Bone surgical instrument

Abstract

To provide a bone surgical instrument capable of preventing generation of cutting powder when drilling a hole in a bone and impact to be applied to the bone.SOLUTION: A bone surgical instrument 1 comprises: a compression member 4 having a through-hole 4a; a body 6 including a support part 7 supporting the compression member so as to move in an axial direction along a central axis A, and a receiving part 8 disposed at an interval apart from a tip end of the compression member in the axial direction; and a guide member 5 connected to the body and guiding a tool along the central axis. The receiving part includes a recessed portion 8b for receiving a tip end of a shaft part of the tool projecting from the through-hole, and the guide member includes a stopper face 5b which is disposed on the base end side of the compression member 4 and on which a large-diameter face of the tool comes into contact, where the receiving part and the guide member have sizes satisfying L2<L1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to bone surgical instruments. [Background technology]

[0002] Conventionally, a bone surgery instrument that guides a drill has been used when drilling a pilot hole for an implant in a bone (see, for example, Patent Document 1). The bone surgery instrument in Patent Document 1 includes a cylindrical shaft member into which a drill is inserted, and a receiving portion that faces the tip of the shaft member and receives the tip of the drill. By radially grasping the bone with the shaft member and the receiving portion and inserting the drill into the shaft member, a pilot hole can be made in the bone while applying radial pressure to the bone. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 059405 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the tip of the drill that penetrates the bone comes into contact with the receiving part. Therefore, the tip of the drill or the receiving part may wear down and generate cutting powder. In addition, when the tip of the drill comes into contact with the receiving part, an impact may be applied to the bone. The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a bone surgery instrument that can prevent the generation of cutting powder and impact on the bone when drilling a hole in the bone. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a bone surgical instrument for guiding a tool for drilling a hole in a bone, the tool having a long shaft portion and a large diameter surface provided at a base end of the shaft portion and having a diameter larger than that of the shaft portion, the tool being provided with a cylindrical compression member having a through hole penetrating the compression member in the longitudinal direction and into which the shaft portion of the tool is inserted, a support portion supporting the compression member so as to be movable in an axial direction along a central axis of the through hole, and a receiving portion disposed at a distance from a tip of the compression member in the axial direction, and a guide member connected to the body and guiding the tool along the central axis of the through hole, the receiving portion having a bone contact surface disposed on the compression member side and brought into contact with a surface of the bone, and a recessed portion recessed on the opposite side of the compression member with respect to the bone contact surface and adapted to receive a tip of the shaft portion protruding from the through hole, the guide member being disposed on the base end side of the compression member, the stopper surface against which the large diameter surface of the tool abuts in the axial direction, a cylindrical portion that is inserted into the through hole from the base end side of the compression member; having the cylindrical portion has a guide hole that is arranged coaxially with the through hole and into which a shaft portion of the tool is inserted, and a base end surface of the cylindrical portion is the stopper surface, The bone surgery instrument, wherein the receiving portion and the guide member have dimensions that satisfy the following relational expression (1). L2 <L3<L1 ···(1) where L1 is the axial distance from the bottom of the recess to the stopper surface, L2 is the axial distance from the bone contact surface to the stopper surface, and L3 is the longitudinal distance of the tool from the tip of the tool to the large diameter surface. [Brief description of the drawings]

[0006] [Figure 1] FIG. 2 is an overall configuration diagram of a bone surgical instrument according to one embodiment, and is a side view of the bone surgical instrument in a state in which a guide member is separated from a main body. [Diagram 2] 2 is a side view of the bone surgery instrument of FIG. 1 with a guide member attached to a main body. FIG. [Diagram 3] 3 is a longitudinal cross-sectional view taken along the central axis of a compression member of the bone surgical instrument of FIG. 2. [Figure 4] 2 is a view of the guide member in FIG. 1 as viewed from the cylindrical portion side. [Diagram 5] FIG. 2 is a side view of an example of an implant used in the bone surgical instrument of FIG. 1. [Figure 6] FIG. 2 is a side view of an example of a tool used in the bone surgery instrument of FIG. 1. [Figure 7] 1A to 1C are diagrams illustrating an example of surgery using a bone surgery instrument. [Figure 8] FIG. 13 is a longitudinal cross-sectional view taken along the central axis of a modified example of the bone surgical instrument. [Figure 9] FIG. 13 is a side view of another modified example of the bone surgical instrument in a state in which the guide member is separated from the main body. [Figure 10] 3 is a top view of the bone surgical instrument of FIG. 2 as viewed from the base end side. FIG. [Figure 11] FIG. 13 is a side view of a bone surgical instrument according to another modified example in a state in which a guide member is separated from a main body. [Figure 12] FIG. 13 is a partial side view of a modified example of a tool in which a large diameter surface is provided on a driver. [Figure 13] FIG. 13 is a partial perspective view of a variation of an implant having a washer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bone surgical instrument and a bone surgical system according to an embodiment of the present invention will be described below with reference to the drawings. The bone surgical system comprises a bone surgical instrument 1 shown in FIGS. 1 to 4, an implant 2 shown in FIG. 5, and a tool 3 shown in FIG.

[0008] 5, the implant 2 is a fixture, such as a screw, that is fixed to a bone B. The implant 2 has a long shaft portion 2a and a head portion 2b that is fixed to the base end of the shaft portion 2a and has a larger diameter than the shaft portion 2a, and the shaft portion 2a is provided with a screw thread.

[0009] As shown in FIG. 6, the tool 3 is a drill that drills a pilot hole in the bone B for inserting the implant 2. The tool 3 has a long shaft portion 3a, a large diameter portion 3b provided on the base end side of the shaft portion 3a, and a connecting portion 3c provided on the base end side of the large diameter portion 3b. The shaft portion 3a has a cutting edge and a spiral groove provided at the tip. A driver that rotates the shaft portion 3a is connected to the connecting portion 3c. The large diameter portion 3b has an outer diameter larger than the outer diameter of the shaft portion 3a, and a surface 3d on the tip side of the large diameter portion 3b is an annular large diameter surface that protrudes radially outward from the outer circumferential surface of the shaft portion 3a.

[0010] The bone surgical instrument 1 is a guide device that guides a tool 3 while applying radial pressure to a bone B. The bone surgical instrument 1 may be provided separately from the implant 2 and the tool 3, or may be provided together with the implant 2 and the tool 3 as a bone surgical system. As shown in FIGS. 1 to 4, the bone surgical instrument 1 includes a compression member 4 that applies pressure to a bone B, a guide member 5 that guides the tool 3, and a main body 6 that supports the compression member 4 and the guide member 5.

[0011] 1 to 3, the compression member 4 is a cylindrical member extending linearly, and has a through hole 4a that passes through the compression member 4 in the longitudinal direction and into which the tool 3 and the implant 2 are inserted. The inner diameter d2 of the through hole 4a is larger than the maximum outer diameter d5 of the implant 2 and the outer diameter d1 of the shaft portion 3a. At least one slit 4b may be provided at the tip of the compression member 4, extending in the longitudinal direction of the compression member 4 from the tip to the base end of the compression member 4. The slit 4b penetrates from the outer peripheral surface to the inner peripheral surface of the compression member 4. An operator can observe the tool 3 and the implant 2 in the through hole 4a from the outside of the compression member 4 via the slit 4b, and check the insertion amount of the tool 3 and the implant 2.

[0012] The tip of the compression member 4 is a contact end that is brought into contact with the surface of the bone B. The tip of the compression member 4 may be provided with a needle-like projection 4c that projects toward a receiving portion 8 (described below) and has a sharp tip. The compression member 4 can be fixed to the bone B by piercing the projection 4c into the surface of the bone B.

[0013] The base end of the compression member 4 may be provided with a pair of holes 4d that communicate with each other in the radial direction of the compression member 4 across the through hole 4a. The holes 4d are used when removing the compression member 4, which is fixed to the bone B by the protrusions 4c, from the bone B. In other words, by rotating a rod that is inserted through the pair of holes 4d, a torque is applied to the compression member 4, and the compression member 4 can be easily separated from the bone B.

[0014] The guide member 5 has a tubular portion 51 that is inserted into the through hole 4a from the base end side of the compression member 4, and a connection portion 52 that connects the tubular portion 51 to the main body 6. The outer diameter d3 of the cylindrical portion 51 is smaller than the inner diameter d2 of the through hole 4a, and the compression member 4 and the cylindrical portion 51 in the through hole 4a are relatively movable in the axial direction. The axial direction is along the central axis A of the through hole 4a, which is the vertical direction in Figures 1 to 3.

[0015] As shown in FIG. 3, the tube portion 51 has a guide hole 5a that penetrates the tube portion 51 in the longitudinal direction and into which the shaft portion 3a of the tool 3 is inserted. The inner diameter d4 of the guide hole 5a is larger than the outer diameter d1 of the shaft portion 3a and smaller than the outer diameter of the large diameter surface 3d. The guide hole 5a is arranged coaxially with the through hole 4a and guides the shaft portion 3a inserted into the guide hole 5a along the central axis A. The annular base end surface 5b of the tube portion 51 is arranged on the base end side of the compression member 4 and functions as a stopper surface that limits the insertion amount of the tool 3 into the bone B by abutting against the large diameter surface 3d of the tool 3 in the axial direction.

[0016] The connecting portion 52 is a plate-like member disposed radially outside the tubular portion 51 and extending parallel to the tubular portion 51. The base end of the connecting portion 52 is connected to the base end of the tubular portion 51. The connecting portion 52 extends beyond the tip of the tubular portion 51, and the tip portion 52a of the connecting portion 52 can be attached to a predetermined attachment portion 10 (described later) of the main body 6. For example, as shown in FIG. 4, the tip portion 52a is U-shaped to fit onto the outside of the attachment portion 10, and the guide member 5 is supported at a predetermined position where the inner surface on the base end side of the tip portion 52a contacts the base end surface of the attachment portion 10. The tip portion 52a also functions as a rotation limiting portion that limits the rotation of the guide member 5 around the central axis A relative to the compression member 4. Although FIG. 1 shows the guide member 5 as being detachable from the main body 6, the guide member 5 may be fixed to the main body 6 and may be integrated therewith.

[0017] The main body 6 includes a support portion 7 that supports the compression member 4, a receiving portion 8 that receives the tip of the tool 3 protruding from the tip of the compression member 4, and a hook-shaped support 9 that connects the support portion 7 and the receiving portion 8 to each other. The pillar 9 is curved in a substantially U-shape or a substantially C-shape, and is disposed radially outward of the bone B so as to surround substantially half the circumference of the bone B. The support portion 7 is fixed to one end of the pillar 9, and the receiving portion 8 is fixed to the other end of the pillar 9. One end of the pillar 9 adjacent to the support portion 7 is an attachment portion 10 to which the guide member 5 is attached.

[0018] The support part 7 is a cylindrical member and has a through hole 7a that penetrates the support part 7 in the longitudinal direction and into which the compression member 4 is inserted. The support part 7 supports the compression member 4 in the through hole 7a so that the compression member 4 is movable in the axial direction. By moving the compression member 4, the distance between the tip of the compression member 4 and the receiving part 8 is adjusted according to the thickness of the bone B.

[0019] The support part 7 is provided with a locking mechanism 11 that fixes and releases the compression member 4 to the support part 7. As shown in FIG. 3, one example of the locking mechanism 11 is a click mechanism having a protrusion that protrudes and retracts from the inner surface of the through hole 7a. A plurality of grooves arranged in the longitudinal direction of the compression member 4 are formed on the outer circumferential surface of the compression member 4. The protrusions are biased radially inward by a spring or the like. When the protrusions are fitted into the grooves, the compression member 4 is fixed in the longitudinal direction to the support part 7. When a longitudinal force of a certain magnitude or more is applied to the compression member 4, the protrusions retract, and the compression member 4 is released from its fixation.

[0020] The locking mechanism 11 may be a mechanism for screwing the compression member 4 to the support part 7. That is, a screw hole penetrating from the outer peripheral surface to the inner peripheral surface of the support part 7 is formed in the support part 7. By tightening a fixing screw inserted into the screw hole, the compression member 4 is fixed to the support part 7, and by loosening the fixing screw, the fixation of the compression member 4 is released.

[0021] The receiving part 8 is a plate-like member perpendicular to an extension of the central axis A of the through hole 4a. The receiving part 8 is disposed at a position spaced apart from the tip of the compression member 4 in the axial direction, and faces the tip of the compression member 4 in the axial direction. The surface of the receiving part 8 facing the compression member 4 is provided with a bone contact surface 8a that is brought into contact with the surface of the bone B, and a recessed part 8b that is recessed on the opposite side to the compression member 4.

[0022] The recess 8b is located on an extension of the central axis A, and receives the tip of the tool 3 passing through the through hole 4a. The recess 8b has a closed bottom on the side opposite to the compression member 4. The bone contact surface 8a is an annular surface surrounding the recess 8b. The bone contact surface 8a may be a flat surface or a curved surface that follows the shape of the surface of the bone B. The receiving portion 8 may have a tapered shape in which the outer diameter gradually decreases from the base end side (the compression member 4 side) toward the tip end side (the opposite side to the compression member 4). As described below, the receiving portion 8 is inserted between the tibia B and tissue present on the posterior side of the tibia B. By making the receiving portion 8 have a tapered shape, the insertion of the receiving portion 8 can be facilitated.

[0023] As described above, the compression member 4 and the guide member 5 have dimensions that satisfy the following relational expressions (i), (ii), (iii), and (iv) with respect to the implant 2, the insertion tool, and the tool 3. The insertion tool (not shown) is an instrument that is connected to the head 2b of the implant 2 and is used to insert the implant 2 into the pilot hole, such as a driver. d1 <d4<d5<d2 ···(i) d4 <d3<d2 ···(ii) d6 <d2 (iii) d2 <d7 (iv) As shown in Fig. 6, d1 is the outer diameter of the shaft portion 3a, and d7 is the outer diameter (diameter) of the large diameter surface 3d. As shown in Fig. 3, d2 is the inner diameter of the through hole 4a, d3 is the outer diameter of the portion of the cylindrical portion 51 that is inserted into the through hole 4a, and d4 is the inner diameter of the guide hole 5a. As shown in Fig. 5, d5 is the maximum outer diameter of the implant 2, and d6 (not shown) is the outer diameter of the insertion tool.

[0024] In a preferred design example, d1 is 2.4 mm to 5.0 mm, d2 is 3.5 mm to 12 mm, d3 is 3.4 mm to 11.9 mm, d4 is 2.4 mm to 5.2 mm, d5 is 3.4 mm to 11.9 mm, and d6 is 4 mm to 11.5 mm. The difference between d1 and d4 corresponds to the clearance between the outer peripheral surface of the shaft portion 3a and the inner peripheral surface of the guide hole 5a. The difference between d2 and d3 corresponds to the clearance between the inner peripheral surface of the through hole 4a and the outer peripheral surface of the guide member 5. The difference between d2 and d5 corresponds to the clearance between the inner peripheral surface of the through hole 4a and the outer peripheral surface of the maximum outer diameter portion of the implant 2. In the case of the above design example, each clearance is suppressed to 1 mm or less, and more preferably to 0.2 mm or less. This eliminates the rattle of the shaft portion 3a in the guide hole 5a and the rattle of the implant 2 in the through hole 4a, and allows the shaft portion 3a and the implant 2 to be guided straight along the central axis A. Moreover, it is more preferable that the outer diameter of the long shaft portion 2a of the implant 2 is 3 mm to 7 mm. If the outer diameter of the implant 2 is too small, the strength of the implant 2 may be insufficient. If the outer diameter of the implant 2 is too large, the implant 2 may affect the bone B and surrounding tissues.

[0025] As described above, the guide member 5 attached to the main body 6 by the connection portion 52 is disposed at a predetermined position in the axial direction relative to the main body 6, and the compression member 4 is movable in the axial direction independently of the guide member 5. Therefore, regardless of the axial position of the compression member 4, the axial distance between the receiving portion 8 and the stopper surface 5b is constant. Here, the guide member 5 and the receiving portion 8 have dimensions that satisfy the following relational expression (1). L2 <L3<L1 ···(1)

[0026] As shown in Fig. 3, L1 is the axial distance from the bottom of the recess 8b to the stopper surface 5b, and L2 is the axial distance from the bone contact surface 8a to the stopper surface 5b. As shown in Fig. 6, L3 is the longitudinal distance of the tool 3 from the tip of the tool 3 to the large diameter surface 3d. By satisfying formula (1), when the tool 3 is inserted into the through hole 4a until the large diameter surface 3d contacts the stopper surface 5b, the tip of the tool 3 is positioned between the bone contact surface 8a and the bottom of the recess 8b in the axial direction and is accommodated in the recess 8b.

[0027] Next, the operation of the bone surgical instrument 1 and the bone surgical system will be described. 7 shows DTO (Distal-tuberosity osteotomy) as an example of use of the bone surgery instrument 1. DTO is a method of performing osteotomy distal to the tuberosity C in high tibial osteotomy (HTO) in order to connect the tuberosity C to a proximal bone fragment D of the tibia B. The bone surgery instrument 1 can also be used to make pilot holes in bones at sites other than the tibia and to insert the implants 2.

[0028] 7, the tibia B is sandwiched in the anterior-posterior direction at the position of the tuberosity C by the compression member 4 and the receiving part 8, and the compression member 4 is moved in a direction approaching the receiving part 8 until the tip of the compression member 4 and the bone contact surface 8a of the receiving part 8 come into contact with the surface of the tibia B, and the compression member 4 is fixed to the support part 7. As a result, the tibia B is gripped in the radial direction by the compression member 4 and the receiving part 8, and compression is applied to the tibia B in a direction that brings the anterior bone fragment B1 and the posterior bone fragment B2 including the tuberosity C closer to each other. The compression member 4 is disposed on the anterior side of the tibia B, and the receiving part 8 is disposed on the posterior side of the tibia B.

[0029] Next, the tool 3 is inserted into the through hole 4a of the compression member 4 via the guide hole 5a of the guide member 5, and a pilot hole is made in the tibia B by the rotating tool 3. During the making of the pilot hole, the tool 3 is guided along the central axis A by the guide hole 5a, so that a pilot hole extending straight along an extension of the central axis A can be made.

[0030] When the tool 3 penetrates the tibia B, the tip of the tool 3 is housed in the recess 8b of the receiving part 8. This prevents the tip of the tool 3 from being exposed to the tissues surrounding the tibia B, and protects the tissues surrounding the tibia B from the tip of the tool 3. In the case of DTO, the tip of the tool 3 that penetrates the tibia B from the front to the rear is prevented from being exposed to the nerves, blood vessels, and the like present at the rear of the tibia B.

[0031] Next, the tool 3 is removed from the pilot hole and holes 4a and 5a, the guide member 5 is removed from the compression member 4 and the main body 6, the implant 2 is inserted into the through hole 4a, and the implant 2 is screwed into the pilot hole by rotating a driver (not shown) connected to the head 2b. As a result, the bone fragment B1 is fixed to the bone fragment B2 by the implant 2.

[0032] Thus, according to this embodiment, a pilot hole is prepared and the implant 2 is screwed into the pilot hole while pressure is applied to the tibia B by the guide member 5 and the receiving part 8. A force that floats the tuberosity C forward is applied to the tuberosity C due to tension in the patellar tendon connected to the tuberosity C. By applying pressure to the tibia B at the position of the tuberosity C, it is possible to prevent the bone fragment B1 including the tuberosity C from floating, and to prepare the pilot hole and insert the implant 2 into the pilot hole while the bone fragment B1 is in appropriate contact with the bone fragment B2.

[0033] Furthermore, when making the pilot hole, the tip of the tool 3 that has penetrated the bone B is accommodated in the recess 8b of the receiving part 8. At this time, the large diameter surface 3d of the tool 3 comes into contact with the stopper surface 5b of the guide member 5, so that the tip of the tool 3 stops before reaching the bottom of the recess 8b, preventing the tip of the tool 3 from contacting the receiving part 8. This allows the receiving part 8 to receive the tip of the tool 3 without causing an impact due to the tool 3 coming into contact with the receiving part 8, reducing the impact on the bone B. Furthermore, wear of the receiving part 8 and the tool 3 and the generation of cutting powder can be prevented.

[0034] Furthermore, when the large diameter surface 3d of the tool 3 contacts the stopper surface 5b, the tip of the tool 3 is positioned beyond the bone contact surface 8a, so that the tool 3 can be reliably penetrated into the bone B and the pilot hole can be reliably penetrated into the bone B. In addition, since the distance from the stopper surface 5b to the large diameter surface 3d is approximately equal to the distance from the receiving part 8 to the tip of the tool 3, the operator can know the remaining cutting distance of the bone B from the distance from the stopper surface 5b to the large diameter surface 3d. Therefore, the operator can take appropriate measures, such as carefully proceeding with cutting of the bone B, when the tip of the tool 3 approaches the surface of the bone B on the receiving part 8 side.

[0035] In the above embodiment, the recess 8b of the receiving portion 8 is a hole having a closed bottom, but the recess 8b may be a hole having an open bottom, i.e., a hole penetrating the receiving portion 8 in the axial direction. In the case of the recess 8b having an open bottom, the position of the bottom of the recess 8b is the position of the surface of the receiving portion 8 opposite the bone contact surface 8a. When the recess 8b is a hole having an open bottom, the receiving portion 8 can be made thinner, making it easier to install the receiving portion 8 on the posterior side of the tibia B.

[0036] In the above embodiment, the tip 3e of the shank 3a of the tool 3 may have an outer diameter different from that of the other parts of the shank 3a. For example, as shown in FIG. 6, the tip 3e of the shank 3a may be tapered toward the tip and may have a smaller diameter than the other parts of the shank 3a. Alternatively, the tip 3e may have a larger diameter than the other parts of the shank 3a. When the tip 3e has an outer diameter different from that of the other parts of the shank 3a, the receiving portion 8 and the guide member 5 have dimensions that satisfy the following relational expressions (2) and (3). In the expressions (2) and (3), H is the dimension of the tip 3e in the longitudinal direction of the tool 3. L1-L2>H (2) L2 <L3-H ···(3)

[0037] L1-L2 is the depth of the recess 8b. By satisfying formula (2), the entire length of the tip 3e can be accommodated within the recess 8b. By satisfying formula (3), when the large diameter surface 3d is in contact with the stopper surface 5b, the entire length of the tip portion 3e is disposed in the recess 8b beyond the bone contact surface 8a. Therefore, by advancing the tool 3 until the large diameter surface 3d contacts the stopper surface 5b, the entire length of the tip portion 3e can be penetrated into the bone B, and a pilot hole having the same diameter over the entire length can be reliably made.

[0038] The greater the length H of the tip portion 3e, the thicker the receiving portion 8. To facilitate placement of the receiving portion 8 on the posterior surface of the tibia B, it is preferable that the receiving portion 8 is thin. Specifically, the length H is preferably 6 mm or less, and more preferably 3 mm or less. The thickness of the receiving portion 8 in the axial direction is preferably 3 mm to 8 mm, and the depth (L1-L2) of the recess 8b is preferably 1.5 mm to 7 mm.

[0039] In the above embodiment, the length dimension of the guide member 5 in the axial direction may be changeable, and the change in the length dimension of the guide member 5 may enable the position of the stopper surface 5b to be changed in the axial direction. For example, the tube portion 51 has a telescope structure in which the inner tube is inserted into the outer tube so as to be movable in the longitudinal direction, and the guide member 5 is extendable in the longitudinal direction. The inner tube can be fixed to the outer tube by a fixing means such as a ratchet mechanism or a screw. If necessary, the connection portion 52 may also be extendable in the longitudinal direction, similar to the tube portion 51. The position of the stopper surface 5b changes stepwise or continuously in the axial direction by the extension and contraction of the tube portion 51. This allows the position of the stopper surface 5b to be changed to a position that satisfies the formula (1) according to the length of the tool 3 to be used, and multiple tools 3 with different lengths L3 can be used for the bone surgery instrument 1. The length of the guide member 5 may be changed by replacing the tube portion 51 as in the modified example shown in FIG. 9, and if the guide member 5 is detachable from the main body 6, the length of the guide member 5 may be changed by replacing the guide member 5.

[0040] In the above embodiment, the guide member 5 includes the cylindrical portion 51 and the connecting portion 52 extending parallel to the cylindrical portion 51 and integral with the cylindrical portion 51, but the configuration of the guide member 5 is not limited to this and can be changed as appropriate. Figures 8 and 9 show other examples of the guide member 5.

[0041] 8 is a cylindrical member that is placed over the compression member 4 from the base end side, and is attached to the main body 6 via the compression member 4. This guide member 5 has a cylindrical slit that extends from the tip surface toward the base end and into which the compression member 4 is inserted so as to be axially movable, and covers the inner and outer circumferential surfaces of the compression member 4. The tip surface of the guide member 5 abuts against the base end surface of the main body 6, so that the guide member 5 is supported at a predetermined position relative to the main body 6. 8 may also be provided with a U-shaped tip portion such as tip portion 52a that fits into attachment portion 10 as a rotation limiting portion that limits rotation relative to compression member 4. Alternatively, a screw that screws guide member 5 to compression member 4 or main body 6, or a pin that pins guide member 5 to compression member 4 or main body 6 may be provided as the rotation limiting portion.

[0042] 9 has a cylindrical portion 51 separate from the connecting portion 52. A through hole 52c, which is coaxial with the central axis A and through which the cylindrical portion 51 passes, is provided at the base end of the connecting portion 52. When the cylindrical portion 51 is inserted into the through hole 4a via the through hole 52c until the flange surface 51a provided at the base end of the cylindrical portion 51 abuts against the base end surface of the connecting portion 52, the cylindrical portion 51 and the stopper surface 5b are supported at a predetermined position. According to this configuration, the length dimension of the guide member 5 and the position of the stopper surface 5b can be changed by replacing the tubular portion 51. Therefore, by replacing the tubular portion 51 with one having dimensions that satisfy formula (1) according to the length L3 of the tool 3 to be used, a plurality of tools 3 having different lengths L3 can be used with the bone surgery instrument 1. The connection part 52 may be fixed to the main body 6 at the attachment part 10 and may be integral with the main body 6. According to this configuration, the bone surgical instrument 1 can be more easily operated.

[0043] In the above embodiment, the first and second composite centers of gravity of the bone surgical instrument 1 are preferably located near the central axis A. The first composite center of gravity is the composite center of gravity of the compression member 4 and the main body 6 in a state in which the compression member 4 is supported by the main body 6. The second composite center of gravity is the composite center of gravity of the compression member 4, the guide member 5, and the main body 6 in a state in which the compression member 4 is supported by the main body 6 and the guide member 5 is attached to the main body 6. When placing the bone surgical instrument 1 on the bone B, the operator holds the bone surgical instrument 1 on the support 9. At this time, the first and second composite centers of gravity are disposed near the central axis A, thereby making it possible to stabilize the posture of the bone surgical instrument 1.

[0044] Preferably, the first composite center of gravity and the second composite center of gravity are located within a hatched range S in Fig. 10. Fig. 10 is a top view of the bone surgery instrument 1 in Fig. 2 as viewed from the base end side in a direction along the central axis A. The range S is within a radius of 11 mm from the central axis A and within 1 mm from the central axis A in the thickness direction of the support 9. The thickness direction of the support 9 is a direction perpendicular to a plane defined by the hook-shaped support 9. In order to stabilize the posture of the bone surgical instrument 1 when it is held on the support 9, it is advantageous for the composite center of gravity in the thickness direction of the support 9 to be close to the central axis A. Therefore, by having the first composite center of gravity and the second composite center of gravity within the range S, the posture of the bone surgical instrument 1 can be made more stable.

[0045] In the above embodiment, at least one of the guide member 5, the main body 6, and the tool 3 may be provided with a buffer portion that buffers the impact when the large diameter surface 3d comes into contact with the stopper surface 5b. 11, the buffer section 12a is made up of a part of the guide member 5 and is provided, for example, at the base end of the tube section 51. The buffer section 12b is made up of a part of the main body 6 and is provided, for example, at the mounting section 10 or in the vicinity of the mounting section 10. A buffer section (not shown) may be provided at the large diameter section 3b or the connection section 3c of the tool 3.

[0046] In order to ensure high strength, the bone surgery instrument 1 is mainly formed from a highly rigid material such as stainless steel, titanium, or a titanium alloy. The buffer parts 12a, 12b have a lower elastic modulus than the guide member 5 and other parts of the main body 6. An example of the buffer parts 12a, 12b is an elastic member or a viscoelastic member made of a resin such as PEEK (polyether ether ketone) or silicone. Another example of the buffer parts 12a, 12b is a structure formed from the same or different material as the guide member 5 and other parts of the main body 6, and is elastically compressible like a compression spring. By providing low elasticity buffer sections 12a, 12b in at least one of the guide member 5, the main body 6 and the tool 3, the impact when the large diameter surface 3d of the tool 3 comes into contact with the stopper surface 5b can be absorbed by the buffer sections 12a, 12b, and the transmission of the impact to the bone B via the compression member 4 and the receiving section 8 can be suppressed.

[0047] In this embodiment, the shaft portion 3a of the tool 3 has the large diameter surface 3d, but instead, the tip surface of a part attached to and detached from the shaft portion 3a may be used as the large diameter surface. For example, as shown in Fig. 12, the part 31 is a driver connected to the connection portion 3c, and the tip surface 31a of the chuck of the driver 31 is the large diameter surface. By attaching the driver 31 to the shaft portion 3a so that the tip surface 31a is located at a predetermined position of the tool 3, the tip surface 31a can be made to function in the same manner as the large diameter surface 3d. This allows a tool 3 that does not have a large diameter surface 3d to be used with the bone surgery instrument 1.

[0048] In the above embodiment, the implant 2 may further include a washer 2c having an outer diameter larger than the outer diameter of the head 2b of the screw, as shown in Fig. 13. In this case, d5 in formula (i) is the outer diameter of the washer 2c, and the outer diameter d5 is smaller than the inner diameter d2 of the through hole 4a. A washer 2c may be used together with the screw, which is sandwiched between the head 2b and the surface of the bone B. By inserting the screw together with the washer 2c into the through hole 4a and screwing it into the pilot hole, the screw can be more firmly fixed to the bone B while applying pressure to the bone B. [Explanation of symbols]

[0049] 1 Bone surgery instruments 2. Implants 3 tools 3a Shaft 3d Large diameter surface 31 parts 4 Compression member 4a Through hole 4b Slit 5 Guide member 51 Cylinder part 5a Guide hole 5b Stopper surface 6 Main unit 7 Support part 8 Receiving part 8a Bone contact surface 8b Recess 12a,12b Buffer section A Center axis B bone

Claims

1. A bone surgery instrument for guiding a tool for drilling a hole in a bone, the tool having a long shaft portion and a large diameter surface provided at a base end of the shaft portion and having a larger diameter than the shaft portion, A cylindrical compression member having a through hole that passes through the compression member in a longitudinal direction and into which a shaft portion of the tool is inserted; A main body having a support portion that supports the compression member movably in an axial direction along the central axis of the through hole, and a receiving portion that is disposed at a distance from a tip of the compression member in the axial direction; a guide member connected to the main body and configured to guide the tool along a central axis of the through hole; The receiving portion has a bone contact surface that is disposed on the compression member side and is brought into contact with the surface of the bone, and a recess that is recessed on the opposite side of the compression member with respect to the bone contact surface and receives a tip of the shaft portion protruding from the through hole, The guide member is disposed on the base end side of the compression member, and has a stopper surface against which the large diameter surface of the tool abuts in the axial direction, and a tubular portion inserted into the through hole from the base end side of the compression member, the cylindrical portion has a guide hole that is arranged coaxially with the through hole and into which a shaft portion of the tool is inserted, and a base end surface of the cylindrical portion is the stopper surface, The receiving portion and the guide member have dimensions that satisfy the following relational expression (1). L2<L3<L1...(1) however, L1 is the distance in the axial direction from the bottom of the recess to the stopper surface, L2 is the distance in the axial direction from the bone contact surface to the stopper surface, L3 is the longitudinal distance of the tool from the tip of the tool to the large diameter surface. It is.

2. a tip portion of the shank of the tool having an outer diameter different from the rest of the shank; 2. The bone surgical instrument according to claim 1, wherein the receiving portion and the guide member have dimensions that satisfy the following relations (2) and (3). L1-L2>H...(2) L2<L3-H...(3) however, H is the dimension of the tip in the longitudinal direction of the tool It is.

3. The length dimension of the guide member in the axial direction is changeable, 3. The bone surgical instrument according to claim 1, wherein the position of said stopper surface is changeable in the axial direction by changing the length dimension of said guide member.

4. A bone surgery instrument for guiding a tool for drilling a hole in a bone, the tool having a long shaft portion and a large diameter surface provided at a base end of the shaft portion and having a larger diameter than the shaft portion, A cylindrical compression member having a through hole that passes through the compression member in a longitudinal direction and into which a shaft portion of the tool is inserted; A main body having a support portion that supports the compression member movably in an axial direction along the central axis of the through hole, and a receiving portion that is disposed at a distance from a tip of the compression member in the axial direction; a guide member connected to the main body and configured to guide the tool along a central axis of the through hole; The receiving portion has a bone contact surface that is disposed on the compression member side and is brought into contact with the surface of the bone, and a recess that is recessed on the opposite side of the compression member with respect to the bone contact surface and receives a tip of the shaft portion protruding from the through hole, The guide member is disposed on a base end side of the compression member and has a stopper surface against which the large diameter surface of the tool abuts in the axial direction, The length dimension of the guide member in the axial direction is changeable, The position of the stopper surface can be changed in the axial direction by changing the length dimension of the guide member, The receiving portion and the guide member have dimensions that satisfy the following relational expression (1). L2<L3<L1...(1) however, L1 is the distance in the axial direction from the bottom of the recess to the stopper surface, L2 is the distance in the axial direction from the bone contact surface to the stopper surface, L3 is the longitudinal distance of the tool from the tip of the tool to the large diameter surface. It is.

5. 5. The bone surgical instrument according to claim 1, further comprising a rotation limiting portion that limits rotation of said guide member relative to said compression member about said central axis.

6. 6. The bone surgery instrument according to claim 1, wherein at least one of the guide member, the main body and the tool is provided with a buffer portion that buffers an impact when the large diameter surface contacts the stopper surface.

7. 7. The bone surgery instrument according to claim 1, wherein the large diameter surface is a tip surface of a part that is detachably attached to the shaft portion.

8. 8. The bone surgical instrument according to claim 1, wherein the compression member and the guide member have dimensions that satisfy the following relationship: d1<d4<d5<d2, d4<d3<d2, and d6<d2 however, d1 is the outer diameter of the shank of the tool, d2 is the inner diameter of the through hole of the compression member, d3 is the outer diameter of the portion of the guide member that is inserted into the through hole, d4 is the inner diameter of the portion of the guide member that is inserted into the through hole, d5 is the maximum outer diameter of the implant that may be inserted into the hole; d6 is the outer diameter of the insertion tool connected to the proximal end of the implant It is.

9. A bone surgery instrument for guiding a tool for drilling a hole in a bone, the tool having a long shaft portion and a large diameter surface provided at a base end of the shaft portion and having a larger diameter than the shaft portion, A cylindrical compression member having a through hole that passes through the compression member in a longitudinal direction and into which a shaft portion of the tool is inserted; A main body having a support portion that supports the compression member movably in an axial direction along the central axis of the through hole, and a receiving portion that is disposed at a distance from a tip of the compression member in the axial direction; a guide member connected to the main body and configured to guide the tool along a central axis of the through hole; The receiving portion has a bone contact surface that is disposed on the compression member side and is brought into contact with the surface of the bone, and a recess that is recessed on the opposite side of the compression member with respect to the bone contact surface and receives a tip of the shaft portion protruding from the through hole, The guide member is disposed on a base end side of the compression member and has a stopper surface against which the large diameter surface of the tool abuts in the axial direction, The receiving portion and the guide member have dimensions that satisfy the following relational expression (1), L2<L3<L1...(1) however, L1 is the distance in the axial direction from the bottom of the recess to the stopper surface, L2 is the distance in the axial direction from the bone contact surface to the stopper surface, L3 is the longitudinal distance of the tool from the tip of the tool to the large diameter surface. and A bone surgical instrument, wherein the compression member and the guide member have dimensions that satisfy the following relationship: d1<d4<d5<d2, d4<d3<d2, and d6<d2 however, d1 is the outer diameter of the shank of the tool, d2 is the inner diameter of the through hole of the compression member, d3 is the outer diameter of the portion of the guide member that is inserted into the through hole, d4 is the inner diameter of the portion of the guide member that is inserted into the through hole, d5 is the maximum outer diameter of the implant that may be inserted into the hole; d6 is the outer diameter of the insertion tool connected to the proximal end of the implant It is.

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