JPH0345697Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is designed to properly fix the central bone fragment and the peripheral bone fragment at the corrective bone resection site in tibial osteotomy, and to fuse both bone fragments. This relates to the blade plate that fixes the blade plate.

[Problems to be solved by conventional technology and the present invention]

Tibial osteotomy, particularly high osteotomy performed on the central side of the tibial tuberosity, has become widely used as a surgical treatment for knee osteoarthritis. The basic idea is to resect a wedge-shaped bone fragment with the bottom on the outside on the tibial tuberosity, and after resection of this wedge-shaped bone fragment,
The deformity is corrected by aligning the central bone fragment and the peripheral bone fragment, and bone fusion is achieved while fixing both bone fragments.

Conventionally, methods have been used to fix these two bone fragments, such as piercing the bone with a staple or two fixing pins, and tightening both piercing pins with threaded metal fittings on both sides of the outside. The former type of staple fixation has poor fixation properties because the staples that have been driven tend to come off, and it cannot cope with sinking between central bone fragments and peripheral bone fragments at the osteotomy before bone union. In addition, in the latter case, which is fixed by piercing two fixing pins and tightening it externally, the metal fittings are exposed to the outside, making it difficult to wear clothes. Also, since the piercing pin protrudes to the outside, there is a risk of infection. Also, both bone fragments before bone union.
It has drawbacks such as not being able to support slnking.

The blade plate of this invention can properly maintain and fix the central bone fragment and peripheral bone fragment at the corrective bone fragment resection site, and can also cope with sinking that occurs before the union of both bone fragments, and can be used for long-term post-therapy. This is done so that it can be done easily.

[Structure of the idea]

Fig. 1 shows a blade plate for the right tibia according to the present invention, in which Fig. 1a is a front view, Fig. 1b is a side view, and Fig. 1c is a bottom view. In the figure, reference numeral 1 denotes a blade portion that is driven into the central bone fragment of the tibia after tibial osteotomy, and has a blade 2 attached to its tip. Reference numeral 3 designates a plate portion that is screwed onto the rough surface of the distal tibia bone fragment, and the upper portion 11 of this plate portion 3 is twisted approximately 30 degrees rearward as shown in Fig. 1a, b, and c, and then the blade is attached. The portion 1 is bent rearwardly inwardly at an angle of 92° with respect to the plate portion 3. (For the left tibia, the posteromedial direction of this blade is opposite to that for the right tibia.) The blade bent in this way points posteriorly to the Gerdy tubercle on the outside of the upper end of the tibia. You can aim and hit. This driving part is the hardest part of the bone on the outer side of the upper end of the tibia. The set screw hole 4 provided in the blade portion 3 is designed to prevent the central bone fragment 5 and the peripheral bone fragment 6 from sinking into each other at the osteotomy, as shown in FIGS. 2a and 2b, before bone union. Taking this into consideration, it is formed into an oval shape with a major diameter of 12 mm. This oblong screw hole slopes further backwards, and when intrusion occurs, the central bone fragment also moves anteriorly relative to the distal fragment, and the anterior central bone fragment is located at the tibial tuberosity in the distal fragment. It is adapted to be closely fixed to a flange portion F (flange).

In order to further clarify the positional relationship between the blade plate of the present invention and the tibial osteotomy, the fifth
This will be explained in comparison with FIG. 6, FIG. 7, and FIG.

Figure 5 shows that after osteotomy of the left tibia, the blade plate is driven into the central bone fragment 5, and the plate 3 is inserted into the distal bone fragment 6.
FIG. 6 is a perspective view showing the left knee as seen from the outside. After performing tibial osteotomy, the blade 1 is driven (inserted) into the central bone fragment 5 and the plate is removed. Part 3 is shown screwed to the tibia. The front edge 13 of the plate is aligned parallel to the anterior ridge 14 of the tibia and fastened. The upper part of the tibia (one side of the central bone) slopes backwards. The part of the plate near the blade is tilted back by 15° relative to the anterior edge 13 of the plate to fit the tibia.

In the above explanation, medial, lateral, anterior, and posterior are used to refer to the medial, lateral, anterior, and posterior aspects of the tibia when viewed from the front side of the patient in an upright position, where the blade plate is attached. , the center line side of the left and right tibias is called the medial side, and the opposite side is called the lateral side.

Furthermore, the term "central" refers to the side of the patient's head, and the term "peripheral" refers to the side of the patient's feet.

As shown in FIG. 5, after osteotomy of the upper part of the tibia, the blade part 1 is driven into the upper lateral condyle of the tibia (Gardey's tubercle; the part protruding outward at the upper end) from the outside of the central tibial bone fragment 5, and the plate part 3 to the outside of the distal tibia bone fragment 6, since the outside of the tibia F is flat, the blade plate is twisted so that it hits just right.

Also, the upper end of the tibia (neck) is as shown in Figure 6.
It is tilted backwards by 15 degrees. In this blade plate, when the front edge 13 of the plate is made vertical, the upper part of the plate part is bent backward by 15 degrees (with the plate part facing upward). This means that when the blade part is driven into the outer side of the upper end of the tibia, its 15 degrees of backward bending bends toward the rear of the tibia, which ultimately matches the backward tilt of the upper end of the tibia.

In addition, all the screw holes provided in the blade plate of the present invention are oval and inclined backward by 15 degrees. This is because when the osteotomy surface sinks, the distal bone fragments move posteriorly and upwardly from the osteotomy surface in the direction of the arrow in Figure 5, and the distal bone fragments move not only upwardly with the central bone fragments but also between the distal bone fragments. It is devised so that the rear of the flange 15 standing in front is in close contact. That is, it is devised to enhance bone fusion by coming into close contact with each other from two directions. In addition, when the blade plate of the present invention is viewed from above (cranial side) at the upper end of the tibia, as shown in Figure 7, the blade is inserted from the anterolateral Gardei tubercle 16, and the farthest part is located posteriorly due to its shape. The direction is inward. Therefore, when the plate part is applied to the outside of the tibial shaft, it is important that the blade part points backward within the range of 10° to 35°, which provides the greatest fixation force.

Furthermore, the lower end of the plate portion of the blade plate of the present invention is not flat, but is slightly curved upward. This is designed to allow the osteotomy to slide smoothly when the osteotomy sinks (it is known that a normal high tibial osteotomy sinks by an average of 4 mm). Without this, experience has shown that bone formation occurs at the tip of the plate, and as a result, the plate cannot accommodate the sinking of the osteotomy, impeding bone union.

Since the blade plate of the present invention has a close relationship with the tibial wedge osteotomy, an outline of the tibial wedge osteotomy will be described below to make it easier to understand the blade plate of the present invention.

Tibial osteotomy using blade plate fixation 1 Diagramming Diagramming is the most important pretreatment for osteotomy. For varus deformity due to knee osteoarthritis, measure the lateral angle FTA of the knee using a frontal X-ray image, and draw a resected cuneiform bone fragment ΔABC to correct it so that it is 170° postoperatively. In this drawing, a line segment AB is drawn 25 mm distally parallel to the tibial loading surface L, and a correction angle ∠ABC is drawn so that the post-operative standing FTA is 170°.

Actually, based on the drawing on this X-ray image, a drawing is made on the tibia as shown in FIG. 3a. When the drawing is deflected, in order to correct the deformation, change the shape of the blade plate as shown in Fig. 4, and use a plate bender 7 to adjust the angle θ between the blade and the plate to θ in Fig. 3a. Bend the bent portions of the plate at points A and B so that they are the same. Since the shape of the tibia varies from person to person, it cannot be made uniform, but in general, when the correction angle (∠ABC in Figure 3 a) is 0°, θ is 77°,
When it is 10°, it is 87°, and when it is 20°, it is 97°. The lower end C of the plate is also bent like the tip of a ski so that the plate can slide well against the tibia. During the actual osteotomy, a Kirschner steel wire 8 is inserted 5 mm distal to the tibia in parallel with the tibia's load-bearing surface toward the rear of the Gardei tubercle on the outside of the upper end of the tibia, and then inserted into the tibia 15 mm distal to the Kirschner steel wire. line in front
AB is drawn, and osteotomy is performed outside line segment AB, then outside line segment BC, and when about 2/3 of the outside of the wedge-shaped bone fragment has been removed, the osteotomy is cut along the Kirsiner steel wire. After driving the blade part of the blade plate, perform the remaining medial 1/3 osteotomy. Finally, complete the osteotomy while creating the anterior flange of the tibia. Check the corrected angle when the blade is approximately 90% driven. After the osteotomy is completed and the deformity is corrected, the central bone fragment and the peripheral bone fragment are brought together and the plate portion is fixed to the outer edge of the tibia with bone screws 9 as shown in FIG. 2b. At this time, the distal bone fragment is shifted slightly inward (section M in the figure) to prevent it from sinking into the central bone fragment, and the extracted bone fragment is placed under the central bone fragment on the outside.
0 is subdivided and bone grafted.

[Function and effect of the idea]

In the blade plate of the present invention, the blade portion is bent in a shape relative to the plate portion, and after twisting the plate toward the rear by approximately 30 degrees at the bent portion, the blade portion will bend approximately 90 degrees backward inward. Because it has a bent shape, it can be driven in the correct direction into the hardest part of the central bone fragment of the tibia that has been corrected by osteotomy, and the bone attachment screw holes provided in the plate can be inserted in the posterior direction. Because it is formed in an oblong shape with an inclination to Even if it moves forward, the screw fixed to the distal bone fragment will move along the oblong oblong hole in the plate, so no undue force will be applied to the fusion of both bone fragments at the osteotomy, and the bone will move forward. There is no negative effect on healing.

[Brief explanation of the drawing]

Figures 1a, b, and c show a blade plate for the right tibia according to the present invention, in which a is a front view, b is a side view, and c is a bottom view. Figure 2 a and b show the drawing and completed drawing of the tibial osteotomy, and figure a shows the measurement of the FTA from the frontal X-ray image and the drawing of the wedge-shaped bone fragment so that it is 170° postoperatively. Figure 1 and Figure b show the state in which the blade plate of the present invention is fixed after the correction is completed. Figures 3a and 3b are explanatory diagrams of drawing a correction angle on the tibia, and Figure 3b shows the state in which the blade plate is attached after osteotomy and correction. FIG. 4 shows the adjustment of the blade plate by the bender. 1...Blade part, 2...Blade tip end part, 3...Plate part, 4...Oval screw hole, 5
...Central bone fragment, 6...Distal bone fragment, 7...Bender, 8...Kirshiner steel wire, 9...Bone screw for plate fixation, Figure 5 shows the blade plate attached to the central bone fragment after osteotomy of the left tibia. A perspective view showing the state in which the plate is driven into the distal bone fragment. Figure 6 is a perspective view showing the state in which the blade part of the blade plate of the present invention is driven into the central bone fragment and the plate part is screwed to the tibia from the outside of the left knee. 7 is a view of the upper end of the left tibia viewed from above (cranial side). 13... Anterior edge of the plate, 14... Anterior rib of the tibia, 15... Anti-slip part of the distal bone fragment, 16... Garday's tubercle.

Claims (1)

[Scope of utility model registration request] A bent blade plate for fixing a central bone fragment and a peripheral bone fragment of an osteotomy in tibial osteotomy,
At the bending point, the blade is twisted approximately 30 degrees backwards relative to the plate (with respect to the patient's upright posture, the front side of the patient is referred to as the front, and the back side is referred to as the rear), and then the blade is twisted approximately 30 degrees backwards relative to the plate (with respect to the patient's upright posture, the front side of the patient is referred to as the front and the back side is referred to as the rear), and then the blade is twisted approximately 30 degrees backwards relative to the plate. After being bent 15 degrees backwards, the bone attachment screws are bent approximately 90 degrees backwards and inwards (the center line side of the patient's upright posture is called inward, and the opposite side is called outward), and the bone attachment screws are provided on the plate. A blade plate for tibial osteotomy, characterized in that all holes are oval and slope backward, and the lower tip of the plate is slightly curved upward.