JPS596049A - Artificial joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to improvements in artificial joints.

An artificial joint is a joint that is attached to the human body and used to replace the joint between the humerus and ulna in an accident, for example, in the elbow joint. If so, it consists of an artificial humerus and an artificial ulna.

In the case of an artificial elbow joint, the artificial ulna and artificial humerus basically only need to be able to bend and extend in one plane, so in the past, generally, either the artificial ulna or the artificial humerus was used. Two prongs are formed at one end, and the other end is pivotally connected to the two prongs, using screws, hinges, etc.

However, since the actual elbow joint performs complex three-dimensional movements in addition to the above-mentioned bending and stretching movements within one plane, various problems occur in the above-mentioned conventional techniques. That is, when a moment load (a force that attempts to bend the artificial ulna in a plane other than the above-mentioned plane with respect to the artificial humerus) is applied to the artificial ulna, and this is repeated, the screw member rotates and loosens. Only certain parts wear out prematurely due to localized edge loading. As a result, problems such as looseness in the joints and poor bending and extension occur.

Note that substantially the same thing as described above also applies to an artificial knee joint consisting of an artificial femur and an artificial tibia. In principle, the artificial tibia bends and extends in one plane relative to the artificial femur, but in some cases moment loads may also act on it, so the artificial elbow must be able to handle such situations. This is because it is no different from a joint.

The present invention was developed against the background of the above-mentioned circumstances. The purpose of this invention is to provide an artificial joint that eliminates the problems in the prior art, and its gist is as follows:
This method consists in connecting two artificial bone members through a pair of spherical bushes.

Hereinafter, the present invention will be explained in more detail based on the drawings showing a practical example in which the present invention is applied to an elbow joint.

1. In Figures 1 and 2, the artificial humerus 10 has bifurcated parts 2 and 4 at one end, a main body part 6 in the middle, and a main body part 4.
and a male threaded member 8 erected at the other end. On the other hand, the artificial ulna 5o has a main body 1 having a hollow hole 12 at one end.
4, and a male threaded member 16 erected at the other end of the main body portion 14. Inside the hollow hole 12 is a tooth 1 having a concave spherical surface 18a.
A spherical bush 18 is mounted on the shaft member 20, and the convex spherical surface 22a of the spherical bush 22 of the fang 2 is tightly fitted into the concave spherical surface. The artificial humerus 1° and the artificial ulna 30 are made of an appropriate metal that does not cause a rejection reaction in the body.The b-shaft member 20 has a main body portion 20a;
The narrow diameter part at the tip and the collar at the end 20. c, and the forked parts 4 and 2 have small diameter holes 4 corresponding to the shaft members.
a and a large diameter hole 2a are bored.

Grooves 22b and 18b for supplying lubricant are formed in the convex spherical surface 22a8 of the two spherical bushings 22 and the concave spherical surface 18a of the one spherical bushing 18, respectively. Also, 1.
The one-spherical bushing 18 is provided with a rib 18c projecting inward on one side of the inner circumferential surface, but the rib may be provided on both sides.

Spacers 32 and 64 are fitted into the male threaded parts 6 and 16 of the artificial humerus 10 and the artificial ulna 30, respectively, and the male threaded members are screwed to the human bones 36 and 68, respectively.

Next, how to use this embodiment will be explained.

1 spherical bush 18 in the hollow hole 1゛2 of the artificial ulnar lobe 0
It is fully compressed, and two spherical bushings 22 are swingably attached to the inside thereof by a known method. After that, artificial humerus 10
And the artificial ulna 60 is coupled (screwed) to the human bones 66 and 38 at the male threaded portions 8 and 16, respectively.

At that time, the direction of the hollow hole 22C of the spear 2 spherical bush 22 and the large diameter hole 2a and small diameter hole 4a of the forks 2 and 4,
Of course, the axes must be aligned.

At that time, if the positions of the holes 2a, 22c and 4a do not match, the artificial humerus 10 and/or the artificial ulna 60
may be removed from the human bones 56 and/or 38 and replaced with spacers 62 and 64 of an appropriate thickness. This eliminates the need to process human bones 36 and 38, which cannot be regenerated, in order to adjust the position of the holes, which is extremely beneficial.

Subsequently, when the shaft member 20 is inserted from one side 2 of the forked portion, the spear 2 spherical bushing 22 is fitted and held thereon.

In the final stage of insertion, the shaft member 20 integrated with the spherical push 22 is pushed into the shaft by press-fitting the large-diameter portion 20c and the small-diameter portion 20b into the large-diameter hole 2a and the small-diameter hole 4a, respectively. It is assembled in the state shown in Figures 1 and 2.

The artificial elbow joint assembled in the above order is the artificial ulna 30
In addition to its original function of bending and extending around the shaft member 20 in a plane perpendicular to the paper plane of Figure 1, it is also capable of performing complex three-dimensional movements due to moment loads. That is, when a force is applied to the artificial ulna 60 in the left-right direction in the fang 1 diagram, for example, the artificial ulna 30 and 211 spherical bush 18 exerts a force on the fang 2 spherical bush 22, the shaft member 20, and the artificial humerus 10. It will bend in the direction of the addition. This also applies when a force is applied in a direction that makes a slight angle to the plane of the paper in Figure 1. At this time, the swing angle of the artificial ulna 30 is regulated by the rib 18c.

Therefore, only specific parts of the artificial humerus 10 and/or the artificial ulna 30 will not be locally worn due to edge loading, etc., and even if the artificial ulna 3o is repeatedly bent and stretched, the artificial humerus 10 and the artificial ulna Since the shaft member 60 is pivotally connected by the shaft member 20 (not a screw member), there is no possibility that the shaft member 20 will loosen and cause play in the pivot joint portion.

Note that the spherical bushes 18 and 22o"+ grooves 18b and 22b are formed to supply and hold lubricant, but it is not essential to do so, and the grooves 18b and/or the grooves 22b can also eliminate this.

Next, another embodiment of the present invention will be described with reference to FIG.

This embodiment differs from the above embodiments in that - pairs of spherical bushings are provided side by side on the left and right. That is, the shaft member 120 extends through the end of the artificial ulna 160.
second spherical bushings 122a and 12 at both ends of the
2b is attached, and the spherical bushes 118a and 118b of the fang 1 are attached to each of the forks 10, 2 and 104 of the artificial humerus 110.

In this example, the moment load is applied to the artificial ulna 160
When the artificial ulna 160, the shaft member 120 and the second spherical bushings 122a and 122b
Spherical bush 118. a and 118b and the artificial humerus 110 will bend in the direction in which the force is applied. In this case, since two sets of spherical bushings are installed side by side on the left and right, the surface pressure of each part is reduced and the rigidity is increased.

It should be noted that the present invention should not be construed as being limited to the above embodiments, and it goes without saying that changes and improvements can be made as appropriate without departing from the spirit of the invention. For example, as mentioned above, the present invention is not limited to artificial elbow joints,
It is also suitably applied to artificial knee joints.

As described above, according to the present invention, even when a load is applied to an artificial bone member in an artificial joint such as an artificial elbow joint or an artificial knee joint, only a specific part of the pivot joint is There is no friction or backlash, and the effect is that an artificial joint that can bend and stretch well over a long period of time can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front view (partial cross section) showing an embodiment of the present invention;
FIG. 2 is an enlarged view of the main part in FIG. 1, and FIG. 6 is an enlarged view (partially in section) of the main part showing another embodiment of the present invention. [Explanation of the symbols of the main parts] Fork part--------------
---2, 4 Artificial bone components --------1--
--------------10,3 [Single shaft member----
−−−−−−−−−−−−−−−−−−−−1−20
Spherical bush, −−−−−−−−−−−−−−−−−
−−−−−−18,22 people bones −1−−−−−−
−−−−−−−−−−−−−−−−−−1−−−36,
68 Figure 2

Claims (1)

[Scope of Claims] 1. An artificial joint in which a first artificial bone member having a bifurcated portion formed at one end and an end of the artificial bone member of the fang 2 are connected by a pivot; A first spherical bushing is installed in a hole drilled in the fork of the artificial bone member or the end of the second artificial bone member, and the first spherical bushing is fitted onto the pivot. An artificial joint characterized in that a second spherical bush is attached. 2. Claim 1, wherein the first artificial bone member is an artificial humerus, and the second artificial bone member is an artificial ulna.
Artificial joints as described in section. 6. The artificial joint according to claim 1, wherein a lubricant supplying hole is formed on the spherical surface of the first spherical bushing and/or the second spherical bushing. 4. The artificial body according to claim 1, wherein the second spherical bushing has a rib on one side, thereby regulating the amount of rocking of the first spherical bushing. joint.