Surgery – Instruments – Orthopedic instrumentation
Reexamination Certificate
2000-06-30
2001-05-01
Recla, Henry J. (Department: 3731)
Surgery
Instruments
Orthopedic instrumentation
C606S060000
Reexamination Certificate
active
06224606
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a bone jointer in order to carry out junction, for example, of a fractured part at a neck of femur. More particularly, the present invention relates to that in which junction of the bone may be carried out corresponding to various types of fracture by easily obtaining the strong fixed state.
The present invention also relates to a bone jointer fixing tool used when the bone jointer is used in order to carry out junction, for example, of a fractured part of the neck of femur. More particularly, the present invention also relates to that in which the bone jointer may easily and accurately be fixed corresponding to various types of fracture.
2. Description of the Related Art
There is an example of bone jointer disclosed in the prior art, such as the Japanese utility model registration No. 3044923, which is owned by the applicant of the present invention, as illustrated in FIG.
20
.
FIG. 20
illustrates the state of fracture at a neck
300
a
of a femur
300
, as well as the structure of a bone jointer in order to carry out junction of such a fracture part, which is shown by letter A.
There is a tube plate
301
placed along the side of the femur
300
. A hemispherical shape of receiver
303
is formed at the top of the tube plate
301
as shown in FIG.
20
. The receiver
303
has a penetration hole
305
.
A hole is formed in the femur
300
, through which a tube
307
is placed, thus the tube
307
is positioned inside the receiver
303
. The tube
307
has a hemispherical shape of head
309
and is movably engaged with the receiver
303
via the head
309
. The tube
307
has a hollow part
311
, and an internal thread
313
is formed on the inner periphery of the head
309
. The receiver
303
has a matt (i.e. slightly rough or sandy) surface, and the same is true to the surface of the head
309
. Accordingly, when the head
309
is received by the receiver
303
, a large frictional force as well as a large fixing force may be obtained.
There is a lag screw
315
provided with a shaft
317
of which cross sectional shape is hexagon. The shaft
317
has an external thread
319
formed at the top thereof, and also has an internal thread
320
formed on the inner periphery of the basement (that is, the lower side of
FIG. 20
) thereof. With this structure, a hole has been formed in advance from the femur
300
toward a bone head
300
b,
and the lag screw
315
is inserted in this hole. Then the lag screw
315
becomes engaged with an internal thread provided on the hole of the bone head
300
b.
There is also a set screw
321
provided on the outer periphery of the receiver
303
of the tube plate
301
. The set screw
321
has an external thread
323
which is to be engaged with the internal thread
313
of the tube
307
. The compression screw
325
has an external thread
327
to be engaged with the internal thread
320
of the lag screw
315
.
Further, the tube plate
301
has a plurality of penetration holes
331
through which the cortical bone screws
329
each serving as the fixing screw may respectively be penetrated. The tube plate
301
also has another penetration hole
335
into which a canulated screw
333
may be penetrated.
According to this structure, when there is a fracture at the neck
300
a
of the femur
300
, for example, a predetermined depth of hole is first drilled from the femur
300
toward the bone head
300
b,
then the internal thread is cut in the bone head
300
b.
After that, the lag screw
315
is inserted to be engaged with the cut internal thread of the bone head
300
b,
and the tube
307
is also inserted therein. In such a state, the basement of the lag screw
315
is inserted in the hollow part
311
inside the tube
307
.
The tube plate
301
has been placed along the side of the femur
300
, and the set screw
321
is inserted in the penetration hole
305
of the receiver
303
of the tube plate
301
. Thus the set screw
321
is engaged with the internal thread
313
of the head
309
of the tube
307
in order to fix the tube
307
on the tube plate
301
. Then the compression screw
325
is inserted in the set screw
321
, so that the compression screw
325
may be engaged with the internal thread
320
provided inside the basement of the lag screw
315
. Accordingly, the lag screw
315
, as well as the bone head
300
b,
will be drew toward the femur
300
in order to apply the pressure to the fracture part A. Then the plurality of the cortical bone screws
329
and the canulated screw
333
are screwed into the femur
300
from the outside of the tube plate
301
in order to fix the fracture part.
However, the prior art has the following disadvantageous point.
According to the prior art as above discussed, both the head
309
of the tube
307
and the receiver
303
of the tube plate
301
are hemispherical shapes, so that the tube
307
may move in all directions relative to the tube plate
301
, in order to cope with any directional force of the tube
307
as well as the lag screw
315
applied to the tube plate
301
.
However, the connection of the set screw
321
to the tube
307
is difficult, and even after the set screw
321
has been connected to the tube
307
, there may occur another problem of the improper positioning due to a clearance between the set screw
321
and the penetration hole
305
of the tube plate
301
. This will cause the inaccurate positioning as well as the weakened fixing force.
Further, when this type of bone jointer is fixed, there has been a demand that the fixing of the jointer should be carried out easily and more accurately.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a bone jointer by which a facile junction of the bone is accomplished, and the accurate positioning with the strong fixing force is surely be obtained.
Further, it is also an object of the present invention to provide a bone jointer fixing tool by which the facile fixing of the bone jointer can be accomplished.
To achieve the object mentioned above, according to claim
1
of the present invention, there is provided a bone jointer comprising, a lag screw inserted from a bone at one side as an object of junction and is engaged with a bone at the other side; a tube plate placed along the bone at one side and provided with a receiving part having a penetration hole; a tube positioned between the lag screw and the tube plate, into which a base of the lag screw is inserted, and provided with a head with which an inner periphery of the receiving part of the tube plate is movably engaged; a set screw inserted from outside of the tube plate and engaged with an inner periphery of the tube in order to fix the tube on the tube plate; a compression screw inserted from outside of the tube plate, penetrating inside the set screw, and engaged with the lag screw, thereby the lag screw as well as the bone on the other side are drew toward the bone at one end; and a washer inserted in a position between the set screw and an outer periphery of the receiving part of the tube plate, rotating during engagement of the set screw with the head of the tube, until the washer stops at a stablest position.
According to claim
2
, there is provided the bone jointer of claim
1
, wherein the washer having a penetration hole drilled at a deviated position from the center of a hemisphere shape of the washer, with a top of the hemisphere shape being cut away.
According to claim
3
, there is provided the bone jointer of claim
1
, wherein a rim of the penetration hole of the tube plate on the side of the washer is formed in an arc shape, and the rim on the side of the head of the tube is also formed in an arc shape, having a linear penetration part between the two rims in arc shapes, thereby contact of the washer with the head of the tube during setting is prevented.
According to claim
4
, there is provided the bone jointer of claim
1
, wherein a thread of the lag screw is sawlike shape having a tapping function.
According to claim
5
, there i
K. K. Hollyx
McGinn & Gibb PLLC
Ngo Lien
Recla Henry J.
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