JP2002017759A - Artificial joint socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a period required for an artificial joint replacing surgery by certainly fixing an artificial joint socket to a bone, improving handling of the artificial joint socket, and simplifying a procedure of mounting the socket on the bone. SOLUTION: A socket body 12 of the artificial joint socket is joined to the bone using a fixing tool, and a peg 22 of which one end is inserted into the bone and the other end is engaged with the socket body 12 prevents rotation of the socket body 12 with respect to the bone. A peg through hole is formed in the socket body 12, one end of the peg 22 is inserted into the peg through hole, and then the other end of the peg 22 is deformed, thereby locking the other end of the peg 22 with the peg through hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial joint socket used in artificial joint replacement.

[0002]

2. Description of the Related Art In artificial joint replacement surgery, a joint having a concave surface and an artificial bone head having a convex surface are used to replace a joint part to perform a joint function. For example, in hip arthroplasty, a hemispherical dome-shaped acetabular socket is fixed to the acetabulum of the hip with bone cement or bone screws and has a concave inner surface inside the acetabular socket. The fitted liner is fitted and fixed. And
A prosthetic head of a stem embedded in the femur is rotatably inserted into the concave inner surface of the liner to perform the function of a hip joint.

However, when there are many bone defects at the concave epiphysis to which the acetabular socket is fixed, the contact area between the concave epiphyseal side bone and the acetabular socket is reduced. Bone fragments are packed in the defect, fixed with screws and fixed, and then mounted with an acetabular socket, or after filling the defect with bone cement, the acetabular socket is mounted on the bone .

[0004] However, in the case of packing bone fragments, especially in a joint where a large load acts like a hip joint,
There may be a problem that the mounting angle of the acetabular socket changes and the dislocation becomes easy. As one measure to solve this problem, Japanese Patent Application Laid-Open No. 2000-116667 discloses that a large lag screw capable of sufficiently withstanding a load is inserted and fixed in the iliac bone, and a socket is connected to the lag screw, so that the acetabular itself can be used. An acetabular socket is disclosed that is unloaded.

[0005]

The above-mentioned Japanese Unexamined Patent Application Publication No.
In the acetabular socket disclosed in 000-116667, an ischial peg is used to prevent the dome-shaped socket body fixed to the shaft of the lag screw from rotating around the lag screw. The ischial peg is arranged at the ischial part of the hip bone, and has a width or thickness larger than that of a long hole provided in the socket body for engaging the ischial peg with the socket body.
Therefore, when installing the acetabular socket, first screw the lag screw into the iliac part of the hip bone,
At a predetermined angle, an ischial peg is inserted and arranged at a site of the ischia where an elongated hole is expected to be located when the socket body is attached to the lag screw. Next, after the socket body is attached to the lag screw, one end of the wire is inserted into the long hole of the socket body and the screw hole that extends through the end of the ischial peg and is screwed with the mounting screw, and is inserted into the ischial portion. Fixed, and
The other end of the wire is inserted into a through hole extending through the mounting screw. Then, the mounting screw is guided to the screw hole of the ischial peg using the wire as a guide, and screwed into the screw hole.

Therefore, there is a problem that the installation of the acetabular socket is troublesome and takes a long time. In addition, it is not easy to match the position of the long hole when the socket body is actually attached to the lag screw with the position of the ischial pegs previously inserted and arranged in the ischial portion,
There is a tendency for the problem of misalignment to occur. Therefore, an object of the present invention is to solve the above-mentioned problems in the prior art,
Achieved a strong fixation of the prosthesis socket used in the prosthesis replacement to the bone, and at the same time, improved the handling of the prosthesis socket and simplified the procedure for attaching the socket to the bone. The purpose is to reduce the time required.

[0007]

SUMMARY OF THE INVENTION In view of the above objects, the present invention provides a method for connecting a socket body to a bone using a fixture, and using a peg having one end inserted into the bone and the other end engaged with the socket body. In an artificial joint socket in which the socket body is prevented from rotating with respect to the bone, a peg insertion hole is formed in the socket body, and one end of the peg is inserted into the peg insertion hole, and then the other end of the peg is An artificial joint socket having a configuration in which the other end of the peg is locked in the peg insertion hole by being deformed.

[0008] In the artificial joint socket of the present invention, preferably, the fixing tool is a lag screw fixed to the bone in advance and connected to the socket body by a connecting member. Preferably, the other end of the peg is divided into two halves by slits, and the other end of the peg is locked in the peg insertion hole by expanding each of the halves. More preferably, the state where the other end of the peg is expanded is maintained by screwing a mounting screw into the slit provided at the other end of the peg.

By adopting this configuration, a fixing tool such as a lag screw is screwed into the bone in advance and fixed, and then the socket main body is connected to the fixing tool to fix the socket main body to the bone. After the peg penetrates the bone through the peg insertion hole, a procedure for locking the peg to the socket body becomes possible.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following, the present invention is described using an example of an artificial joint used in femoral replacement surgery, but this is for the purpose of explanation, and the present invention is limited to an artificial joint socket for a femur. It is not something to be done.

FIG. 1 is a view showing a state of use of an acetabular socket which is one embodiment of the artificial joint socket of the present invention. 2 is a view showing a socket body of the acetabular socket shown in FIG. 1, (a) is a top view,
(B) is a side view, (c) is a view on arrow Z of (b), and (d) is a cross-sectional view taken along line dd of the figure shown in (a).

Referring to FIG. 1, an acetabular socket 10 according to the present invention includes a socket body 12, a lag screw 18 which is a fixture fixed to an iliac portion 16 of a hip bone 14, a socket body 12 and a lag screw 18 And an ischial peg 22 attached to the socket body 12 and inserted into the ischial portion 20 of the hip bone 14. The socket body 12 has a dome shape and has a concave inner surface. The socket body 12 is formed of a material having excellent biocompatibility such as stainless steel, titanium alloy, pure titanium, and cobalt chrome alloy. A resin liner (not shown) further having a concave inner surface is fitted and fixed inside the socket body 12, and the acetabular socket 1
An artificial bone head is inserted into this inner surface so as to be freely rotatable.

As shown in FIG. 2, it is preferable that a rotation stopping projection 24 for preventing the liner from rotating in the socket main body 12 is formed on the peripheral edge of the socket main body 12. Preferably, a plurality of grooves 26 are formed on the outer surface of the socket body 12, as shown in FIGS. 2 (a) and 2 (b). In addition, in the case of the acetabular socket 10 shown in FIG.
2 is formed in a dome shape. This is for adapting to the shape of the hip joint to be replaced. In the case of an artificial joint for replacing another joint, it is not always necessary to take the dome shape. The main body 12 or a resin liner (not shown) fitted and fixed to the main body 12 may have a concave inner surface.

A connecting member for connecting the socket body 12 and a lag screw 18 previously fixed to the iliac portion 16 of the hip bone 14 is, as shown in FIGS. 1 and 2,
It can be formed as a boss 30 extending outward from the socket body 12. The boss 30, ie, the connecting member,
It may be formed integrally with the socket main body 12, or may be formed separately and screwed to the socket main body 12, as shown in FIG. The boss 30 is further formed with a square hole (hexagonal hole 32 in FIG. 2) for fitting into the shaft portion 18a of the lag screw 18 and a screw hole 34 for screwing the lock member.

FIGS. 2A to 2C show the socket body 12.
As shown in detail in (d), a plurality of stepped holes 36 for screwing, a peg insertion hole 38 for inserting and locking the ischial peg 22, a flange 40, and a clip groove 42 are formed. Further formed. A peg insertion hole 38 provided in the socket body 12 for inserting and locking the ischial peg.
Has a long hole shape in order to increase the degree of freedom of the mounting position of the ischial peg 22, and extends in parallel with the peripheral edge of the socket body 12. In addition, at the edge of the peg insertion hole, FIG.
As shown in (d), a convex ridge 44 is formed for engagement with the end of the ischial peg. The convex ridge 44 preferably has a chamfered engagement surface 44a.

As shown in FIG. 2, the flange 40 extends over substantially half of the periphery of the socket body 12 as shown in FIG.
It extends substantially upward at (b). The clip groove 42 is formed along the entire peripheral edge in parallel with the end surface of the socket body 12, and a notch 46 for clip attachment and detachment is further formed as shown in FIG. I have.

FIG. 3 shows a locking member 48 used in the acetabular socket 10 shown in FIG.
(A) is a front view, (b) is a side view. Referring to FIG. 3, the lock member 48 has a disk shape, and has a thread 50 formed on an outer periphery thereof, and is screwed into the screw hole 34 for screwing the lock member shown in FIG. Combine. In the center of one end of the lock member 48, a groove or square hole (hexagonal hole 52 in the figure) for driver engagement is formed. Note that the lock member 48 is preferably formed of the same material as the socket body 12.

FIG. 4 shows the ischial pegs 22 used in the acetabular socket 10 shown in FIG.
(A) is a side view, (b) is a view as viewed from an arrow X in (a), and (c) is a view as viewed from an arrow Y in (a). FIG. 5 is a side view showing the ischial peg 22 in a form reduced in the width direction. Referring to FIG. 4, the ischial pegs 22 are bent in a U-shape, and have a width (vertical direction in FIG. 4 (c)) compared to a thickness (vertical direction in FIG. 4 (c)). Are large and plate-shaped. The ischial peg 22 further includes a peg body 54 that can be inserted into one end of the ischial peg 22, that is, the peg insertion hole 38.
And a peg base 56 at the other end of the ischial peg 22. In the ischial peg 22 shown in FIG.
It is divided into a peg body 54 and a peg base 56 with a bent portion 58 of the U-shape as a boundary. The peg base 56 has a first form that can pass through the peg insertion hole 38 and the peg insertion hole 38.
, And can be deformed into both forms of the second form. The ischial pegs 22 are preferably formed from the same material as the socket body 12.

In order to realize the peg base 56 which can be deformed into the first and second forms as described above, the peg base 56 shown in FIG. . With this configuration,
As shown in FIG. 5, the peg base 56 can pass through the peg insertion hole 38 by deforming the peg base 56, ie, the peg base half 56a, into a reduced position closed inward as shown in FIG. By taking the first configuration, each of the peg base halves 56a is deformed to the expanded position in which the peg base half 56a is expanded outward, so that the second configuration in which the peg base half 56a can be locked in the peg insertion hole 38 can be obtained.

The two-part peg base 56 is formed so as to have resiliency (that is, is elastically deformable), and each of the peg base halves 56a is biased to the expanded position. Preferably, it will only be deformed to a reduced position as shown in FIG. 5 only by applying a physical force. A substantially V-shaped groove 62 as well shown in FIG. 4A is formed on the peripheral surface of the end of the peg base 56.
Are formed, and can be engaged with a convex ridge 44 formed at the peripheral edge of the peg insertion hole 38. Sciatic pegs 2
When the 2 is in the second form, the convex ridge 44 at the edge of the peg insertion hole 38 and the V-shaped groove 62 of the peg base 56 are engaged,
The ischial peg 22 is locked to the socket body 12.

The inclined surface of the V-shaped groove 62 of the peg base 56 further corresponds to the engagement surface 44a of the convex ridge 44 of the peg insertion hole 38 as shown in FIG. It preferably has a chamfered engagement surface 62a. The peg base 56 is further provided with a screw hole 66 into which a mounting screw 64 described later is screwed. The screw hole 66 is preferably formed obliquely so as to penetrate from the end face to the lower face.
In the case of the ischial peg 22 shown in FIG. 4 in which the peg base 56 is divided into two, the screw holes 66
4 are screwed together so that each of the peg base halves 56a is maintained in an expanded state.

FIG. 6 is a view showing an attachment screw 64 for attaching the ischial peg 22 to the peg insertion hole 38 of the socket body 12 of the acetabular socket 10 shown in FIG.
(A) is a side view, (b) is a Z arrow view of (a). Referring to FIG. 6, the mounting screw 64 has a groove 68 or a square hole (a hexagonal hole 70 in the figure) for driver engagement formed on the head 68, and a guide portion 64a from which a thread is removed is formed at the tip. Have been. Further, the mounting screws 6 shown in FIG.
4 is further formed with a through hole 74 for inserting a guide wire extending therethrough in the axial direction. This mounting screw 64
It is also preferably formed from the same material as the socket body 12.

FIGS. 7A and 7B show the hold cap 76 of the acetabular socket 10 shown in FIG. 1, wherein FIG. 7A is a front view and FIG. 7B is a side view. Referring to FIG. 7, the hold cap 76 has a substantially cylindrical shape, and has a stepped hole 36 for screwing the socket body 12 at one end thereof (FIG. 2).
(See (d))), a flange 76a is formed to be locked to the step portion,
The other end has a claw portion 76 elasticized by a cross groove 76b.
c is formed.

The acetabular socket 10 thus configured
Will be described below mainly with reference to FIG. First, a prepared hole is drilled at a predetermined angle in the iliac portion 16 of the hip bone 14 at a predetermined angle, and a lag screw 18 having a screw portion 18b formed at one end and a shaft portion 18a having a hexagonal cross section at the other end is placed under the lower hole. Screw into the hole and fix. The other end of the lag screw 18 is provided with a screw hole 78 extending inside the lag screw 18 in the axial direction.

Next, the hexagonal hole 32 of the boss 30 of the socket body 12 is fitted into the hexagonal section 18a of the lag screw 18 and the socket body 12 is arranged so that the flange 40 is engaged with the iliac end. I do. Then, the socket body 12
A screw 80 is screwed into a screw hole 78 provided at the other end of the lag screw 18 through the hexagonal hole 32 of the boss 30 from inside. After the screw 80 is screwed until the head of the screw 80 contacts the end of the hexagonal hole 32, the screw hole 34 of the boss 30 is further inserted.
The screw 36 is locked by screwing the lock member 48 into the boss 30 and holding the head of the screw 36 between the hexagonal hole 32 of the boss 30 and the lock member 48. Thus, the socket body 12
Is fixed at a predetermined position by the lag screw 18 and the lock member 48. If there is a defect in the bone, the bone is repaired with a filling member 28 (bone fragment, bone cement, etc.).

Next, one end of the ischial peg 22 (that is, the peg base 56) is deformed to a reduced position as shown in FIG. Is inserted into the peg insertion hole 38 from the inside of the socket body 12 while maintaining the first configuration, and penetrates into the ischial portion 20 of the hip bone 14 while maintaining the first configuration. Let it. The V-shaped groove 62 of the peg base 56 is formed by the convex protrusion 4 of the peg insertion hole 38.
When it reaches 4, the peg base half 56 is divided into two
a, the peg base 56 is deformed into a second form that can be locked in the peg insertion hole 38, and the V-shaped groove 62 of the peg base 56 and the convex shape of the peg insertion hole 38 are deformed. The protrusion 44 is engaged.

Finally, the peg insertion hole 3 of the socket body 12
8 and the screw hole 66 of the sciatic peg 22, and one end of the guide wire 82 is fixed to the sciatic portion 20.
Is inserted through the through hole 74 of the mounting screw 64. Then, the mounting screw 64 is guided to the screw hole 66 of the ischial peg 22 by using the guide wire 82 as a guide, and the mounting screw 64 is screwed into the screw hole 6.
Screw into 6.

The mounting screw 64 is provided in the slit 6 of the peg base 56.
By being screwed into the screw hole 66 provided along 0, a force for expanding each of the two divided peg base halves 56a outward acts, and the twisting of the socket body 12 and the ischial peg 22 is performed. Secure locking is achieved. Further, due to the strong engagement between the convex ridge 44 and the V-shaped groove 62, the engagement surface 62 a of the V-shaped groove 62 is changed to the engagement surface 4 of the convex ridge 44.
By conforming to 4a, even if the insertion angle of the ischial peg 22 with respect to the peg insertion hole 38 is slightly different, the mounting angle is corrected to an appropriate mounting angle.

The guide wire 82 is pulled out and removed after the attachment of the attachment screw 64 is completed. Further, if necessary, the socket body 12 is fixed to the bone by a bone screw using the stepped hole 36 for screwing of the socket body 12.
A hold cap 76 is inserted into the unused stepped hole 36 for screwing. Thereafter, a liner (not shown) is fitted into the socket body 12, and a clip is fitted into the grip groove 42 to fix the liner.

With reference now to the embodiment of the acetabular socket 10 provided with the ischial peg 22 provided with a V-shaped groove 62 at the end and including a split and expandable peg base 56, Although the artificial joint socket of the present invention has been described, artificial joint sockets using other types of pegs are possible.

[0031]

According to the artificial joint socket of the present invention, after the socket body is connected to the bone using a fixing tool such as a lag screw, the peg is penetrated into the bone from the inside of the socket body through the peg insertion hole. The peg can be locked to the socket body from above. Therefore, the artificial joint socket can be securely fixed to the bone using the fixing tool and the peg, and at the same time, the operation of attaching the artificial joint socket to the bone is easier compared to the conventional artificial joint socket,
The operation time required for joint replacement can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a use state of an acetabular socket according to the present invention.

FIGS. 2A and 2B are views showing a socket body of the acetabular socket shown in FIG. 1, wherein FIG. 2A is a top view, FIG.
(C) is a view on arrow Z, and (d) is a line d in the view shown in (a).
It is sectional drawing in -d.

3 shows a locking member used in the acetabular socket shown in FIG. 1, wherein (a) is a front view and (b)
Is a side view.

FIGS. 4A and 4B are views showing ischial pegs used in the acetabular socket shown in FIG. 1, wherein FIG. 4A is a side view, FIG. FIG. 3 is a view as viewed from the direction of the arrow Y in FIG.

FIG. 5 is a side view showing a state in which a peg base of the ischial peg shown in FIG. 4 is closed.

FIGS. 6A and 6B are views showing mounting screws for mounting an ischial peg in a peg insertion hole of the socket body of the acetabular socket shown in FIG. 1, wherein FIG. 6A is a side view and FIG. FIG.

7A and 7B are views showing a hold cap of the acetabular socket shown in FIG. 1, wherein FIG. 7A is a front view and FIG. 7B is a side view.

[Explanation of symbols]

 10 acetabular socket 12 ... socket body 18 ... lag screw 22 ... peg 38 ... peg insertion hole

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norio Nakamura 4-11 Kasugaoka, Suita-shi, Osaka 4-302 Senri Kasugadai Danchi 4-302 (72) Inventor Koji Sakai 6-3-15, Nakamikunioka-cho, Sakai-shi, Osaka (72) Inventor Keiji Haraguchi 5-2-25 Segawa, Minoh-shi, Osaka (72) Inventor Shunsaku Nishihara 4-27-33, Higashi-Onohara, Minoh-shi, Osaka (72) Inventor Keisuke Hagio 1--1, Saidera, Suita-shi, Osaka 3-11-203 (72) Inventor Yuki Kishida 2-13-20-205, Kazumi Kazumi, Ibaraki-shi, Osaka (72) Inventor Kazuaki Kato 1402-3, Sano, Susono-shi, Shizuoka F-term (reference) 4C097 AA06 BB04 CC05 SC06

Claims (4)

[Claims] The socket body is connected to the bone using a fastener, and the socket body is prevented from rotating with respect to the bone by a peg having one end inserted into the bone and the other end engaged with the socket body. In the artificial joint socket, a peg insertion hole is formed in the socket body, and one end of the peg is inserted into the peg insertion hole, and then the other end of the peg is deformed by inserting the other end of the peg into the peg insertion hole. An artificial joint socket which is locked in a hole. 2. The artificial joint socket according to claim 1, wherein the fixture is a lag screw which is fixed to a bone in advance and is connected to the socket body by a connecting member. 3. The other end of the peg is divided into two halves by a slit, and the other end of the peg is locked in the peg insertion hole by expanding each of the halves. Or the artificial joint socket according to claim 2. 4. The artificial joint socket according to claim 3, wherein a mounting screw is screwed into the slit provided at the other end of the peg to maintain a state where the other end of the peg is expanded. .