JPH0548917U - Artificial elbow joint and bone cutting jig used for bone cutting to install it - Google Patents

Abstract

(57) [Summary] (Correction) [Structure] A sliding member 2 having a U-shaped curved portion, a press-fitting portion integrally formed in the center of the inner bottom portion of the sliding member, and a stem member 3 connected to the press-fitting portion. The artificial elbow joint L including the humeral component A and the block-shaped osteotomy guide 7 having the overhanging portion including the frontal osteotomy guide surface that guides the reference osteotomy, the humeral component press-fitting of the artificial elbow joint U-shaped bone cutting guide for guiding a bone cutting for a part, and a U-shaped bone guiding a bone cutting for fitting to the U-shaped curved portion of the humeral component. A bone-cutting jig used in a bone-cutting operation for setting an artificial elbow joint having a U-shaped bone-cutting guide 10 having a cutting guide surface. [Effect] By using the artificial elbow joint and the bone cutting jig of the present invention, it is possible to install the artificial elbow joint without a gap between the humeral component and the humerus.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention provides the function of the elbow joint that forms joints due to diseases such as rheumatoid arthritis and osteoarthritis, and causes the joints such as the humerus and ulna to deform or break, resulting in pain and limited range of motion. The present invention relates to an artificial elbow joint used for reconstruction and an osteotomy jig used for osteotomy for installing the artificial hip joint.

[0002]

[Prior Art]

 As shown in FIG. 9, a conventional artificial elbow joint L has a concave sliding member a1 for replacing the joint sliding portion at the distal end of the humerus and a rod-shaped stem member to be inserted into the medullary cavity of the upper arm. The humeral component A is composed of a2, and the ulnar component B is composed of a convex sliding member b1 corresponding to the concave sliding member a1 and a rod-shaped stem member b2 inserted into the ulnar bone marrow cavity. .

The humerus component A of the artificial elbow joint L excavates and cuts the distal end of the humerus into a shape that matches the size and shape of the humeral component A, and applies bone cement to that location. Placed in the humerus with or without press fitting of bone cement.

As the bone cutting jig used at that time, as shown in FIG. 10 (a), a slit in which the screw fixing part c1 having a through hole c5 through which the guide steel wire k penetrates is vertically movable. A block-shaped bone cutting jig C in which c2 is perforated is used. The guide steel wire k inserted along the longitudinal central axis (hereinafter referred to as the medullary cavity axis) T ₅ of the brachial bone marrow cavity T ₂ is passed through the through hole c5 of the screw fixing portion c1 and the bone Fix the cutting jig C at the position where it abuts the humerus T, perform the bone cutting work using the electric saw for operation (not shown) with the side surfaces c3, c3 as the guide surface, and further along the front resection guide surface c4. Perform the bone cutting work with the above-mentioned surgical electric saw. Then, pull the steel wire k for the guide from inside the upper arm bone marrow cavity T _2, the longitudinal central axis of the stem member a2 of the humeral component A the medullary space T ₂ using the surgical reamer (not shown) An insertion hole for insertion is drilled so as to match the medullary cavity axis T ₅ .

The bone cutting work is performed as described above to form a bone cutting surface T ₁ on the humerus T as shown in FIG.

[0006]

[Problems of the prior art]

If the conventional artificial elbow joint L is used to replace the pain caused by diseases such as rheumatoid arthritis and osteoarthritis and the range of motion of the elbow joint is replaced by the artificial elbow joint L described above, Although the pain relief effect and the improvement of the range of motion are remarkable, there was a problem that the humerus T and the humeral component A loosened and subsided with the passage of time after the operation. This is because fixing of the humeral component A to the humerus T corresponds to the humeral component A by using the bone cutting jig C and by using the humeral bone cavity T ₂ and the joint sliding portions at the distal end of the humerus T. It is only to excavate and cut into size and shape, and then press-fit and fix the humeral component A with cement or without cement, for example, humeral component A. This is because no measures have been taken to prevent the humerus from loosening and sinking due to the load from the direction. In addition, the above-mentioned bone resection work involves cutting out a wide range of the joint sliding part at the distal end of the humerus T, and the humerus component A must be supported by the small amount of bone remaining after the bone resection. Therefore, the joint sliding part may be deformed or destroyed.

Further, the above-mentioned bone cutting jig C has the following problems. When performing the bone cutting work of the distal end of the humerus T using the above bone cutting jig C, the guide steel wire k to be inserted along the medullary cavity axis T ₅ is used as a reference as described above. The bone cutting jig C is installed at a predetermined position as an axis, but the distal end of the humerus T has a complicated curved surface shape, and therefore the portion where the bone cutting jig C and the humerus T contact each other. Since there are few, it cannot be fixed stably. As a result, the bone-cutting jig C sways during the bone-cutting work, making it very difficult to perform the accurate bone-cutting work.

[0008] In the osteotomy working with the osteotomy jig C, urchin match the central axis of the stem member a2 of humerus component A on the insertion as described above in the medullary腔軸T ₅ carry out. Bone Therefore along the medullary腔軸T ₅ front osteotomy guide surface c4 of osteotomy jig C installed in the distal end of the guiding steel wire k for insertion Guides humerus T along a Since the bone cutting work is performed, if the bone cutting jig C is displaced from a predetermined position, the concave sliding member a1 and the bone cutting surface T of the humerus component A to be installed on the humerus T are set. There will be a gap between it and ₁ .

If the fixation of the humeral component A of the artificial elbow joint L is insufficient due to the above reasons, even a small gap at the beginning will gradually increase. As a result, it causes changes in bone quality such as bone resorption, which inevitably results in removal and revision of humeral component A.

[0010]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention comprises a sliding member having a U-shaped curved portion, a press-fitting portion integrally formed at the center of the inner bottom portion of the sliding member, and a stem member connected to the press-fitting portion. Bone for the artificial elbow joint with the humerus component and the reference osteotomy for guiding the osteotomy as a reference, a block-shaped osteotomy guide having an overhanging portion with a frontal osteotomy guide surface, and a humeral component press-fitting portion for the artificial elbow joint U-shaped bone-cutting guide surface for guiding the cutting U-shaped bone-cutting guide surface having a U-shaped bone-cutting guide surface and U-shaped bone cutting guide surface for guiding the bone-cutting to fit the U-shaped curved portion of the humeral component It is intended to provide a bone-cutting jig used for a bone-cutting work for setting an artificial elbow joint having a character-shaped bone-cutting guide.

[0011]

【Example】

Embodiments of the present invention will be specifically described below with reference to the drawings. Embodiment 1 FIG. 1 is a perspective view showing a humeral component (hereinafter abbreviated as component) 1 of an artificial elbow joint of the present invention. The component 1 comprises a sliding member 2 made of a polycrystalline alumina ceramic for reproducing a deformed and destroyed distal end of the humerus and a stem member 3 made of a single crystal aluminum ceramic to be inserted into the medullary cavity of the humerus. .

The sliding member 2 has a concave portion 2a at the center, U-shaped portions 2b, 2b for embracing a bone cut bone on the left and right sides of the concave portion 2a, and further, inside the sliding member 2. A press-fitting portion 2d is provided at a connecting portion with the stem member 3 located in the center of the bottom portion 2c. The press-fitting portion 2d has a diameter larger than that of the stem member 3 and has reinforcing portions 2f integrally bridged to both inner walls of the U-shaped curved portion 2b as shown in FIG. It's okay. Since the sliding member 2 is provided with the U-shaped curved portions 2b and 2b, the amount of osteotomy of the humerus T for installing the component 1 may be very small, and the component 1 may be osteotomized. Since the distal end of the humerus T is fixed in a state of embracing it, the bone does not loosen or sink.

The stem member 3 is rod-shaped to be inserted into the medullary cavity of the upper arm, and may have a taper. In addition, a chamfered portion 3a or a groove 3b may be provided at the tip portion to prevent rotation.

As the material of the sliding member 2 and the stem member 3, a ceramic material other than alumina ceramics, for example, zirconia, apatite, etc. may be used, and further, stainless steel, cobalt chromium alloy, pure titanium, titanium alloy, etc. The above metal material, or a combination of the above ceramic material and metal material may be used. Whichever material is used, the surface roughness of the sliding surface 2e of the sliding member 2 is preferably Rmax 6.3 or less. If it is larger than Rmax 6.3, the sliding characteristics of the sliding surface 2e are not sufficient and a large amount of abrasion powder is generated. As for the portion of the inner bottom portion 2c that comes into contact with the bone, it is preferable to use a groove for allowing living bone to grow and enter, coating with apatite, or a porous material of the above material. preferable.

Example 2 Next, a bone cutting jig for setting the above component 1 in the humerus is provided: 1) excavation in the humeral cavity of the humer, 2) basic bone cutting of the distal end of the humer, 3) Press-fitting partial osteotomy of the distal end of the humerus, 4) U-shaped osteotomy to the left and right of the distal end of the humerus, and the actual osteotomy that is roughly divided into the above four steps. Each component of the bone cutting jig of the present invention is made of a metal material such as stainless steel.

[Excavation Work in the Upper Bone Marrow Cavity] In order to perform an accurate bone cutting work for installing the component 1 in the humerus, first, a reference axis serving as a bone cutting reference is set. For this purpose, excavation is performed in the medullary cavity of the humer along the axis of the medullary cavity of the humerus. When the component 1 is placed on the humerus, the following excavation and osteotomy work is performed so that the central axis of the stem member 3 in the longitudinal direction coincides with the axis of the medullary cavity.

As shown in FIG. 2, a guide steel wire k is inserted and fixed in the brachial bone marrow cavity T ₂ along the axis T ₅ of the medullary cavity. Next, a reamer 4 having a through hole 4a in the central axis direction is inserted into the bone of the upper arm bone marrow cavity (hereinafter abbreviated as medullary cavity) T ₂ while inserting the guide steel wire k into the through hole 4a. The medullary cavity T ₂ is excavated by pushing it in until it abuts it and then rotating it along the guide steel wire k. The reamer 4 can be prepared for various excavations by preparing various sizes from small diameter to large diameter and using them in order from small diameter to large diameter. In addition, for the finish, the one having substantially the same size and shape as the stem member 3 of the component 1 is used, and the insertion hole for inserting the stem portion 3 is drilled.

[Basic Bone Cutting Operation of Distal Humerus] Next, a basic bone cutting is performed by using the steel wire for guide k installed so as to coincide with the medullary cavity axis T ₅ as a reference axis for bone cutting.

In the component 1, as shown in FIG. 3, the central axis in the longitudinal direction of the stem member 3 has an inclination of θ ° with respect to the central axis of the sliding member 2.

The humerus T and the ulna that compose a human elbow joint are normally in a position where they have an inclination of 5 ° to 7 ° with each other in a normal state, but in the artificial joint of the present invention, the deformed and destroyed joints are To reconstruct the function, the operator selects and uses a component having the above-mentioned θ ° in the range of 0 ° to 10 ° depending on the case. This basic bone cutting is to cut the portion corresponding to F of the sliding member 2 shown in FIG. 3, and thus forms a surface inclined by θ ° with respect to the plane perpendicular to the medullary cavity axis T _5. I have to do it.

Therefore, the basic bone cutting work was carried out as follows. As shown in FIG. 4, a shaft portion 5b having a shape and dimensions corresponding to the excavated portion of the medullary cavity T ₂ and the stem member 3 of the component 1 and a cylindrical portion having a diameter smaller than the diameter of the shaft portion 5b. A rod 5 having a through hole 5a for inserting the guide steel wire k in the central axis direction is fixed to the humerus T while inserting the guide steel wire k into the through hole 5a.

Next, a tubular guide 6 having a cylindrical shape as a whole and having an insertion hole 6a having a hole diameter substantially the same as the diameter of the cylindrical portion 5c of the rod 5 is attached to the insertion hole 6a. It is attached around the cylindrical portion 5c penetrating therethrough. Next, a block-shaped bone cutting guide 7 consisting of an overhanging portion 7b having a front bone cutting guide surface 7a having an inclination of θ ° and a main body portion 7d having a slit 7c is provided on the stepped portion 6b of the tubular guide 6 with the slits. Fit and install 7c.

Next, the tubular guide 6 fitted with the block-shaped bone cutting guide 7 is pushed until the main body portion 7d of the block-shaped bone cutting guide 7 comes into contact with the humerus T, and then, in that state, A fixing pin (not shown) is arbitrarily inserted into the humerus T through a plurality of pin holes 7e formed in the body 7d to fix the block-shaped osteotomy guide 7 to the humerus T.

After this fixing is completed, a bone cutting operation is performed along the front bone cutting guide surface 7a by using a surgical electric saw (not shown). In this basic osteotomy, while maintaining the guide steel wire k aligned with the medullary cavity axis T ₅ as the reference axis, the block-shaped osteotomy guide 7 is inclined at θ ° at the overhanging portion 7b. The front bone cutting guide surface 7a having a tilt has an inclination of θ ° with respect to a plane perpendicular to the medullary cavity axis T ₅ so as to correspond to the shape of the component 1, and also serves as a reference for the following bone cutting work. It is possible to accurately and accurately form the bone cutting surface.

[Bone cutting work of the press-fitted portion of the distal end of the humerus] Next, bone cut of the press-fitted portion of the distal end of the humerus T into which the press-fitted portion 2d shown in FIGS. As shown in FIG. 5 (a), the rod 5 is inserted into the insertion hole 8d provided in the central axis direction of the guide base 8 including the block-shaped portion 8b having the contact surface 8a having the inclination of θ ° and the tubular portion 8c. of inserting the cylindrical portion 5c, the abutment surface 8a of the guide base 8 pushes up the guide base 8 where in contact with the bone resection plane T _3.

Next, the mounting protrusions 8e, 8e of the guide base 8 are inserted into the mounting holes 9a, 9a of the U-shaped bone cutting guide (hereinafter, abbreviated as guide) 9 having a U-shaped cross section in this state. Insert the above guide 9 into the guide base 8 so that 8e is inserted, and further insert a fixing pin (not shown) arbitrarily into the humerus T by a plurality of pin holes 9b that penetrate vertically and fix it. .

It should be noted that the guide 9 and the guide base 8 may be attachable / detachable by means of the mounting projections 9c, 9c of the guide 9 and the mounting holes 8e, 8e of the guide base 8 as shown in FIG. 5B. .

FIG. 6 is a top view showing a state in which the guide 9 is fixed to the humerus T, and is used for performing a bone cutting operation of a portion corresponding to the press-fitting portion 2d of the component 1 shown in FIGS. 1 and 3. The figure shows that 9 is installed correctly.

After the installation of the guide 9 is completed, an osteotomy electric saw (not shown) is used along the U-shaped bone cutting guide surface (hereinafter referred to as a guide surface) 9d of the guide 9 to cut the bone. An operation is performed to form the bone cutting surface T ₄ shown in FIG. 7.

As described above, also in this bone cutting operation, the guide surface 9d of the guide 9 is used to maintain the component 1 while maintaining the guide steel wire k aligned with the anterior medullary cavity axis T ₅ as the reference axis. It is possible to perform an accurate and reliable bone cutting operation of the press-fitted portion of the distal end of the humerus T into which the press-fitted portion 2d is press fitted. The escapes 9e provided at the two corners of the guide surface 9d are for preventing the damage of the blade of the electric saw for surgery described above.

[U-Shaped Bone Cutting Operation of Distal Humerus] Next, the U-shaped curved portions 2b, 2b at the left and right ends of the sliding member 2 of the component 1 embrace the distal end of the humerus T. Perform bone cutting work to enable

[0032] The guide a steel wire k and the rod 5 withdrawal from intrathecal T _2, the same shape as the stem member 3 before Symbol Component 1 as shown in FIG. 7, has the same dimensions, drilling of the medullary cavity T ₂ A U-shaped bone cutting guide 10 having a stem portion 10a to be inserted into a cut portion and a U-shaped bone cutting guide surface 10b, and a guide block portion 10c having the same shape and size as the press-fitting portion 2d of the component 1 is provided. Insert and fix in the humerus T.

A state in which the U-shaped bone cutting guide 10 is installed on the humerus T is shown in FIG. 8, and in this state, a surgical electric saw (not shown) is used along the above-mentioned U-shaped bone cutting guide surface 10b. Carry out the bone cutting work.

In this bone cutting operation, the stem portion 10a of the U-shaped bone cutting guide 10 has the same shape and the same size as the stem portion 3 of the component 1, and therefore, the excavated portion of the medullary cavity T ₂ without rattling. U-shaped osteotomy guide block surface 10b of the osteotomy guide block portion 10c having the same shape and size as the press-fitted portion 2d of the component 1, so that the distal end of the humerus T is formed into the U-shape of the humeral component 1. It is possible to accurately and surely perform the bone cutting work for fitting the curved portions 2b, 2b.

As described above, if the bone cutting jig of the present invention is used, three types of bones including the block-shaped bone cutting guide 7, the U-shaped bone cutting guide 9 and the U-shaped bone cutting guide 10 are used. The cutting guide ensures accurate bone cutting without any gap between the artificial humeral joint and humeral component 1.

[0036]

[Effect of the device]

 As described above, by using the artificial elbow joint of the present invention, a small amount of bone is cut at the distal end of the humerus, and the bone cut portion at the distal end of the humerus is held and fixed to the humerus. As a result, it can be securely fixed without causing loosening or sinking. Further, by using the bone cutting jig of the present invention, it is possible to surely perform an accurate bone cutting without forming a gap with the humerus component.

[Brief description of drawings]

FIG. 1A is a perspective view showing a humeral component of an artificial elbow joint of the present invention, and FIG. 1B is a plan view of the artificial elbow joint as seen from the side of a stem member.

FIG. 2 is a perspective view showing a state of excavation of an upper arm bone marrow cavity.

FIG. 3 is a partial top view showing the humeral component of the artificial elbow joint of the present invention.

FIG. 4 is a perspective view showing a state of basic bone cutting work of a distal end of a humerus using the bone cutting jig of the present invention.

FIG. 5 (a) is a perspective view showing a bone cutting operation of the press-fitted portion of the distal end of the humerus using the bone cutting jig of the present invention, and (b) is a guide base and a U-shaped bone. It is a perspective view which shows another aspect of a cutting guide.

FIG. 6 is a top view showing a U-shaped bone cutting guide installed on the humerus.

FIG. 7 is a perspective view showing a U-shaped bone cutting operation on the left and right of the distal end of the humerus using the bone cutting jig of the present invention.

FIG. 8 is a side view showing a state in which a U-shaped bone cutting guide is installed on the humerus.

FIG. 9 is a perspective view showing a conventional artificial elbow joint.

FIG. 10A is a perspective view showing a state of bone cutting work for installing a conventional artificial elbow joint on a humerus;
FIG. 4 is a perspective view showing a humerus having a bone cutting surface formed by the above bone cutting work.

[Explanation of symbols]

 1: Humerus component 2: Sliding member 3: Stem member 4: Reamer 5: Rod 6: Tubular guide 7: Block-shaped bone cutting guide 8: Guide base 9: U-shaped bone cutting guide 10: U-shaped bone cutting Guide k: Steel wire for guide T: Humerus A: Humerus component B: Ulna component L: Artificial elbow joint

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Murasawa 3-4-30 Terakami, Niigata City

Claims (2)

[Scope of utility model registration request] 1. An artificial body comprising a sliding member having a U-shaped curved portion, a press-fitting portion integrally formed in the center of an inner bottom portion of the sliding member, and a humerus component formed by connecting a stem member to the press-fitting portion. Elbow joint. 2. A block-shaped osteotomy guide having an overhanging portion provided with a frontal osteotomy guide surface for guiding a reference osteotomy, and a guide for osteotomy for humeral component press-fitting portion of an artificial elbow joint. A U-shaped bone cutting guide having a U-shaped bone cutting guide surface, and a U-shaped bone cutting guide having a U-shaped bone cutting guide surface for guiding the bone cutting to fit the U-shaped curved portion of the humeral component. A bone-cutting jig used for a bone-cutting work for setting up an artificial elbow joint.