a cross-sectional view of the device of FIG. 24A
installed in the femur;
[0057] FIG. 24D is a cross-sectional view of an alternative
embodiment the threaded component shown in FIG. 24A;
[0058] FIG. 25A is a cross-sectional view of a device according to
the present invention installed in the tibia;
[0059] FIG. 25B is a cross-sectional view of an alternative
embodiment of the device of FIG. 25A;
[0060] FIG. 26 is a cross-sectional view of a device according to
the present invention installed in the proximal femur;
[0061] FIG. 27A is a cross-sectional view of a device according to
the present invention installed in the distal femur;
[0062] FIG. 27B is a cross-sectional view of an alternative
embodiment of the device of FIG. 27A installed in the distal
femur;
[0063] FIG. 28A is an exploded view of a device according to the
present invention for use in a long bone;
[0064] FIG. 28B is a cross-sectional view of the device of FIG. 28A
invention installed in a long bone;
[0065] and FIG. 28C is a cross-sectional view of an alternative
embodiment of the device of FIG. 28A.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0066] FIG. 1 represents a typical prior art impacted femoral
component of a hip replacement commonly used in the surgical field
today. Referring now to FIG. 1, there is shown a femoral component
10 having an elongated tapered portion 12, an extended stem portion
14 for connecting component 10 to the prosthetic femoral head, and
a textured surface area 16. In use, tapered portion 12 is driven
into a femur 20 which has been prepared to receive component 10.
Surface area 16 of component 10 is configured to encourage bone
ingrowth to assist in the permanent attachment of component 10
within femur 20. Surface area 16 may contain small beads, fibrillar
wires or other structures known in the art to promote bone
ingrowth. This type of arthroplasty device relies on impaction of
the device into patients' bones for stability.
[0067] The difficulty of achieving true growth of a patient's bone
into metal prostheses is well known in the medical field. FIGS. 2-4
show a device according to the present invention which assists in
overcoming this problem. Femoral hip replacement device, generally
designated as 30, includes an upper outer sleeve 32 which contains
a textured surface area 34, a tubular inner component 36 having a
threaded lower portion 38, and an elongated rod component 42 having
an outwardly extending stem 44. In operation, threaded portion 38
of component 36 engages an internally threaded area which has been
previously incorporated into femur 20. Alternatively, portion 38
may contain self tapping threads for attachment within femur 20.
Sleeve 32 is then installed on the tubular portion of component 36
such that it is held against threaded portion 38 and the inner
walls of femur 20. Elongated rod component 42 is then inserted
through tubular component 36 such that it is tightly held in place
by sleeve 32 and femur 20, as can be best seen in FIG. 2.
[0068] Although device 30 contains surface area 34 to assist bone
ingrowth, threaded section 38 helps to stabilize device 30, as
threaded components are less likely to allow motion between the
device and bone. Bone ingrowth, which is dependent upon the surface
features of the device and motion between the device and the bone,
is thus facilitated by decreasing motion between the arthroplasty
device and a patient's bone.
[0069] The process for installing device 30 is shown in FIGS. 5A-D.
Referring now to FIG. 5A, a tap 50 having a thread cutting end 52
is used to chase threads within femur 20 in the area in which
threaded portion 38 of component 36 is to be affixed within femur
20. Alternatively, portion 38 may be manufactured as a self-tapping
device. After this has been performed, portion 38 is brought into
threaded engagement with femur 20, with tubular portion 36
positioned above the threaded connection (FIG. sleeve 5B). Next,
outer sleeve 32 is forced over tubular portion 36 until the edge of
sleeve 32 contacts threaded portion 38 (FIG. 5C). Finally,
elongated rod component 42 is inserted through tubular portion 36
captured within sleeve 32 such that outwardly extending stem 44 is
properly positioned for attachment within the prosthetic femoral
head. This construction decreases the possibility of motion between
device 30 and femur 20, potentially enhancing bone ingrowth.
[0070] FIG. 6 represents another embodiment of device 30 which a
collar 60 positioned on rod component 42 between stem 44 and sleeve
32 to aid in the positioning of device 30 within femur 20. In this
embodiment, rod component 42 is inserted through tubular portion 36
within sleeve 32 until collar 60 contacts sleeve 32. In this
manner, forces within rod component 42 are transferred to sleeve 32
having textured surface 34 for bone ingrowth, adding additional
stability to device 30.
[0071] FIG. 7 is a sectional view of an alternative embodiment of
device 30 which adds an anti-rotation feature for additional
stability. Referring now to FIG. 7, rod component 62 contains
outwardly extending edges 62a, 62b. Tubular component 64 contains a
pair of channels 64a, 64b within its inner walls corresponding to
edges 62a, 62b. In this manner, rod component 62 cannot rotate
within tubular component 64, adding additional stability to the
arthroplasty device, which potentially promotes bone ingrowth. Rod
component 62 may also contain a cruciform shape, with tubular
component 64 having a corresponding shape.
[0072] Square threads, buttress threads, or reverse buttress
threads may be used in the embodiments requiring threaded devices,
as these decrease hoop stress on the bone. Hoop stress can lead to
fracture of the bone. Taper threads may also be used. In addition,
the threads can be either left or right handed.
[0073] FIGS. 8A-B represent another alternative embodiment for an
arthroplasty device according to the present invention. In this
embodiment, an adjustable component 68 having a first section 68a
and a second section 68b which are movable relative to each other
by a pair of adjusting screws 70 is inserted into femur 20 in order
to fit a patient's bone anatomy better. Screws 70 are adjustable to
shift component 68 between a contracted position (FIG. 8A) and an
expanded position (FIG. 8B). Screws 70 are adjusted by a
corresponding pair of screws 72 which, when turned, control the
adjusting motion provided by screws 70. Alternatively, a wrench may
be used to turn a screw, or gear, which cooperates with a toothed
component to force sections 68a and 68b apart.
[0074] Component 68 is placed into the intramedullary canal of a
bone and expanded. The tighter fit provided by component 68
decreases motion between the prosthesis and the patient's bone.
Adjustable component 68 also allows for compaction of the
cancellous bone with the cortical bone into which the prosthesis
device is inserted. Cancellous bone is rich in cells that promote
bone ingrowth. Prior art impacted devices are generally inserted
into the cortical bone after the removal of most of the cancellous
bone. Thus, expanding components such as component 68 will aid in
the immobilization of the prosthesis and preserve the healing
characteristics of cancellous bone. While the device shown in FIGS.
8A-B show expansion of one component in one direction, multiple
components may be used that expand in multiple directions. A torque
wrench may be used to control the force and help prevent fracture
of the bone into which the device is to be inserted. In addition,
shape memory materials may be used to change the shape of
components within the device. For example, a sleeve made of nitinol
could be inserted in its contracted shape and then open to the
expanded shape after insertion into the base.
[0075] Alternative expansion mechanisms could be used for component
68. For example, a scissor jack-like mechanism or inclined planes
could be used to move the sections to its expanded position. In
addition, multiple sections can be used that expand in multiple
directions.
[0076] In another embodiment, a rod component similar to that shown
in FIGS. 2-6 is inserted between sections of component 68 in its
expanded expansion. The implanted rod may be held in position
within component 68 by adding a taper to the interior surfaces of
sections 68a and 68b.
[0077] Upper outer sleeve 32 which contains textured surface area
34 in FIG. 2 can be adapted to further enhance bone ingrowth in
devices according to the present invention. FIGS. 9A-C demonstrate
several alternative embodiments which may be used to further
promote this growth. Referring now to FIG. 9A, upper outer sleeve
34 contains a plurality of wells 80 along its outer surface which
replaces the textured surface. Wells 80 are filled with collagen
sponges 82 which have been soaked with Base Morphogenetic Protein
(BMP). Sponges 82 are inserted into wells 80 prior to insertion of
device 30 into femur 20. In FIG. 9C, sleeve 34 contains a plurality
of channels 84 which extend along the length of sleeve 34. In this
embodiment, BMP could be injected into channels 84 after insertion
of device 30, or BMP soaked collagen sponges 82 may be forced into
channels 84.
[0078] Another alternative embodiment of an arthroplasty device
according to the present invention is shown in FIGS. 10A-C. A
femoral rod component 90 having an outwardly extending stem 92 and
a collar stop 94 in installed through a sleeve 96 having a textured
area 98 for promoting bone ingrowth. The interior of sleeve 96
contains of pair of grooves 100 which correspond to a pair of wings
102 extending from the outer surface of component 90 such that the
interaction of wings 102 and grooves 100 allow small amounts of
motion between rod component 90 and sleeve 96 to decrease the shear
stress on textured area 98 where bone ingrowth occurs. Shear stress
can cause motion between the device and the patient's bone,
decreasing the chance of bone ingrowth. Devices using anti-rotation
features, such as shown in FIG. 10C and FIG. 7, will have rods with
varying degrees of version, including antiversion and
retroversion.
[0079] FIGS. 11A-E show an alternative embodiment of the device
according to the present invention which uses resorbable components
to temporarily decrease or remove the stress on the bone ingrowth
surfaces of the device. Referring now to FIG. 11A, an arthroplasty
device 100 similar to the device of FIGS. 10A-C is shown, having a
femoral rod component 102 with a outwardly extending stem 103, a
positioning sleeve 104 having a textured area (not shown) for
promoting bone growth, and a solid disc 106 having an threaded
outer surface 108. Disc 106 is initially positioned within a femur
20. Disc 106 has been installed into position within femur 20,
after its interior has been threaded in the appropriate area by
using a tool similar to that shown in FIG. 5A. Alternatively, outer
surface 10B may contain self-tapping threads. Resorbable material
110 is threaded into femur 20, contacting disc 106, and then rod
component 102 is introduced into sleeve 104. Note that component
102 is supported by resorbable material 110 and not sleeve 104.
Preferably, device 100 contains the anti-rotation features shown in
FIG. 10C. Additionally, anti-rotation features can also be added
between disc 106, resorbable material 110 and the end of rod
component 102 for additional stability. Suitable resorbable
materials include a high molecular weight poly-L-lactic acid (PLLA)
polymers, calcium hydroxyapatite, tricalcium phosphate. Other
potentially useful resorbable materials include polydiaoxanone
(PDS), oxidized regenerated cellulose and various forms of
collagen.
[0080] In this relationship, resorbable material 110 temporarily
decreases or removes the stress on the bone ingrowth surfaces of
sleeve 104. The forces on device 100 are transferred from
resorbable material 110 to the ingrowth surfaces of sleeve 104 as
resorbable material 110 disappears. Disc 106 may also contain a
through hole 111 to aid in the drainage of resorbable material 110.
This resorption process generally takes months. Bone will grow into
the ingrowth area of sleeve 104 while device 100 is supported by
resorbable material 108. Eventual transfer of the forces to the
ingrowth area of device 100 is important to prevent bone resorption
that occurs with stress shielding. Resorbable material 110 may also
temporarily eliminate movement through device 100. Eliminating
movement across device 100 decreases forces on the bone ingrowth
surfaces. Motion through device 100 is permitted once resorbable
materials 110 has dissolved, as rod component 102 now contacts
sleeve 104, as can be seen in FIG. 11B.
[0081] A prosthetic hip device according to the present invention
is shown in FIGS. 11C-D. Hip device 112 includes a femoral rod
component 114 having an outwardly extending stem 115, a head 116
mounted on stem 115, an inner acetabular component 117, and an
outer acetabular component 118. A resorbable component 120 is
located between component 118 and rod component 114 to restrict
motion between the acetabular and femoral components of device 112
until resorbable component 120 disappears, allowing time for bone
ingrowth to firmly take hold.
[0082] FIG. 11E shows prosthetic disc replacement device 122
according to the present invention. Device 122 includes an upper
plate 123 and a lower plate 124 connected by a pivot 125.
Resorbable material 126 is placed between plates 123 and 124 before
insertion of device 122 into a position between vertebrae of the
spine.
[0083] FIGS. 12A-B show an alternative embodiment of a prosthetic
disc replacement device 130. Device 130 contains an upper plate 131
and a lower plate 132. Each plate contains a keel-like ingrowth
extension component 134 attached for rotation through plates 131,
132 at a pivot 135. An activation device 136 consisting of a flat
plate is also shown. To install device 130, the device is placed
between vertebrae in the spine of a patient. Activation device 136
is pushed between plates 131 and 132 to force extensions 134 away
from plates 131, 132 to affix device 130 in its proper location
between the vertebrae. Extensions 134 are exposed to the cancellous
bone of the vertebrae, immobilize device 130 and help prevent its
extrusion.
[0084] FIG. 13 shows another embodiment of a method for restricting
motion of the prosthesis relative to the bone when using an
arthroplasty device. Referring now to FIG. 13, there is shown a
femoral component 140 positioned within femur 20. Component 140 is
held firmly in place by a first screw 142 which is affixed
crosswise through component 140 and femur 20. A second screw 144 is
affixed through component 140 and femur 20 in a direction oriented
approximately 90.degree. to first screw 142. A guide is preferably
removably attached to femur 20 or component 140 to help direct a
drill bit through femur 20 and to thread screws 142 and 144 through
the structure. Use of screws 142 and 144 assist in minimizing
motion of component 140 with respect to femur 20, allowing bone
ingrowth between component 140 and femur 20.
[0085] FIG. 14 shows a device which promotes bone ingrowth in a
spinal fusion procedure. Implant 200 consists of a box-like
structure having top and bottom surfaces 200a, 200b, front and rear
surfaces 200c, 200d, and side surfaces 200e, 200f. In this
embodiment, surfaces 200a and 200b are essentially parallel, 200c
and 200d are essentially parallel, and 200e and 200f are
essentially parallel; however, implant 200 can consist of any shape
which will fit between adjacent vertebrae. Surface 200c contains an
aperture 202 which allows access to the interior of implant 200.
Aperture 202 allows for the injection of a bone growth promoting
substance into implant 200. Possible substances include Platelet
Rich Plasma (PRP), bone morphogenetic protein (BMP), or
concentrated leukocytes. Other substances which are available are
discussed in my co-pending patent application Ser. No. 09/897,000,
which application is incorporated by reference herein. Although
implant 200 is preferably manufactured from bone, it could also be
constructed from other compatible materials such as metal or
polymers. Alternatively, the metal or polymer devices could be
filled with bone.
[0086] FIGS. 15A-B show how implant 200 can be filled with an
appropriate bone growth promoting substance. A syringe 206 filled
with a suitable substance 207 is positioned with its needle 208
inserted through aperture 202. As syringe 206 is operated,
substance 207 fills implant 200 with the bone growth promoting
fluid, as can be seen clearly in FIG. 15B. FIG. 16A shows implant
200 in position between adjacent vertebrae 210, 212 while syringe
206 injects growth substance 207 into the implant.
[0087] A drill bit 216 is shown in FIG. 16B which may be used to
create aperture 202 in implant 200. Bit 216 contains a smooth
cylindrical section 216a, a fluted end 216b having a point for
drilling, and a collar stop 216c. Drill bit 216 is particularly
suited for drilling aperture 202 into implant 200, as collar stop
216c acts to prevent bit 216 from traveling too far into implant
200, possibly damaging the device. Drill bit 216 may be helpful
when drilling aperture 202 into a device such as implant 200a,
which has a different shaped structure, as can be seen in FIG. 17.
Aperture 202 can be aligned in any suitable direction within the
device. While aperture 202 can be drilled into implant 200 before
inserting the device into position in the spine, it may be
advantageous to drill aperture 202 into implant 200 after it is
positioned between vertebrae 210, 212. This would avoid weakening
of implant 200, as the device is under compressive forces when in
position. Alternatively, implant 200 could be manufactured with
aperture 202 in place in the device.
[0088] Bone growth promoting substances can be used in many other
arthroplasty devices. FIGS. 18A-B show its use in connection with
an artificial disc replacement (ADR) procedure. An ADR device 220
similar to the device of FIGS. 12A-B contains a pair of extensions
221 for fixing device 220 in the spine and a pair of end plates
222a, 222b each having an aperture 223. End plates 222a, 222b are
separated by an activating structure 226. End plates 222a, 222b may
contain a series of channels which are connected to apertures 223.
When device 220 has been positioned in place between vertebrae 210,
212, syringe 206 can be located with needle 208 inserted into
apertures 223 of end plates 222a, 222b to input growth substance
207 into device 220 to promote bone ingrowth between the device and
the vertebrae.
[0089] FIGS. 19 to 22A-B depict different arthroplasty devices
which can be used in conjunction with bone growth promoting
substances to maximize bone ingrowth between the body and the
implants. An acetabular component for use in hip replacement is
shown in FIG. 19. Component 240 is a cup-shaped device having a
spherical outer surface 242 and a hollow curved inner surface 244.
A front surface 246 contains a plurality of apertures 248.
Apertures 248 are connected to a series of channels which are
connected to a series of outlets 250 which are scattered along
outer surface 242 of device 240. When component 240 is placed in
position during hip replacement surgery, bone growth substance 207
can be injected into apertures 248 such that the substance can
travel through the channels to outlets 250, where it can contact
the hip bone to promote bone ingrowth between device 240 and the
bone. An alternative embodiment to implant device 240 is shown in
FIG. 21. This acetabular component 260 has a spherical outer
surface 262, a hollow curved inner surface 264 and a flat front
surface 266. Along the periphery of surface 266 a series of grooves
268 are channeled into outer surface 262. Grooves 268 may be
parallel channels along outer surface 262, or they may spiral
around outer surface 262. When component 260 is positioned in the
bone during hip surgery, growth substance 207 may be injected into
grooves 268 such that the fluid can flow between component 260 and
the bone to promote bone ingrowth.
[0090] Examples of the present invention for use with femoral
components are shown in FIGS. 20 and 22A-B. Referring now to FIG.
20, a femoral component 280 is shown having a body 282 having an
outer surface 283, a flat top surface 284, and an outwardly
extending stem 286. A plurality of apertures 288 are located on
flat surface 284.
[0091] A series of channels within body 282 are connected to
apertures 288 at one end, while the other ends are connected to a
series of outlets 290 located on outer surface 283. When component
280 is implanted in position within a femur, bone growth substance
207 is injected into apertures 288 such that it will travel through
body 282 and exit through outlets 290 between component 280 and the
bone to promote bone ingrowth. Alternative versions of this device
are shown in FIGS. 22A-B. In FIG. 22A, femoral component 280a
contains a body 282a having an outer surface 283a, a flat top
surface 284a, and an outwardly extending stem 286a. Along the
periphery of surface 284a, a plurality of grooves 292 are channeled
into the outer surface 283a. Grooves 292 may be straight along
outer surface 283a, or they can spiral around component 280a. When
component 280a is fixed in place within a femur, growth substance
207 can be injected into grooves 292 such that the fluid can flow
between the implant 280a and the bone to promote bone ingrowth.
FIG. 22B shows a similar device 280b, except that grooves 294 are
equally spaced around the periphery of upper surface 284b and are
oriented in a parallel fashion along outer surface 283b.
[0092] The principles of the present invention taught in FIGS.
19-22B can be applied to other prosthetic devices such as knee
replacements, shoulder replacement, and spinal fusion cages.
[0093] FIGS. 23A-D teaches several alternative embodiments of the
present invention for use in spinal procedures similar to those
taught in FIGS. 12A-B and FIGS. 18A-B. Referring now to FIG. 23A,
there is shown a spinal device generally indicated at 300 having a
pair of end plates 302a, 302b. Each end plate contains a keel-like
fixation component 304 which is fixed for rotation about a pivot
306 through the interior area of the end plate. Component 304 are
offset from each other with respect to device 300 such that
component 304 rest side by side between end plates 302a, 302b when
device 300 is in the unactivated position. This orientation allows
for larger fixation components to be used in device 300 for better
fixation in position between vertebrae. An activating component 308
is shown alongside device 300. Component 308 consists of a pair of
spherical pusher plates 310. In operation, activating component 308
is forced between end plates 302a, 302b, causing fixation
components 304 to rotate about pivot points 306 outwardly through
end plates 302a, 302b, to extend from device 300 and holding the
device firmly between vertebrae of the spine, as is shown in FIG.
23B.
[0094] FIGS. 23C-D show spinal device 300a in which slots 316 are
incorporated into end plates 302a, 302b such that fixation
components 304 rest within slots 316 when device 300a is in the
unactivated state. Slots 316, which may be shaped such that the end
of each fixation component 304 just fits within said slot, or may
extend along a longer portion of each end plate, to allow for the
use of a larger fixation component with device 300a, improving the
holding power of spinal device 300a when positioned between
vertebrae.
[0095] FIGS. 24A-D show an alternative embodiment for an
arthroplasty device according to the present invention for use in
hip surgery. Referring now to FIGS. 24A-C, there is shown a device
329 having a femoral component 330 with a outwardly extending stem
332, and a hollow passageway 334 extending through the central area
of component 330. Passageway 334 is square shaped in this
embodiment, but it may be shaped in any configuration in which a
component inserted into said passageway cannot rotate, such as an
ellipse, a triangle, pentagon, or hexagon. Component 330 also
contains a recess 336 on its upper surface. Passageway 334 and
recess 336 are connected by a channel 338. An attachment component
340 contains an upper section 342 having a square shape with a
threaded aperture 344 at its upper end and a lower threaded
cylindrical section 346. A screw 348 is also provided with the
device.
[0096] To install femoral component 330 into a femur in a hip
replacement procedure, the inner surface of femur 20 is threaded at
the proper depth using a tool similar to that shown in FIG. 5A.
Attachment component 340 is installed within femur 20 by threading
section 346 into the femur. Component 330 is then located upon
upper section 342 of attachment component 340 by matching the shape
of section 342 with recess 334 in the proper orientation. Screw 348
is then inserted into recess 336 of component 330 through channel
338 and threaded into aperture 344 to hold the device in its proper
position within femur 20. This procedure "pulls" the device into
the femur, helping to prevent fracturing the bone. A torque wrench
may be used to adequately tighten screw 348 to its proper tightness
to prevent splitting femur 20. Attachment component 342 may be
composed of a polymer such as carbon fiber, or alternatively may be
composed of a resorbable material. Device 329 minimizes motion
between the implant and bone, as the matched shape connection
between passageway 334 and upper section 342 of attachment
component 340 allows for virtually no movement.
[0097] An alternative attachment component 340a for component 340
is shown in FIG. 24D. Component 340a contains a similar upper
section 342 containing a threaded aperture 344; however, lower
cylindrical threaded section 346a contains a hollow internal
section 352. Hollow section 352 gives threaded section 346a more
flexibility than a solid component. Hollow threaded components and
polymer threaded components are less likely to cause thigh pain
from excessive stress transfer to the femur at the level of the
threaded component. Furthermore, resorbable components, in
particular, are less likely to cause stress shielding of the
proximal femur.
[0098] FIGS. 25A-B show an embodiment of the present invention for
use in a prosthetic knee device. Device 400 includes a cylindrical
component 402 having a threaded outer surface and a recess 404
having a threaded inner surface. An articulating component 406
includes a planar section 408 having an extension 410 with a
treaded end 412.
[0099] To install device 400, the internal surface of tibia 416 is
threaded internally using a device similar to that shown in FIG. 5A
at the desired depth. Component 402 is then threadably engaged
within tibia 416. Articulating component 406 is then threadably
affixed to component 402 by threading end 412 of extension 410 into
recess 404 until surface 408 contacts tibia 416.
[0100] Referring now to FIG. 25B, prosthetic device 420 includes a
cylindrical component 422 having a threaded outer surface and an
aperature 423 having a threaded inner surface, and an upper
component 424 having a planar surface 426 and an aperture 428 in
the central region. The upper surface of component 424 is sized
such that a cover 430 may be snapped into position on the upper
surface. Cover 430 may be constructed of polyethylene. A bolt 432
having a head 433 is also included with device 420.
[0101] To install device 420, the internal surface of tibia 416 is
threaded internally using a device similar to that shown in FIG. 5A
at the desired depth. Upper component 424 is placed on the upper
surface of tibia 416 and bolt 432 is placed through aperture 428
and is threaded into aperture 423 of component 422 until head 433
contacts the upper surface of component 424. Cover 430 is then
snapped into position on component 424.
[0102] In FIGS. 25A-B, components 402 and 422 may be composed of
metal or a polymer, or could also be made from a resorbable
material. Components 406 and 429 may be constructed from titanium
or chrome cobalt.
[0103] FIG. 26 shows a device 444 embodying the present invention
for use in treating the hip socket. In this embodiment, a fracture
450 of a femur 451 is shown at the base of the femoral head 452.
Device 444 includes a femoral repair component 453 consisting of a
cylindrical member 454 having a threaded end section 456. Component
453 also contains an aperture 458 which is oriented angularly
toward femoral head 452. Aperture 458 may be threaded internally. A
second component 460 of device 444 consisting of a connecting rod
461 having a threaded end 462 is connected to femoral head 452 by a
threaded aperture 464 within femoral head 452.
[0104] To install device 444 for repair of the fractured femur,
threaded end section 456 is located within femur 451 using the
techniques previously discussed. The correct angular position of
component 460 relative to component 453 and femoral head 452 is
determined, and threaded end 462 is affixed within femoral head
452. Rod 461 is sized such that the end can be inserted into
aperture 458 of component 453 using a small amount of force to
overcome the friction fit between the components. Rod 461 is then
inserted into aperture 458 until femoral head 452 is positioned
against femur 451. The interaction between rod 461 and component
453 acts to hold head 452 in the correct position to heal.
[0105] FIGS. 27A-B show an embodiment of the present invention for
use in repairing a fracture of the distal end of the femur. Repair
device 480 includes a component 482 having a solid first section
484 with a threaded outer surface and a narrower cylindrical second
section 486. To install repair device 480, the internal surface of
femur 488 is threaded at a section on the opposite side of fracture
490 from distal end 492 of femur 488 using a device similar to that
shown in FIG. 5A. Threaded section 484 of component 482 is affixed
within femur 488 such that section 486 is spaced apart from distal
end 492 of femur 488 when the two sections of femur 488 are held
together tightly along fracture 490. A hole 496 is then drilled
across the distal end 492 of femur 488, passing through section 486
of component 482. A screw 498 is then placed into hole 496, passing
through section 486 of component 482 and is threaded into femur 488
as shown at 500. This device holds the sections of femur 488
tightly together to aid in the healing process. Threaded section
484 can be made from a resorbable material, non-resorbable
polymers, metal, or a combination of materials. For example,
section 484 could be made with a metal core surrounded by a
resorbable component.
[0106] The device 480a of FIG. 27B is similar to device 480 shown
in FIG. 27A except for the design of component 482. Component 482a
is constructed like the component shown in FIG. 24D in that first
section 484a is hollow with a threaded outer surface. As discussed
previously, the hollow section allows more flexibility than a solid
component. The installation of device 480a follows the same methods
of that taught for device 480.
[0107] FIGS. 28A-C show a fixation device 500 for use in long
bones. Referring now to FIG. 28A, a first component 502 contains a
solid cylindrical portion 504 having an outer threaded surface 506,
and a cylindrical portion 508 having a lesser diameter than portion
504 and containing a threaded portion 510 located along its length.
A second component 512 comprises a cylindrical disc having a
threaded outer surface 514 and a central aperture 516 which is
threaded. In addition, a pair of screws 520 are provided.
[0108] Fixation device 500 is shown on its installed position in
FIG. 28B. A long bone 540 is shown having a fracture 542. Threads
are made on the internal surfaces of bone 540 in the appropriate
positions in the manner previously described. Component 502 is then
positioned within the upper section 540a of bone 540 by engaging
outer threaded surface 506 into the threaded position in section
540a to fix component 502 in its proper location. Component 512 is
then positioned onto threaded portion 510 of cylindrical portion
508 while component 512 is being threaded into lower section 540b
of bone 540. Component 512 is rotated until it is firmly coupled to
both component 502 and bone 540. In this embodiment, left handed
threads may be used for threaded 510 and also for threaded outer
surface 514 and threaded aperture 516. In this manner, the action
of installing component 502 of device 500 acts to pull the
components together. After device 500 has been installed in bone
540, holes may be drilled into upper section 540a and lower section
540b through the upper and lower ends of component 502 and screws
520 inserted to prevent rotation of long bone 540 about device
500.
[0109] FIG. 28C shows device 500 installed within long bone 540
without the use of screws 520.
[0110] Another embodiment for use with the arthroplasty devices
according to the present invention involves the use of bone cells.
Bone and bone cells are grown onto the prosthesis prior to
implanting the device into a patient. To accomplish this task, bone
cells are initially harvested from a patient. Osteoblasts could be
harvested from a patient's iliac crest; a piece of iliac crest bone
could be surgically removed. In "Culture of Animal Cells" by R. Ian
Freshney, Wiley-Liss New York 2000, which is incorporated herein by
reference, techniques for harvesting osteoblasts are described on
pps. 370-372. Also described in the article are cell culture
techniques. U.S. Pat. No. 6,544,290, which issued on Apr. 8, 2003,
to Lee et al, which patent is hereby incorporated by reference,
teaches a method culturing cells onto a resorbing calcium phosphate
material. The present invention contemplates the culturing of cells
onto arthroplasty devices made of titanium, chrome, cobalt,
ceramic, or other non-resorbable materials.
[0111] In the present invention, bone is harvested from a patient,
and the bone then treated to remove the cells. The cells are
cultured and grown onto the prosthesis in a lab. The device, now
covered with living bone cells, is subsequently implanted into the
patient. These cells, which include osteoblasts, osteocytes, donor
bone cells, stem cells or other pluripotential cells, and other
cells that are capable of transforming into osteoblasts or
osteocytes, will promote the bone ingrowth to improve the stability
of the device in the body. Alternatively, the bone cells could be
added to the device at the time of surgery.
[0112] To foster the improved bone ingrowth, the titanium
components would have surface treatments. For example, the surfaces
could be porous, beaded, plasma sprayed, or covered with fibrillar
wire to promote ingrowth. Alternatively, the cells could be
cultured onto arthroplasty devices made of other metals, or
materials such as ceramic and hydroxyapatite coated metals. In
addition, to attempt to improve the ingrowth characteristics of
this process, bone growth promoting substances such as
TGF-.alpha.,-.beta.1, -2; EGF, IGF-I; PDGF, FGF, BMP-1, VEGF and
other similar substances may be added to the cell culture
medium.
[0113] It is contemplated that features of the various embodiments
may be combined. For example, the expandable component taught in
FIGS. 8A-B could be used with the threaded component of FIGS. 2-7.
Also, although the drawings are directed primarily to the use of
the invention in prosthetic hips, the principles may be applied to
other prosthetic joints, such as knees, shoulders, ankles and
wrists. In addition, bone cells harvested from the patient could be
added to the bone growth promoting substance used in other
embodiments. These cells could also be combined with a cell culture
media or a synthetic matrix.
[0114] While the present invention has been shown and described in
terms of preferred embodiments thereof, it will be understood that
this invention is not limited to any particular embodiment, and
that changed and modifications may be made without departing from
the true spirit and scope of the invention as defined in the
appended claims.
* * * * *