U.S. patent application number 10/914629 was filed with the patent office on 2006-02-16 for systems and methods for the fixation or fusion of bone.
Invention is credited to Mark A. Reiley.
Application Number | 20060036251 10/914629 |
Document ID | / |
Family ID | 35800968 |
Filed Date | 2006-02-16 |
United States Patent
Application |
20060036251 |
Kind Code |
A1 |
Reiley; Mark A. |
February 16, 2006 |
Systems and methods for the fixation or fusion of bone
Abstract
A stem-like bone fixation device allows for bony in-growth on
its surface and across fracture fragments or between bones that are
to be fused.
Inventors: |
Reiley; Mark A.; (Piedmont,
CA) |
Correspondence
Address: |
RYAN KROMHOLZ & MANION, S.C.
POST OFFICE BOX 26618
MILWAUKEE
WI
53226
US
|
Family ID: |
35800968 |
Appl. No.: |
10/914629 |
Filed: |
August 9, 2004 |
Current U.S.
Class: |
606/301 ;
606/323; 606/329; 606/331; 606/907 |
Current CPC
Class: |
A61F 2002/30604
20130101; A61F 2230/0058 20130101; A61F 2002/30235 20130101; A61F
2002/30841 20130101; A61F 2002/4238 20130101; A61F 2210/0004
20130101; A61F 2002/30777 20130101; A61F 2002/30062 20130101; A61F
2310/00359 20130101; A61F 2/4465 20130101; A61F 2230/0023 20130101;
A61F 2310/00179 20130101; A61F 2002/30787 20130101; A61F 2310/00017
20130101; A61F 2002/30156 20130101; A61F 2310/00329 20130101; A61B
17/8625 20130101; A61F 2002/30785 20130101; A61F 2310/00353
20130101; A61F 2/0077 20130101; A61B 17/68 20130101; A61F
2002/30405 20130101; A61B 17/8685 20130101; A61F 2/30767 20130101;
A61F 2220/0025 20130101; A61F 2310/0097 20130101; A61F 2/4455
20130101; A61B 17/866 20130101; A61B 17/846 20130101; A61F 2002/305
20130101; A61F 2002/3085 20130101; A61F 2230/0069 20130101; A61F
2/447 20130101; A61F 2310/00023 20130101; A61F 2002/3023 20130101;
A61F 2002/448 20130101; A61F 2/28 20130101; A61F 2002/30622
20130101; A61B 17/864 20130101; A61F 2310/00796 20130101; A61F
2002/30576 20130101; A61F 2002/30179 20130101; A61B 17/1615
20130101; A61F 2002/3082 20130101; A61F 2310/00029 20130101; A61F
2310/00131 20130101; A61B 17/70 20130101 |
Class at
Publication: |
606/072 |
International
Class: |
A61B 17/58 20060101
A61B017/58 |
Claims
1. A bone fixation device for stabilizing bone segments comprising
a stem adapted for passage between bone segments, at least a
portion of the stem including a surface permitting bony
in-growth.
2. A bone fixation device as in claim 1 wherein the stem structure
is of a cylindrical configuration.
3. A bone fixation device as in claim 1 wherein the stem is of a
conical configuration.
4. A bone fixation device as in claim 1 wherein the stem is
cannulated.
5. A bone fixation device as in claim 1 wherein the stem includes a
threaded end portion for coupling with another stem.
6. A bone fixation device as in claim 1 wherein the stem comprises
a prosthetic material.
7. A bone fixation device as in claim 1 wherein the stem comprises
a biologic material.
8. A bone fixation device as in claim 1 wherein the stem includes a
fenestration permitting passage of another stem.
9. A bone fixation device as in claim 1 wherein the stem is
cannulated.
10. A bone fixation device as in claim 1 wherein the stem is
threaded.
11. A bone fixation device according to claim 1 further comprising
a coupling to couple the stem with another stem:
12. A method for bone fracture fixation using the bone fixation
device as defined in claim 1.
13. A method for bone fixation using the bone fixation device as
defined in claim 1.
Description
FIELD OF THE INVENTION
[0001] This application relates generally to the fixation of
bone.
BACKGROUND OF THE INVENTION
[0002] Many types of hardware are available both for fracture
fixation and for the fixation of bones that are to fused
(arthrodesed).
[0003] Metal and absorbable screws are routinely used to fixate
bone fractures and osteotomies. It is important to the successful
outcome of the procedure that the screw is able to generate the
compressive forces helpful in promoting bone healing.
SUMMARY OF THE INVENTION
[0004] The invention provides bone fixation devices and related
methods for stabilizing bone segments. The systems and methods
include a stem-like structure adapted for passage between adjacent
bone segments. At least a portion of the stem-like structure
includes a surface that enhances bony in-growth. Boney in-growth
into the stem-like structure helps speed up the fusion process or
fracture healing time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of a bone fixation stem having
a boney in-growth surface of a mesh configuration.
[0006] FIG. 2 is a perspective view of an alternative embodiment of
a bone fixation stem having a boney in-growth surface of a beaded
configuration.
[0007] FIG. 3 is a perspective view of an alternative embodiment of
a bone fixation stem having a boney in-growth surface of a
trabecular configuration.
[0008] FIG. 4 is a schematic view of a bone fixation stem of the
type shown in Fig. being inserted into bone across a fracture line
or bone joint.
[0009] FIG. 5 is a schematic view of a bone fixation stem
positioned within bone and illustrating a boney in-growth surface
of the stem extending across a fracture line or bone joint.
[0010] FIG. 6 is a front plan view of an alternative embodiment of
a bone fixation stem having a boney in-growth surface in which the
stem has a conical configuration.
[0011] FIG. 7 is front plan view of an alternative embodiment of a
bone fixation stem having a boney in-growth surface in which the
stem has a beveled distal tip.
[0012] FIGS. 8A and 8B are schematics illustrating the insertion of
a conical bone fixation stem of the type shown in FIG. 6 to reduce
the gap between bone segments.
[0013] FIG. 9 is a schematic illustrating a guidewire being
introduced into bone across bone segments.
[0014] FIG. 10 is a schematic similar to FIG. 9 and illustrating a
drill bit being introduced over the guidewire.
[0015] FIG. 11 is a schematic similar to FIG. 10 and illustrating a
bore formed in the bone remaining after withdrawal of the drill
bit.
[0016] FIG. 12 is a schematic similar to FIG. 11 and illustrating
insertion of a bone fixation stem into the pre-formed bore.
[0017] FIG. 13 is an exploded front plan view illustrating the
coupling of a pair of bone fixation stems by threaded
engagement.
[0018] FIG. 14 is a schematic illustrating a pair of bone fixation
stems coupled together and inserted into bone across multiple bone
segments.
[0019] FIG. 15 is a front plan view illustrating passage of a bone
fixation stem through a fenestration in another bone fixation
stem.
[0020] FIG. 16 is a schematic illustrating the placement of a
series of bone fixation stems in bone.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Although the disclosure hereof is detailed and exact to
enable those skilled in the art to practice the invention, the
physical embodiments herein disclosed merely exemplify the
invention that may be embodied in other specific structure. While
the preferred embodiment has been described, the details may be
changed without departing from the invention, which is defined by
the claims.
[0022] FIG. 1 shows a device 10 sized and configured for the
fixation of bone fractures or for the fixation of bones which are
to be fused (arthrodesed). The device 10 comprises an elongated,
stem-like structure. The device 10 can be formed--e.g., by
machining, molding, or extrusion--from a material usable in the
prosthetic arts, including, but not limited to, titanium, titanium
alloys, tantalum, chrome cobalt, surgical steel, or any other total
joint replacement metal and/or ceramic, sintered glass, artificial
bone, any uncemented metal or ceramic surface, or a combination
thereof. Alternatively, the device 10 may be formed from a suitable
durable biologic material or a combination of metal and biologic
material, such as a biocompatible bone-filling material. The device
10 may be molded from a flowable biologic material, e.g., acrylic
bone cement, that is cured, e.g., by UV light, to a non-flowable or
solid material.
[0023] The device 10 can take various shapes and have various
cross-sectional geometries. The device 10 can have, e.g., a
generally curvilinear (i.e., round or oval) cross-section, or a
generally rectilinear cross section (i.e., square or rectangular),
or combinations thereof. As will be described in greater detail
later, the device 10 can be conical or wedge shaped.
[0024] The structure 10 includes surface texturing 12 along at
least a portion of its length to promote bony in-growth on its
surface. The surface texturing 12 can comprise, e.g., through
holes, and/or various surface patterns, and/or various surface
textures, and/or pores, or combinations thereof. The device 10 can
be coated or wrapped or surfaced treated to provide the surface
texturing 12, or it can be formed from a material that itself
inherently possesses a surface conducing to bony in-growth, such as
a porous mesh, hydroxyapetite, or other porous surface. The device
10 may further be covered with various other coatings such as
antimicrobial, antithrombotic, and osteoinductive agents, or a
combination thereof. The surface texturing 12 may be impregnated
with such agents, if desired.
[0025] The configuration of the surface texturing 12 can, of
course, vary. By way of examples, FIG. 1 shows the surface 12 as an
open mesh configuration; FIG. 2 shows the surface 12 as beaded
configuration; and FIG. 3 shows the surface 12 as a trabecular
configuration. Any configuration conducive to bony in-growth will
suffice.
[0026] In use (see FIGS. 4 and 5), the device 10 is inserted into a
space between two adjacent bone surfaces, e.g., into a fracture
site or between two bones (e.g., adjacent vertebral bodies) which
are to be fused together. In FIG. 4, the device 10 is shown being
tapped into bone through bone segments 14 (i.e., across a fracture
line or between adjacent bones to be fused) with a tap 16. The bone
may be drilled first to facilitate insertion of the device 10. The
bony in-growth surface 12 along the surface of the device 10
accelerates bony in-growth into the device 10. Boney in-growth into
the device 10 helps speed up the fusion process or fracture healing
time.
[0027] The bony in-growth surface 12 may cover the entire outer
surface of the device 10, as shown in FIG. 4, or the bony in-growth
surface 12 may cover just a specified distance on either side of
the joint surface or fracture line, as shown in FIG. 5.
[0028] The size and configuration of the device 10 can be varied to
accommodate the type and location of the bone to be treated as well
as individual anatomy.
[0029] As FIG. 6 shows, the device 10 can be angled or tapered in a
conical configuration. The degree of angle can be varied to
accommodate specific needs or individual anatomy. A lesser degree
of angle (i.e., a more acute angle) decreases the risk of splitting
the bone as the device 10 is tapped into the bone or the fracture
segments 14. The device 10 may also include a beveled distal tip 18
to further add in insertion of the device 10 into bone, as shown in
FIG. 7. As shown in FIGS. 8A and BB, the conical shape also helps
drive the joint surfaces or fracture fragments together, reducing
the gap (G) between the bone segments 14.
[0030] In FIGS. 9 to 12, the device 10 is cannulated, having a
central lumen or throughbore 20 extending through it, to assist in
the placement of the device 10 within bone.
[0031] In use, the physician can insert a conventional guide pin 22
through the bone segments 14 by conventional methods, as FIG. 9
shows. A cannulated drill bit 24 can then be introduced over the
guide pin 22, as seen in FIG. 10. A single or multiple drill bits
24 can be employed to drill through bone fragments or bone surfaces
to create a bore 26 of the desired size and configuration. In the
illustrated embodiment, the drill bit 24 is sized and configured to
create a conical bore 26 similar in size and configuration to the
device 10. The bore 26 is desirably sized and configured to permit
tight engagement of the device 10 within the bore 26 and thereby
restrict movement of the device 10 within the bore 26. The
pre-formed bore 26 may be slightly smaller than the device 10,
while still allowing the device 10 to be secured into position
within the bore 26 by tapping. As seen in FIG. 11, the drill bit 24
is then withdrawn. The device 10 is then inserted into the bore 26
over the guide pin 22, as FIG. 12 shows. The guide pin 22 is then
withdrawn.
[0032] Alternatively, the device 10 itself can include screw-like
threads along the body for screwing the device into place. In the
arrangement, the device 10 be self-tapping. Also in this
arrangement, the device 10 can be cannulated for use with a guide
pin 22, or it need not be cannulated.
[0033] Multiple devices 10 may be employed to provide additional
stabilization. While the use of multiple devices 10 will now be
described illustrating the use of multiple devices 10 of the same
size and configuration, it is contemplated that the devices 10 may
also be of different size and/or configuration, e.g., one device 10
is of a cylindrical configuration and a second device 10 is of a
conical configuration.
[0034] In many cases, it may be desirable to couple a series of
devices 10 together, e.g., to provide stabilization over a larger
surface area. A series of devices 10 may be coupled together be any
suitable means, e.g., by a snap fit engagement or a groove and tab
key arrangement. In one embodiment, a series of devices 10 are
coupled by threaded engagement. As illustrated in FIG. 13, a first
device 10A includes a recess 28 at one end providing a series of
internal threads 30. In the illustrated embodiment, the first
device 10 is of a cylindrical configuration, but may be of any
desired configuration. The internal threads 30 couple with a series
of complementary external threads 32 on a second device 10B of a
similar or of a different configuration to couple the first and
second devices 10A and 10B together.
[0035] The devices 10A and 10B are desirably coupled together prior
to being inserted into the pre-formed bore 26. The series of
internal and external threads 30 and 32 provide an interlocking
mechanism that permits a series of devices 10 to be stacked and
connected to cover a larger area or multiple bone segments 14
(e.g., a bone having multiple fractures) and thereby provides
additional stabilization, as seen in FIG. 14.
[0036] FIG. 15 illustrates another embodiment in which a device 10'
includes an opening or fenestration 34 to allow another device 10
to pass through, thereby providing additional stabilization. The
fenestration 34 can be sized and configured to permit another
device 10 to be passed through the device 10' at virtually any
angle. The fenestration 34 can also be sized and configured to
limit movement of the second device 10 relative to the second
device 10'.
[0037] In use, and as shown in FIG. 16, the physician taps a first
device 10' having a fenestration 34 through the bone segments. A
second device 10 is then inserted (e.g., by tapping) through the
fenestration 34 of the first device 10' into place.
[0038] It is further contemplated that device 10' may also be
adapted for coupling with another device 10A (e.g., by a series of
external and internal threads), permitting the devices 10' and 10A
to be additionally stacked and connected, as also shown in FIG.
16.
[0039] The foregoing is considered as illustrative only of the
principles of the invention. Furthermore, since numerous
modifications and changes will readily occur to those skilled in
the art, it is not desired to limit the invention to the exact
construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without
departing from the invention, which is defined by the claims.
* * * * *