JPH06189987A - Joint constitution material - Google Patents

Abstract

PURPOSE:To enable a simple joint replacement operation to be undertaken, and provide a large joint moving area by forming a joint constitution material having a bone tissue, at a proxal end adjacent to a bone tissue at a distal end, in such a way as having at least one surfaces sliding on the surface of at least one bone edge section. CONSTITUTION:This joint constitution material 1 made of sapphire or the like has a spherical outer surface 1a, and this surface 1a is mirror finished, for example, to 0.05 or less with surface roughness of Ra via chemical treatment. When this material 1 is used to replace a thumb CM joint, each of bone edges P2 and D2 of a broken proximal lateral bone D and a broken distal lateral bone D are so made as to smoothly slide on the outer surface 1a of the material 1. According to this construction, a problem regarding a complication due to a dislocation between a stem and a bone as seen in an artificial joint fitted with a stem and fixed in a myeloid cavity can be eliminated, and a very large joint moving area can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to osteoarthritis in major parts that form joints of the human body such as shoulder joints, hip joints, and spines, in addition to finger joints such as thumb CM joints and MP joints. Rheumatoid joints, joints that have been unable to function satisfactorily due to destruction due to diseases such as trauma, that is, directly caused by damage to the articular cartilage, gradually deforming the joint surface, resulting in deterioration of joint function and The present invention relates to a joint component that replaces a joint in order to restore the function of a severely diseased joint that induces joint pain or the like and eventually impairs daily life and cures the disease.

[0002]

2. Description of the Related Art The shape and material of a joint-constituting object that replaces a joint whose function cannot be sufficiently fulfilled for some reason is as follows.
The structure of the human body joint including its original shape and soft tissue, the biomechanical balance depending on the arrangement of muscles and ligaments around the joint, the mobility in various directions required for the joint, and their movement. Depending on the size and direction of the joint load at
It is decided in consideration of overall suitability.

As a joint component used conventionally, for example, as in the invention of US Pat. No. 4,242,757, a proximal bone member having a medullary cavity support portion to be inserted into a proximal medullary cavity and a distal medullary cavity are provided. A distal bone member having a medullary cavity support portion to be inserted into the medullary cavity, and these two members are fixed to bone tissue by inserting and fixing the medullary cavity support portion into the medullary cavity, and At each joint sliding surface formed at the tip of the joint located on the opposite side, each member biomechanically balances due to the compression force and support of the surrounding soft tissue, and various joint sliding surfaces are formed. There is a thing which gives a function close to the function of the original joint by giving such a shape, and thereby the joint function is reconstructed.

Further, as in the invention of US Pat. No. 4,367,562, it comprises a medullary cavity support portion to be inserted into the proximal side bone marrow cavity and a medullary cavity support portion to be inserted into the proximal side bone marrow cavity, and is integrally molded from silicon. There was an articulated structure object. This is an integrated joint component that does not have a joint sliding surface, and was designed to restore the joint function by utilizing the elasticity of silicon.

[0005]

However, the above-mentioned prior art has the following problems.

[0006] That is, in a joint component comprising a proximal side bone member and a distal side bone member and having a medullary cavity support portion inserted into the proximal side bone marrow cavity and the distal side bone marrow cavity, respectively, The inner support member originally functions as an anchor for both members, but also has a function of transmitting the load generated in the joint to the bone tissue, and sometimes an excessive load is transmitted to the bone. In addition, the joint part has become large due to the design requirement by pursuing the function of the joint sliding surface and limiting the rotation direction and the rotation angle, and the bone resection amount has also increased accordingly.

As described above, the excessive stress transmission in the body which is a mechanical factor and the deterioration of the supporting ability of the bone tissue for receiving the joint structure object caused by the unnecessary bone resection due to the design of the joint structure object are caused. If so, these causes bone resorption, loosening between the member and the bone, etc., and as a long time elapses after the artificial joint replacement operation is performed, local destruction of surrounding bone tissue begins and destruction occurs. As the range of pain increased, pain that had improved could reappear and joint function could return to pre-operative levels.

If such a situation is caused,
Again, it is necessary to perform joint component replacement surgery, in which case the joint structure body must be implanted in the bone tissue that has been destroyed and lost more extensively than the first surgery,
More difficult techniques are required and the patient experiences great pain.

In addition, since both members made of an artificial material are slid on the sliding surface, the members may wear due to wear and the wear pieces may be taken into the living body, which has various adverse effects on the living body. Was there.

Next, in the joint component formed integrally from silicon, the joint component also bends and extends in accordance with the bending and extension of the joint, but by repeated bending and extension in the living body. There has been a problem that the silicon constituting the joint component deteriorates in a relatively short period of time and the joint component replacement operation must be performed immediately.

[0011]

In order to solve the above-mentioned problems, the present invention provides a joint component which constitutes a joint of a living body and is adjacent to bone tissue on the proximal end side and bone tissue on the distal end side. And a joint component characterized by being formed of at least one curved surface so as to slide on at least one epiphyseal surface and made of a material that is stable in vivo and does not show any harm. It is a thing.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a joint component 1 of a preferred embodiment of the present invention, which is made of sapphire and has a spherical outer surface 1a. The outer surface 1a has a surface roughness Ra of 0.05 or less by chemical treatment. It is finished to the mirror surface. Further, FIG. 2 shows that the thumb CM joint J is replaced with this joint component 1, and the proximal bone P is cut into a spherical surface by the method described later.
And the end face P ₂ , D _{2 of the} distal bone D and the joint component 1
The outer surface 1a of the above slides smoothly.

Such a joint-constituting object 1 does not have a stem, and therefore, a problem of complication caused by a deviation between the stem and the bone, which is often seen in an artificial joint for fixing the stem in the bone marrow cavity, may occur. Absent. Further, the flexion, extension, and other movements of the thumb CM joint J replaced with the joint component 1 are performed by sliding the spherical outer surface 1a of the joint component 1 with the epiphyses P ₂ and D _2. Therefore, it has a very wide range of motion.

When the joint-constituting object 1 is produced only by mechanical treatment, fine irregularities may be present on the outer surface, which is not preferable in terms of sliding characteristics.

As the material of the joint component 1, the polycrystal ceramics such as alumina and zirconia, the ceramic material such as single crystal sapphire, the inorganic material such as bioglass and carbon, or the biocompatibility such as cobalt / chromium alloy is used. It is possible to use a metal material having the above or an organic material such as ultra-high molecular weight polyethylene, polyurethane, PVA, or the like, which does not show biotoxicity. However, even if it is a medical material such as silicon, a material having poor durability in a living body is not preferable.

The thumb C using the joint component 1
In the replacement operation of the M joint J, first, the joint component 1 having a diameter of 8 mm to 11 mm is prepared for each 1 mm, and the joint component has the same size and shape (not shown). ) And a reamer for excavation (not shown) corresponding to these are prepared. Next, an reamer for excavation having an appropriate size is selected, and the CM joint J portion of the thumb is excavated by using the reamer, and the bone distal end P ₁ of the proximal bone P and the bone proximal of the distal bone D are proximally excavated. Curved bone end faces P ₂ and D ₂ were formed at the end D ₁ . After this bone excavation work, the most suitable size of the joint component 1 for replacing the joint is confirmed using the above-mentioned indication, and then the joint component 1 of that size is used for the proximal bone P and the distal bone. It was placed between D and its stability was finally confirmed, and finally, the joint capsule was reinforced using a half-section tendon of APL.

In this replacement operation, it is not necessary to excavate the bone marrow cavity in the proximal bone P and the distal bone D as described above, and the bone distal end P ₁ and the bone proximal end D of both bones are respectively removed. _{In addition} , since the curved end faces P ₂ and D ₂ are formed with a small amount of bone excavation, the operation time is greatly shortened and the bleeding amount is significantly reduced, which is very safe for the patient. . In addition, joint replacement of the hands and toes generally impairs the ability to support joint components when the functions of the surrounding ligaments and joint wraps are impaired, so replacement must be performed very carefully. However, it is safe because the surgical procedure is simple and does not require special skill in this replacement surgery.

After the above-mentioned replacement, the fixing device (not shown) is attached to the affected area for 3 to 4 weeks, and then the range of motion ROM is set.
I trained to increase. One year after the operation for 20 replacement cases, the pain was significantly reduced, the ROM of range of motion and the pinch force were improved, and subluxation and dislocation did not occur. The postoperative course is good. .

The above-described embodiments do not limit the scope of the present invention, and there are other application parts such as a toe joint, a shoulder joint, and the like, and various states of destruction of joints are possible. Therefore, the joint-constituting object 1 that replaces the joint needs to have a shape and size according to the case.

FIG. 3 shows a joint-constituting object of the present invention having another shape. (A) is a joint-constituting object 1 having a substantially triangular pyramid shape having a spherical surface 1 at its tip, and (b) is an elliptic sphere. Is a gourd-shaped joint constituent object 1, and (d) is a joint constituent object 1 having a substantially cylindrical center and hemispherical ends. Object 1
The spherical surface 1b slides on the epiphyseal surface P ₂ of the distal bone B or the epiphysial surface D ₂ of the proximal bone D. The shape of the surface that slides on the bone end faces P ₂ and D ₂ is not limited to the spherical surface 1b and may be a curved surface.

Further, the joint-constituting object 1 of the present invention replaces the joint portion alone, and as shown in FIG. 4, it replaces the joint portion with a plurality of spherical joint-constituting objects 1. May be.

[0023]

EFFECTS OF THE INVENTION The joint component of the present invention is capable of performing a simpler joint replacement operation that shortens the operation time of the medullary cavity support portion and reduces the amount of bleeding, and is like a joint component having a stem. Since the complications caused by the displacement with the bone are not exceeded, it is possible to install the joint component more safely for the patient, and the joint component realizes a larger range of motion of the joint.

[Brief description of drawings]

FIG. 1 is a perspective view of a joint component according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a joint component according to an embodiment of the present invention.

FIG. 3 is a perspective view of a joint component of the present invention, (a)
Is a joint component having a substantially triangular pyramid shape with a spherical tip, (b) is an ellipsoidal joint component 1, (c) is a gourd-shaped joint component 1, and (d) has a substantially central portion. The joint component 1 has a cylindrical shape and both ends are hemispherical.

FIG. 4 is a perspective view showing a joint-constituting object using a plurality of joints at the same location.

[Explanation of symbols]

1 glenoid object 1a outer surface 1b spherical P proximal bone D distal bone P ₁ Bone distal end D ₁ Bone proximal end P ₂ epiphyseal face D ₂ epiphyseal surface J thumb CM joint

Claims (1)

[Claims] 1. A joint component that constitutes a joint of a living body and is adjacent to bone tissue on the proximal end side and bone tissue on the distal end side,
A joint component, which is formed of at least one curved surface so as to slide on at least one epiphyseal surface and is made of a material that is stable in the body and does not show harm.