JP2008125706A - Guide instrument for osteotomy of tibial proximal end - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a guide instrument for osteotomy which is not easily position-shifted and is easily positioned accurately in final instrument fixation. <P>SOLUTION: The guide instrument 10 for the osteotomy comprises: a shaft part 20 whose lower part is fixed to an ankle by an ankle clamp 21 and shaft extending in the longitudinal direction is made parallel with a tibial axis; a T-shaped cut guide part 40 provided with a guide part 45 with a slit 41 for guiding the osteotomy surface of the tibial proximal end 62 and a guide leg part 42 extending downward from the guide part 45; and a rod part 30 linked with the upper part of the shaft part 20, extending obliquely upwards and provided with a function of receiving the guide leg part 42 of the T-shaped cut guide part 40 and adjusting elevation/lowering of the T-shaped cut guide part 40. Near the upper end of the rod part 30, a temporary fixing pin 50 for temporary fixation at the reference position of axis matching of the tibial axis is projected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an osteotomy guide device used to accurately osteotomy the proximal end of the tibia before placing an artificial knee joint.

  In order to install the artificial knee joint, it is necessary to shape (bone cut) the proximal tibia and the proximal femur constituting the knee joint. In particular, the proximal part of the tibia must be accurately boned so as to be a plane having a predetermined inclination. Also, the amount of bone cutting must be adjusted precisely. If the inclination of the plane and the amount of osteotomy are not appropriate when osteotomy is performed, after the artificial knee joint is installed, it may cause a sense of incongruity of the knee joint or a decrease in the knee joint.

  A conventional osteotomy guide instrument at the proximal end of the tibia is known that includes an anchor member that is fixed to the upper part of the tibia and an instrument part that is fixed to the upper part of the anchor member and includes a slot (for example, Patent Document 1). reference). The guide instrument secures the anchor member in the middle of the tibia, then uses computer image guidance to accurately position the instrument portion and pin the instrument portion to the proximal portion of the tibia. The cutting edge is guided by the slot of the instrument part, and the proximal end of the tibia is cut into a plane having a predetermined inclination. In this guide instrument, the stability of the guide instrument is enhanced by bringing the fork-like structure provided between the anchor member and the instrument part into contact with the tibia during a series of operations.

Further, a tibial milling guide device is known as another osteotomy device for the proximal tibia, and is used to cut the proximal tibia end flatly with an end mill (see, for example, Patent Document 2). The tibial milling guide device includes a rod-shaped alignment guide disposed outside the bone marrow along the tibial axis, a reference guide attached to the upper portion of the alignment guide, and a lower member fixed to the lower portion of the alignment guide. Yes. At the time of use, the alignment guide is fixed to the tibia by a bone screw inserted into a hole near the upper portion of the alignment guide after the lower portion is fixed to the ankle by the lower member and the upper portion is adjusted to a predetermined position by the reference guide. The reference guide is then removed, and instead the milling base assembly and milling template are secured. The milling template is placed on the articular surface of the proximal tibia and cuts the proximal tibia by manipulating the end mill along the template groove.
JP 2004-202239 A Japanese Patent Application Laid-Open No. 8-55956

In the osteotomy guide instrument, when the instrument part is pinned to the proximal part of the tibia, the guide instrument is secured only by the anchor member, and therefore the instrument part may be displaced due to impact when the pin is driven. There is. Further, even in the tibial milling guide device, when the upper part of the alignment guide is fixed by the bone screw, the alignment guide is only fixed to the ankle by the lower member, so that it is easily displaced.
If the position of the instrument part or the alignment guide is shifted, it is necessary to start again from the alignment, which may lead to an extended operation time.
Further, in the osteotomy guide device and the tibial milling guide device, since the procedure for accurate positioning is complicated, the operation time tends to be long unless it is a skilled operator.

  Therefore, an object of the present invention is to provide an osteotomy guide device that is less likely to be misaligned in the final fixation of the device and that is easy to accurately position.

  The osteotomy guide device of the present invention includes a shaft portion whose lower portion is fixed to the ankle by an ankle clamp, and a longitudinally extending axis parallel to the tibial axis, and a slit that guides the osteotomy surface at the proximal end of the tibia. A T-shaped cut guide portion having a guide portion having a guide portion and a guide leg portion extending downward from the guide portion; and an upper portion of the shaft portion, extending obliquely upward, and having the guide leg portion of the T-shaped cut guide portion And a rod portion having a function of adjusting the elevation of the T-shaped cut guide portion, and a temporary fixing pin for temporarily fixing at a reference position for axis alignment of the tibial axis protrudes in the vicinity of the upper end of the rod portion. It is characterized by.

  Since the osteotomy guide device is attached to the front of the shin part, the reference point for alignment in the inner and outer directions of the shaft part is a position 1/3 from the inner side of the tibial rough surface on the front surface of the tibia (the tibial rough surface). Referred to as the reference position), or the second middle toe. In the present invention, the upper portion of the shaft portion can be temporarily fixed by driving a temporary fixing pin into the tibial rough surface reference position. That is, from the initial stage of fixing the osteotomy guide device, the upper portion of the shaft portion is fixed to the tibia and the lower portion is fixed to the ankle. Therefore, when the shaft portion is adjusted parallel to the tibial axis, the height of the T-shaped cut guide portion is determined, and the T-shaped cut guide portion is fixed to the tibia with a pin or the like, the shaft portion is displaced. There is almost nothing.

  Further, by driving the temporary fixing pin into the rough tibial rough surface reference position, the position of the upper part of the shaft in the inner / outer direction can be positioned almost accurately. Further, if the position of the lower portion of the shaft is aligned with reference to the temporary fixing pin, the shaft portion can be adjusted in parallel to the tibial axis. Therefore, positioning accuracy similar to the conventional method can be achieved by a simple procedure.

  According to the present invention, it is possible to obtain an osteotomy guide device that is less likely to be misaligned in the final fixation of the device and that is easy to accurately position.

  The osteotomy guide device 10 of the present invention shown in FIGS. 1 to 7 is roughly composed of a shaft portion 20, a rod portion 30, and a T-shaped cut guide portion 40. Each component will be described below.

(T-shaped cut guide 40)
As shown in FIGS. 1 to 5B, the T-shaped cut guide portion 40 includes a guide portion 45 at an upper portion and guide leg portions 42 at a lower portion.
The guide portion 45 is thin in the vertical direction, has a curved shape when viewed from above, and includes a substantially horizontal slit 41 penetrating from the front direction A to the rear direction P. The vertical dimension of the slit 41 is set so that a cutting blade used for bone cutting can be inserted. The guide leg portion 42 extends obliquely downward and can be inserted into the rod portion 30. A male screw 47 is formed on the surface of the guide leg portion 42 and is screwed with a female screw formed on the inner surface of the adjustment nut 34 of the rod portion 30. As shown in FIGS. 5A and 5B, a rotation prevention groove 48 having a U-shaped cross section is formed on the side surface of the guide leg portion 42 along the longitudinal direction of the guide leg portion 42. A pin (not shown) that engages with the rotation prevention groove 48 protrudes inside.

4 to 5B illustrate in detail the form of the T-shaped cut guide portion 40 suitable for the present invention.
4 shows a T-shaped cut guide portion 40 for the left leg, and when viewed from the front direction A, only the left side extends long. On the lower surface side of the guide portion 45, a plurality of protrusions (three in this figure) extend in the front-rear direction (AP direction), and through holes 43 and 44 are formed in the protrusion portions. These through holes 43 and 44 are used for inserting a fixing pin when the position of the T-shaped cut guide portion 40 is determined and the T-shaped cut guide portion 40 is permanently fixed to the proximal portion of the tibia. Thus, the form in which the guide portion 45 extends in only one direction is suitable for minimally invasive surgery (MIS). Further, a guide leg portion 42 having an external thread formed on the outer surface is attached to the lower portion of the T-shaped cut guide portion 40. Note that the numerical value (3 °) written on the upper surface of the guide portion 45 is the inclination angle of the slit 41 formed in the guide portion 45 and is lowered by 3 ° from the front direction A toward the rear direction P ( Means 3 ° backward). Usually, a plurality of types of T-shaped cut guide portions 40 having different backward inclinations of the slit 41 (usually in the range of backward inclination 0 ° (horizontal) to backward inclination 7 °) are prepared and appropriately selected according to the patient's condition.

  5A and 5B show a T-shaped cut guide portion 40 that can be used for both the right leg and the left leg, and has a shape extending symmetrically when viewed from the front. In the T-shaped cut guide portion 40, four through holes 43 and 44 are formed on the lower surface of the guide portion 45. Further, as shown in FIG. 5B, a step 46 is formed on the rear side of the T-shaped cut guide portion 40 by removing the upper side from the slit 41. Thereby, when cutting the bone, the position where the tip of the cutting blade contacts the proximal part of the tibia can be visually confirmed. When cutting the bone, it is possible to cut the bone accurately according to a predetermined angle by setting the cutting edge along the lower side of the step.

(Rod 30)
As shown in FIGS. 1 to 3, the rod portion 30 includes a rod upper portion 36 that extends obliquely upward, and a rod lower portion 31 that extends substantially vertically downward and is inserted into the shaft portion 20.
The rod upper portion 36 includes a temporary fixing pin 50 protruding in the rear direction P and a pin head 51 protruding in the front direction A coaxially with the temporary fixing pin 50. When the osteotomy guide device 10 is fixed to the tibia, the temporary fixing pin 50 is driven into the tibial rough surface reference position at an initial stage. Thereby, the upper vicinity of the osteotomy guide device 10 is temporarily fixed until the osteotomy guide base 10 is accurately positioned. The pin head 51 can be used for hitting with a hammer when driving the temporary fixing pin 50, and can also be used for removing the temporary fixing pin 50.

Although the temporary fixing pin 50 and the pin head 51 appear to be a single pin in appearance, they are actually separated as shown in FIG. The guide leg 42 is inserted. That is, even after the temporary fixing pin 50 is driven into the tibial rough surface reference position, the guide leg portion 42 can slide up and down. Therefore, the T-shaped cut guide portion 40 can be attached and detached before and after the temporary fixing pin 50 is fixed. Therefore, the T-shaped cut guide portion 40 can be arbitrarily replaced during the operation.
In the vicinity of the temporary fixing pin 50, a rod through hole 35 is formed. The rod through hole 35 is used for inserting a fixing pin when the positions of the rod portion 30 and the shaft portion 20 are determined and the rod portion 30 is permanently fixed to the proximal portion of the tibia. The direction of the rod through-hole 35 is substantially the AP direction, but is slightly inclined from the horizontal while the temporary fixing pin 50 is horizontal. Thereby, the upper side of the rod part 30 can be reliably fixed to the proximal end of the tibia by a synergistic effect of the temporary fixing by the temporary fixing pin 50 and the main fixing by the fixing pin.

An adjustment nut 34 is rotatably attached to the rod upper portion 36. When the adjustment nut 34 is rotated, the guide leg portion 42 screwed into the female screw on the inner surface of the adjustment nut 34 is raised or lowered, thereby adjusting the height of the guide portion 45.
At this time, the rotation preventing groove 48 of the guide leg portion 42 is engaged with the pin protruding into the rod, so that the guide portion 45 moves only in the vertical direction with respect to the rod 30. Therefore, when the adjustment nut 34 is rotated, the guide portion 45 can move up and down without rotating.

  A plurality of score lines 38 are preferably formed in the rod lower portion 31 along the outer circumferential direction. In this embodiment, the rod lower portion 31 is fixed to the upper portion of the shaft portion 20 by a spring bias. However, by forming this score line 38, the locking position of the rod lower portion 31 is positioned stepwise. It becomes easy and stability at the time of fixation becomes high.

(Shaft 20)
As shown in FIGS. 1 and 6A to 7, the shaft portion 20 includes a shaft main body 200 extending in the vertical direction and an ankle clamp 21 fixed to the lower portion of the shaft main body 200. The shaft body 200 can be formed from a cylindrical body. Moreover, the upper end part of the shaft 20 can have a locking means by spring bias for fixing the rod lower part 31.

The locking means by the spring bias is composed of a shaft sleeve 29, a shaft button 32, and a spring 33. As shown in FIG. 6A, a shaft sleeve 29 having one opening in each of the upward direction and the lateral direction is fixed to the upper end of the shaft main body 200. The spring 33 and the shaft button 32 are sequentially inserted from the lateral hole (button insertion hole 291) of the shaft sleeve. Since the button insertion hole 291 does not penetrate the shaft sleeve 29, the spring 33 is sandwiched between the inner surface of the shaft sleeve 29 and the shaft button 32. The shaft button 32 is formed with a button through hole 321 penetrating in the vertical direction. A protruding plate (not shown) is fixed to the inner wall of the button through hole 321 in a direction orthogonal to the through direction of the hole. Both the inner diameter of the button through hole 321 and the inner diameter of the upper opening (shaft opening 292) of the shaft sleeve 29 are formed larger than the outer diameter of the rod lower portion 31, and the shaft opening 292 and the button through hole 321 are formed. , The rod lower portion 31 can be inserted from the shaft opening 292 to the inside of the shaft main body 200. Since the shaft button 32 is always spring-biased by the spring 33 toward the outer side of the button insertion hole 291, the rod lower portion 31 inserted into the shaft body 200 is connected to the protruding plate of the button through hole 321 of the shaft button 32 and the shaft. It is sandwiched between the inner surface of the main body 200 and is locked to the shaft portion 20. At this time, since the protruding plate is caught by the score line 38 of the rod lower portion 31, the locked state is stabilized.
The locked state between the shaft portion 20 and the rod lower portion 31 can be released by pushing the shaft button 32 in the button insertion hole 291. When the shaft button 32 is pushed in and the shaft opening 292 and the button through hole 321 are aligned, the rod lower portion 31 is released from the locked state, and the rod lower portion 31 can be slid in the vertical direction.

  Note that the rod lower portion 31 and the shaft sleeve 29 are provided with a rotation preventing means to prevent the rod 30 from rotating with respect to the shaft portion 20 when the rod lower portion 31 is slid up and down. . First, as illustrated in FIG. 6A, one or two anti-rotation surfaces 311 are formed on the side surface of the rod lower portion 31 along the axial direction of the rod lower portion 31. Therefore, the cross section of the rod lower portion 31 has a shape obtained by cutting off a part of a circle as shown in FIG. 6B (in this example, two anti-rotation surfaces 311 are formed). As shown in FIG. 6B, a rotation prevention pin 293 is inserted horizontally in the shaft opening 292 of the shaft sleeve 29 (in this example, one rotation prevention pin is inserted). Have been). Due to the rotation prevention pin 293, the shaft opening 292 has the same size and shape as the section of the rod lower part 31. Therefore, if the rod lower portion 31 is inserted into the shaft opening 292 with the rotation preventing surface 311 aligned with the rotation preventing pin 293, the rod lower portion 31 and the shaft opening 292 can be prevented from rotating.

Such fixing by the spring bias is easy to release the lock, so that the position can be adjusted quickly. In addition, since the structure is simple, troubles such as failure are unlikely to occur. Further, it can be firmly fixed in cooperation with the score line 38 formed in the rod lower portion 31. In particular, when vibration is transmitted to the osteotomy guide device when cutting with a cutting blade, there is a risk that the screw may become loose when fixed with a screw. On the other hand, the fixing method as in the present embodiment is advantageous in that no loosening due to vibration occurs.
In addition, the rod lower part 31 and the shaft main body 20 can also be fixed using other locking methods.

  As shown in detail in FIG. 7, the ankle clamp 21 provided at the lower portion of the shaft portion 20 includes an L-shaped clamp base 211 and two arms 212 fixed to both ends thereof. . A spring is incorporated in a joint portion between the clamp base 211 and the arm 212, and the arm 212 is biased to close in the direction of the clamp base 211. In order to attach the ankle clamp 21 to the ankle, first, the arm 212 is opened and brought into contact with the clamp base 211, and then the arm 212 is automatically closed by opening the arm 212, so that the arm 212 is closed between the clamp base 211 and the arm 212. Ankle can be pinched. Such an ankle clamp 21 has an advantage that it can be easily fixed to the ankle. The ankle clamp 21 shown in the present embodiment is merely an example, and another form of ankle clamp can be used. For example, instead of providing the arm 212, an ankle clamp 21 using a separate spring member that spans both ends of the clamp base 21 can be used. The ankle clamp 21 as shown in FIG. It is easy to apply to patients who are difficult to fix.

In the present embodiment, an inner / outer direction adjusting means is provided between the shaft body 200 and the ankle clamp 21.
The inner / outer direction adjusting means is used for alignment in the inner direction M and the outer direction L. The inner / outer direction adjusting means shown in FIG. 7 includes a distal plate 22 formed along one piece of the clamp base 211, a slide rail 23 that receives the distal plate 22, and a distal knob 26. The distal plate 22 has a slide part having an inverted trapezoidal cross section, and the slide part is inserted into a slide rail 23 having a shape corresponding to the inverted trapezoid so as to be slidable in the inner and outer directions (ML direction). Yes.
One end of a hollow distal rod 24 is orthogonally attached to the slide rail 23. A hole is formed in the slide rail 23 so as to communicate with the hollow portion of the distal rod 24. A pole member 262 of the distal knob 26 can be inserted into the hollow portion of the distal rod 24 and the hole of the slide rail 23. A grip portion 261 of the distal knob 26 is attached to one end of the pole member 262. A male screw 263 is formed on the outer surface of the other end of the pole member 262 and is screwed to a female screw formed on the inner surface of the distal rod 24. When the pole member 26 is inserted into the hollow portion of the distal rod 24 and the gripping portion 261 of the distal knob 26 is rotated in a predetermined direction, the male screw 263 of the pole member 262 is screwed into the female screw inside the distal rod 24. The pole member 262 moves in the distal rod 24, and the other end of the pole member 262 protrudes into the slide rail 23. The other end of the pole member 262 first comes into contact with the slide portion of the distal plate 22 inserted into the slide rail 23 and further presses the distal plate 22 toward the clamp base 21. At this time, since the slide portion has an inverted trapezoidal shape, the distal plate 22 is not detached from the slide rail 23 but is fixed in the slide rail 23.

In order to use this inner / outer direction adjusting means, first, the lower portion of the shaft portion 20 is fixed by the ankle clamp 21, and then the slide rail 23 is slid in the ML direction with respect to the distal plate 22, so that the slide rail 23 is desired. When the position is reached, the distal knob 26 is rotated to further fix the distal plate 22 to the slide rail 23.
By providing the inside / outside direction adjusting means, the ML direction of the osteotomy guide device 10 can be adjusted even after the ankle clamp 21 is fixed to the patient's ankle.

In the present embodiment, a front-rear direction adjusting means is further provided between the shaft body 200 and the ankle clamp 21.
The front-rear direction adjusting means is used for alignment in the front direction A and the rear direction P. The front-rear direction adjusting means shown in FIG. 7 includes a distal sleeve 25, a distal button 27, and a spring 28. The structure of the front-rear direction adjusting means is almost the same as that of the shaft locking means. The distal sleeve 25 fixed to the lower end of the shaft body 200 has a hole (button insertion hole 251) opened in the ML direction and a hole (rod insertion hole 252) penetrating in the AP direction. The button insertion hole 251 and the rod insertion hole 252 communicate with each other inside the distal sleeve 25. The spring 28 and the distal button 27 are sequentially inserted into the button insertion hole 251. Since the button insertion hole 251 does not penetrate the distal sleeve 25, the spring 28 is sandwiched between the inner surface of the distal sleeve 25 and the distal button 27. Further, the button button 271 is formed in the distal button 27 so as to be inserted in the AP direction, and a protruding plate (not shown) oriented in the direction perpendicular to the hole penetration direction is fixed to the inner wall of the button through hole 271. Has been. Both the inner diameter of the rod insertion hole 252 and the inner diameter of the button through hole 271 of the distal sleeve 25 are formed larger than the outer diameter of the distal rod 24. Therefore, if the rod insertion hole 252 and the button through hole 271 are matched, the distal rod 24 can be inserted into the rod insertion hole 252.

Since the distal button 27 is always spring-biased by the spring 28 toward the outer side of the button insertion hole 251, the distal rod 24 has the protruding plate of the button through hole 271 of the distal button 27 and the rod insertion hole 252 of the distal sleeve 25. Between the inner sleeve and the distal sleeve 25. It is preferable to form a plurality of score lines 242 in the distal rod 24 along the outer circumferential direction. In this embodiment, the distal rod 24 is fixed to the distal sleeve 25 by a spring bias. However, a protruding plate is caught on the score line 242 so that the locking position of the distal rod 24 is positioned stepwise. It becomes easier and the locked state is stabilized.
The locked state of the distal rod 24 and the distal sleeve 25 can be released by pushing the distal button 27 in the button insertion hole 251. If the distal button 27 is pushed in and the rod insertion hole 252 and the button through-hole 271 are aligned, the locking state of the distal rod 24 is released, and the distal sleeve 25 can be slid in the AP direction.
By providing the front-rear direction adjusting means, the AP direction of the osteotomy guide device 10 can be adjusted even after the ankle clamp 21 is fixed to the ankle of the patient.

  The distal rod 24 and the distal sleeve 25 are provided with anti-rotation means to prevent the distal sleeve 25 from rotating relative to the distal rod 24 when the distal rod 24 is slid in the AP direction. ing. First, as shown in FIG. 7, a rotation preventing surface 241 is formed on the side surface of the distal rod 24 along the axial direction of the distal rod 24. Therefore, the cross section of the distal rod 24 is shaped like a part of a circle. An anti-rotation pin 253 is inserted in the ML direction inside the rod insertion hole 252 of the distal sleeve 25. Due to the rotation prevention pin 253, the rod insertion hole 252 has the same size and shape as the cross section of the distal rod 24. Therefore, if the distal rod 24 is inserted into the rod insertion hole 252 with the anti-rotation surface 241 aligned with the anti-rotation pin 253, the distal rod 24 and the distal sleeve 25 can be prevented from rotating.

  In the present embodiment, the inner / outer direction adjusting means and the front / rear direction adjusting means have different structures. These are merely examples, and other than the means shown in the embodiment, well-known means can be arbitrarily applied in consideration of ease of formation, ease of operation, adjustment accuracy, and the like.

  Each component of the osteotomy guide device 10 is formed from a metal certified as a medical metal, sealed in a sterilized state, and opened and used during surgery.

  A method of using the osteotomy guide device 10 of the present embodiment will be described with reference to FIGS.

(1. Assembly of osteotomy guide device 10)
As shown in FIG. 1, the osteotomy guide device 10 is assembled, and it is confirmed that the tilting direction of the rod portion 30, the direction of the ankle clamp 21, and the protruding direction of the temporary fixing pin 50 are all arranged in the rear direction P. To do. Further, the T-shaped cut guide portion 40 is positioned so that the curve of the guide portion 45 is convex in the front direction A, and is screwed into the rod portion 30. When performing an operation, it is preferable that the sterilized enclosure is provided in an already assembled state.

(2. Attaching the osteotomy guide device 10 to the leg)
The osteotomy guide 10 is fixed to the front side of the shin part, and when viewed from the front direction A, the osteotomy guide 10 coincides with the tibial axis and is lateral (external direction L or medial direction M). ), The shaft portion 20 must be accurately positioned so as to be parallel to the tibial axis. Here, an approximate positioning method will be described.
After exposing the proximal end of the tibia by a surgical technique, as shown in FIG. 8, the ankle clamp 21 of the osteotomy guide device 10 is fixed to the patient's ankle from the front direction A (tibial side). Thereafter, the shaft button 32 is pressed to slide the rod portion 30 in the vertical direction, so that the position of the temporary fixing pin 50 matches the height of the tibial rough surface reference position. Then, as shown in FIGS. 9 and 10, the temporary fixing pin 50 is driven into the tibial rough surface 61 of the tibia 60. At this time, as shown in FIG. 9, the reference position of the tibial rough surface into which the temporary fixing pin 50 is driven is observed in the tibial rough surface 61 from above, and the length of the tibial rough surface 61 in the ML direction is equally divided into three. 1/3 of the position. When the tibia rough surface reference position is moved straight forward in the backward direction P, the tibia axis is reached. Therefore, when checking the tibia axis from the front direction A, the tibial rough surface reference position is used. By driving the temporary fixing pin into the rough tibial surface reference position, the position in the vicinity of the temporary fixing pin 50 can coincide with the tibial axis when observed from the front side.

(3. Accurate positioning of the guide instrument 10 for osteotomy)
By repeatedly observing the osteotomy guide device 10 and the shin from the front direction A and the lateral direction, the osteotomy guide device 10 is accurately positioned. Mainly, by accurately positioning the shaft portion 20, the osteotomy guide device 10 can be disposed at a substantially appropriate position. At this time, since the upper side of the osteotomy guide device 10 is already temporarily fixed at an accurate position by the temporary fixing pin 50, only the lower part of the osteotomy guide device 10, that is, the shaft portion 20 needs to be adjusted. Only at the bottom.
For positioning in the ML direction, the shaft portion 20 is observed from the front direction A. When the shaft portion 20 is deviated from the tibial axis, the grip portion 261 of the distal knob 26 is rotated to loosen the fixation of the distal plate 22, and the slide rail 23 is slid in the ML direction. When the lower portion of the shaft portion 20 coincides with the tibial axis, the distal plate 22 is fixed by the distal knob 26.
For positioning in the AP direction, the shaft is observed from the lateral direction. When the shaft portion 20 is not parallel to the tibial axis, the distal button 25 is pushed to slide the distal sleeve 25 in the AP direction while releasing the locking between the distal rod 24 and the distal sleeve 25. When the shaft portion 20 is parallel to the tibial axis, the distal button 27 is released, and the distal sleeve 25 is locked to the distal rod 24.

(4. Fixed fixing of the upper part of the rod part 30)
As shown in FIGS. 8 to 10, the rod 30 is fixed to the tibia 60 by inserting the fixing pin 53 into the rod through hole 35 of the rod 30 and driving it into the rough tibial surface 61. As can be seen from FIG. 10, the fixing pin 53 is slightly inclined with respect to the temporary fixing pin 50. If the fixing pin 53 is driven at such an angle, not only can the rotation of the osteotomy guide device 10 be prevented, but even if a force in the direction of pulling the osteotomy guide device 10 away from the tibia 60 is applied, The stop pin 50 does not fall off. Further, as shown in FIG. 9, when the fixing pin 53 and the temporary fixing pin 50 are observed from above, it can be seen that they are substantially parallel. In this way, fixing at an angle in the vertical direction is suitable for preventing vertical oscillation.
By driving the fixing pin 53, the osteotomy guide device 10 is securely fixed to the tibia.

(5. Height adjustment of T-shaped cut guide 40)
The height of the T-shaped cut guide portion 40 is adjusted by rotating the adjustment nut 34. At this time, as shown in FIG. 10, it is important to position the slit 41 of the T-shaped cut guide portion 40 on the extension line of the osteotomy planned surface AA of the proximal tibia end 62. Since the height of the T-shaped cut guide portion 40 can be finely adjusted by using the adjustment nut 34, the amount of osteotomy can be set accurately. When the osteotomy planned surface AA is inclined backward, the T-shaped cut guide portion 40 having the slit 41 matching the inclination angle is selected.

(6. Fixed fixing of T-shaped cut guide 40)
As shown in FIGS. 8 to 10, the fixing pins 54 and 55 are inserted into the through holes 43 and 44 of the T-shaped cut guide portion 40 and driven into the proximal tibia end 62. Thereby, the T-shaped cut guide part 40 is completely fixed to the tibia 60. As can be seen from FIG. 9, the fixing pin 54 and the fixing pin 55 are not parallel, but are slightly inclined. Thereby, the T-shaped cut guide part 40 is reliably fixed to the tibia proximal end 62. When viewed from the side as shown in FIG. 10, the fixing pins 54 and 55 are fixed to the tibia 60 in parallel. Thus, if it fixes at an angle in a horizontal direction, it is suitable for preventing the rocking | fluctuation of a horizontal direction.

(7. Osteotomy of proximal end of tibia 62)
A cutting blade is inserted into the slit 41 of the T-shaped cut guide 40 to cut the proximal tibia end 62 along the planned osteotomy surface AA. When the amount of osteotomy is insufficient, the fixing pins 54 and 55 are removed, and the adjustment nut 34 is rotated to lower the T-shaped cut guide portion 40. The T-shaped cut guide portion 40 can be fixed again with the fixing pins 54 and 55 and the bone can be cut with the cutting blade.
At the time of osteotomy, since the T-shaped cut guide portion 40 is securely fixed to the tibia 60, the inclination of the slit 41 does not change due to the vibration of the cutting blade, and the slit 41 does not deviate from the set position. Osteotomy can be performed along the plane AA.

It is a perspective view of the guide instrument for osteotomy which concerns on this invention. It is a partial expansion perspective view of the guide instrument for osteotomy concerning the present invention. It is a fragmentary sectional view of the guide instrument for osteotomy which concerns on this invention. It is a perspective view of the T type cut guide part suitable for the guide instrument for osteotomy of this invention. It is a front view of another T-shaped cut guide part suitable for the guide instrument for osteotomy of this invention. It is a perspective view of another T-shaped cut guide part suitable for the guide instrument for osteotomy of this invention. It is a partial exploded view of the guide instrument for osteotomy according to the present invention. It is a top view of the shaft sleeve of the guide instrument for osteotomy which concerns on this invention. It is a partial exploded view of the guide instrument for osteotomy according to the present invention. It is a schematic perspective view which shows a mode that the guide instrument for osteotomy concerning this invention was fixed to the left leg. It is a schematic top view which shows a mode that the guide instrument for osteotomy concerning this invention was fixed to the left leg. It is a schematic side view which shows a mode that the guide instrument for osteotomy concerning this invention was fixed to the left leg.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Osteotomy guide instrument, 20 Shaft part, 21 Ankle clamp, 22 Distal plate, 23 Slide rail, 24 Distal rod, 25 Distal sleeve, 26 Distal knob, 27 Distal button, 28 Spring, 29 Shaft sleeve, 30 Rod, 31 Lower rod, 32 Shaft button, 33 Spring, 34 Adjustment nut, 35 Rod through hole, 36 Rod upper, 40 T-shaped cut guide part, 41 Slit, 42 Guide leg part, 43, 44 Through hole, 45 Guide part, 50 Temporary Stop pin, 51 pin head, 53, 54, 55 fixation pin, 60 tibia, 61 tibial rough surface, 62 proximal tibia.

Claims (8)

A shaft part whose lower part is fixed to the ankle by an ankle clamp and whose longitudinally extending axis is parallel to the tibial axis;
A T-shaped cut guide portion comprising a guide portion having a slit for guiding the osteotomy surface at the proximal end of the tibia and a guide leg portion extending downward from the guide portion;
A rod portion linked to the upper portion of the shaft portion, extending obliquely upward, and receiving a guide leg portion of the T-shaped cut guide portion, and having a function of adjusting the elevation of the T-shaped cut guide portion;
An osteotomy guide device, wherein a temporary fixing pin for temporarily fixing to a reference position for axial alignment of the tibial axis protrudes in the vicinity of the upper end of the rod portion.   The rod part and the shaft part are fixed by a spring bias, and the rod part is slidable in the vertical direction with respect to the shaft part by releasing the spring bias. 2. The osteotomy guide device according to 1.   The osteotomy guide device according to claim 1 or 2, wherein the T-shaped cut guide portion includes a plurality of through holes for pin-fixing to the tibia.   The osteotomy guide device according to any one of claims 1 to 3, wherein the T-shaped cut guide portion is detachable even after temporary fixing of the temporary fixing pin.   The osteotomy guide device according to any one of claims 1 to 4, wherein the shaft portion includes an inner / outer direction adjusting means for aligning the inner and outer directions at a lower portion thereof. .   The inner / outer direction adjusting means includes a slide rail extending in the inner / outer direction, a distal plate that is slidably engaged with the slide rail, and a distal knob that presses and fixes the distal plate against the slide rail. The osteotomy guide device according to claim 5, which is provided.   The osteotomy guide device according to any one of claims 1 to 6, wherein the shaft portion is provided with a front-rear direction adjusting means for positioning in the front-rear direction at a lower portion thereof.   The front-rear direction adjusting means includes a distal rod extending in the front-rear direction, a distal sleeve through which the distal rod is inserted, and a fixing means for fixing the distal rod and the distal sleeve by a spring bias, and a spring 8. The osteotomy guide device according to claim 7, wherein the distal sleeve is slidable in the front-rear direction with respect to the distal rod by releasing the bias.

Images