Guiding device

Abstract

The guiding device comprises: a guiding part (2) for guiding the bone-shaving tool; a traction part (4) disposed at intervals from the guiding part (2) in a first direction; a connecting part (5) for connecting the guiding part (2) and the traction part (4); and a fixing part (6) for fixing the guiding part (2) relative to the tibia. The guiding part has a guiding hole (2a) that penetrates the guiding part (2) in the first direction and extends into a second direction that intersects the first direction; the traction part (4), when viewed from above in the first direction, is disposed in an area that at least overlaps with the guiding hole (2a).

Description

Technical Field

[0001] This invention relates to a guiding device, and more particularly to a guiding device for longitudinal osteotomy in TCVO. Prior Technology

[0002] In cases of medial osteoarthritis of the knee, joint instability known as the "seesaw effect" may occur due to wear and tear on the cartilage and bone of the tibialis joint in the medial thigh. To improve this symptom, a tibial condylar valgus osteotomy (TCVO) is usually performed.

[0003] As shown in Figure 14, the transconjunctival osteotomy (TCVO) is a surgical procedure that alters the shape of articular surface B by osteotomizing the proximal end of the tibia A into an L-shape. This improves the fit of articular surface B and moves the load line (see dashed line) outward. In TCVO, the osteotomy is performed transversely from the medial cortical bone of the tibia A to the medial border of the tibial roughness, and then longitudinally from the medial border of the tibial roughness to the lateral intercondylar eminence or the center of the intercondylar eminence. In Figure 14, symbol C represents the femur, and symbol D represents the fibula. In osteotomy procedures like TCVO, a guiding device for bone cutting instruments such as a guide bone saw is sometimes used to precisely and easily cut the bone (see, for example, Patent Document 1).

[0004] [Patent Literature] [Patent Document 1] Japanese Patent No. 6989668. Summary of the Invention

[0005] As described above, in TCVO, longitudinal osteotomy (symbol L1) and transverse osteotomy (symbol L2) are performed. During longitudinal osteotomy, a bone-shaving tool is inserted into the tibia from the front and then cuts backward. Behind the tibia A are soft tissues such as the popliteal artery and vein, and the tibial nerve. Traditional guiding devices, as described in Patent Document 1, do not protect these soft tissues. Therefore, currently, longitudinal osteotomy is performed by highly skilled physicians while protecting the soft tissues. For example, the physician may use a hammer to strike a chisel while carefully performing the osteotomy, judging from changes in sound that the chisel has reached the hard cortical bone posterior to the tibia A.

[0006] The present invention was developed in view of the above circumstances, and its purpose is to provide a guiding device that can simultaneously achieve precise longitudinal osteotomy and protect the soft tissue behind the tibia in TCVO surgery.

[0007] A guide device of the present invention comprises: a guide portion disposed anterior to the tibia and guiding a bone-cutting tool for cutting the tibia; a traction portion disposed posterior to the tibia and spaced apart from the guide portion in a first direction; a connecting portion connecting the guide portion and the traction portion; and a fixing portion fixing the guide portion relative to the tibia; the guide portion having a guide hole for inserting the bone-cutting tool, extending through the guide portion in the first direction and into a second direction intersecting the first direction; the traction portion, when viewed from above in the first direction, being disposed in a region at least overlapping with the guide hole.

[0008] According to the present invention, it is possible to achieve precise longitudinal osteotomy and protect the soft tissue behind the tibia simultaneously in TCVO. Simple Explanation of the Diagram

[0009] Figure 1 is an assembled perspective view of a guidance device related to an implementation configuration. Figure 2 is a perspective view of (a) the first guide section and (b) the second guide section. Figure 3 shows a cross-sectional view (a) and a longitudinal cross-sectional view (b) of the traction unit. Figure 4 shows an example of an X-ray fluoroscopic image of the guide and traction sections located on the tibia. Figure 5 is a schematic diagram of an example of a locking mechanism. Figure 6 shows the configuration diagram of other examples of locking mechanisms. Figure 7 is an illustration of how to use the guidance device in TCVO. Figure 8 is an illustration of how to use the guidance device in TCVO. Figure 9 is an illustration of how to use the guidance device in TCVO. Figure 10 is an illustration of how to use the guidance device in TCVO. Figure 11 is an illustration of how to use the guidance device in TCVO. Figure 12 shows (a) a three-dimensional diagram of the first unit and the second unit assembled with the left foot, and (b) a three-dimensional diagram of the first unit and the second unit assembled with the right foot. Figure 13 is a schematic diagram showing the retainer when used for (a) the left foot and (b) the right foot. Figure 14 is an explanatory diagram of TCVO. Implementation

[0010] The following description refers to a guide device related to an embodiment of the present invention, with reference to the drawings. The guide device 1 of this embodiment is used to guide the osteotomy tool and guide pin used in TCVO. As shown in FIG14, in TCVO, the proximal end of the tibia A is osteotomized into an L-shape by longitudinal and transverse osteotomies. In FIG14, the symbol L1 represents the longitudinal osteotomy line, and the symbol L2 represents the transverse osteotomy line. The guide device 1 is specifically used for longitudinal osteotomy.

[0011] As shown in Figures 1 and 2(a) and (b), the guiding device 1 includes: two guiding parts 2 and 3, which are used selectively; a traction part 4, which is arranged in a first direction at intervals from the guiding part 2 or 3; a connecting part 5, which connects the guiding part 2 or 3 to the traction part 4; a fixing part 6, which fixes the guiding part 2 or 3 relative to the tibia A; and an adjusting part 7, which adjusts the position of the fixing part 6.

[0012] During TCVO, the anteroposterior and long-side directions of the tibia A are positioned slightly vertically and slightly horizontally, respectively, while the anterior and posterior aspects of the tibia A are positioned superiorly and inferiorly, respectively. Soft tissues such as the genicular artery and vein, and the tibial nerve are located posterior to the tibia A. A longitudinal osteotomy of the tibia A is performed using an osteotomy tool T, proceeding from anterior to posterior (see Figures 10 and 11).

[0013] As shown in Figures 7 to 11, guiding parts 2 and 3 are positioned anterior to the tibia A, traction part 4 is positioned posterior to the tibia A, and connecting part 5 is positioned medially to the tibia A. Therefore, the first direction corresponds to the anterior-posterior direction and the vertical direction of the tibia A, and the second direction, described later, corresponds to the long side direction and the horizontal direction of the tibia A. The guiding device 1 in Figure 1 is for the left foot. The guiding device for the right foot has a structure symmetrical to the guiding device 1 in Figure 1 with respect to the plane of the first direction (see Figure 12(b)).

[0014] As shown in Figures 2(a) and (b), guide parts 2 and 3 are rectangular, slightly flat components with the same or slightly similar shapes. Guide part 2 has a guide hole 2a for inserting a bone-cutting tool T, and is used when cutting the tibia A with the bone-cutting tool T (see Figure 10). Guide part 3 has a plurality of needle holes 3a for inserting a guide pin P, and is used to drill a plurality of bone holes in the tibia A with the guide pin P before cutting the tibia A to form a hole line L3.

[0015] The guide hole 2a is an elongated hole that penetrates the first guide portion 2 in the first direction and extends into the second direction, with a width slightly greater than the thickness of the bone-shaving tool T. The second direction is the direction that intersects with the first direction, preferably the direction that is orthogonal to the first direction. The first guide portion 2 guides the bone-shaving tool T within the guide hole 2a to both the first and second directions. A plurality of pinholes 3a are circular holes that pass through the second guide portion 3 in the first direction and are spaced apart in the second direction, and have an outer diameter slightly larger than that of the guide pin P. The second guide portion 3 guides the guide pin P in the pinholes 3a to the first direction.

[0016] The traction section 4 is positioned posterior to the tibia A and between the soft tissue, with the tip of the osteotomy tool T and the guide pin P protruding from the posterior of the tibia A to protect the soft tissue. The traction section 4 is formed from a thin, plate-like component positioned in the second direction, as shown in Figures 3(a) and (b), and has a uniform thickness. Figure 3(a) is a cross-sectional view of the traction section 4 cut in the width direction, and Figure 3(b) is a longitudinal cross-sectional view of the traction section 4 cut along its central axis in the long side direction. In the top view in the first direction, the traction section 4 is positioned at least in the area overlapping with the guide hole 2a and the plurality of pin holes 3a, preferably in a wider area than the guide sections 2 and 3, to more reliably protect the soft tissue.

[0017] As shown in Figures 3(a) and (b), the traction part 4 is curved in both the long and wide directions and has a spoon-shaped curved shape similar to the one protruding from the opposite side of the retaining part 8. This curved shape allows the traction part 4 to be positioned along the curved rear of the tibia A and prevents the tips of the osteotomy tool T and the guide pin P from disengaging from the traction part 4.

[0018] As shown in Figure 4, in order to allow simultaneous X-ray observation of the traction portion 4 located behind the tibia A and the osteotomy line L1 formed by the osteotomy tool T, the traction portion 4 preferably has X-ray permeability. For example, if the traction portion 4 is made of stainless steel, it preferably has a uniform thickness of 0.5 mm to 0.8 mm.

[0019] The connecting part 5 has: a holding part that selectively holds the two guide parts 2 and 3; a slightly L-shaped support part 9; a beam-shaped support part 10 extending from the support part 9 in a direction intersecting the first direction; and a mounting part 11 provided at the front end of the support part 10 and on which the holding part 8 is mounted.

[0020] The retaining part 8 is a frame-shaped member extending in the second direction and has an insertion hole 8a for inserting the guide parts 2 and 3 in the first direction. Each guide part 2 and 3 has protrusions 2b and 3b on its outer surface. By hooking the protrusions 2b and 3b onto the surface opposite to the traction part 4 of the retaining part 8, the guide parts 2 and 3, once inserted into the insertion hole 8a, are held in the retaining part 8. The guide parts 2 and 3 can be easily removed from the retaining part 8 simply by lifting them to the opposite side of the traction part 4. The retaining part 8 may also have other structures if it is intended to replaceably retain the guide parts 2 and 3.

[0021] Thus, the first guide part 2 and the second guide part 3 are held in the same position by the holding part 8, and the rows of guide holes 2a and the plurality of needle holes 3a are arranged in the same position. Therefore, the position of the hole line L3 formed by the guide needle P can be made to coincide with the position of the osteotomy line L1 formed by the osteotomy tool T. The retaining part 8 further includes: a mounting hole 8b for mounting the retaining part 8 on the mounting part 11, and a threaded hole 8c (see FIG. 13). The mounting hole 8b is provided at the base end of the retaining part 8 and extends through in a first direction. The threaded hole 8c extends radially through the cylindrical wall surrounding the mounting hole 8b.

[0022] The support section 9 has: a first straight portion 9a extending in a first direction; and a second portion 9b extending from the end of the first portion 9a on the side of the traction portion 4 in a direction intersecting the first direction. The traction portion 4 is fixed to the front end of the second portion 9b. The support portion 10 extends in the same direction as the second portion 9b, and the base end of the support portion 10 is provided with a hole 10a penetrating in the first direction. By passing through the hole 10a in the first portion 9a, the support portion 10 is movably supported by the support portion 9 in the first direction.

[0023] The base end of the support portion 10 is provided with a threaded hole for inserting a fixing screw 10b into the central axis of the hole 10a. A groove 9c (see FIG. 6) extending in a first direction is formed on the outer peripheral surface of the first portion 9a. The groove 9c is used to determine a predetermined angle of the support portion 10 relative to the long side axis of the first portion 9a. By adjusting the support portion 10 relative to the first portion 9a so that the front end of the fixing screw 10b will be inserted into the groove 9c, and then tightening the fixing screw 10b, the support portion 10 will be fixed to the first portion 9a at a predetermined angle in the same direction as the second portion 9b.

[0024] The support portion 10 may have a plurality of pinholes 10c arranged along the long side of the support portion 10 and passing through the support portion 10 in a first direction. By inserting the guide pin P through the pinholes 10c into the tibia A, the guide device 1 can be fixed to the tibia A (for example, see FIG8).

[0025] The mounting part 11 is a columnar or cylindrical component disposed in the first direction and fixed to the front end of the support part 10. By inserting the mounting part 11 into the mounting hole 8b and then tightening the mounting screw 11b through the threaded hole 8c, the retaining part 8 will be fixed to the mounting part 11. The outer peripheral surface of the mounting portion 11 has a groove 11a extending in the first direction and receiving the front end of the mounting screw 11b (see Figures 13(a) and (b)). The groove 11a is used to determine the angle of the retaining portion 8 relative to the supporting portion 10. By adjusting the retaining portion 8 relative to the mounting portion 11 so that the front end of the mounting screw 11b will be inserted into the groove 11a, and then tightening the mounting screw 11b, the retaining portion 8 will be fixed to the supporting portion 10 at a predetermined angle configured in the first direction relative to the traction portion 4.

[0026] The fixing part 6 has a first holding part 6a and a second holding part 6b that are opposite to each other in the first direction and clamp the tibia A in the anterior-posterior direction. The first gripping part 6a located in front of the tibia A is one or more protrusions that protrude toward the traction part 4. The one or more protrusions 6a are provided at the end of the mounting part 11 that protrudes from the mounting hole 8b toward the traction part 4 and are fixed relative to the support part 10.

[0027] The second gripping part 6b, located posterior to the tibia A, is the contact surface that contacts the posterior surface of the tibia A, and is positioned in the first direction closer to the guide parts 2 and 3 than the traction part 4. The contact surface 6b can be flat or curved. The second gripping part 6b is integrally formed with the traction part 4.

[0028] The tibia A is held by the holding parts 6a and 6b, so that the traction part 4, the mounting part 11, the retaining part 8, and the guiding parts 2 and 3 are fixed relative to the tibia A. In addition, by the protrusion 6a being embedded in the surface of the tibia A, the mounting part 11, the retaining part 8, and the guiding parts 2 and 3 are firmly fixed to the tibia A. To further stabilize the position of the fixing part 6 relative to the tibia A, the pinhole 10c at the foremost end of the support part 10 can penetrate the support part 10 and the mounting part 11. By inserting the guide pin P into the tibia A through the mounting part 11, misalignment of the retaining part 8 and the guide parts 2 and 3 relative to the tibia A can be prevented more reliably (see, for example, Figure 8).

[0029] The adjustment unit 7 consists of a support unit 10 movable in a first direction, a locking mechanism for fixing and releasing the support unit 10 relative to the support column 9. By moving the support unit 10 and the first gripping part 6a together in the first direction, and then fixing the support unit 10 to the support column 9 through the locking mechanism, the distance between the gripping parts 6a and 6b can be adjusted so that the gripping parts 6a and 6b can stably grip the tibia A. To facilitate operation of the support unit 10, a handle 9d can also be provided on the first part 9a.

[0030] As shown in Figure 5, an example of a locking mechanism is a ratchet mechanism 12 provided on the support portion 9 and the support portion 10. The ratchet mechanism 12 includes a plurality of slots 12a formed on the outside of the first portion 9a and arranged in a first direction, and protrusions 12b held by the support portion 10 and engaging with the slots 12a, wherein the protrusions 12b are positioned toward the first portion 9a. The ratchet mechanism 12 restricts the movement of the support portion 10 relative to the support portion 9 to only in the direction near the traction portion 4, and holds the support portion 10 at predetermined intervals.

[0031] As shown in Figure 6, another example of a locking mechanism is a stop for mechanically fixing the support 10 to the support column 9. The stop is the aforementioned fixing screw 10b, which can fix or release the support 10 relative to the support column 9 by rotating the fixing screw 10b. The stop can also be in other forms than the fixing screw 10b. To more securely fix the support 10 to the support column 9, the locking mechanism may simultaneously have a ratchet mechanism 12 and a stop 10b.

[0032] Next, referring to Figures 7 to 11, the method of using the guide device 1 will be described. Figures 7 to 11 are perspective views of the tibia A viewed from the oblique front, and Figure 11 is a side view of the tibia A viewed from the outside. As shown in Figure 7, the traction part 4 is inserted between the posterior surface of the tibia A and the soft tissue. Next, the distance between the holding parts 6a and 6b is adjusted using the adjusting part 7, and the tibia A is securely held by the holding parts 6a and 6b. In this way, the retaining part 8 and the traction part 4 are fixed to the tibia A by the fixing part 6.

[0033] As needed, as shown in Figure 8, two guide pins P are inserted into the tibia A through the pinhole 10c. This will more securely fix the entire guide device 1 to the tibia A. As mentioned earlier, it is best to insert one guide pin P into the foremost pinhole 10c. Next, as shown in FIG8, the second guide part 3 is inserted into the fitting hole 8a and the retaining part 8 holds the second guide part 3.

[0034] Next, as shown in Figure 9, a drill bit 20 is used to drill a bone hole in the tibia A through a guide pin P that passes through the pinhole 3a of the second guide section 3. By changing the pinhole 3a and drilling multiple bone holes, a hole line L3 consisting of multiple bone holes arranged in the second direction can be formed. At this time, the movement of the guide pin P is restricted only to the first direction due to the pinhole 3a. Therefore, each bone hole can be formed along the first direction.

[0035] Furthermore, as shown in Figures 10 and 11, the second guide part 3 is replaced with the first guide part 2. A bone-shaving tool T, resembling a chisel, is inserted into the guide hole 2a of the first guide part 2, and longitudinal osteotomy is performed by cutting the tibia A along the hole line L3. In this case, the movement of the bone-shaving tool T is limited to the first and second directions due to the guide hole 2a. Therefore, the bone-shaving tool T can be moved precisely along the hole line L3.

[0036] Thus, according to this embodiment, the osteotomy tool T, used for longitudinal osteotomy, is guided to the first and second directions by the first guide portion 2. This allows the osteotomy tool T to be moved precisely without wobbling, thereby accurately osteotomizing the tibia A. Furthermore, since a traction portion 4 exists between the posterior surface of the tibia A and the soft tissue, the soft tissue can be protected by the tip of the osteotomy tool T protruding from the posterior surface of the tibia A and the tip of the guide pin P. Thus, in TCVO, precise longitudinal osteotomy and protection of the soft tissue behind the tibial artery can be achieved simultaneously.

[0037] Furthermore, the first guide portion 2 and the second guide portion 3 are interchangeably held by the holding portion 8, and the row of pinholes 3a is positioned in the same location as the guide holes 2a. Therefore, the osteotomy tool T inserted into the guide hole 2a is automatically aligned with the position of the hole line L3. This allows for easy osteotomy of the tibia A along the hole line L3.

[0038] As described above, the left foot guide device 1 and the right foot guide device have a configuration in which the planes are symmetrical about each other with respect to the first direction. A portion of the guide device 1 can be used for both the left and right feet simultaneously. Specifically, as shown in Figures 12(a) and (b), the guidance device 1 may include: a first unit 1A for both left and right feet, a second unit 1L for left feet, and a second unit 1R for right feet.

[0039] The first unit 1A includes guide parts 2 and 3, a first gripping part 6a, a holding part 8, a support part 10, a mounting part 11, and screws 10b and 11b. Each second unit 1L and 1R includes a traction part 4, a second gripping part 6b, and a support part 9. The two second units 1L and 1R are generally symmetrical in a top view (plane of symmetry) in a first direction. By removing or inserting the first part 9a from the hole 10a in the support part 10, the first unit 1A can be removably installed on each of the second units 1L and 1R. Furthermore, the first unit 1A can be installed on either of the two second units 1L and 1R such that the first unit 1A installed on the second unit 1L for the left foot and the first unit 1A installed on the second unit 1R for the right foot are symmetrical about the plane of symmetry.

[0040] Specifically, the support 10 can be mounted in different directions on the left foot first part 9a and the right foot first part 9a by rotating around the axis of the first direction. In Figures 12(a) and (b), in order to use the same fixing screw 10b to fix the support 10 to the right foot first part 9a, the groove 9c of the right foot first part 9a is set at a position offset by 180° around the long side axis of the first part 9a relative to the groove 9c of the left foot first part 9a.

[0041] As shown in Figures 13(a) and (b), the angle of the retaining part 8 relative to the supporting part 10 can be changed between two angles in a planar view looking towards the first direction, where the retaining part 8 is symmetrically arranged relative to the long side axis of the supporting part 10. Figures 13(a) and (b) show the retaining part 8 and the mounting part 11 viewed from the traction part 4 side towards the first direction. In one configuration example, the mounting part 11 has slots 11a at two locations in the circumferential direction. This allows the retaining part 8 to be mounted on the mounting part 11 at two angles relative to either the traction part 4 of the second unit 1L or 1R in the first direction.

[0042] The traction part 4 and the second part 9b inserted into the body are preferably free of screws or other such structures. By designating the second units 1L and 1R as dedicated to the left and right feet, the structure of the second units 1L and 1R, which include the traction part 4 and the support part 9, can be simplified. For example, by welding the second part 9b to the components constituting the traction part 4 and the second gripping part 6b, each second unit 1L and 1R can be formed from a single component. On the other hand, by using the first unit 1A disposed outside the body for both the left and right feet, the guide device 1 can be used on both the left and right feet.

[0043] In the above-described embodiment, in order to enable the guide device 1 to be used on both the left and right feet, the retaining part 8, the supporting part 10, and the mounting part 11 are composed of different components and assembled by screws 10b and 11b. However, in the case of a guide device 1 that is dedicated to the left foot or the right foot, the retaining part 8, the supporting part 10, and the mounting part 11 can be connected by means of welding or other methods to form an integral unit.

[0044] In the above embodiment, the second gripping part 6b is integrated with the traction part 4, but it can also be replaced by a separate entity from the traction part 4. In this case, the second gripping part 6b can move in a first direction relative to the traction part 4 and the support part 9, and the distance between the gripping parts 6a and 6b can be adjusted by moving at least one of the gripping parts 6a and 6b in the first direction. In the above embodiment, the guiding device 1 has two types of guiding parts 2 and 3, but it can also be replaced by having only guiding part 2. In this case, the guiding part 2 can be directly fixed to the support part 10 by welding, for example, to form an integral part with the connecting part.

[0045] 1: Guiding device 1A: Unit 1 1L, 1R: Unit 2 3a: Pinhole 4: Traction Unit 5: Connecting part 6: Fixing part 6a: First Control Department 6b: Second Control Section 7: Adjustment Department 8: Retaining part (connecting part) 9: Support section (connecting section) 10: Support section (connecting section) A: Tibia T: Bone-shaving tools P: Guide pin

Claims

1. A guiding device comprising: a guiding portion disposed anterior to the tibia and guiding a bone-shaving tool for cutting the tibia; another guiding portion disposed anterior to the tibia and guiding a needle; a traction portion disposed posterior to the tibia and spaced apart from the guiding portion in a first direction; a connecting portion for connecting the guiding portion and the other guiding portion to the traction portion; and a fixing portion for fixing the guiding portion relative to the tibia; the guiding portion having a guiding hole through which the bone-shaving tool is inserted and extending in a second direction intersecting the first direction; the other guiding portion having a plurality of needle holes through which the needle is inserted and respectively through the other guiding portion in the first direction and arranged in the second direction; the traction portion being disposed in a region at least overlapping with the guiding hole when viewed from above in the first direction.

2. A guiding device comprising: a guiding portion disposed anterior to the tibia and guiding a bone-shaving tool for cutting the tibia; another guiding portion for guiding a needle; a traction portion disposed posterior to the tibia and spaced apart from the guiding portion in a first direction; a connecting portion connecting the guiding portion and the traction portion; and a fixing portion fixing the guiding portion relative to the tibia; the guiding portion having a guiding hole through which the bone-shaving tool is inserted and extending in a second direction intersecting the first direction; the traction portion being disposed in a region at least overlapping with the guiding hole when viewed from above in the first direction; the other guiding portion having a plurality of needle holes through which the needle is inserted and respectively through the other guiding portion in the first direction and arranged in the second direction; The connecting part has a retaining part that selectively holds the guide part and the other guide part, so that the guide hole and the plurality of pinholes are arranged in the same position.

3. A guiding device comprising: a guiding portion disposed anterior to the tibia and guiding a bone-shaving tool for cutting the tibia; a traction portion disposed posterior to the tibia and spaced apart from the guiding portion in a first direction; a connecting portion connecting the guiding portion and the traction portion; and a fixing portion fixing the guiding portion relative to the tibia; the guiding portion having a guiding hole for inserting the bone-shaving tool, extending through the guiding portion in the first direction and into a second direction intersecting the first direction; the traction portion, when viewed from above in the first direction, being disposed in an area at least overlapping the guiding hole; the fixing portion having a first holding portion and a second holding portion that are opposite each other in the first direction and clamp the tibia in a front-rear direction; the guiding device further comprising an adjusting portion for adjusting the distance between the first holding portion and the second holding portion in the first direction.

4. The guidance device as described in claim 3, wherein, The connecting part has: a support portion extending in the first direction; and a support portion movably supported in the first direction on the support portion; a first grip portion fixed relative to the support portion; and an adjusting part having a locking mechanism for fixing and releasing the support portion relative to the support portion.

5. The guiding device as described in any one of claims 1 to 4, comprising a first unit, a second unit for the left foot, and a second unit for the right foot; the first unit includes the guiding portion and a portion of the connecting portion; the second unit for the left foot and the second unit for the right foot each include the traction portion and another portion of the connecting unit on which a portion of the connecting portion is removably mounted; the second unit for the left foot and the second unit for the right foot are symmetrical about each other with respect to the first direction; the first unit can be mounted to either the second unit for the left foot or the second unit for the right foot.

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