U.S. patent application number 09/932485 was filed with the patent office on 2002-09-12 for acetabular bone plate.
Invention is credited to Haidukewych, George J..
Application Number | 20020128653 09/932485 |
Document ID | / |
Family ID | 26957151 |
Filed Date | 2002-09-12 |
United States Patent
Application |
20020128653 |
Kind Code |
A1 |
Haidukewych, George J. |
September 12, 2002 |
ACETABULAR BONE PLATE
Abstract
An acetabulum bone plate includes a central, support portion
which is shaped to cover the posterior wall of the acetabulum and a
pair of tabs which extend therefrom and attach to the pelvis.
Spikes formed on the underside of the central portion engage bone
fragments and fix them in place when fragment screws that extend
through openings in the central portion are tightened. The fragment
screws are angled away from the hip joint.
Inventors: |
Haidukewych, George J.;
(Rochester, MN) |
Correspondence
Address: |
QUARLES & BRADY LLP
411 E. WISCONSIN AVENUE
SUITE 2040
MILWAUKEE
WI
53202-4497
US
|
Family ID: |
26957151 |
Appl. No.: |
09/932485 |
Filed: |
August 17, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60274906 |
Mar 9, 2001 |
|
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Current U.S.
Class: |
606/286 ;
606/280; 606/298; 606/902; 606/907; 623/22.21 |
Current CPC
Class: |
Y10S 606/902 20130101;
Y10S 606/907 20130101; A61B 17/8066 20130101; A61B 17/8061
20130101 |
Class at
Publication: |
606/69 ;
623/22.21 |
International
Class: |
A61F 002/32; A61B
017/56 |
Claims
1. A bone plate for attachment to the acetabulum wall of a subject
which comprises: a support portion formed from metal and curved in
shape to wrap around a portion of the acetabulum wall, and having a
width sufficient to cover a posterior region of the acetabulum wall
extending substantially from its rim to its base; a pair of tabs
integrally formed with the support portion and extending from
opposite ends thereof, the tabs each having a width substantially
less than the width of the support portion and each having openings
for receiving bone screws that fasten the tabs to bone surface
adjacent the acetabulum wall; and wherein the support portion
includes openings for bone screws that fasten the support portion
to the acetabulum wall.
2. The bone plate as recited in claim 1 in which the openings in
the support portion are shaped to direct the bone screws therein
away from the hip joint defined by the acetabulum wall.
3. The bone plate as recited in claim 2 in which the screws passing
through the support portion are directed at an angle from
45.degree. to 60.degree. away from perpendicular.
4. The bone plate as recited in claim 1 in which the support
portion and the tabs are formed from titanium.
5. The bone plate as recited in claim 1 in which the support
portion has a substantially straight edge which is positioned along
the rim of the acetabulum wall, and a curved edge which is
positioned near the base of the acetabulum wall.
6. The bone plate as recited in claim 1 which includes spikes
integrally formed on the bottom surface of the support portion and
extending away therefrom to engage and penetrate the acetabulum
wall when the support portion is fastened in place.
7. The bone plate as recited in claim 6 which includes a plurality
of spikes located along an edge of the support portion which
extends along the ridge of the acetabulum wall.
8. The bone plate as recited in claim 7 in which the openings in
the support portion are shaped to direct the bone screws therein
away from the hip joint defined by the acetabulum wall.
9. The bone plate as recited in claim 8 in which the support
portion, tabs and spikes are formed from titanium.
Description
[0001] RELATED PATENT APPLICATIONS
[0002] This application is based on U.S. Provisional Application
Serial No. 60/274,906 filed on Mar. 9, 2001 and entitled
"Acetabular Bone Plate".
BACKGROUND OF THE INVENTION
[0003] The field of the invention is implantable plates which are
attached to damaged or diseased bones, and more particularly, to
bone plates attached to the surface of the pelvis.
[0004] A bone plate is a plate that is fastenable to the surface of
a bone to immobilize a fracture in the bone or to support and
stabilize a diseased region of the bone. The plate is typically
made of a surgical grade metal such as stainless steel or titanium
which has a very high tensile strength. The plate may be shaped to
fit the contour of specific bone surfaces as described in U.S. Pat.
No. 4,454,876; U.S. Pat. No.4,800,874; U.S. Pat. No. 5,904,684 and
U.S. Pat. No. 6,004,353, or the bone plate may be shaped by the
surgeon during the operation as described in U.S. Pat. No.
4,573,458; U.S. Pat. No. 5,746,742 and U.S. Pat. No. 5,785,712. The
bone plate is typically attached to the bone with screws that pass
through judiciously placed holes in the plate.
[0005] The acetabulum is a circular-shaped ridge, or wall, of bone
that defines a socket for receiving the semi-spherical head of the
femur to form the hip joint. The most common fracture of the
acetabulum is in its posterior wall. Multiple fractures forming
small wall fragments are often found, and these multiple bone
fragments must be fixed. This is currently done by cutting and
bending multiple bone plates to fix the multiple bone fragments in
place. This is a lengthy and challenging procedure for the surgeon.
In addition, because the acetabulum wall forms part of a working
joint, care must be taken when fastening each bone plate in place
that none of the screws pass into the joint itself and interfere
with joint operation.
SUMMARY OF THE INVENTION
[0006] The present invention is a bone plate which is shaped to fit
the surface of the posterior acetabulum wall for fixing fractures
therein. More particularly, the shaped bone plate includes a
central portion which is shaped to fit directly over the posterior
wall of the acetabulum and narrower tabs which extend in opposite
directions from the central portion. Openings are provided in the
central portion and the tabs for receiving mounting screws, and the
openings in the central portion are shaped to guide screws away
from the hip joint. Spikes are formed on the underside of the
central portion to engage and fix multiple bone fragments.
[0007] A general object of the invention is to provide a bone plate
which can be used to fix fractures of the posterior acetabulum
wall. The wide central portion of the bone plate provides support
in the fracture zone and the tabs hold it firmly in place. Multiple
bone fragments are fixed to the bone plate by screws passing
through openings in the central portion and spikes on its
underside.
[0008] The foregoing and other objects and advantages of the
invention will appear from the following description. In the
description, reference is made to the accompanying drawings which
form a part hereof, and in which there is shown by way of
illustration a preferred embodiment of the invention. Such
embodiment does not necessarily represent the full scope of the
invention, however, and reference is made therefore to the claims
herein for interpreting the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a pictorial representation of the preferred
embodiment of a bone plate which practices the present invention
attached to the pelvis;
[0010] FIG. 2 is a top view of the bone plate in FIG. 4;
[0011] FIG. 3 is a side view of the bone plate in FIG. 1;
[0012] FIG. 4 is a view in cross-section through a central portion
of the bone plate of FIG. 1; and
[0013] FIG. 5 is a bottom view of the bone plate of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] Referring particularly to FIGS. 2 and 3, the acetabular bone
plate 5 is comprised of a central, support portion 10 disposed
between integrally formed tab portions 12 and 14. The bone plate 5
is preferably formed of a titanium alloy to allow postoperative MR
imaging of the joint. Stainless steel may also be used, but this
limits the use of subsequent MR imaging which may become necessary
to diagnose postoperative complications.
[0015] The support portion 10 of the bone plate 5 has a width that
is approximately twice the width of the tab portions 12 and 14. It
is also about twice the width of currently available bone plates.
As shown best in FIG. 3, the support portion 10 is curved to wrap
around the circular-shaped posterior acetabulum wall. As shown best
in FIG. 1, the support portion 10 substantially covers the
posterior acetabulum wall 20, from its rim to its base. One tab
portion 12 is secured in place on the pelvis by up to three small
(i.e. 3.5 or 4.0 mm) fragment screws 22, and the other tab portion
14 is secured in place by up to three small fragment screws 24. The
tab portions 12 and 14 can be bent as needed by the physician to
fit the contour of the bone surface. The central, support portion
10 is thus firmly fixed in place to provide support for
substantially the entire posterior wall 20.
[0016] Bone fragments formed by fractures in the posterior
acetabulum wall are fixed to the bottom surface of the support
portion 10. This is achieved by a set of from one to three small
fragment screws 26 which pass through openings 28 in the support
portion 10 and into the underlying bone. As shown best in FIG. 4, a
buttress 27 is formed to one side of each opening 28 and the
openings 28 are formed at an angle of from 45.degree. to 60.degree.
from perpendicular. This enables the fragment screws 26 to be
inserted at an angle such that their ends extend away from the hip
joint preventing accidental joint penetration. The underside of
each screw head 30 engages the sloped surface of the buttress 27 to
securely tighten the central portion 10 against the bone surface
and fix bone fragments in place.
[0017] As shown best in FIGS. 3 and 5, a set of spikes 16 are
formed on the underside of the support portion 10. These spikes 16
pierce the underlying bone when the bone plate 5 is fastened in
place with screws 22, 24 and 26. They serve to fix to the support
portion 10 underlying bone fragments. In the preferred embodiment
three spikes 16 are formed along a straight edge 32 of the support
portion 10, which extends along the rim of the acetabulum wall.
These rim spikes 16 are very useful in fixing small comminuted and
small rim fractures. Another set of spikes 16 are located near the
opposite, curved edge 34 of the support portion 10. These spikes 16
engage near the base of the acetabulum. These spikes also prevent
displacement of the underlying fracture fragments when the screws
are tightened, driving the spikes into the underlying bone.
[0018] Referring particularly to FIG. 2, the acetabulum bone plate
5 is symmetrical about a central axis 36. As a result, the same
bone plate 5 can be used on either the right or left side of the
hip simply by rotating it 180.degree. such that the straight edge
32 aligns with the rim of the acetabulum wall.
[0019] The acetabular bone plate 5 facilitates the repair of
fractures. Because of its shape, a single bone plate 5 may be used
to fix multiple fragments. The support portion 10 is shaped and
sized to provide mechanical support for the entire posterior wall
of the acetabulum. The use of a single device to make such repairs
saves considerable operating time.
* * * * *