Guide device

Abstract

The present invention provides a guide device (1) that is used for resection of a bone in a region where a bone plate is located. In order to resect the bone to make the bone conform to the shape of a bone contact surface of the bone plate, the guide device comprises: a fixed part (2) that is fixed to the bone and has a resection region (S) located at a resection site of the bone; and a guide part (3) that guides a cutting tool or a guide member in the resection region (S). The guide part (3) guides the cutting tool or the guide member along a plate surface (P) having the same or substantially the same shape as the bone contact surface of the bone plate.

Description

Guide Device

[0001] The present invention relates to a guide device.

[0002] Conventional treatments for osteoarthritis of the ankle (foot OA) include ankle arthrodesis, total ankle arthroplasty, 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 develops when the cartilage between the tibia A and talus B wears down.

[0003] Distal tibial oblique osteotomy (DTOO) has been proposed as a new osteotomy for foot osteoarthritis (OA) (see, for example, Non-Patent Documents 1 and 2). Fig. 11 illustrates DTOO. In DTOO, the distal tibia A is osteotomized obliquely toward the distal tibiofibular joint D (S1), and the distal tibial fragment A2 is rotated distally by enlarging the osteotomy E (S2). This allows the talus B to be sandwiched between the medial and lateral condyles of the tibia A, improving ankle joint stability. After rotation of the distal tibial fragment A2, the tibia A is fixed with a bone plate 30 (S4).

[0004] Kota Watanabe and seven others, "Modified distal tibial oblique osteotomy for osteoarthritis of the ankle: Operative procedure and preliminary results," Journal of Orthopaedic Science, March 2019, Vol. 24, No. 2, pp. 306-311; Tsukasa Teramoto and 11 others, "The Teramoto distal tibial oblique osteotomy (DTOO): surgical technique and applicability for ankleosteoarthritis with varus deformity," Strategies in Trauma and Limb Reconstruction, April 2018, Vol. 13, No. 1, pp. 43-49

[0005] Rotation of the distal tibial fragment A2 creates a protrusion F that protrudes medially (S2). The protrusion F causes skin tension when the incision is closed. Therefore, the protrusion F is resected (S3), and then the bone plate 30 is placed on the medial surface of the tibia A. At this time, the protrusion F needs to be resected so that the shape of the medial surface after resection matches the shape of the bone contact surface 30a of the bone plate 30.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a guide device that can resect bone so as to fit the shape of the bone contact surface of a bone plate.

[0007] One aspect of the present invention is a guide device used to resect bone in an area where a bone plate is to be placed, comprising: a fixed portion that is fixed to the bone and has a resection area that is to be placed at the resection site of the bone; and a guide portion that guides a cutting tool or a guide member that guides the cutting tool in the resection area, wherein the guide portion guides the cutting tool or the guide member along a plate surface that has the same or approximately the same shape as the bone contact surface of the bone plate.

[0008] According to the present invention, it is possible to effectively resect the bone so as to fit the shape of the bone contact surface of the bone plate.

[0009] 1A is a perspective view of a guide device according to a first embodiment. FIG. 1B is a side view of the guide device of FIG. 1A. FIG. 1C is a plan view of the guide device of FIG. 1A. FIG. 1D is a diagram illustrating the positional relationship between an extension line of a guide pin and a plate surface. FIG. 1E is a diagram illustrating a method of using the guide device of FIG. 1A. FIG. 1F is a diagram illustrating a method of using the guide device of FIG. 1A. FIG. 1G is a perspective view of a guide device according to a second embodiment. FIG. 4A is a side view of the guide device of FIG. 4A. FIG. 4B is a plan view of the guide device of FIG. 4A. FIG. 4C is a diagram illustrating the positional relationship between an extension surface of a guide slit and a plate surface. FIG. 4D is a diagram illustrating a method of using the guide device of FIG. 4A. FIG. 4G is a diagram illustrating a method of using the guide device of FIG. 4A. FIG. 4G is a perspective view of a guide device including a confirmation member. FIG. 4D is a side view of the confirmation member in use. FIG. 8A is a perspective view of a guide device according to a third embodiment. FIG. 8A is a side view of the guide device of FIG. 8A. FIG. 8B is a plan view of the guide device of FIG. 8A. FIG. 8C is a diagram illustrating the positional relationship between an extension surface of a first and second guide slit and a plate surface. FIG. 8D is a diagram illustrating a method of using the guide device of FIG. 8A. FIG. 8D is a diagram illustrating a method of using the guide device of FIG. 8A. FIG. 8E is a cross-sectional view of a tibia resected using the guide device of FIG. 8A. FIG. 8F is a diagram illustrating a DTOO procedure.

[0010] First Embodiment A guide device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 11 illustrates a distal tibial oblique osteotomy (DTOO), which is an application example of the guide device 1 according to this embodiment. In DTOO, the skin covering the ankle joint is incised, and the distal tibia A is osteotomized obliquely toward the distal tibiofibular joint D (S1). The osteotomy portion E is then enlarged to rotate the distal tibial fragment (epiphyseal portion) A2 distally (S2). A bone plate 30 is then placed on the medial surface of the tibia A across the enlarged osteotomy portion E and fixed to the tibia A with screws 40 (S4). The left, right, upper, and lower sides of FIG. 11 correspond to the medial, lateral, proximal, and distal sides of the tibia A, respectively.

[0011] The bone plate 30 is a strip-shaped member having a shaft portion 31 on the base end side and a head portion 32 on the tip end side. The shaft portion 31 is positioned in the diaphysis A1 proximal to the osteotomy portion E, and the head portion 32 is positioned in the epiphysis A2 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 three-dimensionally curved in the width direction and length direction to fit the shape of the medial surface of the distal tibia A. The bone plate 30 and the bone contact surface 30a may be twisted about a longitudinal axis so that the head portion 32 is positioned anterior or posterior to the tibia A relative to the shaft portion 31 when the shaft portion 31 is positioned on the medial surface.

[0012] The rotation of the epiphysis A2 generates a protrusion F (S2). The protrusion F is the medial portion of the epiphysis A2 that protrudes medially beyond the surface of the distal tibia A before rotation. In DTOO, the opening angle of the osteotomy E is larger than in other osteotomies such as LTO (low tibial osteotomy) and HTO (high tibial osteotomy), resulting in a larger protrusion of the protrusion F. Furthermore, the soft tissues, such as the skin, covering the ankle joint are very thin. Therefore, particularly in DTOO, the protrusion F is likely to cause problems such as skin tension during incision closure. Therefore, the protrusion F is resected using a cutting tool such as a bone saw or chisel (S3), 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 resect the protrusion F so that the shape of the medial surface after resection of the protrusion F matches the shape of the bone-contacting surface 30a.

[0013] 1A to 1C, the guide device 1 has a width direction X, a length direction Y, and a height direction Z, which are perpendicular to one another. In the guide device 1 for DTOO, the width direction X corresponds to the anterior-posterior direction of the tibia A, the length direction Y corresponds to the longitudinal direction of the tibia A, and the height direction Z corresponds to the left-right direction (medial-lateral direction) of the tibia A. One side and the other side in the length direction Y are the tip side and the base side, which correspond to the distal side and the proximal side, respectively, of the tibia A. One side and the other side in the height direction Y are the upper side and the lower side, which correspond to the medial side and the lateral side, respectively, of the tibia A.

[0014] The guide device 1 includes a fixing portion 2 that is fixed to the tibia A and has a resection area S that is placed in the protrusion (resection site) F, and a guide portion 3 that guides a guide member 51 (see FIGS. 3A and 3B ) for guiding a cutting tool. Fig. 1B is a side view of the guide device 1 as seen in the width direction X from the guide portion 3 side, and Fig. 1C is a plan view of the guide device 1 as seen from above in the height direction Z. The entire guide device 1 is formed from a material that has high biocompatibility and high rigidity, for example, a metal such as stainless steel.

[0015] The cutout area S is a spatial area that is wider in the width direction X and the length direction Y than the protrusion F in a plan view. The fixing part 2 has a body part (first part) 4 and a tip part (second part) 5 that are arranged on either side of the cutout area S, and an arm part 6 that connects the body part 4 and the tip part 5. The body part 4, the tip part 5, and the arm part 6 are integrally formed.

[0016] The body portion 4 is in the shape of a strip extending in the longitudinal direction Y, and the tip portion 5 is disposed at a distance from the tip of the body portion 4 in the longitudinal direction Y. A resection region S is defined between the body portion 4 and the tip portion 5. The body portion 4 is disposed in the diaphysis A1 proximal to the protrusion F along the longitudinal direction of the diaphysis A1, and the tip portion 5 is disposed in the epiphysis A2 distal to the protrusion F.

[0017] The body portion 4 and the tip portion 5 each have a lower surface (contact surface) 4a, 5a on the underside that contacts the surface of the tibia A. The lower surfaces 4a, 5a are positioned on the plate surface P (see FIG. 1A ). The plate surface P is an imaginary surface having the same or substantially the same shape as the bone contact surface 30a of the bone plate 30. FIG. 1B shows only the central axis of the plate surface P. Specifically, the lower surface 4a has the same or substantially the same shape as the base end portion of the plate surface P corresponding to the shaft portion 31, and the lower surface 5a is positioned at or near the tip of the plate surface P. Therefore, in a plan view viewed from above in the height direction Z, the distal portion of the plate surface P, including the portion corresponding to the head portion 32, is positioned in the resection area S (see FIG. 1C ).

[0018] The arm 6 is cantilevered and extends from the tip of the body 4 to the tip 5, with the tip 5 being provided at the tip of the arm 6. To prevent the arm 6 from interfering with the observation of the protruding portion F of the resection area S, the width of the arm 6 is preferably narrower than the width of the body 4. The arm 6 is designed to have a shape that does not interfere with the tibia A and surrounding tissues during surgery, and does not interfere with instruments such as guide pins 51 and 52. In the example shown in the figure, the arm 6 is generally C-shaped and curved in a direction that protrudes upward, and the tip 5 is the tip of a cantilever-shaped member that constitutes the arm 6.

[0019] The fixing portion 2 has one or more holes 2a that penetrate the fixing portion 2 in the height direction Z as fixing means for fixing the fixing portion 2 to the tibia A. The fixing portion 2 is fixed to the tibia A by inserting a guide pin 52 into the tibia A through the holes 2a (see FIGS. 3A and 3B ). The holes 2a are provided in at least the body portion 4 and the tip portion 5. In the example shown, the body portion 4 has three holes 2a arranged at intervals in the length direction Y, and the tip portion 5 has one hole 2a. Furthermore, the arm portion 6 may have one or more holes 2a.

[0020] The guide portion 3 has a strip-like shape extending in the longitudinal direction Y in parallel with the arm portion 6 in a plan view (see FIG. 1C ), and is disposed in front of or behind the protrusion F. The guide portion 3 is disposed at a distance from the arm portion 6 in the width direction X, and is located outside the plate surface P in the width direction X. The base end of the guide portion 3 is fixed to the tip end of the body portion 4 by a connection portion 7 extending in the width direction X.

[0021] The guide section 3 has a plurality of pin holes 3a arranged in a row at intervals in the longitudinal direction Y as guide holes for guiding the guide members 51, into which the guide members 51 are respectively inserted. In this embodiment, the guide members 51 are long, thin guide pins. Each pin hole 3a has a diameter slightly larger than that of the guide pin 51 and penetrates the guide section 3 substantially in the width direction X. The guide pin 51 passing through each pin hole 3a traverses the resection area S in the width direction X.

[0022] 1A and 1C , extension lines β of the central axes α of the multiple pin holes 3 a are aligned along the plate surface P. As a result, the multiple pin holes 3 a restrict the multiple guide pins 51 to positions along the plate surface P in the resection area S so that the multiple guide pins 51 are aligned along the plate surface P at intervals in the longitudinal direction Y.

[0023] Specifically, as shown in FIG. 2 , when viewed in the longitudinal direction Y, the extension line β of each pin hole 3 a passes through two points Q1 and Q2 at or near both ends of the plate surface P in the width direction. Therefore, when viewed in the width direction X, the extension lines β of the multiple pin holes 3 a are arranged in a line along the curved plate surface P. Furthermore, when the bone contact surface 30 a has a shape twisted around the longitudinal axis, the angle of the multiple extension lines β gradually changes from the base end toward the tip end when viewed in the longitudinal direction Y. As will be described later, when cutting along the upper end of the guide pin 51 that penetrates the tibia A, the points Q1 and Q2 may be positioned offset downward from both ends of the plate surface P by a distance equal to the radius of the guide pin 51.

[0024] 3A to 3C, a method of using the guide device 1 will be described. The method of use includes a first step of fixing the fixing portion 2 to the surface of the bone, a second step of inserting the guide pin 51 into the bone through the pin hole 3a of the guide portion 3, and a third step of cutting off the protruding portion F along the guide pin 51 with a cutting tool.

[0025] 3A , in the first step after enlarging the osteotomy portion E, the body portion 4 and the tip portion 5 are placed on the medial surfaces of the diaphysis A1 and the epiphysis A2, respectively, and positioned so that the resection area S is located at the protrusion F. Next, a guide pin 52 is inserted into the tibia A through the holes 2a in the body portion 4 and the tip portion 5, and the body portion 4 and the tip portion 5 are fixed to the diaphysis A1 and the epiphysis A2, respectively.

[0026] Next, in a second step, a plurality of guide pins 51 are inserted into the epiphysis A2 in the anterior-posterior direction through the plurality of pin holes 3 a. In the example of Fig. 3A, five guide pins 51 are inserted into the epiphysis A2 through five selected pin holes 3 a.

[0027] 3B , after the guide pin 51 is inserted into the epiphysis A2, the guide device 1 is removed from the tibia A, leaving the guide pin 51 in the epiphysis A2. At the protrusion F, the guide pin 51 is positioned inside the epiphysis A2.

[0028] 3C , in a third step, a bone cutting tool such as a bone saw or a bone chisel is used to cut the epiphysis A2 along the upper ends of the guide pins 51, thereby removing the bone tissue covering the guide pins 51. This results in the removal of protrusions F that protrude beyond the plate surface P defined by the guide pins 51. After the third step, the guide pins 51 are removed from the epiphysis A2, and the bone plate 30 is then placed on the medial surface of the tibia A at the same position as the fixation portion 2 and fixed to the tibia A with the screws 40.

[0029] As described above, according to this embodiment, the multiple guide pins 51 inserted into the tibia A using the guide unit 3 are aligned along the plate surface P, which has 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 protruding portion F of the tibia A can be resected to fit the shape of the bone contact surface 30a. This also allows the bone contact surface 30a to fit well with the medial surface of the distal tibia A after resection, allowing the incision to be closed without tensioning the skin after the bone plate 30 is fixed.

[0030] Conventionally, the protrusion F is removed by a physician using a cutting tool to finely cut the bone while referring to the bone contact surface 30a, so that the shape of the cut surface of the tibia A approximates the bone contact surface 30a. Such precise cutting requires a physician's advanced technique. In particular, when the bone contact surface 30a is a three-dimensionally curved and twisted surface, it is difficult to accurately cut the bone to fit the bone contact surface 30a. According to this embodiment, even when the bone contact surface 30a has such a complex curved shape, the protrusion F can be easily removed to fit the bone contact surface 30a without relying on a physician's advanced technique.

[0031] Furthermore, according to this embodiment, the fixation unit 2 has a body portion 4 and a tip portion 5 that are positioned on either side of the resection area S. This allows a user, such as a physician, to accurately recognize the position of the resection area S and accurately and easily position the fixation unit 2 relative to the tibia A so that the resection area S is positioned at the protrusion F. Furthermore, by fixing the body portion 4 and the tip portion 5 to the diaphysis A1 and the epiphysis A2, respectively, using the guide pin 52, the diaphysis A1 and the epiphysis A2 are fixed after enlargement of the osteotomy 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.

[0032] Furthermore, according to this embodiment, the lower surfaces 4 a, 5 a of the fixation portion 2 are positioned on the plate surface P. Therefore, the user can determine the position of the fixation portion 2 where the lower surfaces 4 a, 5 a fit the shape of the medial surface of the tibia A as the appropriate position of the bone plate 30. Furthermore, by fixing the fixation portion 2 to the tibia A at that position, the plate surface P is also determined to be an appropriate position with respect to the tibia A. Therefore, by cutting the tibia A along the plate surface P and then placing the bone plate 30 in the same position as the fixation portion 2, the bone contact surface 30 a can be well-fitted to the medial surface of the tibia A.

[0033] In this embodiment, the bone is cut along the upper end of the guide pin 51. Alternatively, the bone may be cut along the hole left after the guide pin 51 is removed. In this case, the position and angle of the central axis α and extension line β of the pin hole 3a may be designed so that the lower end of the hole is aligned with the plate surface P. In this case, after step S2, the guide device 1 and guide pin 51 are removed from the tibia A. Thereafter, the tibia A is cut along the hole formed by the guide pin 51, and the protruding portion F is resected.

[0034] Second Embodiment Next, a guide device according to a second embodiment of the present invention will be described. The guide device 10 according to this embodiment differs from the first embodiment in that it has a guide slit 13a that serves as a guide hole to guide the cutting tool. In this embodiment, only the configurations different from the first embodiment will be described, and the same reference numerals will be used to designate the same configurations as the first embodiment, and the description thereof will be omitted.

[0035] 4A to 4C, the guide device 10 includes a fixing portion 12 that is fixed to the tibia A and a guide portion 13 that guides a cutting tool 50 (see FIG. 6B). FIG. 4B is a side view of the guide device 10 as viewed in the width direction X from the guide portion 13 side, and FIG. 4C is a plan view of the guide device 10 as viewed from above in the height direction Z. The fixing portion 12 has a body portion 4 and a tip portion (second portion) 15 that are disposed on both sides of the resection area S, and arm portions 16 that connect the body portion 4 and the tip portion 15. The body portion 4, tip portion 15, and arm portions 16 are integrally formed.

[0036] The tip portion 15 is disposed at a distance from the tip of the body portion 4 in the longitudinal direction Y, and a resection area S is defined between the body portion 4 and the tip portion 15. The tip portion 15 has a lower surface (contact surface) 15a that is flat or curved, and the lower surface 15a is disposed at or near the tip of the plate surface P. The arm portions 16 are disposed outside the plate surface P in the width direction X, and the resection area S is disposed between the arm portions 16 and the guide portion 13. This allows the user to easily view the entire protruding portion F of the resection area S from above in the height direction Z while using the guide device 10.

[0037] The fixing portion 12 has one or more cylindrical sleeves 12a protruding from the upper surface of the fixing portion 12 in the height direction Z as a fixing means for fixing the fixing portion 12 to the tibia A. The fixing portion 12 is fixed to the tibia A by inserting a guide pin 52 through the sleeve 12a into the tibia A (see FIGS. 6A and 6B ). The sleeves 12a are provided on at least the body portion 4 and the tip portion 15. In order to more stably fix the fixing portion 12 to the tibia A, two sleeves 12a may be provided on the tip and base ends of the body portion 4.

[0038] The guide portion 13 has a strip-like shape extending in the longitudinal direction Y in parallel with the arm portion 16 in a plan view (see FIG. 4C ). The guide portion 13 is spaced apart from the arm portion 16 in the width direction X and is located outside the plate surface P in the width direction X. The guide portion 13 has a guide slit 13a that extends in the longitudinal direction Y and serves as a guide hole for guiding a cutting tool 50, such as a bone saw or 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 penetrates the guide portion 13 substantially in the width direction X. The cutting tool 50 passing through the guide slit 13a traverses the resection area S in the width direction X.

[0039] The center plane γ of the guide slit 13a has a shape corresponding to the shape of the plate surface P, and an extension plane δ of the center plane γ is disposed along the plate surface P. The center plane γ is a plane connecting the center points of the guide slit 13a in the height direction Z. The extension plane δ is a plane extending from the center plane γ in the width direction X. As a result, the guide slit 13a restricts the cutting tool 50 to a position along the plate surface P in the resection region S so that the cutting tool 50 moves along the plate surface P.

[0040] Specifically, as shown in FIG. 5 , when viewed in the longitudinal direction Y, the extension plane δ passes through two points Q1 and Q2 at or near both ends of the plate surface P in the width direction. FIG. 5 shows the planes γ and δ at a certain position in the longitudinal direction Y. The planes γ and δ are curved surfaces formed by a set of straight lines extending in the width direction X, and when viewed in the width direction X, the planes γ and δ curve in accordance with the curvature of the plate surface P. When the bone contact surface 30 a has a shape twisted around the longitudinal axis, the angle of the straight lines when viewed in the longitudinal direction Y gradually changes from the proximal end toward the distal end. As in the first embodiment, the points Q1 and Q2 may be positioned offset downward from both ends of the plate surface P by a distance equal to the radius of the guide pin 51.

[0041] The base end and tip end of the guide portion 13 are fixed to the body portion 4 and tip end portion 15, respectively, by the connecting portion 7. With the guide device 10 fixed to the tibia A, the tibia A is cut using a cutting tool passing through the guide slit 13a. By fixing both ends of the guide portion 13 to the fixing portions 12, the positional stability of the guide portion 13 relative to the tibia A is improved, and the tibia A can be cut accurately as desired.

[0042] 6A and 6B, a method of using the guide device 10 will be described. The method of use includes a first step of fixing the fixing portion 12 to the surface of the bone, and a second step of cutting the protrusion F along the guide slit 13a of the guide portion 13 with a cutting tool 50.

[0043] 6A , in the first step after enlarging the osteotomy portion E, the body portion 4 and the tip portion 15 are placed on the medial surfaces of the diaphysis A1 and epiphysis A2, respectively, and positioned so that the resection area S is located at the protrusion F. Next, a guide pin 52 is inserted into the tibia A through the sleeves 12a of the body portion 4 and the tip portion 15, and the body portion 4 and the tip portion 15 are fixed to the diaphysis A1 and epiphysis A2, respectively.

[0044] 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 epiphysis A2 is cut by moving the cutting tool 50 along the guide slit 13a. Since the cutting tool 50 moves along the plate surface P, the protruding portion F that protrudes beyond the plate surface P is resected. After the second step, the guide device 10 is removed from the tibia, and then the bone plate 30 is placed on the medial surface of the tibia A at the same position as the fixation portion 12 and fixed to the tibia A with the screws 40.

[0045] As described above, according to this embodiment, the cutting tool 50 in the guide slit 13a moves along the plate surface P, which has the same or substantially the same shape as the bone contact surface 30a in the resection area S. Therefore, by moving the cutting tool 50 along the guide slit 13a, the protruding portion F of the tibia A can be resected so as to fit the shape of the bone contact surface 30a. This also allows the bone contact surface 30a to fit well with the medial surface of the distal tibia A after resection, allowing the incision to be closed without tensioning the skin after the bone plate 30 is fixed.

[0046] Furthermore, similar to the first embodiment, according to this embodiment, the fixing portion 12 has a body portion 4 and a tip portion 15 that are arranged on both sides of the resection area S. Therefore, the user can accurately recognize the position of the resection area S and accurately and easily position the fixing portion 12 relative to the tibia A. Furthermore, by fixing the body portion 4 and the tip portion 15 to the diaphysis A1 and the epiphysis A2, respectively, using the guide pins 52, it is possible to prevent the epiphysis A2 from moving during cutting with the cutting tool 50.

[0047] Furthermore, as in the first embodiment, according to this embodiment, the lower surfaces 4 a, 15 a of the fixing portion 12 are disposed on the plate surface P, so that the user can easily position the bone plate 30 and the plate surface P at appropriate positions relative to the tibia A. Furthermore, by disposing the bone plate 30 at the same position as the fixing portion 12, the bone contact surface 30 a can be well fitted to the medial surface of the tibia A.

[0048] 7A and 7B , the guide device 10 may further include a confirmation member 17 for confirming the shape of the cutting surface of the bone in the resection area S. The confirmation member 17 is a component separate from the components consisting of the fixed portion 12 and the guide portion 13, and is, for example, a plate-shaped component. The confirmation member 17 is detachable from the fixed portion 12 and is placed in the resection area S.

[0049] The confirmation member 17 has two semi-cylindrical fitting surfaces 17a, 17b as positioning portions for positioning the confirmation member 17 relative to the fixed portion 12. The fitting surfaces 17a, 17b are fitted radially into the sleeves 12a of the body portion 4 and the tip portion 15, thereby positioning the confirmation member 17 at a predetermined position relative to the fixed portion 12. The positioning portions may have a structure other than the fitting surfaces. Furthermore, the confirmation member 17 may be detachable from the guide portion 13 instead of the fixed portion 12.

[0050] The confirmation member 17 has a confirmation surface 17c that contacts the bone. As shown in Fig. 7B , the confirmation surface 17c has the same shape as the portion of the plate surface P in the resection area S, and when positioned by the positioning portions 17a and 17b, the confirmation surface 17c coincides with the plate surface P. In Fig. 7B , the connecting portion 7 and the guide portion 13 are omitted. After cutting with the cutting tool 50, the user can attach the confirmation member 17 to the fixing portion 12 and confirm that the cutting surface has a shape that conforms to the plate surface P based on the conformity of the confirmation surface 17c with the shape of the surface of the epiphysis A2.

[0051] Third Embodiment Next, a guide device according to a third embodiment of the present invention will be described. The guide device 20 according to this embodiment differs from the second embodiment in that it has two guide slits 23a and 23b as guide holes. In this embodiment, configurations different from the first and second embodiments will be described, and configurations common to the first and second embodiments will be assigned the same reference numerals and will not be described again.

[0052] 8A to 8C, the guide device 20 includes a fixing portion 12 that is fixed to the tibia A and a guide portion 23 that guides the cutting tool 50. Fig. 8B is a side view of the guide device 20 as seen in the width direction X from the guide portion 23 side, and Fig. 8C is a plan view of the guide device 20 as seen from above in the height direction Z. The fixing portion 12 is as described in the second embodiment.

[0053] The guide portion 23 has a generally columnar shape extending in the longitudinal direction Y in parallel with the arm portion 16 in a plan view. The guide portion 23 is disposed at a distance from the arm portion 16 in the width direction X, and is positioned outside the plate surface P in the width direction X. The base end and tip end of the guide portion 23 are fixed to the body portion 4 and tip end portion 15, respectively, by the connection portion 7.

[0054] The guide portion 23 has a first guide slit 23a and a second guide slit 23b that extend in the longitudinal direction Y (see FIG. 8B ). The two guide slits 23a, 23b are arranged in a height direction Z that intersects with the plate surface P and are generally parallel to each other. Each guide slit 23a, 23b passes straight through the guide portion 23 in the width direction X, and the cutting tool 50 passing through the guide slits 23a, 23b crosses the resection area S generally in the width direction X. In the referenced drawings, each guide slit 23a, 23b consists of two slits, one on the distal end side and one on the proximal end side, and is discontinuous in the portion corresponding to the bone resection portion E. However, instead, the guide slits 23a, 23b may be formed from a single continuous slit.

[0055] The central planes γ1, γ2 of the two guide slits 23a, 23b are inclined relative to each other in the height direction Z so that the extension planes δ1, δ2 intersect with each other in the resection region S, and the extension planes δ1, δ2 are disposed along the plate surface P. As a result, the guide slits 23a, 23b restrict the cutting tool to a position along the plate surface P in the resection region S so that the cutting tool moves along the plate surface P.

[0056] The first central plane 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 the length direction Y. The second central plane 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 the length direction Y. The first extended plane δ1 and the second extended plane δ2 are planes obtained by extending the central planes γ1 and γ2 in the width direction X, respectively.

[0057] Specifically, as shown in Fig. 9, when viewed in the longitudinal direction Y, the two center planes γ1 and γ2 are inclined in opposite directions toward each other as they approach the plate surface P. Due to this inclination of the center planes γ1 and γ2, the two extension planes δ1 and δ2 intersect with each other between two points Q1 and Q2, with one extension plane δ1 passing through point Q2 and the other extension plane δ2 passing through point Q1. The intersection point Q3 of the two extension planes δ1 and δ2 is located on the plate surface P or below the plate surface P. In the illustrated example, the guide slits 23a and 23b are linear, and the surfaces γ1, γ2, δ1, and δ2 are flat. However, as in the second embodiment, the guide slits 23a and 23b and the surfaces γ1, γ2, δ1, and δ2 may be curved.

[0058] 10A to 10C, a method of using the guide device 20 will be described. The method of use includes a first step of fixing the fixing portion 12 to the surface of the bone, and a second step of cutting the protrusion F along the two guide slits 23a, 23b of the guide portion 23 with a cutting tool 50. As in the second embodiment, in the first step, the body portion 4 and the tip portion 15 are fixed to the diaphysis A1 and epiphysis A2, respectively.

[0059] Next, as shown in Fig. 10A, in the second step, the cutting tool 50 is inserted into the epiphysis A2 in the anterior-posterior direction through the first guide slit 23a and moved along the first guide slit 23a to cut the epiphysis A2. Similarly, as shown in Fig. 10B, the cutting tool 50 is inserted into the epiphysis A2 in the anterior-posterior direction through the second guide slit 23b and moved along the second guide slit 23b to cut the epiphysis A2. As a result, as shown in Fig. 10C, the protruding portion F protruding beyond the plate surface P is resected along two planes. Fig. 10C is a cross-sectional view of the epiphysis A2.

[0060] As described above, according to this embodiment, the cutting tool 50 in the guide slits 23a, 23b moves along the plate surface P, which has the same or substantially the same shape as the bone contact surface 30a in the resection area S. Therefore, by moving the cutting tool 50 along the guide slits 23a, 23b, it is possible to resect the protruding portion F of the tibia A so as to fit the shape of the bone contact surface 30a. This also allows the incision in the skin to be closed without tensioning the skin.

[0061] Furthermore, according to this embodiment, the epiphysis A2 is cut along the two extension planes δ1 and δ2, and the cut surface of the epiphysis A2 after the protrusion F is removed consists of two planes that form an angle with each other. This allows the protrusion F to be removed so as to better fit the bone contact surface 30a, which is curved in the width direction. Other advantages of this embodiment are the same as those of the second embodiment, and therefore will not be described here. The guide device 20 of this embodiment may also further include the confirmation member 17 described in the second embodiment.

[0062] 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 to be used. Therefore, the guide devices 1, 10, and 20 may be provided as part of a system for osteotomy. The system includes the guide device 1, 10, or 20 and the bone plate 30, and may further include one or more screws 40 for fixing the bone plate 30 to the tibia A.

[0063] Although the embodiments and modifications of the present invention have been described above, the specific configuration of the present invention is not limited to the above-described embodiments and modifications, and various design modifications are possible within the scope of the present invention. Furthermore, the configurations shown in the above-described embodiments and modifications can be combined as appropriate. For example, the fixing portions 2 and 12 may be fixed to the bone using any means other than the guide pin 52, and in that case, the fixing portions may have other structures instead of the hole 2 a and the sleeve 12 a.

[0064] The fixation portion may have only one of the body portion (first portion) and the tip portion (second portion). For example, in the first embodiment, the fixation portion 2 may not have the tip portion 5. In this case, the user may visually position the body portion 4 relative to the tibia A so that the resection area S is positioned on the protrusion F. Furthermore, to prevent the epiphysis A2 from moving when the guide pin 52 is inserted, the diaphysis A1 and the epiphysis A2 may be fixed using any means other than the guide device 1.

[0065] The guide device 1 of the first embodiment may also include a confirmation member 17. In this case, the epiphysis A2 may be cut along the guide pin 51 while the guide device 1 is fixed to the tibia A, and after cutting, the confirmation member 17 may be attached to the guide device 1 to confirm the shape of the cutting surface.

[0066] The guide device of the present invention can be used not only for DTOO but also for any bone surgery in which bone in the area where a bone plate is to be placed is resected to match the shape of the bone-contacting surface of the bone plate. For example, the guide device may be used for resecting a protrusion in HTO. The specific configuration of the guide device, such as the shapes of the body, tip, and arms, is designed depending on the bone surgery to be performed.

[0067] DESCRIPTION OF SYMBOLS 1, 10, 20 Guide device 2, 12 Fixation portion 3, 13, 23 Guide portion 3a Pin hole (hole, guide hole) 4 Body portion (first portion) 5, 15 Tip portion (second portion) 13a, 23a, 23b Guide slit (guide hole) 30 Bone plate 30a Bone contact surface 50 Cutting tool 51 Guide pin (guide member) A Distal tibia D Projection portion (resection site) P Plate surface α Central axis β Extension line γ, γ1, γ2 Central plane δ, δ1, δ2 Extension plane

Claims

1. A guide device used to resect bone in a region where a bone plate will be placed, comprising: a fixed part that is fixed to the bone and has a resection region that is to be placed at the resection site of the bone; and a guide part that guides a cutting tool or a guide member that guides the cutting tool in the resection region, wherein the guide part guides the cutting tool or the guide member along a plate surface that has the same or approximately the same shape as the bone-contacting surface of the bone plate.

2. The guide device according to claim 1, wherein the fixation portion has a first portion and a second portion disposed on either side of the resection area, and the bone-contacting surfaces of the first portion and the second portion are disposed on the plate surface.

3. A guide device as described in claim 1, wherein the guide portion has a guide hole into which the cutting tool or the guide member is inserted and which restricts the cutting tool or the guide member to a position along the plate surface at the resection site.

4. The guide device according to claim 3, wherein the guide hole has a plurality of holes arranged in a line and into which the guide members are respectively inserted, and the extension lines of the central axes of the plurality of holes are arranged along the plate surface.

5. The guide device according to claim 3, wherein the guide hole has a guide slit into which the cutting tool is inserted, and an extension plane of the center plane of the guide slit is disposed along the plate surface.

6. The guide device according to claim 3, wherein the guide hole has a first guide slit and a second guide slit into which the cutting tool is respectively inserted and which are arranged in a direction intersecting the plate surface, the first central plane of the first guide slit and the second central plane of the second guide slit are inclined relative to each other so that a first extension plane of the first central plane and a second extension plane of the second central plane intersect each other in the resection area, and the first extension plane and the second extension plane are arranged along the plate surface.

7. The guide device according to claim 1, further comprising a confirmation member that is detachable from the fixed portion or the guide portion and that is positioned in the resection area, the confirmation member having a confirmation surface that has the same shape as the plate surface.

Images