JP3699585B2 - Osteotomy device for proximal femur - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an osteotomy device for a proximal end of a femur for installing a stem of an artificial hip joint to be applied to a human body on the femur.
[0002]
[Prior art]
As a means for restoring the function of a hip joint that has lost its normal function due to an accident or illness, there is a method of prosthetic an artificial hip joint.
[0003]
A hip prosthesis has a stem embedded in the femur and an artificial headball fixed to the tip of the hip joint. On the other hand, if the acetabular side is severely damaged, the headball slides on the corresponding part of the acetabulum. Although the hip joint is a part that receives a very large load, the stem material embedded in the femur is made of a metal material that is not harmful to the living body, such as a titanium alloy. Yes. In order to fix the stem, the metal material is not toxic, but does not chemically react with the living body and adhere to it, so it is often adhered to the femur using bone cement or the like. It was.
[0004]
However, even when bone cement is used in this way, if a gap begins to form between the bone cement and the stem after many years of use, the load will concentrate on the intertrochanteric portion of the bone due to loosening, which is the cause. Bone resorption occurs between the trochanters. As such a state progresses, the stem cannot be supported safely due to a lack of bone mass, and a replacement of the hip prosthesis is forced.
[0005]
FIG. 1 shows a stem A for replacement used in recent years. This stem A has a plate-like vertical overhanging edge A1 at the proximal end and a plate-like horizontal crossing over the vertical overhanging edge A1. Equipped with an overhanging edge A2, and the stem A is stably supported by the remaining bone by excising the bone at the intertrochanteric region where the bone mass has decreased and joining the overhanging edge and the osteotomy surface. It was developed to be able to.
[0006]
However, the hip replacement replacement stem having a plate-like vertical overhanging edge and a plate-like horizontal overhanging edge intersecting the vertical overhanging edge at the proximal end as described above is installed. In the past, there has been no suitable dedicated surgical instrument in order to perform accurate bone cutting.
[0007]
[Problems to be solved by the invention]
As described above, since there was no appropriate dedicated surgical instrument for installing the stem, conventionally, the accuracy of the surgeon's experience, technology, and can must be relied on, and the osteotomy surface and the stem There was a risk that loosening was likely to occur between them, causing pain that could not be tolerated by the patient, and re-substitution was required due to the progress of bone resorption.
[0008]
Therefore, in view of such a conventional problem, the present invention provides a replacement for an artificial hip joint having a plate-like vertical overhanging edge at the proximal end and a plate-like horizontal overhanging edge intersecting the vertical overhanging edge. It is an object of the present invention to provide a prosthetic stem that can be installed without loosening by accurate bone cutting, and to safely prosthesis the affected area for a long period of time even after replacement.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a stem-type cutting guide and an extra-bone cutting guide that is fixed on the stem-type cutting guide and includes a curved guide arm that extends in a horizontal direction outside the bone. Among these cutting guides, the stem-type cutting guide is provided with a blade guide slit extending in the vertical direction from the upper end surface, and using this, the outer surface of the vertical overhang edge is used. The bone cutting guide is formed so as to form a bone surface to be face-to-face joined, while the extra-osseous cutting guide extends a horizontal blade guide slit to the curved guide arm and uses this Thus, it is possible to perform osteotomy for forming a bone surface to be face-to-face bonded to the lower surface of the horizontal overhanging edge.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0011]
Following normal reaming of the distal femur and broaching of the proximal portion, in this embodiment, osteotomy is performed in five stages, Step 1 to Step 5, as shown in FIG. That is, a bone for installing a replacement stem A for a hip prosthesis having a plate-like vertical overhanging edge A1 and a plate-like horizontal overhanging edge A2 intersecting the vertical overhanging edge A1 at the proximal end. In cutting, in step 1, bone cutting is performed to form a bone surface that is face-to-face joined to the lower surface of the horizontal overhanging edge A2. Further, in step 2, bone cutting is performed as a preparation for forming a portion to be fitted with the swing preventing projection A3 formed at the center of the horizontal overhanging edge A2, and in step 3, the vertical cutting is performed. Bone cutting is performed to form a bone surface that is face-to-face joined to the outer surface of the overhang edge A1. Further, in step 4, bone cutting for bolting is performed in order to fix the stem to the bone with a bolt, and in step 5, it is engaged with the swing preventing projection A3 formed at the center of the horizontal overhanging edge A2. Make a final osteotomy of the part.
[0012]
Preparation before osteotomy (setting of cutting guide)
First, prior to the osteotomy in steps 1 to 5, the stem type cutting guide 13 is attached to the tip of the broach handle 1 as shown in FIG. 2, and the stem type cutting guide 13 is inserted into the femoral bone marrow cavity. As shown in FIGS. 3A and 3B, the outer shape of the stem type cutting guide 13 is substantially the same as the outer shape of the replacement stem A excluding the horizontal overhanging edge A2 and the vertical overhanging edge A1. Match.
[0013]
Further, the proximal end surface thereof is provided with a shaft 13a for setting an after-bone cutting guide, which will be described later, and a blade guide slit 13b for guiding the blade at the time of bone cutting in Step 3 from the upper end surface. ing.
[0014]
Next, as shown in FIGS. 4 to 8, the extra-osseous cutting guide 18 is installed on the shaft 13 a of the stem-type cutting guide 13, and the pin 15 for preventing excessive osteotomy is inserted from the extra-osseous cutting guide 18 to the stem-type cutting guide 13. (See FIG. 8). As shown in FIG. 4, the extraosseous cutting guide 18 has a fitting portion 18b integrally provided at the upper end of a vertical bar-shaped handle 18a and a curved guide arm 18c integrally provided at the lower end thereof. The joint portion 18b is provided with a fitting through hole 18d and a lock bolt 18e acting in the fitting through hole 18d. On the other hand, the curved guide arm 18c is horizontally oriented with respect to the handle 18a from one side to the other side. A blade guide slit 18f is formed which extends and guides the blade when cutting the bone in step 1.
[0015]
As shown in FIG. 5, an extra-osseous cutting guide 18 is mounted on the stem-type cutting guide 13, and a lock bolt 18 e is fastened with a screwdriver 22 mounted on the tip of a T-type ratchet handle 21. The cutting guide 18 is fixed. Subsequently, as shown in FIG. 6, a small hole is formed in the femur by the drill 16 through a round hole-shaped drill guide hole 18 g provided at one end of the blade guide slit 18 f. The drill guide hole 18g is positioned coaxially with the drill guide hole 13c (see FIG. 3) provided in the blade guide slit 13b of the stem type cutting guide 13, so that the drill guide hole of both members is formed by this drilling. 13c and 18g will communicate. The reason why there are a plurality of drill guide holes 18g as shown in FIG. 7 is that the positions of the guide holes differ depending on the size of the stem type cutting guide 13 (= stem size).
[0016]
Finally, as shown in FIG. 8, the pin 15 is inserted from the drill guide hole 18g, leaving the rear end portion, and preparation for bone cutting is completed.
[0017]
Osteotomy operation Next, the osteotomy operations of Step 1 to Step 5 are performed as shown in FIGS.
[0018]
First, as shown in FIG. 9, the blade 19a of the oscillator 19 is acted on by guiding the blade guide slit 18f of the curved guide arm 18c to perform horizontal bone cutting (step 1). Subsequently, as shown in FIG. 10, a 6 mmφ drill is caused to act by guiding a large-diameter drill guide hole 18h provided on the side opposite to the position where the pin 15 is installed, and is formed at the central portion of the horizontal overhang edge A2. Bone cutting is performed as a preparatory preparation for forming a portion to be fitted with the swinging prevention projection A3 (step 2). After the above osteotomy is performed, as shown in FIG. 11, the pin 15 is driven out from the curved guide arm 18c toward the opposite side using the slot hammer 2 and the pin driving device 14, and the lock bolt 18e is loosened. Then, the extrabone cutting guide 18 is removed.
[0019]
Next, as shown in FIG. 12, the blade 19a of the oscillator 19 is acted on by the guidance of the blade guide slit 13b of the stem type cutting guide 13 installed in the femur, and vertical bone cutting is performed ( Step 3). Further, as shown in FIG. 13, the drill guide 17 is fixed, and bone cutting for bolting is performed to fix the stem to the bone with a bolt (step 4).
[0020]
After the above osteotomy, the drill guide 17 and the stem-type cutting guide 13 are removed, but at this stage, the osteotomy has been completed only on one side both in the horizontal and vertical directions. Therefore, using the already formed osteotomy surface as a guide, osteotomy is also performed on the opposite side to obtain an osteotomy state as shown in FIG.
[0021]
Finally, as shown in FIG. 14, the final osteotomy is performed on the portion that fits with the swing preventing projection A3 formed at the center of the horizontal overhanging edge A2 by the chisel 24 provided with the bowl-shaped blade 24a ( Step 5).
[0022]
As mentioned above, although the embodiment of the present invention has been specifically exemplified, the present invention is not limited to the above-described embodiment, and may be arbitrarily modified within a range not departing from the object of the invention, such as improvement as necessary. It goes without saying that it can be in the form.
[0023]
【The invention's effect】
As described above, according to the present invention, a prosthetic hip joint having a plate-like vertical overhanging edge at the proximal end and a plate-like horizontal overhanging edge intersecting the vertical overhanging edge by accurate bone cutting. The replacement stem can be installed without loosening, and the affected part can be safely prosthetic for a long period of time even after replacement.
[Brief description of the drawings]
FIGS. 1A and 1B are explanatory diagrams for illustrating a bone cutting step according to an embodiment of the present invention.
FIGS. 2A and 2B are perspective views showing a mounting method and a state of a stem type cutting guide in the embodiment of the present invention.
3A and 3B are shape comparison diagrams of the stem-type cutting guide shown in FIG. 2 and the replacement stem to be mounted.
FIG. 4 is an explanatory view showing a state in which an extra-bone cutting guide constituting the instrument of the present invention is attached to a stem-type cutting guide.
FIG. 5 is another explanatory view showing a state in which the extra-bone cutting guide constituting the instrument of the present invention is fixed to the stem-type cutting guide.
FIG. 6 is an explanatory view showing a state in which a pin hole is formed by the extra-bone cutting guide.
FIG. 7 is a front view showing the extra-osseous cutting guide in a fixed state.
FIG. 8 is an explanatory view showing a state where a pin is inserted into an extra-bone cutting guide.
FIG. 9A is an explanatory diagram showing a horizontal osteotomy method in the embodiment of the present invention, and FIG. 9B is an explanatory diagram showing corresponding steps.
FIG. 10A is an explanatory view showing a bone cutting method as a preparatory preparation for forming a portion that fits with a swing prevention protrusion in the embodiment of the present invention, and FIG. 10B shows the corresponding steps. It is explanatory drawing for showing.
FIG. 11 is an explanatory view showing a pin punching method in the embodiment of the present invention.
FIG. 12A is an explanatory diagram showing a vertical osteotomy method in the embodiment of the present invention, and FIG. 12B is an explanatory diagram showing corresponding steps.
FIG. 13A is an explanatory view showing a bone cutting method for screwing in an embodiment of the present invention, and FIG. 13B is an explanatory view showing corresponding steps.
FIG. 14A is an explanatory view showing a final osteotomy method for forming a portion to be fitted with the swing preventing projection in the embodiment of the present invention, and FIG. 14B is a view showing corresponding steps. It is explanatory drawing of.
[Explanation of symbols]
A Replacement stem A1 Vertical overhanging edge A2 Horizontal overhanging edge A3 Oscillation prevention protrusion 1 Broach handle 13 Stem type cutting guide 13a Shaft 13b Blade guide slit 13c Drill guide hole 15 Pin 16 Drill 17 Drill guide 18 Extra-bone Cutting guide 18a Handle 18b Fitting portion 18c Curved guide arm 18d Fitting through hole 18e Lock bolt 18f Blade guide slit 18g Drill guide hole 19 Oscillator 19a Blade 21 Ratchet handle 22 Cutting driver 24a Blade 24 chisel

Claims (2)

An osteotomy device that uses a stem-type cutting guide that is inserted into the femoral bone marrow cavity so that the extra-osseous cutting guide is detachably fixed, and includes a blade guide slit that extends vertically from the upper end surface of the stem-type cutting guide. In addition, the osteotomy instrument for the proximal end of the femur comprising a horizontal blade guide slit in a curved guide arm extending in the horizontal direction from the lower end of the extra-bone cutting guide. Coaxial through holes are provided in the blade guide slit of the stem-type cutting guide and the blade guide slit of the extra-bone cutting guide, and excessive bone cutting is prevented by inserting a common pin into these through holes. The osteotomy device for the proximal end of the femur according to claim 1, characterized in that it is configured as described above.

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