JPH0529510U - Acetabular resection device - Google Patents

Abstract

(57) [Summary] [Structure] A revolving handle is attached to a cutting guide having a hemispherical shape as a whole so that a reamer connecting portion in a notch portion of the guide is swingable in a left-right direction. An acetabular bone resection device, wherein a reamer is attached to the connecting portion so as to be swingable in a predetermined movement range in the vertical direction. [Effect] When the acetabular bone resection device of the present invention is used, operability is good, operation time does not take long, safety is high, and accurate bone resection can be realized.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is intended to improve marked joint function deterioration and severe pain that occur when the human hip joint is highly deformed and destroyed by related diseases such as osteoarthritis, rheumatoid joint, and head necrosis. In arthroplasty, the acetabular prosthesis member, which has an approximately hemispherical shell and is provided with outer protruding shells at circumferential intervals at the periphery, is used to embed in the pelvic acetabulum. The present invention relates to a bone resection device as a surgical instrument.

[0002]

[Prior Art]

 The shape of the acetabular prosthesis member will be described with reference to the drawings. 11 is a plan view of the acetabular prosthesis member A 2, and FIG. 12 is a sectional view taken along line III III of FIG. As shown in both figures, the acetabular prosthesis member A has a substantially hemispherical shell as a whole, and has a peripheral edge a1 provided with outwardly projecting edges a2 at intervals in the circumferential direction.

The outer overhanging edge a2 contacts the cortical bone of the pelvic acetabular portion, and compared with the conventional acetabular prosthesis member A, the supporting area of the acetabular hard bone portion, that is, the cortical bone portion is substantially larger. The acetabular prosthesis member A is stably fixed by increasing the resistance against minute movements and movements such as rotation and inclination of the acetabular prosthesis member A, thereby extending the life of the acetabular prosthesis member A. It's for spreading.

In order to embed the acetabular prosthetic member A having such a shape in the pelvic acetabular portion, it is necessary to partially cut the acetabulum corresponding to the lateral overhanging edge a1. For example, in the surgical instrument device shown in U.S. Pat. No. 4,802,468, the purpose is to perform bone resection in accordance with a ridge-shaped protrusion over the entire circumference, and the outer acetabular prosthesis member A is provided with a space therebetween. It is not possible to perform bone resection into a shape in which the protruding edge a2 is embedded.

Such acetabular bone resection with respect to the acetabular prosthesis member A has been so far accurately and reliably controlled, and there is a dedicated instrument device capable of safely and stably performing a total hip arthroplasty. Instead, the surgeon performed bone resection using general surgical instruments such as fleas.

In the conventional bone resection using the above-mentioned general surgical instrument, a kerf forming guide is used in a portion into which the side surface of the outer overhanging edge a 2 is inserted, and a cleaver groove is formed in the acetabulum. A fleas insertion guide that guides the insertion of fleas in the depth direction is formed in the kerf, and the bone is cut so that the fleas follow the guide. After performing the bone resection in a general shape in this way, the accuracy of the bone resection is confirmed using a trial resection having the same size and outer shape as the acetabular prosthesis member A.

[0007] In the above-described method, usually, sufficient accuracy cannot be achieved. Therefore, after removing the trial excision again, the operator observes the condition of the bone resection and finds the defective portion with a surgical instrument such as a chisel or a file. The bone cut surface is cut or aligned with, and the final shape is finished by repeating the correction work many times while applying the trial extraction.

[0008]

[Problems of the prior art]

 In such a conventional surgical instrument, many years of skill are required for bone resection in order to accurately perform the bone resection operation by inserting a chisel along the guide surface.

In many cases, the acetabular prosthesis member A must be inserted while leaving an incorrect bone resection surface. Therefore, when the acetabular prosthetic member A is installed on the acetabulum, the fixing force cannot be obtained. That is, a gap of about 0.1 mm to 2 mm is created between the acetabular prosthesis member A and the bone cutting surface over a part or the entire circumference, which is the original purpose of the acetabular prosthesis member A. It is not possible to prevent movement that attempts to rotate or tilt with respect to the lid.

Further, in addition to the fact that a certain amount of force is required to insert a chisel, an excessive amount of force may be applied to a portion that is difficult to insert, which may result in inaccurate bone resection. is there. In addition, the guide itself may move within the acetabulum or may come off the acetabulum. If this kind of situation occurs during surgery, most of the cases the bone resection cannot be performed again, and the surgery itself for installing the acetabular prosthesis member A on the acetabulum must be stopped.

Further, depending on the position of the outer overhanging edge a1, the insertion position of the flea for bone resection may not be visible depending on the standing position of a normal operator. This is a very dangerous task. In some cases, it may irreparably damage surrounding tissue, and in such situations the operator must be very nervous. This impedes the sloppy progression of the surgery, and thus puts a great burden on the patient.

As described above, the first drawback of the conventional method is the lack of accuracy of osteotomy.

In the osteotomy of the outer overhanging edge a1 of the acetabular prosthesis member A, the flea insertion angle and depth are particularly important, and even if either the angle or the depth is improperly inserted, Installation of the lid prosthesis member A is not successful.

Further, the second problem of the conventional method is that the operability is poor and the operation time is long. The conventional method requires not only bone cutting with a chisel, but also finishing adjustment of the bone cutting surface with a file or the like.After that, the bone is checked using a trial extraction of the same size and outer shape as the acetabular prosthesis member A. It is necessary to repeat the cut adjustment. Therefore, the operation time becomes long, which imposes a great burden on the operator and the patient.

The third problem of the conventional method is to ensure safety. When a chisel is used as a bone-cutting instrument, the chisel's cutting edge pierces the inside of the acetabulum, making the cutting edge invisible to the operator. Since it is not possible to confirm where the cutting edge is cutting, it depends on the sense of the operator's hand. Therefore, it is a fundamentally insecure means.

[0016]

Means for Solving the Problems In order to solve the above problems, the present invention provides a bone resection device for performing bone resection to embed an acetabular prosthesis member having an outer overhanging edge at intervals in the circumferential direction of the opening edge. The device is: (a) It has a hemispherical shell as a whole, is provided with shell pieces and notches in the circumferential direction, and stands upright in the direction of the center of the hemisphere from a guide base near the top of the hemisphere. (B) A reamer connecting part having a structure such that the reamer shaft can be vertically swung within a predetermined operating range within the notch of the cutting guide. A swivel handle mounted on the swivel shaft of the resection guide so as to be swingable; and (c) a plurality of spiral cutting blades, one end of which is rotatably mounted on the swivel handle, and Mounted on an electric drive for giving rotation at the other end. Providing acetabular bone resection device consisting of: reamer to.

[0017]

【Example】

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

FIG. 1 is an exploded perspective view showing a acetabular bone resection device 1 (hereinafter, simply referred to as a device).

In the figure, 10 is a resection guide, 20 is a rotation handle, and 30 is a reamer having a plurality of spiral cutting blades 31 for bone resection, which are the basic components of the device 1. All of these are made of stainless metal.

Of these, the excision guide 10 is shown in a perspective view of FIG. 2. The excision guide 10 has a hemispherical shape as a whole, and the portion corresponding to the vicinity of the top of the hemisphere is the guide base 11, and in the circumferential direction. The guide base 11 is provided with a plurality of shell pieces 12 and a notch portion 15 which is a gap between a pair of side surfaces 12a, 12a of the shell piece 12, and from the central portion of the inner surface 11a of the guide base 11. The rotating shaft 13 is continuous and stands upright in the direction of the center of the hemisphere.

The plurality of shell pieces 12 are provided with screw holes 12c through which a fixing screw 60 or 61 described later penetrates vertically from the peripheral edge portion 12b. Further, inside the inner wall of the shell piece 12, an internal space 14 is formed which is rotationally symmetric with respect to the rotation axis 13.

The rotating shaft 13 has a cylindrical shape as a whole, and has a male screw portion 13a at its tip and a screw hole 13b for fixing in the central axis direction.

Next, the rotation handle 20 is shown in a perspective view of FIG. The turning handle 20 is composed of a cylindrical main body 21 and a reamer connecting portion 22, and has a bearing hole 23 bored in the longitudinal direction from the bottom surface of the main body 21 and for receiving the turning shaft 13.

A through hole 22a is bored at the tip of the shaft reamer connecting portion 22, and a reamer shaft portion 22c having a rod-shaped reamer shaft 22b protruding obliquely upward is formed in the through hole 22a in the vertical direction. It is fixed by a hinge pin 22d so that it can swing within a specific operating range.

Next, the reamer 30 is shown in a perspective view of FIG. The reamer 30 has a plurality of spiral cutting blades 31 arranged around the reamer 30, a reamer bearing hole 32 is bored inward from the bottom surface, and a chuck shaft 33 to be attached to a drive unit is provided at the tip. It is arranged.

Next, a method of assembling a device using each of the above-described basic constituent elements will be described below. First, the cutting guide 10 is fixed to a predetermined position of the acetabulum by a method described later, and then the turning shaft 13 of the cutting guide 10 is inserted into the bearing hole 23 of the turning handle 20.

At this time, the reamer connecting portion 22 of the turning handle 20 is housed in one of the plurality of notches 15 of the cutting guide 10 so as to be swingable in the left-right direction.

Next, insert the reamer shaft 22b of the turning handle 20 mounted on the cutting guide 10 as described above into the bearing hole 32 of the reamer 30 with the sleeve 40 made of polyethylene shown in FIG. The reamer 30 is attached to the swivel handle 20 by.

A sectional view of the device 1 assembled in this way is shown in FIG.

Since the circumference of the sleeve 40 slides on the wall surface of the bearing hole 32 of the reamer 30, the sleeve 40 is excellent in heat resistance, sliding characteristics, and wear resistance. A material that can withstand a high temperature of about 150 ° in the previous sterilization process is required.

Examples of such materials include resin materials such as Teflon and MC nylon in addition to polyethylene.

Next, a method of fixing the resection guide to the acetabular bone will be described. FIG. 7 is a perspective view showing a state in which the resection guide 10 is embedded in the acetabulum B of the acetabulum. The acetabulum B has an almost hemispherical recess, but since it is deformed due to joint disease, it is trimmed using a dedicated spherical reamer (not shown) to make it spherical.

When the diameter of the spherical surface of the acetabulum A trimmed in this way is 50 mm, a cutting guide 10 having a slightly larger size, preferably a spherical surface having a diameter larger by 2 mm, is prepared, and the cutting rod 50 shown in FIG. The threaded portion 13a at the tip of the rotary shaft 13 of the cutting guide 10 is screwed into the female threaded portion 50c to assemble the cutting guide 10 and the driving rod 50. Subsequently, while holding the shaft portion 50a by hand, the hammer rod strikes the hammering rod head 50b from above, and the cutting guide 10 is pressed onto the acetabulum B.

After that, the driving rod 50 is removed, a fixing screw 60 having a length of about 30 mm shown in FIG. 9 (a) is inserted into the screw hole 12c of the cutting guide 10 in which the fixing screw 60 is press-fitted, and the head 60a thereof is not manually rotated. Insert a male screw 60b to the bone bottom of the acetabulum B.

At this time, usually, two or three fixing screws 60 are used to ensure the fixation between the resection guide 10 and the acetabulum B, but if it is considered that the fixing property is still poor, Use a longer fixing screw 61 as shown in Fig. 9 (b), or screw the fixing screw 61 into the bone bottom through the screw hole 13b of the revolving shaft 13 of the cutting guide 10 to fix it. You can also increase your strength.

The straight diameter of the head 61a of the fixing screw 61 screwed into the screw hole 13b of the rotating shaft 13 is smaller than the diameter of the rotating shaft 13, and the fixing screws 60 and 61 are still inserted. However, the bearing hole 23 of the turning handle 20 can be inserted into the turning shaft 13.

Further, instead of the fixing screws 60 and 61 as described above, a pin having a similar size and shape may be used to fix the cutting guide 10, and a shell piece of the cutting guide 10 may be used. You may perform by providing a protrusion on the outer surface of 12.

Next, bone resection using the device 1 of the present invention will be described. As described above, the cutting guide 10 embedded in the acetabulum B is attached with the turning handle 20 and the turning handle 20 is attached with the reamer 30 by the above-described method. Next, as shown in FIG. The chuck portion 33 of 30 is attached to a commercially available electric drive device C.

To perform the bone resection, while operating the electric drive device C, the operator pushes down the electric drive device C with one hand so that the reamer 30 presses the acetabulum B, and also in the left and right directions. Is rotated with the other hand to the left and right to swing the reamer 30 in the cutout portion 15 in the left-right direction to perform bone resection with the spiral cutting blade 31 of the rotating reamer 30. .. Further, the turning handle 20 is detached from the turning shaft 13, and the turning handle 20 is reattached to the turning shaft 13 in the other cutout portion 15 so that the reamer connecting portion 22 is accommodated, and the above-mentioned work is repeated. Perform bone resection at that location. By doing this for all the notches 15, it is possible to make the shape compatible with the shape of the acetabular prosthesis member to be embedded.

As described above, the device 1 of the present invention is easy to operate and excellent in operability, and can easily and accurately perform bone resection within a predetermined operation range in both vertical and horizontal directions. In addition, since the bone resection can be performed while observing the state of the bone resection and the condition of the bone resection surface by the spiral cutting edge 31 of the reamer 30, if any trouble occurs, it is possible to notice immediately. It is also safe because you can stop the work immediately and prevent a fatal accident.

Regarding the above-mentioned movement in the left-right direction, the width of the reamer connecting portion 22 of the rotating handle 20 is made slightly larger than the diameter of the reamer 30 as shown in FIG. This is to prevent the reamer 30 from coming into contact with the shell piece 12 of the cutting guide 10, and thus the size of the cutout portion 15 depends on the width of the reamer connecting portion 22 and the diameter of the reamer 30. Design and manufacture considering the difference.

Further, the electric drive device C needs to change the rotation speed according to the bone quality of the acetabulum B, but a rotation speed of about 3,000 to 40,000 rpm is preferable, and generally a high-speed rotation. Rotating the reamer 30 by several times is superior in cutting performance. Compared with the conventional bone resection, the device 1 of the present invention uses the above electric drive device C as a power source, so that a bone resection that is quick, that is, does not require a long operation time, can be realized. However, at low speeds, the reamer 30 may bite into the bone of the acetabulum B, and rotation may be interrupted, or the reamer 30 may be repelled from the bone even when trying to contact the bone and the reamer 30. I need to know.

[0043]

[Effect of the device]

 As described above, when the acetabular bone resection device of the present invention is used, operability is good, operation time does not take long, safety is high, and accurate bone resection can be realized.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an acetabular bone resection device of the present invention.

FIG. 2 is a perspective view showing a resection guide of the acetabular bone resection device of the present invention.

FIG. 3 is a perspective view showing a rotation handle of the acetabular bone resection device of the present invention.

FIG. 4 is a perspective view showing a reamer of the acetabular bone resection device of the present invention.

FIG. 5 is a perspective view showing a sleeve used in the acetabular bone resection device of the present invention.

FIG. 6 is a partially cutaway sectional view showing the acetabular bone resection device of the present invention.

FIG. 7 is a perspective view showing a state in which a guide for resecting the acetabular bone resection device of the present invention is installed on the acetabulum.

FIG. 8 is a perspective view showing a driving rod used to install a guide for resection of the acetabular bone resection device of the present invention on the acetabulum.

FIG. 9 is a perspective view of a fixing screw used to install the guide of the acetabular bone resection device resection of the present invention on the acetabulum.

FIG. 10 is a top view showing the acetabular bone resection device of the present invention and an electric drive device which is a power source of the device.

FIG. 11 is a top view showing an acetabular prosthesis member having an outwardly projecting edge, in which the acetabular bone resection device of the present invention is used.

12 is a sectional view taken along line III-III in FIG.

[Explanation of symbols]

 A: Acetabular prosthesis member B: Acetabulum C: Electric drive device 1: Acetabular bone resection device 10: Resection guide 11: Guide base 12: Shell piece 13: Rotation axis 14: Internal space 15: Notch 20: Rotation Handle 21: Body part 22: Reamer connection part 23: Revolving bearing hole 30: Reamer 31: Spiral cutting edge 32: Reamer bearing hole 33: Chuck part 40: Sleeve 50: Driving rod 60: Fixing screw

Claims (1)

[Scope of utility model registration request] 1. A bone resection device for performing bone resection for embedding an acetabular prosthesis member having an outwardly extending edge at intervals in the circumferential direction of an opening edge, the device comprising: (a) a hemispherical shell as a whole. A cutting guide having a shell piece and a cutout portion in the circumferential direction, and a swivel shaft standing upright in the direction of the center of the hemisphere from a guide base near the top of the hemisphere; The reamer shaft is attached to the revolving shaft of the resection guide so that the reamer connecting part having a structure in which the reamer shaft part can swing vertically within a predetermined operation range can swing left and right. (C) A reamer having a plurality of spiral cutting blades, which is rotatably attached to the above-mentioned rotation handle at one end and is attached to an electric drive device for giving a rotational force at the other end; Acetabular bone resection device.