TWI902211B - Guidance device - Google Patents

Abstract

The guiding device (1) is used to cut the bone in the area where the bone plate is to be placed. The guiding device has a fixing part (2) and a guiding part (3) in order to cut the bone to fit the shape of the bone contact surface of the bone plate. The fixing part has a cutting area (S) that is fixed to the bone and placed at the cutting site of the bone. The guiding part guides the cutting tool or guiding component in the cutting area (S). The guiding part (3) guides the cutting tool or guiding component along a plate surface (P) that has the same or substantially the same shape as the bone contact surface of the bone plate.

Description

Guiding device

This invention relates to a guidance device.

Traditional treatments for ankle osteoarthritis (foot OA) include ankle arthrodesis, total ankle replacement, and low tibial osteotomy (LTO). As shown in Figure 11, the ankle joint is composed of the tibia A, talus B, and fibula C. Foot OA occurs when the cartilage between the tibia A and talus B wears down.

As a novel osteotomy technique for ankle osteoarthritis (OA) of the foot, a distal tibial oblique osteotomy (DTOO) is disclosed (e.g., as shown in Non-Patent References 1 and 2). Figure 11 illustrates DTOO. In DTOO, the distal tibia A is diagonally osteotomized toward the distal tibiofibular joint D (S1), and the distal tibial plate A2 is rotated distally through the widened osteotomy portion E (S2). This causes the talus B to be sandwiched between the medial and lateral condyles of the tibia A, thereby improving ankle joint stability. After rotation of the distal tibial plate A2, the tibia A is fixed by the bone plate 30 (S4).

[Patent References] Non-Patent Reference 1: Kota Watanabe and 7 others, “Modified distal tibial oblique osteotomy for osteoarthritis of the ankle: Operative procedure and preliminary results”, Journal of Orthopedic Science, March 2019, Vol. 24, No. 2, pp. 306-311 Non-Patent Reference 2: Tsukasa Teramoto and 11 others, “The Teramoto distal tibial oblique osteotomy (DTOO): surgical technique and applicability for ankle osteoarthritis with varus deformity”, Strategies in Trauma and Limb Reconstruction, April 2018, Vol. 13, No. 1, pp. 43-49

Rotation of the distal tibia plate A2 creates a medial protrusion F (S2). This protrusion F causes skin tension when the incision is sutured. Therefore, the protrusion F (S3) is removed, and then the bone plate 30 is placed on the medial surface of the tibia A. At this point, the protrusion F needs to be removed so that the shape of the removed medial surface conforms to the shape of the bone contact surface 30a of the bone plate 30.

The present invention was made in view of the above circumstances, and the purpose of the present invention is to provide a guide device capable of removing bone heads to match the shape of the bone contact surface of a bone plate.

One aspect of the invention is a guiding device for removing bone in an area where a bone plate is to be placed. It comprises: a fixing part having a cutting area fixed to the bone and disposed at the removal site of the bone; and a guiding part guiding a cutting tool or a guiding component for guiding the cutting tool in the cutting area; wherein the guiding part guides the cutting tool or the guiding component along a plate surface having the same or substantially the same shape as the bone contact surface of the bone plate.

According to the present invention, it has the effect of removing bone heads to match the shape of the bone contact surface of the bone plate.

(First Embodiment) The guiding device according to the first embodiment of the present invention is described herein with reference to the accompanying drawings. Figure 11 shows a high oblique osteotomy of the tibia (DTOO) as an example of the guiding device 1 according to the present embodiment. In the DTOO, the skin covering the ankle joint is cut, and then the distal tibia A is diagonally osteotomized toward the distal tibiofibular joint D (S1), and the distal tibia plate A2 is rotated distally through the widened osteotomy portion E (S2). Thereafter, a bone plate 30 is placed across the widened osteotomy portion E on the medial surface of the tibia A and fixed to the tibia A with screws 40 (S4). In Figure 11, the left, right, upper, and lower sides correspond to the medial, lateral, proximal, and distal sides of the tibialis A, respectively.

The bone plate 30 is a strip-shaped component having a axial portion 31 on the basal side and a head portion 32 on the anterior side. The axial portion 31 is disposed on the bony shaft A1, which is closer to the end than the osteotomy portion E, and the head portion 32 is disposed on the epiphysis A2, which is more distal to the osteotomy portion E. The bone plate 30 has a bone contact surface 30a on one side in the thickness direction that contacts the surface of the tibia A. The bone contact surface 30a is curved in a three-dimensional manner in the width and length directions to match the shape of the medial surface of the distal tibia A. The bone plate 30 and the bone contact surface 30a can also be twisted about the axis in the length direction so that when the axis 31 is positioned on the inner side, the head 32 is positioned closer to the anterior or posterior side of the tibia A than the axis 31.

The protrusion F is created by rotation of the epiphysis A2 (S2). The protrusion F is the medial portion of the epiphysis A2 that protrudes medially from the surface of the distal tibia A before rotation. In DTOO, compared with other osteotomies such as LTO (low tibia osteotomy) and HTO (high tibia osteotomy), the protrusion F is larger due to the larger opening angle of the osteotomy E. In addition, the soft tissues such as the skin covering the ankle joint are very thin. Therefore, especially in DTOO, the protrusion F is prone to causing problems such as skin tension when suturing the cut wound. Therefore, the protrusion F is removed (S3) using cutting tools such as a bone saw or bone chisel, and then the bone plate 30 is placed on the medial surface of the distal tibia A (S4). The guide device 1 is used to cut off the protrusion F so that the shape of the inner surface of the cut protrusion F matches the shape of the bone contact surface 30a.

As shown in Figures 1A to 1C, the guide device 1 has mutually orthogonal width direction X, length direction Y, and height direction Z. In the guide device 1 used for DTOO, the width direction X corresponds to the anterior-posterior direction of the tibia A, the length direction Y corresponds to the length direction of the tibia A, and the height direction Z corresponds to the lateral direction (medial-lateral direction) of the tibia A. One side and the other side of the length direction Y are the anterior side and the basal side corresponding to the distal side and the proximal side of the tibia A, respectively. One side and the other side of the height direction Y are the superior side and the inferior side corresponding to the medial side and the lateral side of the tibia A, respectively.

The guiding device 1 includes: a fixing part 2 having a cutting area S disposed on the protrusion (resection site) F and fixed to the tibia A; and a guiding part 3, a guiding component 51 for guiding the cutting tool (as shown in Figures 3A and 3B). Figure 1B is a side view of the guiding device 1 viewed from the side of the guiding part 3 along the width direction X, and Figure 1C is a top view of the guiding device 1 viewed from above in the height direction Z. The entire guiding device 1 is made of a material with high biocompatibility and high rigidity, such as stainless steel or other metals.

The cutting area S is a spatial area. When viewed from above, this spatial area is wider in the width direction X and the length direction Y than the protrusion F. The fixing part 2 includes: a torso (first part) 4 and a front end (second part) 5 disposed on both sides of the cutting area S, and an arm part 6 connecting the torso 4 and the front end 5. The torso 4, the front end 5, and the arm part 6 are integrally formed.

The trunk 4 is strip-shaped, extending along the length direction Y. The anterior end portion 5 is spaced apart from the front end of the trunk 4 along the length direction Y. The cutting area S is defined between the trunk 4 and the anterior end portion 5. The trunk 4 is positioned on the proximal side of the protrusion F of the bony shaft A1 along the length direction of the bony shaft A1, while the anterior end portion 5 is positioned on the distal side of the protrusion F of the epiphyseal portion A2.

The trunk 4 and the anterior end portion 5 each have a lower surface (contact surface) 4a and 5a on their lower sides that contact the surface of the tibia A. The lower surfaces 4a and 5a are disposed on the plate surface P (as shown in FIG. 1A). The plate surface P is a virtual surface having the same or substantially the same shape as the bone contact surface 30a of the bone plate 30. In FIG. 1B, only the central axis of the plate surface P is drawn. Specifically, the lower surface 4a has the same or substantially the same shape as the basal end portion of the plate surface P corresponding to the axial portion 31, and the lower surface 5a is disposed at or near the front end of the plate surface P. Therefore, when viewed from above in the height direction Z, the front end portion of the plate surface P, including the portion corresponding to the head portion 32, is disposed within the cutting area S (as shown in FIG. 1C).

The arm portion 6 has a cantilever shape extending from the anterior end of the trunk 4 to the anterior end portion 5, with the anterior end portion 5 located at the front end of the arm portion 6. To prevent the arm portion 6 from obstructing the identification of the protrusion F in the cutting area S, the width of the arm portion 6 is preferably narrower than the width of the trunk 4. The arm portion 6 is designed to have a shape that will not interfere with the tibia A and surrounding tissues during surgery, nor with instruments such as guide pins 51 and 52. In the illustrated example, the arm portion 6 is slightly C-shaped, curving upwards. The anterior end portion 5 is the anterior end of the cantilever-shaped component constituting the arm portion 6.

The fixing part 2 has one or more holes 2a passing through it along the height direction Z, serving as a fixation device for fixing the fixing part 2 to the tibia A. A guide pin 52 is passed through the hole 2a and inserted into the tibia A, fixing the fixing part 2 to the tibia A (as shown in Figures 3A and 3B). Holes 2a are provided at least in the trunk 4 and the anterior end 5. In the illustrated example, the trunk 4 has three holes 2a arranged at intervals along the length direction Y, and the anterior end 5 has one hole 2a. Alternatively, the arm part 6 may also have one or more holes 2a.

The guide section 3, viewed from above, is a strip-shaped part that extends roughly along the length direction Y with the arm section 6 (as shown in FIG. 1C), and is positioned on the front or rear side of the protrusion F. The guide section 3 is positioned at a distance from the arm section 6 in the width direction X, and is located on the outer side of the plate surface P in the width direction X. The base end of the guide section 3 is fixed to the front end of the torso section 4 via a connecting part 7 extending in the width direction X.

The guide portion 3 has a plurality of pin holes 3a, which are guide holes for guiding the guide member 51. These pin holes 3a are arranged in a row along the length direction Y and at intervals, so that the guide member 51 is inserted into the pin holes 3a. In this embodiment, the guide member 51 is an elongated guide pin. The diameter of each pin hole 3a is slightly larger than the diameter of the guide pin 51, and it passes through the guide portion 3 approximately along the width direction X. The guide pin 51 passing through each pin hole 3a traverses the cutting area S along the width direction X.

As shown in Figures 1A and 1C, the extension line β of the central axis α of the plurality of pin holes 3a is arranged along the plate surface P. Thus, the plurality of pin holes 3a restricts the plurality of guide pins 51 to a position along the plate surface P in the cutting area S, such that the plurality of guide pins 51 are arranged at intervals along the length direction Y of the plate surface P.

Specifically, as shown in Figure 2, when viewed from the length direction Y, the extension lines β of each pin hole 3a pass through two points Q1 and Q2 at or near the two ends of the plate surface P in the width direction. Therefore, when viewed from the width direction X, the extension lines β of the plurality of pin holes 3a are arranged in a row along the curved plate surface P. Furthermore, if the bone contact surface 30a has a shape that is twisted around the axis of the length direction, when viewed from the length direction Y, the angle of the plurality of extension lines β gradually changes from the base side to the anterior side. As will be described later, when cutting along the upper end of the guide pin 51 that penetrates the tibia A, points Q1 and Q2 can be positioned at a distance from both ends of the plate surface P offset downwards by a distance equal to the radius of the guide pin 51.

Next, the use of the guide device 1 will be explained with reference to Figures 3A to 3C. The method of use includes: first step, fixing the fixing part 2 to the surface of the bone; second step, inserting the guide pin 51 through the pin hole 3a of the guide part 3 into the bone; third step, using a cutting tool to cut off the protrusion F along the guide pin 51.

As shown in Figure 3A, after widening the osteotomy section E, in the first step, the trunk 4 and the anterior end portion 5 are placed on the inner surfaces of the diaphysis A1 and the epiphysis A2, respectively, with the cutting area S positioned at the location of the protrusion F. Next, the guide pin 52 is inserted into the tibia A through the hole 2a in the trunk 4 and the anterior end portion 5, fixing the trunk 4 and the anterior end portion 5 to the diaphysis A1 and the epiphysis A2, respectively.

Next, in the second step, a plurality of guide pins 51 pass through a plurality of pin holes 3a and penetrate the epiphysis A2 in the anterior-posterior direction. In the example of Figure 3A, five guide pins 51 pass through five selected pin holes 3a and are then inserted into the epiphysis A2.

As shown in Figure 3B, after inserting the guide pin 51 into the epiphysis A2, the guide device 1 is removed from the tibia A, leaving the guide pin 51 in the epiphysis A2. In the protrusion F, the guide pin 51 is placed inside the epiphysis A2.

Next, as shown in Figure 3C, in the third step, a bone-cutting tool such as a bone saw or chisel is used to cut along the upper ends of the plurality of guide pins 51 to the epiphysis A2 and remove the bone tissue covering the guide pins 51. Thus, the protrusion F extending beyond the plate surface P defined by the plurality of guide pins 51 is removed. After the third step, the guide pins 51 are removed from the epiphysis A2, and then the bone plate 30 is placed on the medial side of the tibia A at the same position as the fixation part 2 and fixed to the tibia A with screws 40.

In this embodiment, a plurality of guide pins 51 inserted into the tibia A using the guide portion 3 are arranged along a plate surface P having the same or substantially the same shape as the bone contact surface 30a. Therefore, by cutting the tibia A along the guide pins 51, the protrusion F of the tibia A can be removed to match the shape of the bone contact surface 30a. Furthermore, this allows the bone contact surface 30a to fit well with the medial surface of the removed distal tibia A, thus enabling the incision to be sutured without stretching the skin after fixing the bone plate 30.

Traditionally, the removal of the protrusion F is performed by a surgeon using a cutting tool to precisely cut the bone head while referencing the bone contact surface 30a, ensuring that the shape of the cut surface of the tibia A closely approximates the bone contact surface 30a. Such precise cutting requires a high level of skill from the surgeon. Specifically, when the bone contact surface 30a is a three-dimensional curved and twisted surface, it is difficult to precisely cut the bone head to match the bone contact surface 30a. According to this embodiment, even when the bone contact surface 30a has such a complex curved shape, it can be performed without relying on a surgeon's advanced skills, and the protrusion F can be easily removed to match the bone contact surface 30a.

Furthermore, according to this embodiment, the fixation part 2 has a trunk 4 and an anterior end 5 disposed on both sides of the cutting area S. Thus, users such as doctors can accurately identify the location of the cutting area S and can accurately and easily position the fixation part 2 relative to the tibia A, so that the cutting area S is positioned on the protrusion F. Additionally, the trunk 4 and the anterior end 5 are fixed to the diaphysis A1 and epiphysis A2 respectively using the guide pin 52, thereby fixing the widened diaphysis A1 and epiphysis A2 of the osteotomy part E. This prevents the epiphysis A2 from moving when the guide pin 51 is inserted and allows the guide pin 51 to be accurately inserted into the desired position.

Furthermore, according to this embodiment, the lower surfaces 4a and 5a of the fixing part 2 are disposed on the plate surface P. Therefore, the user can determine the appropriate position of the bone plate 30 by matching the shape of the lower surfaces 4a and 5a of the fixing part 2 with the inner surface of the tibia A. In addition, by fixing the fixing part 2 to the tibia A at this position, it is also possible to determine that the plate surface P is in an appropriate position relative to the tibia A. Therefore, by cutting the tibia A along the plate surface P and then disposing the bone plate 30 at the same position as the fixing part 2, the bone contact surface 30a can be made to fit well with the inner surface of the tibia A.

In this embodiment, the bone is cut along the upper end of the guide pin 51. However, alternatively, the bone can be cut along the hole after removing the guide pin 51. In this case, the position and angle of the central axis α and the extension line β of the pin hole 3a can be designed so that the lower end of the hole is along the plate surface P. In this case, the guide device 1 and the guide pin 51 are removed from the tibia A after step S2. Thereafter, the tibia A is cut along the hole formed by the guide pin 51, and the protrusion F is removed.

(Second Embodiment) Next, a guiding device according to a second embodiment of the present invention will be described. The guiding device 10 of this embodiment differs from that of the first embodiment in that it has a guide slit 13a that serves as a guide hole for guiding a cutting tool. In this embodiment, structures different from those in the first embodiment will be described; however, structural designations common to the first embodiment use the same symbols and will not be elaborated upon here.

As shown in Figures 4A to 4C, the guiding device 10 includes a fixing part 12 fixed to the tibia A, and a guiding part 13 (as shown in Figure 6B) for guiding the cutting tool 50. Figure 4B is a side view of the guiding device 10 viewed from the side of the guiding part 13 along the width direction X, and Figure 4C is a top view of the guiding device 10 viewed from above along the height direction Z. The fixing part 12 includes a trunk 4 and a front end (second part) 15 disposed on both sides of the cutting area S, and an arm part 16 connecting the trunk 4 and the front end 15. The trunk 4, the front end 15, and the arm part 16 are integrally formed.

The front end portion 15 is spaced apart from the front end of the torso 4 in the longitudinal direction Y, and the cutting area S is defined between the torso 4 and the front end portion 15. The front end portion 15 has a flat or curved lower surface (contact surface) 15a, which is disposed at or near the front end of the plate surface P. The arm portion 16 is disposed outside the plate surface P in the width direction X, and the cutting area S is disposed between the arm portion 16 and the guide portion 13. Thus, when using the guide device 10, the user can easily identify the entire protrusion F of the cutting area S from above in the height direction Z.

The fixing part 12 has one or more cylindrical sleeves 12a, which serve as fixing devices for fixing the fixing part 12 to the tibia A and protrude from the upper surface of the fixing part 12 along the height direction Z. The fixing part 12 is fixed to the tibia A by passing a guide pin 52 through the sleeve 12a and inserting it into the tibia A (as shown in Figures 6A and 6B). The sleeves 12a are provided at least on the trunk 4 and the anterior end 15. Two sleeves 12a can be provided on the anterior end and the basal end of the trunk 4 to more stably fix the fixing part 12 to the tibia A.

The guide portion 13, viewed from above, has a strip-like shape extending parallel to the arm portion 16 along the length direction Y (as shown in FIG. 4C). The guide portion 13 is spaced apart from the arm portion 16 in the width direction X and is located outside the width direction X of the plate surface P. The guide portion 13 has a guide slit 13a extending along the length direction Y and serving as a guide hole for guiding a cutting tool 50, such as a bone saw or bone chisel, into which the cutting tool 50 is inserted. The guide slit 13a has a slit width slightly larger than the thickness of the cutting tool 50 and extends approximately through the guide portion 13 in the width direction X. The cutting tool 50, guided by the narrow slit 13a, moves across the cutting area S in a slightly wider direction X.

The central surface γ of the guide slot 13a has a shape corresponding to the shape of the plate surface P, and the extended surface δ of the central surface γ is disposed along the plate surface P. The central surface γ is a plane connecting the center point of the guide slot 13a in the height direction Z. The extended surface δ is a surface obtained by extending the central surface γ along the width direction X. Thus, the guide slot 13a restricts the cutting tool 50 to a position along the plate surface P in the cutting area S, allowing the cutting tool 50 to move along the plate surface P.

Specifically, as shown in Figure 5, when viewed from the length direction Y, the extending surface δ passes through two points Q1 and Q2 at or near the two ends of the plate surface P in the width direction. Figure 5 illustrates surfaces γ and δ at certain locations in the length direction Y. Surfaces γ and δ are curved surfaces composed of a set of straight lines extending along the width direction X, and when viewed from the width direction X, surfaces γ and δ are curved according to the curvature of the plate surface P. If the bone contact surface 30a has a twisted shape around the axis of the length direction, when viewed along the length direction Y, the angle of this straight line gradually changes from the base side to the front side. Similar to the first embodiment, points Q1 and Q2 can be configured at positions offset downward from the two ends of the plate surface P by a distance equal to the radius of the guide pin 51.

The base and front end of the guide portion 13 are fixed to the trunk 4 and the front end 15, respectively, via the connecting portion 7. With the guide device 10 fixed to the tibia A, the tibia A is cut using a cutting tool that passes through the guide slit 13a. Since both ends of the guide portion 13 are fixed to the fixing portion 12, the positional stability of the guide portion 13 relative to the tibia A is improved, and the tibia A can be cut with high precision as needed.

Next, referring to Figures 6A and 6B, this describes how to use the guide device 10. The method of use includes: first, fixing the fixation part 12 to the bone surface; second, using the cutting tool 50 to cut the protrusion F along the guide slit 13a of the guide part 13.

As shown in Figure 6A, after widening the osteotomy section E, the first step is to place the trunk 4 and the anterior end portion 15 on the inner surfaces of the diaphysis A1 and the epiphysis A2, respectively, and position the cutting area S at the location of the protrusion F. Next, the guide pin 52 is passed through the sleeve 12a of the trunk 4 and the anterior end portion 15 and inserted into the tibia A to fix the trunk 4 and the anterior end portion 15 to the diaphysis A1 and the epiphysis A2, respectively.

Next, as shown in Figure 6B, in the second step, the cutting tool 50 is inserted into the epiphysis A2 in the anterior-posterior direction through the guide slit 13a, and the cutting tool 50 is moved along the guide slit 13a to cut the epiphysis A2. Since the cutting tool 50 moves along the plate surface P, the protrusion F protruding from the plate surface P will be removed. After the second step, the guide device 10 is removed from the tibia, and then the bone plate 30 is placed on the inner side of the tibia A at the same position as the fixing part 12, and fixed to the tibia A with screws 40.

In this embodiment, the cutting tool 50 in the guide slit 13a moves along a plate surface P having the same or substantially the same shape as the bone contact surface 30a in the cutting area S. Therefore, by moving the cutting tool 50 along the guide slit 13a, the protrusion F of the tibia A can be cut to match the shape of the bone contact surface 30a. Furthermore, this allows the bone contact surface 30a to conform well to the medial surface of the distal tibia A after removal, enabling the wound to be sutured without stretching the skin after fixing the bone plate 30.

Furthermore, similar to the first embodiment, according to this embodiment, the fixing part 12 has a trunk 4 and an anterior end 15 disposed on both sides of the cutting area S. Therefore, the user can accurately identify the position of the cutting area S, and the fixing part 12 can accurately and easily position the tibia A. In addition, by using the guide pin 52 to fix the trunk 4 and the anterior end 15 to the diaphysis A1 and the epiphysis A2 respectively, the epiphysis A2 can be prevented from moving during the cutting process of the cutting tool 50.

Furthermore, similar to the first embodiment, according to this embodiment, since the lower surfaces 4a and 15a of the fixing part 12 are disposed on the plate surface P, the user can easily position the bone plate 30 and the plate surface P at an appropriate position relative to the tibia A. In addition, by setting the bone plate 30 in the same position as the fixing part 12, the bone contact surface 30a can fit well against the inner surface of the tibia A.

As shown in Figures 7A and 7B, the guide device 10 may also include a confirmation component 17 for confirming the shape of the cut surface of the bone in the cutting area S. The confirmation component 17 is a component separate from the components constituting the fixing part 12 and the guide part 13, and may be, for example, a plate-like component. The confirmation component 17 is detachably mounted to the fixing part 12 and disposed in the cutting area S.

The confirming component 17 has two semi-cylindrical mating surfaces 17a and 17b, which serve as positioning parts for positioning the confirming component 17 relative to the fixing part 12. The mating surfaces 17a and 17b are radially fitted into the sleeve 12a of the trunk 4 and the front end 15, so that the confirming component 17 is positioned relative to the fixing part 12 in a predetermined position. The positioning part may also have a structure other than the mating surfaces. Alternatively, the confirming component 17 may be detachably mounted to the guide part 13 instead of the fixing part 12.

The confirmation component 17 has a confirmation surface 17c that contacts the bone. As shown in FIG7B, the confirmation surface 17c has the same shape as a portion of the plate surface P within the cutting area S, and the confirmation surface 17c aligns with the plate surface P when positioned by the positioning parts 17a and 17b. In FIG7B, the connecting part 7 and the guide part 13 are omitted. After the user makes a cut using the cutting tool 50, the confirmation component 17 is installed on the fixing part 12, and based on the matching of the confirmation surface 17c with the surface shape of the epiphysis A2, it can be confirmed whether the cutting surface has a shape along the plate surface P.

(Third Embodiment) Next, a guiding device according to a third embodiment of the present invention will be described. The guiding device 20 of this embodiment differs from that of the second embodiment in that it has two guide slits 23a and 23b serving as guide holes. In this embodiment, the construction different from that of the first and second embodiments will be described. The same symbols are used for constructions common to the first and second embodiments, and therefore will not be elaborated upon here.

As shown in Figures 8A to 8C, the guiding device 20 includes a fixing part 12 fixed to the tibia A and a guiding part 23 for guiding the cutting tool 50. Figure 8B is a side view of the guiding device 20 viewed from the side of the guiding part 23 along the width direction X, and Figure 8C is a top view of the guiding device 20 viewed from above along the height direction Z. The fixing part 12 is as described in the second embodiment.

The guide section 23, viewed from above, extends parallel to the arm section 16 along the length direction Y and is generally cylindrical in shape. The guide section 23 is arranged at intervals with the arm section 16 in the width direction X, and is located on the outer side of the plate surface P in the width direction X. The base end and the front end of the guide section 23 are respectively fixed to the torso section 4 and the front end section 15 through the connecting part 7.

The guide section 23 has a first guide slit 23a and a second guide slit 23b extending along the length direction Y (as shown in FIG8B). The two guide slits 23a and 23b are arranged side by side along the height direction Z intersecting the plate surface P. Each guide slit 23a and 23b passes straight through the guide section 23 in the width direction X, and the cutting tool 50 passing through the guide slits 23a and 23b traverses the cutting area S along the slightly wider direction X. In the reference diagram, each guide slit 23a, 23b is composed of two slits on the anterior and basal sides. Although they are discontinuous in the part corresponding to the osteotomy E, they can also be formed by a single continuous slit.

The central surfaces γ1 and γ2 of the two guide slots 23a and 23b are inclined to each other in the height direction Z, such that the extending surfaces δ1 and δ2 intersect each other in the cutting area S, and the extending surfaces δ1 and δ2 are arranged along the plate surface P. Thus, the guide slots 23a and 23b restrict the cutting tool to a position along the plate surface P in the cutting area S, allowing the cutting tool to move along the plate surface P.

The first central surface γ1 of the first guide slit 23a is a plane passing through the center point of the first guide slit 23a in the height direction Z at each position in the width direction X and length direction Y. The second central surface γ2 of the second guide slit 23b is a plane passing through the center point of the second guide slit 23b in the height direction Z at each position in the width direction X and length direction Y. The first extension surface δ1 and the second extension surface δ2 are surfaces obtained by extending the central surfaces γ1 and γ2 in the width direction X, respectively.

Specifically, as shown in Figure 9, when viewed from the length direction Y, the two central surfaces γ1 and γ2 tilt in opposite directions and approach each other as they approach the plate surface P. Due to the tilt of the central surfaces γ1 and γ2, the two extended surfaces δ1 and δ2 intersect each other between two points Q1 and Q2, with one extended surface δ1 passing through point Q2 and the other extended surface δ2 passing through point Q1. The intersection point Q3 of the two extended surfaces δ1 and δ2 is located above or below the plate surface P. In the illustrated example, each guide slot 23a, 23b is straight. Although surfaces γ1, γ2, δ1, and δ2 are flat, the guide slots 23a, 23b and surfaces γ1, γ2, δ1, and δ2 can be curved (as shown in the second embodiment).

Next, referring to Figures 10A to 10C, the use of the guide device 20 will be described. The method of use includes: first, fixing the fixation part 12 to the bone surface; second, using a cutting tool 50 to cut the protrusion F along the two guide slits 23a and 23b of the guide part 23. Similar to the second embodiment, in the first step, the trunk 4 and the anterior end 15 are fixed to the diaphysis A1 and epiphysis A2, respectively.

Next, as shown in Figure 10A, in the second step, the cutting tool 50 is inserted into the epiphysis A2 through the first guide slit 23a in a front-to-back direction, and then the cutting tool 50 is moved along the first guide slit 23a to cut the epiphysis A2. Similarly, as shown in Figure 10B, the cutting tool 50 is inserted into the epiphysis A2 through the second guide slit 23b in a front-to-back direction, and the cutting tool 50 is moved along the second guide slit 23b to cut the epiphysis A2. Thus, as shown in Figure 10C, the protrusion F extending beyond the plate surface P is cut along both surfaces. Figure 10C is a cross-sectional view of the epiphysis A2.

In this embodiment, the cutting tool 50 in the guide slits 23a and 23b moves along a plate surface P having the same or substantially the same shape as the bone contact surface 30a in the cutting area S. Therefore, by moving the cutting tool 50 along the guide slits 23a and 23b, the protrusion F of the tibia A can be removed to match the shape of the bone contact surface 30a. This also allows the skin wound to be sutured without stretching the skin.

Furthermore, according to this embodiment, the epiphysis A2 is cut along two extending surfaces δ1 and δ2, and the cut surface of the epiphysis A2 after removing the protrusion F consists of two surfaces that form an angle with each other. Thus, the protrusion F can be removed to better fit the bone contact surface 30a, which curves in the width direction. Other effects of this embodiment are the same as in the second embodiment, and therefore will not be described in detail here. The guide device 20 of this embodiment may also include the confirmation component 17 described in the second embodiment.

As described above, the guide devices 1, 10, and 20 of each embodiment are designed based on the shape of the bone contact surface 30a of the bone plate 30 used. Therefore, the guide devices 1, 10, and 20 can be configured as part of a system for osteotomy. The system includes the guide devices 1, 10, or 20 and the bone plate 30, and may also include one or more screws 40 for securing the bone plate 30 to the tibia A.

The embodiments and variations of the present invention have been described above. However, the specific structure of the present invention is not limited to the above embodiments and variations, and various design changes can be made without departing from the spirit of the present invention. Furthermore, the structures shown in the above embodiments and variations can be appropriately combined. For example, the fixing parts 2 and 12 can be fixed to the bone using any device other than the guide pin 52. In this case, the fixing parts can have an alternative structure to replace the hole 2a and the sleeve 12a.

The fixation device may consist of only one of a trunk (first part) and a front end (second part). For example, in the first embodiment, the fixation device 2 does not need to have a front end 5. In this case, the user can visually position the trunk 4 relative to the tibia A, such that the cutting area S is located on the protrusion F. Furthermore, any device other than the guide device 1 can be used to fix the trunk A1 and the epiphysis A2 to prevent the epiphysis A2 from moving when the guide pin 52 is inserted.

The guide device 1 of the first embodiment may also include a confirmation component 17. In this case, with the guide device 1 fixed to the tibia A, the epiphysis A2 is cut along the guide pin 51. After cutting, the confirmation component 17 can be installed on the guide device 1 to confirm the shape of the cut surface.

The guiding device of this invention is not limited to DTOO and can be used in any bone surgery in which bone in the area where a bone plate is placed is removed to match the shape of the bone contact surface of the bone plate. For example, the guiding device can be used for protrusion removal in HTO. The specific structure of the guiding device, such as the shape of the trunk, anterior end, and arm portion, is designed according to the bone surgery to be performed.

1, 10, 20: Guiding device 2, 12: Fixing part 2a: Hole 3, 13, 23: Guiding part 3a: Pin hole 4: Trunk 4a, 5a, 15a: Lower surface 5, 15: Anterior end part 6, 16: Arm part 7: Connecting part 12a: Sleeve 13a, 23a, 23b: Guiding slit 17: Confirmation component 17a, 17b: Fitting surface 17c: Confirmation surface 30: Bone plate 30a: Bone contact surface 31: Shaft part 32: Head part 40: Screw 50: Cutting tool 51, 52: Guiding pin/guiding component A: Distal tibia A1: Shaft A2: Epiphysis/Distal Tibial Flap B: Talus C: Fibula D: Distal Tibifibular Joint E: Osteotomy Section F: Prominent Section P: Plate Surface Q1, Q2: Points Q3: Intersection S: Cutting Area S1~S4: Steps α: Central Axis β: Extension Line γ, γ1, γ2: Central Surface δ, δ1, δ2: Extension Surface

Figure 1A is a perspective view of the guide device according to the first embodiment. Figure 1B is a side view of the guide device of Figure 1A. Figure 1C is a top view of the guide device of Figure 1A. Figure 2 is a diagram illustrating the positional relationship between the extension line of the guide pin and the plate surface. Figure 3A is a diagram illustrating the method of using the guide device of Figure 1A. Figure 3B is a diagram illustrating the method of using the guide device of Figure 1A. Figure 3C is a diagram illustrating the method of using the guide device of Figure 1A. Figure 4A is a perspective view of the guide device according to the second embodiment. Figure 4B is a side view of the guide device of Figure 4A. Figure 4C is a top view of the guide device of Figure 4A. Figure 5 is a diagram illustrating the positional relationship between the extended surface of the guide slot and the plate surface. Figure 6A is an explanatory diagram illustrating the use of the guide device of Figure 4A. Figure 6B is an explanatory diagram illustrating the use of the guide device of Figure 4A. Figure 7A is a perspective view of the guide device including the confirmation component. Figure 7B is a side view of the confirmation component in use. Figure 8A is a perspective view of the guide device according to the third embodiment. Figure 8B is a side view of the guide device of Figure 8A. Figure 8C is a top view of the guide device of Figure 8A. Figure 9 is a diagram showing the positional relationship between the extended surfaces of the first and second guide slots and the plate surface. Figure 10A is an explanatory diagram illustrating the use of the guide device of Figure 8A. Figure 10B is an explanatory diagram illustrating the use of the guide device of Figure 8A. Figure 10C is a cross-sectional view of the tibia removed using the guide device shown in Figure 8A. Figure 11 is a step diagram illustrating DTOO.

1: Guide device 2: Fixing part 2a: Hole 3: Guide part 3a: Pin hole 4: Trunk 4a: Lower surface 5: Front end 5a: Lower surface 6: Arm part 7: Connecting part S: Cutting area P: Plate surface α: Central axis β: Extension line

Claims (7)

A guiding device for removing bone in a region where a bone plate is to be placed after osteotomy and widening, comprising: a fixing part fixed to the bone after osteotomy and widening, and having a cutting area disposed at the removal site of the bone; and a guiding part fixed to the fixing part for guiding a cutting tool or a guiding component for guiding the cutting tool in the cutting area; wherein the guiding part guides the cutting tool or the guiding component by means of a plate having the same or substantially the same shape as the bone contact surface of the bone plate, thereby enabling the removal of protrusions protruding from the bone contact surface due to osteotomy and widening. The guide device as described in claim 1, wherein the fixing part has a first part and a second part disposed on both sides of the cutting area, the contact surfaces of the first part and the second part with the bone being disposed on the plate surface. The guiding device as described in claim 1, wherein the guiding portion has a guiding hole for the cutting tool or the guiding component to be inserted and for restricting the cutting tool or the guiding component to a position along the plate surface of the cut portion. The guide device as described in claim 3, wherein the guide hole has a plurality of holes arranged in a row and for insertion of the guide member, and the extensions of the central axis of the plurality of holes are arranged along the plate surface. The guiding device as described in claim 3, wherein the guiding hole has a guiding slit for insertion of the cutting tool, and an extension surface of the central surface of the guiding slit is arranged along the plate surface. The guiding device as described in claim 3, wherein the guiding hole has a first guiding slit and a second guiding slit, the first guiding slit and the second guiding slit being respectively inserted into the cutting tool and arranged in a direction intersecting the plate surface, the first center surface of the first guiding slit and the second center surface of the second guiding slit being inclined to each other such that the first extension surface of the first center surface and the second extension surface of the second center surface intersect each other in the cutting area, the first extension surface and the second extension surface being arranged along the plate surface. The guide device as described in claim 1 further includes a confirmation component that can be detached from the fixing part or the guide part and configured in the cutting area, the confirmation component having a confirmation surface with the same shape as the plate surface.