JP2789097B2 - Artificial joint members - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial joint member for replacing a joint having reduced joint function due to a disease such as osteoarthritis or rheumatism and restoring joint function. is there.

(Prior art)

Conventional artificial joint members include an artificial elbow joint shown in FIG. 3 and an artificial knee joint shown in FIG. 4, and when performing joint replacement using these, as shown in FIG. When attached to a part of the distal end (joint part), the bone is fixed after performing osteotomy in a shape suitable for the joint member E as shown in, for example, FIGS. 3 (a) and 4 (a). Was.

In addition, since the strength of fixing the joint member to the bone is insufficient with such a surface replacement type, when a higher fixing strength is required, as shown in FIGS. 3 (b) and 4 (b). The joint member F is provided integrally with a shaft-shaped stem S, which is inserted into the medullary cavity of the bone or supported by the cortical bone portion of the bone, so that fixation, supportability, and stability can be achieved. In general, those having a shape and structure for obtaining are generally used.

[Problems to be solved by the invention]

In the conventional artificial joint as described above, the artificial joint member itself is securely attached, for example, stress is applied to the component itself of the artificial joint from a direction other than the original load direction, or the properties of the bone are different depending on the joint and the individual case to be applied. It may not be possible, and may loosen, shift, sink, etc. as it is used for a long period of time, and may move from its original position where it was initially installed, which may disturb the joint function (motor function).

In addition, increasing the contact area with the bone to give the joint member greater support and fixing strength to the bone increases the size of the joint member itself, thereby increasing the amount of osteotomy. Forced to

As a result, it is difficult to perform the replacement surgical procedure, the operation time is prolonged, and the natural bone is thinned or thinned due to the large amount of osteotomy. It was easy to break and could cause an intraoperative fracture.

The above inconveniences not only determine the life of the artificial joint, but also make it impossible to cope with long-term clinical use, and limit the indication cases and indication age.

[Means for solving the problem]

In order to eliminate the inconvenience, the artificial joint member can be mounted at a more accurate position, and in order to obtain more stable fixation with the bone, a boss portion is formed on the back side of the joint surface and the boss portion is formed. A mounting hole is provided apart from the joint surface and in a transverse direction, and a screw is provided in the mounting hole.
By inserting a shaft and the like, a stronger connection with the bone was achieved.

[Action]

1. Sufficient initial fixation can be obtained by connecting the artificial joint member and the bone with a screw, a shaft or the like.

2. Since the screw and the shaft are interposed between the joint member and the bone, the installation position of the screw and the shaft is automatically determined in accordance with the installation position of the screw and the shaft.

3.Because the bone and the articulated member that have been cut according to the shape of the articulated member for joint replacement are fixed with screws, shafts, etc., when installing and driving the articulated member into the bone, the impact may cause a fracture. Is prevented.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a humerus J and an artificial elbow joint 1 attached thereto. The artificial elbow joint 1 slides on an ulna (not shown).
1a, a stem 1b is integrally planted on the back side of the joint surface 1a, and a root of the stem 1b forms a thick boss 1c, and the boss 1c serves as a mounting hole. A threaded hole 1d is spaced apart from the joint surface 1a and transversely.

A cutout K, a stem insertion hole M, and screw insertion holes R and R 'are previously formed in a humerus J to which such an artificial elbow joint member 1 is attached. 1b
Is inserted into the stem insertion hole M, and the screw holes R, R 'made in the humerus J in a stable position in which the hole surface of the boss 1c abuts the inner surface of the notch K and the artificial elbow joint 1 Screw 1d
The artificial elbow joint 1 is attached to the humerus J by screwing the screw S in a state in which
Instead of the natural joint surface, the artificial joint surface 1a is replaced and repaired as shown in FIG.

FIG. 2 shows an artificial knee joint 10. The artificial knee joint 10 has a joint hole 10c formed integrally with the joint surface 10a and the side (back side) of the femoral bone D as a mounting hole. Through hole 1
0d is left open. On the other hand, a boss 10c of the artificial knee joint 10 is fitted into the femur D, and a cutout K and screw holes R and R 'are provided for compatibility. With the joint 10 pressed against the notch K of the femur D such that the boss 10c of the artificial knee joint 10 is fitted into the notch K, the femur D
By screwing the screw S through the screw holes R and R ', the joint 10 is stably attached to the femur D, and the joint surface is replaced.

The artificial joints 1 and 10 may be made of a metal material such as stainless steel, Co-Cr alloy, pure titanium, titanium alloy, or the like, which has no or little harm to the living body in vivo, alumina, zirconia. And a simple substance such as a ceramic material such as apatite, a synthetic resin material such as polyethylene, or a composite material thereof.

By the way, in order to fix the artificial joints 1 and 10 to the bone, in the above-described embodiment, an example was given in which the artificial joints 1 and 10 were screwed with the screw (bolt) S as a fixing means. Alternatively, the joint member may be fixed to the bone by inserting a straight shaft or a tapered fixing pin into these mounting holes.

The screws, shafts, and fixing pins are made of a material such as metal, ceramic, or synthetic resin, like the joint members.

As described above, the joints 1 and 10 are directly joined to the bone and fixed by the screw S or the shaft, so that a strong initial fixation can be obtained. Also, as shown in FIG. 1 (b), in the artificial elbow joint 1, the joint member is mounted even when the compressive load is applied from the humerus J to the sink in the axial direction of the medullary cavity (the direction of the arrow in the figure). Since the position is regulated by the position where the screw S is screwed, that is, by the screw hole 1d, there is an effect of preventing further sinking in the arrow direction.

In addition, in the artificial elbow joint replacement, as shown in FIG. 1, during the operation of osteotomy of the humerus J, if there is a thin part in the bone due to the shape and size of the elbow joint, the fracture from that part However, since the joint member according to the present invention is fixed between the bones by screws S or the like, the fracture can be prevented and the broken bone fragments can be fixed.

〔The invention's effect〕

As described above, according to the artificial joint member of the present invention, a mounting hole is provided on the back side of the joint surface, and a screw, a shaft, or the like is inserted through a bone through the mounting hole and attached to the bone. Since sufficient fixation can be obtained from the initial stage of replacement, the gospel of shortening the initial fixation period is brought to the patient. In addition, it is possible to prevent the occurrence of loosening, displacement, sinking, and the like even when used for a long period of time. As a result, it is possible to extend the indication cases and the indication age of the artificial joint. Therefore, it is possible to recover the function lost due to diseases such as osteoarthritis and rheumatism, and it greatly contributes to human welfare.

[Brief description of the drawings]

FIG. 1 (a) is a three-dimensional oblique view for explaining a method of attaching the artificial elbow joint according to the embodiment of the present invention to the humerus.
FIG. 1 (b) is a three-dimensional perspective view showing a state where the artificial elbow joint according to the embodiment of the present invention is mounted on the humerus. FIG. 2 (a) is a front view for explaining a method of mounting the artificial knee joint on the femur according to the embodiment of the present invention, and FIG. 2 (b).
1 is a front view showing a state where an artificial knee joint according to an embodiment of the present invention is mounted on a femur. 3 (a) and (b) are three-dimensional perspective views of a conventional artificial elbow joint, and FIG. 4 (a).
(B) is a three-dimensional perspective view of a conventional artificial knee joint,
FIG. 5 is a front view showing an example of the shape of a cut humerus when an artificial elbow joint is mounted. 1: Artificial elbow joint, J: Humerus 10: Artificial knee joint, D: Femur 1a, 10a: Joint surface, 1d: Screw hole 10d: Through hole S: Screw

Claims (1)

(57) [Claims] An artificial joint having an articulating surface on one side, a boss formed on the back side of the articulating surface, and a mounting hole spaced from the articulating surface at the boss and extending transversely. Element.