JPH0716501B2 - Bioprosthesis - Google Patents

Description

TECHNICAL FIELD The present invention relates to a bioprosthesis used for prosthesis of a bone defect portion or a resection portion due to an accident, a disease, or the like.

[Prior Art] Artificial prostheses, which are conventionally used as a combination of a natural bone and a prosthesis, mainly consist of Co-Cr-Mo alloy, stainless steel,
Some are made of ceramic material.

For example, as shown in FIG. 4, a prosthesis in which the shaft portion a is inserted into the medullary cavity b of the bone B, the end surface of the bone B is brought into contact with the stepped portion, and the cement C is used for fixation. As shown in FIG. 5A and FIG. 5, in the prosthesis E in which the joint e having the tapered surface on the inner wall is integrally formed to receive the end B ₁ of the tapered bone B, the joint e There is _{one in} which the end portion B ₁ of the bone B is inserted into the concave portion and the two are joined by a bolt F without using cement.

In addition, as described in Japanese Examined Patent Publication No. 57-33056, there is a delivery body made of a ceramic material for joining a tubular bone portion composed of two bolt-like joint materials provided with external threads.

[Problems of the prior art] However, in general, in the case of surgical treatment by bone replacement, the bone is sensitive to the replacement material, the property of the bone itself is changed, and the replacement material is repeatedly repeated for a long time. The load acts, and the fracture strength due to fatigue becomes a problem.

Therefore, in the prosthesis A as shown in FIG. 4 which is most often used, the end face of the bone B comes into contact with the step D and the load is intensively applied. On the other hand, in bone, excessive concentrated load causes weakening of bone or bone resorption, resulting in peeling or breakage of cement C used for joining, and as a result, fixation with bone. There was a phenomenon that it could not be maintained. Moreover, the metal, ceramics, etc. forming the prosthesis have much greater rigidity than bone, and the rigidity changes rapidly at the joint, and it is almost impossible to follow changes in bone. Therefore, the bone and the cement and the cement insertion shaft portion are easily displaced from each other, which causes rattling. Once such rattling occurs, the rattling of the prosthesis becomes even greater, which eventually leads to bone destruction.

Further, in the case where the prosthesis E shown in FIG. 5 is joined to the bone B, in order to cut the end portion of the bone B into a conical shape that matches the taper surface of the joint portion e, a surgical method is used. Not only the number of steps is increased, but also the outer peripheral portion of the bone, which is a high-strength portion, is scraped off, resulting in the inconvenience that the bone is easily broken especially at the joined end portion.

Further, the one disclosed in Japanese Examined Patent Publication No. 57-33056 has a complicated structure and is extremely difficult to screw into and assemble into bone, making it impractical.

[Means for solving problems]

In view of the above, in order to hold the shaft part to be inserted into the bone and the bone into which the shaft part is inserted from the outer periphery with a cylindrical body, the shaft part is integrally screwed with the main body. To do.

〔Example〕

 Examples of the present invention will be specifically described below.

FIG. 1 is a diagram showing a state in which the prosthesis EP is attached to the bone B. Reference numeral 1 denotes a shaft to be inserted into the medullary cavity b of the bone B, and a screw groove 3 is provided on a main body 2 integrated with the shaft 1. Has been formed. A cylindrical body 4 that holds the bone B by being in close contact with the outer periphery of the lower end portion of the bone B is screwed into the screw groove 3, and the cylindrical body 4 is prevented from rotating at an optimum position. It is fixed with a nut 5. The prosthesis EP thus configured is prevented from falling off the bone B by the shaft 1 and is fixed to the bone B by fixing and holding the bone B, so that cement is used as a fixing means. No need to use.

Further, as another embodiment of the prosthesis EP according to the present invention, as shown in FIG. 2, the shaft 1 to be inserted into the bone B and the main body 2 are made as one body, and the cylindrical body 6 is attached to the main body 2. Insert, body 2
It is also possible to screw and fix the screw holes 2a pre-drilled at various positions through screw holes 6a formed in the cylindrical body 6 with screws 7 at optimum positions.

By the way, as the cylindrical bodies 4 and 6 for holding the bone B from the outer periphery, axial notches 4a are formed as shown in FIG. 3 in order to increase the adhesion to the bone B and to further secure and hold the bone B. It is preferable. By forming the notch 4a in this way, it is possible to adapt to the difference in the shape of the joint between the bone B and the prosthesis, gradually absorb and absorb the difference in rigidity, and follow the movement of the bone B to cover the entire joint. It is possible to disperse the applied stress. Also, not limited to the cut 4a,
By making the cylindrical bodies 4 and 6 thinner toward the tips, the followability to the movement of the bone B can be improved.

The material for forming the shaft 1, the main body 2, and the cylindrical bodies 4, 6 is not limited to metal, but may be ceramic material.

〔The invention's effect〕

As described above, according to the prosthesis of the present invention, it is extremely easy to attach to a living bone, and the degree of compatibility with the bone is increased. As a result, a large joint strength is obtained and stable use for a long period of time is achieved. It is possible that many people can save the affected limb by prosthesis after being removed due to accident or disease, and it is a great place to contribute to human welfare today.

[Brief description of drawings]

1 and 2 are sectional views showing a state in which the biological prosthesis according to the present invention is attached to bone, and FIG. 3 is another example of only a cylindrical body constituting the biological prosthesis according to the present invention. FIG. 4 is a cross-sectional view showing a state in which a bioprosthesis according to a conventional example is attached to a bone. 1: Shaft, 2: Main body, 3: Thread groove 4: Cylindrical body, B: Bone

Claims (2)

[Claims] 1. A shaft to be inserted into the medullary canal of a natural bone, and a main body which is integral with the shaft and has a thread groove formed around the shaft, and a cylindrical body which is open to at least the shaft is screwed to the main body, A bioprosthesis configured to be fixed at an arbitrary position. 2. A cylinder to be inserted into a medullary canal of natural bone, and a main body which is integral with the shaft and has a plurality of screw holes at axially different positions, and a cylindrical body which is open to at least the shaft. A living body prosthesis configured to be screwed and fixed at an arbitrary position.