U.S. patent application number 10/841354 was filed with the patent office on 2004-12-23 for internal brace for distraction arthroplasty.
Invention is credited to Manspeizer, Sheldon.
Application Number | 20040260302 10/841354 |
Document ID | / |
Family ID | 33519444 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040260302 |
Kind Code |
A1 |
Manspeizer, Sheldon |
December 23, 2004 |
Internal brace for distraction arthroplasty
Abstract
An internal brace for distraction arthroplasty includes femoral
and tibial components which can be fixed to a patient's femur and
tibia and which in combination distract or separate the knee joint
without substantially hindering mobility of the knee.
Inventors: |
Manspeizer, Sheldon; (White
Plains, NY) |
Correspondence
Address: |
DARBY & DARBY P.C.
P. O. BOX 5257
NEW YORK
NY
10150-5257
US
|
Family ID: |
33519444 |
Appl. No.: |
10/841354 |
Filed: |
May 7, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60480090 |
Jun 19, 2003 |
|
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Current U.S.
Class: |
606/90 ; 602/26;
623/20.31; 623/23.39 |
Current CPC
Class: |
A61B 2017/567 20130101;
A61F 2/3836 20130101; A61F 2002/3895 20130101; A61B 2017/0268
20130101 |
Class at
Publication: |
606/090 ;
623/020.31; 623/023.39; 602/026 |
International
Class: |
A61F 005/042; A61F
002/38 |
Claims
1. An internal brace for distraction arthroplasty, comprising a
femoral component for attachment to the distal end of a patient's
femur, said femoral component including a condylar protrusion
having a rounded bottom surface, a tibial component for attachment
to the proximal end of a patient's tibia, said tibial component
including an upper tray for engaging the bottom of said condylar
protrusion so as to enable relative rotation between the two
components, and means for attaching the femoral component to the
patient's femur and the tibial component to the patient's tibia
with the undersurface of the condylar protrusion engaging the upper
surface of said tibial tray, said protrusion and tray positioned in
the joint between the femur and tibia and functioning to distract
the joint.
2. An internal brace according to claim 1, wherein said condylar
protrusions and upper tray in combination form a ledge for
distracting said joint.
3. An internal brace according to claim 2, wherein said femoral and
tibial components are attached to the medial side of the patient's
knee with the wedge formed by said condylar protrusion and tibial
tray adapted to fit into the meniscal space in the patient's medial
joint.
Description
[0001] This invention relates to a brace for use with patients
suffering from osteoarthritis in the knee. More particularly, the
invention relates to an internal brace which can be fixed to a
patient's femur and tibia and which distracts or separates the knee
joint without substantially hindering mobility of the knee.
BACKGROUND OF THE INVENTION
[0002] The main radiological finding of a unicompartment
osteoarthritis of the knee is the loss or decrease in the articular
cartilage space. The secondary findings are spur formation and/or
synovitis of the knee. The articular cartilage that is lost in the
knee generally occurs in either one of two ways; first in the
medial joint and then extending to the patellofemoral joint and
eventually to the lateral joint. When this situation occurs the
patient has a varus deformity of the knee. The other situation that
occurs is a loss of the lateral joint articular cartilage
initially, then loss of the patellofemoral cartilage space, and
eventually, loss of the medial joint compartment space. In this
situation one has a valgus deformity of the knee. Present also in a
primary osteoarthritis or unicompartment arthritis of the knee is
loss of the meniscal space due to an extrusion of the meniscus
and/or tears of the meniscus. In other words, generally there is a
primary loss of the articular cartilage followed by secondary
degenerative changes of the menisci.
[0003] The other situations that can occur are a primary tear of
the lateral meniscus which can lead to lateral joint arthritis, or
tear of the medial meniscus leading to secondary osteoarthritis of
the medial joint. The latter situation often occurs in traumatic
injuries in young people who later on develop osteoarthritis of the
knee. In both situations, the end result is that there is a loss or
decrease in either the medial or lateral joint space with
associated tearing or extrusion of the medial meniscus or lateral
meniscus.
[0004] There are ways to prevent or treat the collapse of the
medial and lateral joint. The present techniques include a
unispacer, a unicompartment knee replacement, a meniscal transplant
or allograft, a high tibial osteotomy, and/or an unloading external
brace. All of these techniques seek to prevent further collapse of
the medial and lateral joints, i.e., they provide for decompression
of the medial and lateral joints. All of these methods except for
bracing have limitations in that they do not encourage
replenishment or regeneration of the articular cartilage but rather
replace the surface of the articular cartilage.
[0005] An object of the invention is to provide an internal brace
for the medial and/or lateral joint of the knee which will prevent
this process from progressing.
[0006] Another object is to provide an internal knee brace which
will provide for decompression of the medial and/or lateral joints
without removing or replacing articular cartilage.
[0007] A still further object of the invention is to provide an
internal brace for a knee joint in which the adjacent joint
surfaces are forced apart in order to give the cartilage between
the surfaces a chance to regenerate.
SUMMARY OF THE INVENTION
[0008] An internal brace of the knee must provide for the rolling
motion of the knee, the rotational motion of the knee, and the
sagittal plane motion of the knee for flexion and extension. The
knee joint includes a meniscal space that forms a triangular shape
along the anterior, posterior, lateral and medial aspect of the
knee. The invention provides an implantable brace for use in a knee
joint which functions as a wedge in this meniscal space to distract
or pry open the joint where there has been unicompartment
articulate cartilage narrowing, while enabling motion of the knee
both in anterior and posterior rolling motions, and providing for
rotational and sagittal plane motion.
THE DRAWINGS
[0009] FIG. 1 is a side sectional view along the line 1-1 of FIG. 2
showing the femoral and tibial components of a brace in accordance
with the invention;
[0010] FIG. 2 is a front view of the brace;
[0011] FIG. 3 is a front view of a knee joint showing the brace
installed in the medial joint; and
[0012] FIG. 4 is a side view of the knee joint shown in FIG. 3.
DETAILED DESCRIPTION
[0013] A brace according to the invention comprises a femoral
component 10 and a tibial component 12. The femoral component 10
includes an elongated stem 14 and a condylar protrusion 16 which
has a convex lower surface 18.
[0014] The tibial component 12 includes a stem 20 and an upper tray
22 which includes a concave upper surface 24 to receive the mating
concave lower surface 18 of the condylar protrusion 16 when the
brace is installed. Each component includes holes 26 for attachment
to the knee by means of screws.
[0015] Tray 22 of tibial component 12 is contoured to match the
contour of the tibial plateau whereas the curvature of the condylar
protrusion 16 of femoral component 10 should conform to the
curvature of the condyle.
[0016] FIGS. 3 and 4 show the brace installed in the medial joint.
Portions of the patient's femur 30 and tibia 32 are removed to
receive the stems 14 and 20, respectively. The brace components 10
and 12 are secured by screw fixation underneath the medial
collateral ligament (not shown). When installed, the condylar
protrusion 16 and tibial tray 22 form a wedge that fits into the
triangular meniscal space in the medial joint thereby separating
the femur and tibia, with the separation dependent on the thickness
of the two components. Because of the complementary curvatures of
the engaging surfaces of the condylar protrusion 16 and tibial tray
22, installment of the brace will not impede normal movement of the
knee.
[0017] The brace may be installed on either the medial or lateral
side and serves to distract or decompress a diminished knee
compartment of either the medial or lateral joint. In either case,
the collateral ligament (medial or lateral) is preserved in
introducing the brace to the knee joint.
[0018] Enforcement of the brace may require excision of the medial
portion of the meniscus or placement of the brace above the
meniscal surface. The same type of incision that is used in a
unicompartment can be used for insertion of the brace. At the time
of surgery, any narrowing of the joint can be determined
radiologicaly and restoration of the joint space can be affirmed by
means of X-rays. It is possible that decompression of the medial or
lateral joint may result in increased compression on the opposite
joint, in which case the use of a brace on both sides of the joint
may be indicated.
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