JP2022092413A - Artificial hip joint system - Google Patents

Abstract

To provide an artificial hip joint system that suppresses risks of an artificial condyle being dislocated from the acetabulum by taking the wrong postures.SOLUTION: The artificial hip joint system includes: an artificial condyle having a condyle part slidably engaging the acetabulum of the pelvis; and an artificial ligament unit connecting the condyle part to the acetabulum. The artificial ligament unit has: a bioabsorbable artificial ligament; a pelvis side fixture fixing one end part of the artificial ligament to the pelvis; and a condyle side fixture fixing the other end part of the artificial ligament to the condyle part. According to the artificial hip joint system, since the other end part of the artificial ligament is fixed to the condyle part and the one end part of the artificial ligament is fixed to the pelvis, the condyle part of the artificial condyle can be connected to the pelvis via the artificial ligament. Thus, it is possible to suppress separation of the condyle part from the pelvis and to reduce risks of dislocation of the condyle part from the acetabulum by excessive bending or the wrong posture of the artificial condyle with respect to the pelvis.SELECTED DRAWING: Figure 2

Description

The present invention relates to an artificial hip joint system that connects the acetabulum of the pelvis and the artificial head with an artificial ligament.

The hip joint of a normal person has a hemispherical depression on the pelvic side (“acetabulum”), a spherical protrusion at the top of the femur that fits the acetabulum (“femoral head”), and the soft part that surrounds them. It has a tissue (“joint capsule”) and a supporting tissue (“head ligament”) containing feeding vessels connecting the acetabulum and the femoral head. The joint movement of the hip joint is realized by the rotational movement of the femoral head in the acetabulum.

If the femoral neck is fractured or damaged due to a fall or impaired blood flow and joint movement is significantly impaired, joint function should be reconstructed by surgery to remove the damaged head and replace it with an artificial femoral head (artificial head replacement). Is being done.

One of the complications that tends to occur relatively early after the operation of the artificial head replacement is the dislocation of the artificial head due to excessive flexion of the hip joint or poor posture. When dislocated, he cannot walk due to severe pain and joint dysfunction. To reduce the dislocation, it is necessary to reduce the femoral head to the original open bone by pulling the lower limb on the dislocated side, but it is difficult to reduce the soft tissue such as the joint capsule and muscle around the hip joint. If traction alone is not enough, the joint must be surgically dissected to reduce the dislocation and repair the soft tissue.

As measures to prevent dislocation after surgery of the artificial head replacement, there are measures on the operator side and measures on the patient side. As a measure on the part of the surgeon, there is an improvement in the surgical technique. Various minimally invasive surgical methods have been devised to reduce surgical invasion and restore joints to their original state as much as possible, and have been discussed for a long time at orthopedic societies. As measures on the patient side, starting with standing walking training after surgery, there is lifestyle guidance that avoids excessive flexion of the hip joint and poor posture, and there are many discussions at rehabilitation societies. In the past, the above efforts have been successful in preventing dislocation. However, in recent years, the number of femoral neck fractures in the elderly with dementia has increased, and rehabilitation guidance has been limited. This is because the number of dementia patients who cannot understand the guidance to avoid poor posture due to dementia and forget that they have undergone surgery has increased.

Regarding the present invention, the search for the prior art document information was carried out with the international patent classification as the search field, but the corresponding document could not be found. Prevention of dislocation, which is one of the postoperative complications of artificial head replacement, has achieved certain results by improving surgery on the operator side and postoperative rehabilitation on the patient side as described above. That seems to be the reason. However, in modern times, the number of elderly patients with dementia, which has never been experienced before, is increasing. The number of elderly patients with dementia who cannot understand the rehabilitation to prevent dislocation after surgery, that is, lifestyle guidance training to avoid poor posture, and forget that the patients themselves are undergoing surgery is increasing. Since the conventional measures have become insufficient, the inventor of the present application has devised a new artificial hip joint system. Instead of the prior art document information, the prior art will be described with reference to the drawings.

FIG. 1 is a front view showing the state of the hip joint subjected to the conventional typical bipolar artificial head replacement, showing the relationship between the artificial head 101, the acetabulum H4 of the pelvis H3, and the femur H1. ing. A stem 111 is installed in the femoral bone marrow cavity H2 created in the femur H1. The inner head 113 is fitted to the stem neck 112 protruding from the upper end of the stem 111, the socket 114 is slidably engaged with the spherical convex surface of the inner head 113, and the spherical convex surface of the socket 114 is slidably engaged. Further, the outer cup 115 is fitted to the outside thereof to form the artificial head 101. The inner head 113 smoothly rotates with respect to the socket 114, and the outer cup 115 smoothly rotates with respect to the acetabulum H4 of the pelvis H3, whereby the artificial head 101 functions as a bipolar artificial head.

Anatomically, the pelvic bone and the femoral head are connected by a head ligament containing blood vessels, and the head ligament nourishes the femoral head from the side of the bone and the joint capsule, which is the periarticular tissue. It forms a joint with a soft tissue called. The head ligament and joint capsule contribute to the maintenance of blood flow and the stability of the joint in the tissues around the joint including the femoral head. In the bipolar artificial head replacement technique, the femoral head damaged by a femoral neck fracture or the like is removed and replaced with an artificial head, but the head ligament dissection and the joint incision are indispensable. Generally, the joint capsule is surgically repaired by suturing after an incision, but there has been no surgery to repair the head ligament.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an artificial hip joint system that reduces the risk of the artificial head dislocating from the acetabulum by taking a poor posture.

In order to solve the above problems, the inventor of the present application is a bioabsorbable artificial ligament capable of acquiring the original stability of the joint and avoiding premature dislocation after the operation without impairing the conventional advantages of the artificial head replacement. We devised an artificial hip joint system using.

That is, the artificial hip joint system of the present invention includes an artificial head having a bone head that slidably engages with the pelvic bone head, and an artificial ligament unit that connects the bone head to the pelvic bone. The artificial ligament unit includes a bioabsorbable artificial ligament, a pelvic side fixing tool for fixing one end of the artificial ligament to the pelvis, and a femoral head side fixing tool for fixing the other end of the artificial ligament to the bone head. And, characterized by having (claim 1).

According to this artificial hip joint system, one end of the bioabsorbable artificial ligament is fixed to the pelvis, and the other end of the artificial ligament is fixed to the bone head. Can be connected to. For this reason, the afferent rotational movement performed by the head of the bone with respect to the acetabulum of the pelvis is suppressed for a certain period of time until the artificial ligament is absorbed by the living body, but the distance between the head of the bone and the acetabulum is large. It is kept constant and can reduce the risk of the head being dislocated from the acetabulum due to excessive flexion of the artificial head with respect to the pelvis or poor posture. Further, after the above-mentioned fixed period has passed and the artificial ligament is absorbed by the living body, the afferent rotational movement performed by the bone head on the acetabulum of the pelvis can be tolerated.

Further, since the artificial ligament has bioabsorbability, even when the artificial ligament is installed in the hip joint, it is possible to suppress the occurrence of inflammation due to the artificial ligament being regarded as a foreign substance.

In the artificial hip joint system, the artificial head further includes a stem provided on the femur and a stem neck provided on the upper end of the stem, and the head is an inner provided on the stem neck. It has a head, a socket slidably engaged with the outer periphery of the inner head, and an outer cup fitted to the outer periphery of the socket and slidable with respect to the inner peripheral surface of the acetabulum. It is preferable that the other end of the artificial ligament is fixed to the outer cup of the head-side fixture (claim 2).

According to this configuration, the socket is slidably engaged with the outer circumference of the inner head, and after the artificial ligament is absorbed by the living body, the outer cup is slidable with respect to the inner peripheral surface of the acetabulum. Therefore, the artificial head can be made to function as a bipolar artificial head.

In the artificial hip joint system, the outer cup is formed with an insertion hole through which the artificial ligament can be inserted, and the pelvic side fixture has one end of the artificial ligament in the ischium of the pelvis in the acetabulum. It is preferable that the fixture is fixed from the peripheral side, and the other end of the artificial ligament inserted into the insertion hole is fixed to the inner peripheral surface of the outer cup of the pelvic head side fixture (claim 3).

According to this configuration, since the artificial ligament is fixed to the ischium, which has a relatively high strength among the bones constituting the pelvis, the risk of the pelvic-side fixator coming off the pelvis can be reduced. Therefore, the artificial ligament can be fixed to the pelvis relatively stably.

In the artificial hip joint system, the artificial ligament unit includes a bioabsorbable additional artificial ligament provided separately from the artificial ligament, and one end of the additional artificial ligament to the pelvic bone of the pelvis and the inner circumference of the ostomyous ligament. Further having an additional pelvic side fixture to be fixed from the side, the additional artificial ligament is inserted into the insertion hole together with the artificial ligament, and the head-side fixture is each of the artificial ligament and the additional artificial ligament. It is preferable to fix the other end to the inner peripheral surface of the outer cup (claim 4).

According to this configuration, in addition to fixing the artificial ligament to the ischium, the additional artificial ligament is fixed to the pubis, so that the risk of the artificial ligament coming off the pelvis can be further reduced. Therefore, the artificial ligament can be more stably fixed to the pelvis.

As described above, according to the present invention, it is possible to provide an artificial hip joint system that reduces the risk of the artificial head dislocating from the acetabulum by taking a poor posture.

It is a front view which shows the state which the conventional typical bipolar type artificial head is installed in the pelvis. It is a front view which shows the whole structure of the artificial hip joint system which concerns on 1st Embodiment of this invention. It is a side view of the artificial ligament inserted into the insertion hole of the outer cup of the artificial hip joint system, the screw type fixative connected to the artificial ligament, and the button type fixative as seen from the outer peripheral side of the outer cup. It is a bottom view of the artificial ligament inserted into the insertion hole of the outer cup of the artificial hip joint system, the screw type fixator connected to the artificial ligament, and the button type fixator as seen from the inner peripheral side of the outer cup. It is a front view which shows the state before installing the outer cup and the artificial ligament unit in the pelvis. It is a front view which shows the whole structure of the artificial hip joint system which concerns on 2nd Embodiment of this invention. A screw-type fixture connected to the first artificial ligament and the second artificial ligament inserted into the insertion hole of the outer cup of the artificial hip joint system according to the second embodiment of the present invention, and a button-type fixative are attached to the outer peripheral side of the outer cup. It is a side view seen from. The screw-type fixture connected to the first artificial ligament and the second artificial ligament inserted into the insertion hole of the outer cup of the artificial hip joint system according to the second embodiment of the present invention, and the button-type fixator are attached to the inner circumference of the outer cup. It is a bottom view seen from the side. It is a front view which shows the state before the outer cup of the artificial hip joint system which concerns on 2nd Embodiment of this invention, the 1st artificial ligament and the 2nd artificial ligament are installed in the pelvis.

1. 1. First Embodiment Hereinafter, the artificial hip joint system G according to the first embodiment of the present invention will be described with reference to FIGS. 2 to 5.

As shown in FIG. 2, the artificial hip joint system G includes an artificial head 1 fixed to the femur H1 and an artificial ligament unit 2 connecting the artificial head 1 to the pelvis H3. As the femur to which the artificial hip joint system G is applied, the femur H1 from which the femoral head has been resected is used. The femur H1 is formed with a femoral bone marrow cavity H2 that extends in the vertical direction and opens at the upper part.

The artificial head 1 includes a stem 11 installed in the femoral medullary cavity H2 of the femur H1, a stem neck 12 continuously provided at the upper end of the stem 11, and a side of the stem neck 12 continuous with the stem 11. Has a bone head 4 provided at the opposite end (tip). Since a known stem 11 is used, detailed description thereof will be omitted.

The stem neck 12 is a rod-shaped member formed so that the diameter becomes slightly smaller from the end portion on the stem 11 side toward the tip portion.

The bone head 4 has an inner head 13 attached to the stem neck 12, a socket 14 slidably engaged with the outer periphery of the inner head 13, and a socket 14 fitted to the outer periphery of the socket 14 and inside the acetabulum H4. It has an outer cup 15 slidable with respect to the peripheral surface. As described above, the inner head 13 is slidably provided with respect to the socket 14, and the outer cup 15 is slidably provided with respect to the acetabulum H4, whereby the artificial head 1 functions as a bipolar artificial head. do.

As shown in FIG. 2, the inner head 13 has a spherical outer peripheral surface that is slidable with respect to the inner peripheral surface (recessed portion 14a described later) of the socket 14. Further, the inner head 13 is formed with a fitting hole 13a for fixing the stem neck 12. The inner diameter of the fitting hole 13a is almost constant. The inner head 13 is fitted to the stem neck 12 by press-fitting the tip of the stem neck 12 into the fitting hole 13a. That is, the more the tip of the stem neck 12 formed in a slightly tapered shape is pushed into the fitting hole 13a, the more the tip of the stem neck 12 and the inner circumference of the fitting hole 13a come into close contact with each other. As a result, the inner head 13 is fixed to the stem neck 12. The inner head 13 is formed of, for example, a cobalt-chromium alloy, ceramic, or the like.

As shown in FIG. 2, the socket 14 is fitted and fixed to the inner peripheral surface (recessed portion 15a described later) of the outer cup 15. The socket 14 is formed with a recess 14a to which the inner head 13 is slidably engaged. The socket 14 is formed of, for example, a resin of ultrahigh molecular weight polyethylene.

The peripheral surface of the recess 14a has a shape corresponding to the outer peripheral surface (spherical surface) of the inner head 13. With the inner head 13 engaged with the recess 14a, the outer peripheral surface of the inner head 13 slides with the peripheral surface of the recess 14a, so that the inner head 13 rotates with respect to the socket 14.

As shown in FIG. 2, the outer cup 15 has a hemispherical outer peripheral surface that is slidable with respect to the inner peripheral surface of the acetabulum H4. The outer cup 15 is formed with a recess 15a that fits into the socket 14. The outer cup 15 is made of a metal such as a cobalt-chromium alloy.

With the socket 14 fitted in the recess 15a, the outer peripheral surface of the outer cup 15 slides with the inner peripheral surface of the acetabulum H4, so that the outer cup 15 rotates with respect to the acetabulum H4. The outer diameter of the outer cup 15 is appropriately set according to the inner diameter of the acetabulum H4 so that the outer cup 15 engages with the sliding ability with respect to the inner peripheral surface of the acetabulum H4.

As shown in FIG. 3, the artificial ligament unit 2 includes a bioabsorbable artificial ligament 22 and a button-type fixative 23 for fixing the artificial ligament 22 to the pelvic head 4 (corresponding to the “pelvic head side fixing tool” of the present invention). And a screw type fixator 21 (corresponding to the "pelvis side fixture" of the present invention) for fixing the artificial ligament 22 to the pelvis H3.

The artificial ligament 22 is composed of one or a plurality of string-like members folded back in the screw type fixative 21. The artificial ligament 22 has a folded-back portion 22c, which is a folded-back portion of the screw-type fixative 21, and a first portion 22a and a second portion 22b extending bifurcated from the folded-back portion 22c. The folded-back portion 22c corresponds to one end of the present invention, and the end of the first and second portions 22a and 22b opposite to the folded-back portion 22c corresponds to the other end of the present invention.

Anatomically, the head ligament has both a function as a feeding blood vessel to the femoral head and a function for the purpose of stabilizing the hip joint, and the artificial ligament 22 has a function for the purpose of stabilizing the hip joint. Specifically, the artificial ligament 22 is used for stable maintenance of the hip joint (joint between the bone head 4 and the acetabulum H4) for a certain period after the operation of fixing the artificial head 1 to the femur H1 (artificial head replacement). Play an important role.

Further, the hip joint is a spherical joint that performs afferent rotational movement, unlike a multidimensional movement that has both rotational movement and sliding movement such as a knee joint. Therefore, if soft tissues (not shown) such as the joint capsule around the hip joint separated by the above surgery are sutured and then engrafted and restored to their original state, the stability of the hip joint after the artificial head replacement surgery is almost stable. It is believed to have been achieved.

Therefore, as the material of the artificial ligament 22, it is preferable to use a material having a property of being able to maintain the strength so as not to be torn for a certain period of time until the soft tissue is engrafted and restored to the original state. Further, since one end of the artificial ligament 22 is fixed to the inner peripheral surface (joint sliding surface) of the acetabulum H4, the material of the artificial ligament 22 has a property of being able to maintain the strength for a certain period of time. In addition, it is more preferable to use a material having a property that does not induce an inflammatory reaction in the hip joint. As such a material, for example, a bioabsorbable material such as animal intestine, dermal collagen hydrochloride, polyglycolic acid, polydioxanone, and oxidized cellulose polygratin 910 is used.

As shown in FIGS. 3 and 4, the button-type fixture 23 is formed in a rectangular shape in a plan view. As the material of the button type fixture 23, it is preferable to use the same metal as the material of the outer cup 15. This is because when a metal different from the metal used in the outer cup 15 is used as the material of the button type fixture 23, ions are generated due to the potential difference between the metals, which may cause local inflammation.

In the button-type fixative 23, two insertion holes 23a and 23b through which the artificial ligament 22 can be inserted are formed side by side in the longitudinal direction. The first portion 22a of the artificial ligament 22 is inserted into the insertion hole 23a, and the second portion 22b of the artificial ligament 22 is inserted into the insertion hole 23b.

As shown in FIG. 4, the recess 15a of the outer cup 15 is formed with a recess 151 for fitting the button-type fixture 23. The recess 151 is formed in a rectangular shape corresponding to the button-type fixture 23 so that the button-type fixture 23 can be stably fitted. Further, the recess 151 is formed with an insertion hole 151a through which the artificial ligament 22 can be inserted.

The button-type fixative 23 is recessed with the first and second portions 22a and 22b of the artificial ligament 22 inserted into the insertion holes 151a of the outer cup 15 and the insertion holes 23a and 23b of the button-type fixative 23. It is fitted to 151. In this state, the other end of the artificial ligament 22 is ligated. That is, the ends of the first and second portions 22a and 22b on the opposite side of the folded portion 22c are joined together. As a result, the artificial ligament 22 is fixed to the outer cup 15 via the button-type fixative 23.

The screw type fixative 21 is a screw type anchor that fixes one end of the artificial ligament 22 to the ischium H5 of the pelvis H3 from the inner peripheral side (inside the joint) of the acetabulum H4. The screw type fixative 21 has a screw portion 210 screwed to the ischium H5 and a connection portion 211 extending from an end portion of the screw portion 210 in a direction opposite to the screwing direction. As the material of the screw type fixture 21, a metal material such as a titanium alloy is used.

The threaded portion 210 has a double helix screw structure in order to improve the pull-out strength with respect to the ischium H5.

An insertion hole 211a through which the artificial ligament 22 can be inserted is formed in the connection portion 211 in a direction orthogonal to the screwing direction of the screw portion 210.

With the threaded portion 210 screwed into the ischium H5, the artificial ligament 22 is inserted into the insertion hole 211a of the connecting portion 211, so that one end of the artificial ligament 22 is fixed to the ischium H5.

(Assembly method)
Hereinafter, a method of assembling the artificial hip joint system G (artificial head replacement) of the first embodiment will be described.

As shown in FIGS. 3 and 5, the outer cup 15 and the acetabulum H4 are connected by using the artificial ligament unit 2.

Specifically, in a state where the artificial ligament 22 is inserted into the insertion hole 211a of the screw type fixative 21, the screw type fixative 21 is fixed (screwed) from the inside of the acetabular H4 joint to the ischium H5.

Then, the other end of the artificial ligament 22 is inserted into the insertion hole 151a from the outer peripheral side of the outer cup 15. Further, in this state, the outer cup 15 is engaged with the acetabulum H4.

Further, as shown in FIG. 4, the artificial ligament 22 drawn out from the insertion hole 151a to the inner peripheral side of the outer cup 15 is inserted into the insertion holes 23a and 23b of the button type fixative 23. Specifically, the first portion 22a is inserted into the insertion hole 23a, and the second portion 22b is inserted into the insertion hole 23b. In this state, the button type fixture 23 is fitted into the recess 151 from the inner peripheral side of the outer cup 15. Then, the other end of the artificial ligament 22 (the ends of the first and second portions 22a and 22b opposite to the folded portion 22c) is ligated.

By such a procedure, the outer cup 15 and the acetabulum H4 can be connected by using the artificial ligament unit 2.

Next, as shown in FIG. 2, the artificial head 1 is assembled.

Specifically, the socket 14 is fitted to the inner peripheral surface of the outer cup 15 engaged with the acetabulum H4. Further, the stem neck 12 of the stem 11 installed in the femoral medullary cavity H2 is fitted into the fitting hole 13a of the inner head 13. Further, the inner head 13 is engaged with the inner peripheral side of the socket 14 so as to be able to smoothly rotate.

By such a procedure, the artificial head 1 of the present invention can be connected to the acetabulum H4 in the same manner as the conventional bipolar type artificial head, and the artificial ligament 22 further stabilizes the joint after the artificial head replacement. Can be improved.

(Action effect)
According to the artificial hip joint system G according to the first embodiment, one end of the artificial ligament 22 is fixed to the ischium H5 of the pelvis H3, and the other end of the artificial ligament 22 is fixed to the outer cup 15 of the bone head 4. The bone head 4 of the artificial head 1 can be connected to the ischium H5 via the artificial ligament 22. Therefore, for a certain period until the artificial ligament 22 is absorbed by the living body, the outer cup 15 of the bone head 4 suppresses the afferent rotational movement performed on the acetabulum H4 of the pelvis H3, but the bone head The distance between the outer cup 15 of 4 and the acetabulum H4 is kept constant to reduce the risk of the head 4 dislocating from the acetabulum H4 due to excessive flexion of the artificial head 1 with respect to the pelvis H3 or poor posture. Can be done. Further, after the certain period of time has passed and the artificial ligament 22 is absorbed by the living body, the outer cup 15 of the bone head 4 can allow the afferent rotational movement performed on the acetabulum H4 of the pelvis H3.

Further, since the artificial ligament 22 is bioabsorbable, even when the artificial ligament 22 is installed in a joint, it is possible to suppress the occurrence of inflammation due to the artificial ligament 22 being regarded as a foreign substance.

Further, after the socket 14 is slidably engaged with the outer periphery of the inner head 13 and the artificial ligament is absorbed by the living body, the outer cup 15 becomes slidable with respect to the acetabulum H4, so that the artificial head is slidable. 1 can be made to function as a bipolar artificial head.

Further, since the artificial ligament 22 is fixed to the ischium H5, which has a relatively high strength among the bones constituting the pelvis H3, the risk of the screw type fixative 21 coming off from the pelvis H3 can be suppressed. Therefore, the artificial ligament 22 can be stably fixed to the pelvis H3.

Further, since the screw type fixture 21 fixes the artificial ligament 22 from the inner peripheral side (inside the joint) of the acetabulum H4, the risk of the bone head 4 separating from the acetabulum H4 can be reduced. As a result, the risk of the head 4 dislocating from the acetabulum H4 can be reduced.

2. 2. Second Embodiment The artificial hip joint system K according to the second embodiment will be described with reference to FIGS. 6 to 9, focusing on the differences from the artificial hip joint system G of the first embodiment.

As shown in FIG. 6, the artificial hip joint system K of the second embodiment is a double bundle in which an artificial ligament 22 is added with another artificial ligament instead of the single bundle artificial ligament unit 2 using the artificial ligament 22. It differs from the artificial hip joint system G of the first embodiment in that the artificial ligament unit 3 is used.

The artificial ligament unit 3 includes the artificial ligament 22 used in the first embodiment (hereinafter referred to as "first artificial ligament 22" in the second embodiment), the button type fixing tool 23, and the screw type fixing tool 21 (hereinafter referred to as "screw type fixing tool 21"). , In addition to the "first screw type fixator 21" in the second embodiment), the second artificial ligament 25 provided separately from the first artificial ligament 22 (corresponding to the "additional artificial ligament" of the present invention). And a second screw type fixator 24 (corresponding to the "additional pelvis side fixture" of the present invention) for fixing one end of the second artificial ligament 25 to the pelvis H3.

As the second artificial ligament 25, one having the same material and shape as the first artificial ligament 22 is used. That is, the second artificial ligament 25 is composed of one or a plurality of string-shaped members folded back in the second screw type fixative 24.

The second artificial ligament 25 is composed of one or a plurality of string-like members folded back in the second screw type fixative 24. The second artificial ligament 25 has a folded-back portion 25c, which is a folded-back portion of the second screw type fixative 24, and a first portion 25a and a second portion 25b extending bifurcated from the folded-back portion 25c. The folded-back portion 25c corresponds to one end of the present invention, and the end of the first and second portions 25a and 25b opposite to the folded-back portion 25c corresponds to the other end of the present invention.

As shown in FIGS. 7 and 8, the second artificial ligament 25 is inserted into the insertion hole 151a of the outer cup 15 together with the first artificial ligament 22. Further, the first portion 25a of the second artificial ligament 25 is inserted into the insertion hole 23a of the button-type fixative 23 together with the first portion 22a of the first artificial ligament 22, and the second portion 25b is inserted together with the second portion 22b. It is inserted through the hole 23b.

The material and shape of the second screw type fixative 24 are the same as the material and shape of the first screw type fixative 21. That is, the second screw type fixture 24 is a screw type anchor that fixes one end of the second artificial ligament 25 to the pubic bone H6 of the pelvis H3 from the inner peripheral side (inside the joint) of the acetabulum H4, and is attached to the pubic bone H6. It is composed of a screw portion 240 to be screwed and a connection portion 241 for fixing the second artificial ligament 25 to the screw portion 240.

An insertion hole 241a through which the second artificial ligament 25 can be inserted is formed in the connection portion 241 in a direction orthogonal to the axial direction of the screw portion 240.

Hereinafter, the method of assembling the artificial hip joint system K (artificial head replacement) of the second embodiment will be described focusing on the differences from the first embodiment.

As shown in FIGS. 7 and 9, with the first artificial ligament 22 inserted into the insertion hole 211a of the first screw type fixative 21, the screw type fixative 21 is placed on the inner peripheral side (intra-articular side) of the acetabulum H4. ) To fix (screw) to the ischium H5. Further, with the second artificial ligament 25 inserted into the insertion hole 241a of the second screw type fixative 24, the second screw type fixative 24 is fixed to the pubic bone H6 from the inner peripheral side (inside the joint) of the acetabulum (inside the joint). (Screw).

Then, the first artificial ligament 22 and the second artificial ligament 25 are inserted into the insertion hole 151a from the outer peripheral side of the outer cup 15 in a state where the first artificial ligament 22 and the second artificial ligament 25 are bundled. Further, the first portion 22a of the first artificial ligament 22 and the first portion 25a of the second artificial ligament 25 are bundled and inserted into the insertion hole 23a of the button-type fixative 23, and the second portion 22b and the second portion 25b are inserted. Is inserted into the insertion hole 23b in a bundled state. In this state, the button type fixture 23 is fitted into the recess 151 from the inner peripheral side of the outer cup 15.

Then, the other end of the first artificial ligament 22 (the ends of the first and second portions 22a and 22b opposite to the folded portion 22c) is ligated, and the other end of the second artificial ligament 25 (the first). 1. The ends of the second portions 25a and 25b opposite to the folded portion 25c) are ligated.

The procedure for assembling the artificial bone head 1 is the same as that of the first embodiment, and thus is omitted.

According to the artificial hip joint system K according to the second embodiment, in addition to fixing the first artificial ligament 22 to the ischium H5, the second artificial ligament 25 is fixed to the pubic bone H6, so that the first artificial ligament 22 is the pelvis. It is possible to further suppress the withdrawal from H3.

Further, since the second screw type fixture 24 fixes the second artificial ligament 25 from the inner peripheral side (inside the joint) of the acetabulum H4, the risk of the bone head 4 separating from the acetabulum H4 is further reduced. As a result, the risk of the head 4 dislocating from the acetabulum H4 can be further reduced.

(Modification example)
The above embodiment is merely an example of a preferred specific example of the present invention, and the present invention is not limited to the above embodiment.

For example, in the first embodiment, the screw type fixative 21 formed of a metal material was used as the pelvic side fixative, but it is such a screw type fixative 21 that can be used as the pelvic side fixative. Not limited to this, for example, a pelvic side fixture formed of a bioabsorbable material such as a material (HA / PLLA) containing bioceramic powder such as hydroxyapatite in poly (L-lactide) may be used.

If the acetabulum H4 is deformed or the outer cup 15 is moved inward due to age-related changes in the patient, contact between the pelvic side fixator and the outer cup 15 may occur. When a bioabsorbable material is used as a pelvis, the inflammatory reaction due to such contact can be suppressed.

The pelvis-side fixator formed by HA / PLLA has lower strength than the screw-type fixator 21 formed of a metal material, and depending on the shape, the pelvis-side fixator may break relatively easily. is expected. Therefore, when the artificial ligament 22 is fixed to the ischium H5 of the pelvis H3 by using the pelvic side fixture formed by HA / PLLA, a screw hole that can be screwed by the pelvic side fixator is formed in the ischium H5, and the artificial ligament is formed. The folded-back portion 22c of 22 may be fastened to the screw hole in a state of being wound around the pelvic side fixture.

In this case, the shape of the pelvic side fixative does not have to be the shape of the screw type anchor as in the screw type fixator 21 of the first embodiment, and for example, the set screw (JIS B 1117, JIS B 1118, JIS). It may have the shape of B 1177).

This also applies to the pelvic side fixture that can be used in the second embodiment.

Needless to say, various design changes are possible within the scope of the claims of the present invention.

1 Artificial head 2 Artificial ligament unit 3 Artificial ligament unit 4 Bone head 11 Stem 12 Stem neck 13 Inner head 14 Socket 15 Outer cup 21 1st screw type fixture (pelvic side fixture)
22 First artificial ligament (artificial ligament)
23-button fixture (fixture on the head side)
24 Second screw type fixture (additional pelvic side fixture)
25 Second artificial ligament (additional artificial ligament)
G Artificial hip joint system H1 Femur H2 Femur bone marrow cavity H3 Pelvis H4 Acetabulum H5 Ischium H6 Pubis K Artificial hip joint system

Claims (4)

It comprises an artificial head having a head that slidably engages with the acetabulum of the pelvis and an artificial ligament unit that connects the head to the acetabulum.
The artificial ligament unit includes a bioabsorbable artificial ligament, a pelvic-side fixture that fixes one end of the artificial ligament to the pelvis, and a head-side fixture that fixes the other end of the artificial ligament to the head. And, an artificial hip joint system characterized by having. In the artificial hip joint system according to claim 1,
The artificial head further comprises a stem provided on the femur and a stem neck provided on the upper end of the stem.
The bone head is fitted to an inner head provided on the stem neck, a socket slidably engaged with the outer periphery of the inner head, and the outer periphery of the socket and on the inner peripheral surface of the acetabulum. With a slidable outer cup,
The head-side fixture is an artificial hip joint system characterized in that the other end of the artificial ligament is fixed to the outer cup. In the artificial hip joint system according to claim 2,
The outer cup is formed with an insertion hole through which the artificial ligament can be inserted.
The pelvic side fixator fixes one end of the artificial ligament to the ischium of the pelvis from the inner peripheral side of the acetabulum.
The head-side fixture is an artificial hip joint system characterized in that the other end of the artificial ligament inserted into the insertion hole is fixed to the inner peripheral surface of the outer cup. In the artificial hip joint system according to claim 3,
The artificial ligament unit includes a bioabsorbable additional artificial ligament provided separately from the artificial ligament, and an additional pelvis in which one end of the additional artificial ligament is fixed to the pubis of the pelvis from the inner peripheral side of the acetabulum. With a side fixture,
The additional artificial ligament is inserted into the insertion hole together with the artificial ligament.
The head-side fixture is an artificial hip joint system characterized in that the other ends of the artificial ligament and the additional artificial ligament are fixed to the inner peripheral surface of the outer cup.

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