Guide for forming screw insertion holes
The screw insertion hole guide stabilizes the position and orientation of the second sacral vertebra (S2) using projections and support parts, addressing misalignment issues and enabling precise, minimally invasive hole formation.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- G CUBE CO LTD
- Filing Date
- 2025-11-27
- Publication Date
- 2026-06-08
AI Technical Summary
Existing screw insertion hole guides for the second sacral vertebra (S2) are prone to misalignment and displacement due to the lack of distinctive features, leading to increased surgical invasiveness and difficulty in forming screw insertion holes with precision.
A screw insertion hole forming guide that stabilizes position and orientation using projections and support parts designed to fit the first sacral vertebra (S1) and second sacral vertebra (S2), employing a geometric constraint structure by inserting projections into existing screw insertion holes and stabilizing with bone surface contact.
Enables precise and minimally invasive formation of screw insertion holes in the second sacral vertebra (S2) by stabilizing the guide's position and orientation through a combination of bone surface contact and geometric constraints.
Smart Images
Figure 0007870983000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a guide for forming a screw insertion hole used in spinal fixation surgery, and more particularly to a guide for forming a screw insertion hole that assists in forming a screw insertion hole in the second sacral vertebra S2.
Background Art
[0002] Spinal fixation surgery is known as a surgical procedure for eliminating spinal instability or correcting deformities. In spinal fixation surgery, in order to form a screw insertion hole at a target site of a vertebra, a three-dimensional guide for forming a screw insertion hole dedicated to the patient, designed based on the bone shape of the patient, may be used.
[0003] The guide for forming a screw insertion hole described in Patent Document 1 includes a pair of left and right guide cylinders, a connecting portion that connects the guide cylinders to each other, and a plurality of support portions provided on the connecting portion. This guide is applied to the bone surface so that each of the plurality of support portions contacts a feature point on the surface of the vertebra in which the screw insertion hole is to be formed during use. Then, a screw insertion hole can be formed at the target site by inserting a probe into the pair of left and right guide cylinders in this state. However, the second sacral vertebra S2, which is the second sacral vertebra from the top, has fewer feature points than the first sacral vertebra S1 and the vertebrae constituting the thoracic vertebra. For this reason, this guide was likely to be displaced on the surface of the second sacral vertebra S2 during the operation. That is, the position and orientation of this guide with respect to the second sacral vertebra S2 were difficult to stabilize, and there were cases where a screw insertion hole as planned could not be formed.
[0004] The screw insertion hole forming guide described in Patent Document 2 comprises a first guide member and a second guide member corresponding to the first sacral vertebra S1, and a third guide member (a guide member corresponding to the second sacral vertebra S2) connected to one of these guide members via a plate. This guide aims to stabilize the position and orientation by having the proximal openings of each of the three support guide members contact the surface of the corresponding sacral vertebra. However, this guide also had the same problem as the guide described in Patent Document 1, namely, the problem of being prone to misalignment on the surface of the second sacral vertebra S2, which has few distinctive features.
[0005] Furthermore, the problem of displacement can be resolved by inserting a K-wire (Kirschner Wire) into the screw insertion hole created in the first sacral vertebra (S1) to temporarily fix the guide. However, this method may require additional skin incisions and muscle dissection to fix the guide, potentially leading to increased surgical invasiveness. Moreover, this method was difficult to perform without a highly skilled surgeon. [Prior art documents] [Patent Documents]
[0006] [Patent Document 1] Patent No. 5638373 [Patent Document 2] Special Publication No. 2022-502232 [Overview of the project] [Problems that the invention aims to solve]
[0007] The present invention has been made in view of these circumstances, and aims to provide a screw insertion hole forming guide that can easily stabilize the position and orientation relative to the second sacral vertebra S2, and that can form a screw insertion hole in the second sacral vertebra S2 as planned with minimal invasiveness. [Means for solving the problem]
[0008] To solve the above problems, the screw insertion hole formation guide according to the present invention is a guide used in spinal fusion surgery to form a screw insertion hole in a target site located on the right or left side of the second sacral vertebra S2 after forming a screw insertion hole in the right and / or left side of the first sacral vertebra S1, and comprises a guide body, a guide cylinder provided on the guide body having a proximal opening end that is close to the target site when in use and a distal opening end located on the opposite side, one or a pair of projections provided on the guide body that can be inserted into the screw insertion hole formed in the right and / or left side of the first sacral vertebra S1, and at least one support part provided on the guide body, the at least one support part having a contact surface shaped to match the surface shape of the first sacral vertebra S1 and / or the second sacral vertebra S2.
[0009] If the target site is located on the right side of the second sacral vertebra S2, the projection may consist of a right-side projection that can be inserted into a screw insertion hole formed on the right side of the first sacral vertebra S1, and may further include a left-side projection that can be inserted into a screw insertion hole formed on the left side of the first sacral vertebra S1.
[0010] Furthermore, if the target site is located on the left side of the second sacral vertebra S2, the projection may consist of a left-side projection that can be inserted into a screw insertion hole formed on the left side of the first sacral vertebra S1, and may further include a right-side projection that can be inserted into a screw insertion hole formed on the right side of the first sacral vertebra S1. [Effects of the Invention]
[0011] According to the present invention, it is possible to provide a screw insertion hole forming guide that allows for easy stabilization of the position and orientation relative to the second sacral vertebra S2, and enables the formation of a screw insertion hole in the second sacral vertebra S2 as planned with minimal invasiveness. [Brief explanation of the drawing]
[0012] [Figure 1] This is a 3D model diagram of a conventional screw hole forming guide used to form screw holes in the right and left portions of the first sacral vertebra, S1. [Figure 2] Figure 1 is a 3D model showing the screw insertion hole formation guide positioned on the spine. [Figure 3] This is a 3D model diagram of a screw insertion hole forming guide according to the first embodiment of the present invention, used to form a screw insertion hole in the right side of the second sacral vertebra (S2). [Figure 4] Figure 3 is a 3D model showing the screw insertion hole formation guide positioned on the spine. [Figure 5] This is a 3D model diagram of a screw insertion hole forming guide according to the first embodiment of the present invention, used to form a screw insertion hole in the left portion of the second sacral vertebra (S2). [Figure 6] Figure 5 is a 3D model showing the screw insertion hole formation guide positioned on the spine. [Figure 7] This is a 3D model diagram of a screw insertion hole forming guide according to a second embodiment of the present invention, used to form a screw insertion hole in the right side of the second sacral vertebra, S2. [Figure 8] Figure 7 is a 3D model showing the screw insertion hole formation guide positioned on the spine. [Figure 9] This is a 3D model diagram of a screw insertion hole forming guide according to a second embodiment of the present invention, used to form a screw insertion hole in the left portion of the second sacral vertebra, S2. [Figure 10] Figure 9 is a 3D model showing the screw insertion hole formation guide positioned on the spine. [Modes for carrying out the invention]
[0013] [Conventional guide for forming screw insertion holes] First, with reference to Figures 1 and 2, a conventional screw insertion hole forming guide 10 used to form a screw insertion hole in the first sacral vertebra S1 will be described. Note that in each figure, the X, Y, and Z directions are orthogonal to each other. Therefore, if Figure 1(A) is a front view, then (B) is a bottom view, and (C) is a rear view.
[0014] The guide 10 for forming a screw insertion hole is a dedicated guide for the patient designed based on the bone shape data of the patient obtained by CT imaging or the like, and includes a right guide cylinder 11, a left guide cylinder 12, a base 13, a first connecting portion 14, a second connecting portion 15, and seven support portions 16a to 16g provided on the base 13.
[0015] The right guide cylinder 11 has a proximal opening end 11b that is close to the bone surface during use and a distal opening end 11a located on the opposite side. Similarly, the left guide cylinder 12 has a proximal opening end 12b that is close to the bone surface during use and a distal opening end 12a located on the opposite side.
[0016] The base 13 has one end connected to a portion near the proximal opening end 11b of the right guide cylinder 11 and the other end connected to a portion near the proximal opening end 12b of the left guide cylinder 12, and has a substantially inverted U shape in a view in the XY plane (see FIG. 1(B)). The first connecting portion 14 has one end connected near the distal opening end 11a of the right guide cylinder 11 and the other end connected near the distal opening end 12a of the left guide cylinder 12. Further, the second connecting portion 15 has one end connected to the top of the base 13 and the other end connected to the middle portion of the first connecting portion 14.
[0017] The seven support portions 16a to 16g have contact surfaces 16a' to 16g' designed to contact (fit) the characteristic points on the surface of the first sacral vertebra S1 without gaps. By inserting a probe from each of the distal opening ends 11a of the right guide cylinder 11 and the distal opening ends 12a of the left guide cylinder 12 in the state where all seven contact surfaces 16a' to 16g' are in contact with the characteristic points of the first sacral vertebra S1, that is, in the state shown in FIG. 2 where the guide 10 for forming a screw insertion hole is applied to a predetermined position, screw insertion holes can be formed as planned in each of the right and left portions of the first sacral vertebra S1.
[0018] Furthermore, the proximal open end 11b of the right guide tube 11 and the proximal open end 12b of the left guide tube 12 may be designed to contact the surface of the first sacral vertebra S1 when the screw insertion hole forming guide 10 is applied to the first sacral vertebra S1, or they may be designed to be slightly separated from the surface of the first sacral vertebra S1.
[0019] [Guide for forming screw insertion holes according to the first embodiment] Next, with reference to Figures 3 to 6, the screw insertion hole forming guides 20 and 30 according to the first embodiment of the present invention, used to form a screw insertion hole in the second sacral vertebra S2, will be described. Note that in these figures as well, the X, Y, and Z directions are orthogonal to each other. Therefore, if Figure 3(A) and Figure 5(A) are front views, then (B) is a bottom view and (C) is a rear view.
[0020] The screw insertion hole forming guide 20 is a patient-specific guide designed based on the patient's bone shape data obtained by CT scanning or the like, and comprises a guide body, a guide cylinder 21 provided on the guide body, a projection 22, and five support parts 25a to 25e.
[0021] The guide tube 21 has a proximal open end 21b that is close to the bone surface when in use, and a distal open end 21a located on the opposite side.
[0022] The projection 22 is a rod-shaped body of a thickness and length that can be inserted into a screw insertion hole formed in the right-side portion of the first sacral vertebra S1.
[0023] The guide body includes a first protruding portion 23 that extends generally in the Z direction from the part of the guide tube 21 near the distal open end 21a to the base of the projection 22, and a second protruding portion 24 that extends generally in the -Z direction from the middle part of the guide tube 21.
[0024] The five support sections 25a to 25e are all approximately hemispherical in shape. Of the support sections 25a to 25e, support sections 25a and 25b are provided on the guide cylinder 21, support section 25c is provided on the first protruding section 23, and support sections 25d and 25e are provided on the second protruding section 24.
[0025] The five support parts 25a to 25e have contact surfaces 25a' to 25e'. Of the contact surfaces 25a' to 25e', contact surfaces 25a' to 25c' are designed to make seamless contact (fit) with characteristic points on the surface of the right side of the first sacral vertebra S1, and contact surfaces 25d' and 25e' are designed to make seamless contact (fit) with characteristic points on the surface of the right side of the second sacral vertebra S2. By inserting the probe from the distal open end 21a of the guide cylinder 21 in the state shown in Figure 4, with all five contact surfaces 25a' to 25e' in contact with the characteristic points of the sacral vertebrae S1 and S2, a screw insertion hole can be formed as planned in the target area, the right side of the second sacral vertebra S2.
[0026] The proximal open end 21b of the guide tube 21 may be designed to contact the surface of the second sacral vertebra S2 when the screw insertion hole forming guide 20 is applied to the sacral vertebrae S1 and S2, or it may be designed to be slightly separated from the surface of the second sacral vertebra S2.
[0027] The screw insertion hole forming guide 30 is a guide specifically designed for the patient based on the patient's bone shape data obtained by CT scanning or the like, and comprises a guide body, a guide cylinder 31 provided on the guide body, a projection 32, and five support parts 35a to 35e.
[0028] The guide tube 31 has a proximal open end 31b that is close to the bone surface when in use, and a distal open end 31a located on the opposite side.
[0029] The projection 32 is a rod-shaped body of a thickness and length that can be inserted into a screw insertion hole formed in the left side of the first sacral vertebra S1.
[0030] The guide body includes a first protruding portion 33 that extends generally in the Z direction from the part of the guide tube 31 near the distal open end 31a to the base of the projection 32, and a second protruding portion 34 that extends generally in the -Z direction from the part of the guide tube 21 near the distal open end 31a.
[0031] The five support sections 35a to 35e are all approximately hemispherical in shape. Of the support sections 35a to 35e, support section 35a is provided on the guide cylinder 31, support section 35b is provided across the guide cylinder 31 and the first protruding section 33, support section 35c is provided on the first protruding section 33, and support sections 35d and 35e are provided on the second protruding section 34.
[0032] The five support parts 35a to 35e each have contact surfaces 35a' to 35e'. Of the contact surfaces 35a' to 35e', contact surfaces 35a' to 35c' are designed to make seamless contact (fit) with characteristic points on the surface of the left side of the first sacral vertebra S1, and contact surfaces 35d' and 35e' are designed to make seamless contact (fit) with characteristic points on the surface of the left side of the second sacral vertebra S2. By inserting the probe from the distal open end 31a of the guide cylinder 31 in the state shown in Figure 6, with all five contact surfaces 35a' to 35e' in contact with the characteristic points of the sacral vertebrae S1 and S2, a desired screw insertion hole can be formed in the target area, the left side of the second sacral vertebra S2.
[0033] The proximal open end 31b of the guide tube 31 may be designed to contact the surface of the second sacral vertebra S2 when the screw insertion hole forming guide 30 is applied to the sacral vertebrae S1 and S2, or it may be designed to be slightly separated from the surface of the second sacral vertebra S2.
[0034] In this way, by using the screw insertion hole forming guide 10 to form one screw insertion hole each in the right and left portions of the first sacral vertebra S1, and then using the screw insertion hole forming guides 20 and 30 in any order, one screw insertion hole each can be formed in the right and left portions of the second sacral vertebra S2.
[0035] As described above, the screw insertion hole formation guide 20 (Figures 3 and 4) is equipped with a projection 22 that can be inserted into a screw insertion hole formed on the right side of the first sacral vertebra S1. In other words, the screw insertion hole formation guide 20 employs a "geometric constraint structure by inserting a projection into an existing screw insertion hole" in addition to the "stabilization structure by contact with the bone surface" adopted by conventional screw insertion hole formation guides. Therefore, with the screw insertion hole formation guide 20, even though the number of contact surfaces that come into contact with the surface of the second sacral vertebra S2 is relatively small, the position and orientation of the second sacral vertebra S2 are stabilized by three-dimensional constraint based on the center of the existing screw insertion hole.
[0036] The same can be said for the screw insertion hole forming guide 30 (Figures 5 and 6).
[0037] The screw insertion hole formation guide 20 can be used if a screw insertion hole is formed in the right-side portion of the first sacral vertebra S1. If a screw is already inserted in this screw insertion hole, the screw must be removed first to allow the use of the screw insertion hole formation guide 20.
[0038] Similarly, the screw insertion hole formation guide 30 can be used if a screw insertion hole is formed in the left side of the first sacral vertebra S1. If a screw is already inserted in this screw insertion hole, the screw insertion hole formation guide 30 can be used after the screw is removed.
[0039] [Guide for forming screw insertion holes according to the second embodiment] Next, with reference to Figures 7-10, a screw insertion hole forming guide 40, 50 according to a second embodiment of the present invention, used to form a screw insertion hole in the second sacral vertebra S2, will be described. Note that in these figures as well, the X, Y, and Z directions are orthogonal to each other. Therefore, if Figure 7(A) and Figure 9(A) are front views, then (B) is a bottom view and (C) is a rear view.
[0040] The screw insertion hole forming guide 40 is a patient-specific guide designed based on the patient's bone shape data obtained by CT scanning or the like, and comprises a guide body, a guide tube 41 provided on the guide body, a right-side projection 42, a left-side projection 43, and seven support parts 47a to 47g.
[0041] The guide tube 41 has a proximal open end 41b that is close to the bone surface when in use, and a distal open end 41a located on the opposite side.
[0042] The right-side projection 42 is a rod-shaped body of a thickness and length that can be inserted into a screw insertion hole formed on the right side of the first sacral vertebra S1. The left-side projection 43 is a rod-shaped body of a thickness and length that can be inserted into a screw insertion hole formed on the left side of the first sacral vertebra S1. In this embodiment, the right-side projection 42 is longer than the left-side projection 43.
[0043] The guide body includes a first protruding portion 44 extending generally in the Z direction from the distal open end 41a of the guide tube 41 to the base of the right-side projection 42, a second protruding portion 45 extending generally in the -Z direction from the middle of the guide tube 41, and left and right connecting portions 46 extending from the second protruding portion 45 in a large curve to the base of the left-side projection 43.
[0044] The seven support sections 47a to 47g are all roughly hemispherical in shape. Of the support sections 47a to 47g, support sections 47a and 47b are provided on the guide cylinder 41, support section 47c is provided on the first protruding section 44, and support sections 47e and 47f are provided on the second protruding section 45. Support sections 47d and 47g are provided on the left and right connecting sections 46.
[0045] The seven support parts 47a to 47g each have contact surfaces 47a' to 47g'. Of the contact surfaces 47a' to 47g', contact surfaces 47a' to 47c' are designed to make seamless contact (fit) with characteristic points on the surface of the right side of the first sacral vertebra S1, contact surface 47d' is designed to make seamless contact (fit) with characteristic points on the surface of the left side of the first sacral vertebra S1, contact surfaces 47e' and 47f' are designed to make seamless contact (fit) with characteristic points on the surface of the right side of the second sacral vertebra S2, and contact surface 47g' is designed to make seamless contact (fit) with characteristic points on the surface of the left side of the second sacral vertebra S2. By inserting the probe from the distal open end 41a of the guide tube 41 in the state shown in Figure 8, where all seven contact surfaces 47a' to 47g' are in contact with characteristic points of the sacral vertebrae S1 and S2, that is, with the screw insertion hole formation guide 40 positioned in the predetermined location, a screw insertion hole can be formed as planned in the right side of the second sacral vertebra S2, which is the target site.
[0046] The proximal open end 41b of the guide tube 41 may be designed to contact the surface of the second sacral vertebra S2 when the screw insertion hole forming guide 40 is applied to the sacral vertebrae S1 and S2, or it may be designed to be slightly separated from the surface of the second sacral vertebra S2.
[0047] The screw insertion hole forming guide 50 is a patient-specific guide designed based on the patient's bone shape data obtained by CT scanning or the like, and comprises a guide body, a guide tube 51 provided on the guide body, a right-side projection 52, a left-side projection 53, and seven support parts 58a to 58g.
[0048] The guide tube 51 has a proximal open end 51b that is close to the bone surface when in use, and a distal open end 51a located on the opposite side.
[0049] The right-side projection 52 is a rod-shaped body of a thickness and length that can be inserted into a screw insertion hole formed in the right-side portion of the first sacral vertebra S1. The left-side projection 53 is a rod-shaped body of a thickness and length that can be inserted into a screw insertion hole formed in the left-side portion of the first sacral vertebra S1. In this embodiment, the left-side projection 53 is longer than the right-side projection 52.
[0050] The guide body includes a first protrusion 54 extending generally in the Z direction from the part of the guide tube 51 near the distal open end 51a to the base of the left projection 53, a second protrusion 55 and a third protrusion 56 extending generally in the -Z direction from the part of the guide tube 51 near the distal open end 51a, and a left and right connecting portion 57 extending from the second protrusion 55 in a large curve to the base of the right projection 52.
[0051] The seven support sections 58a to 58g are all approximately hemispherical in shape. Of the support sections 58a to 58g, support section 58b is provided on the guide cylinder 51, support section 58d is provided across the guide cylinder 51 and the first protruding section 54, support section 58c is provided on the first protruding section 54, support section 58f is provided on the second protruding section 55, and support section 58g is provided on the third protruding section 56. In addition, support sections 58a and 58e are provided on the left and right connecting sections 57.
[0052] The seven support parts 58a to 58g each have contact surfaces 58a' to 58g'. Of the contact surfaces 58a' to 58g', contact surfaces 58b' to 58d' are designed to make seamless contact (fit) with characteristic points on the surface of the left side of the first sacral vertebra S1, contact surface 58a' is designed to make seamless contact (fit) with characteristic points on the surface of the right side of the first sacral vertebra S1, contact surfaces 58f' and 58g' are designed to make seamless contact (fit) with characteristic points on the surface of the left side of the second sacral vertebra S2, and contact surface 58e' is designed to make seamless contact (fit) with characteristic points on the surface of the right side of the second sacral vertebra S2. By inserting the probe from the distal open end 51a of the guide tube 51 in the state shown in Figure 10, with all seven contact surfaces 58a' to 58g' in contact with characteristic points of the sacral vertebrae S1 and S2, that is, with the screw insertion hole formation guide 50 positioned in the predetermined location, a screw insertion hole can be formed as planned in the right side of the second sacral vertebra S2, which is the target site.
[0053] The proximal open end 51b of the guide tube 51 may be designed to contact the surface of the second sacral vertebra S2 when the screw insertion hole forming guide 50 is applied to the sacral vertebrae S1 and S2, or it may be designed to be slightly separated from the surface of the second sacral vertebra S2.
[0054] In this way, by using the screw insertion hole forming guide 10 to form one screw insertion hole each in the right and left portions of the first sacral vertebra S1, and then using the screw insertion hole forming guides 40 and 50 in any order, one screw insertion hole each can be formed in the right and left portions of the second sacral vertebra S2.
[0055] As described above, the screw insertion hole forming guide 40 (Figures 7 and 8) includes a right-side projection 42 that can be inserted into a screw insertion hole formed on the right side of the first sacral vertebra S1 and a left-side projection 43 that can be inserted into a screw insertion hole formed on the left side of the first sacral vertebra S1. Therefore, with the screw insertion hole forming guide 40, the position and orientation relative to the second sacral vertebra S2 are further stabilized by stronger three-dimensional constraint than in the first embodiment.
[0056] The same can be said for the screw insertion hole forming guide 50 (Figures 9 and 10).
[0057] [Differentiation] Although the first and second embodiments of the screw insertion hole forming guide according to the present invention have been described above, the present invention is not limited to these embodiments.
[0058] For example, the screw insertion hole forming guide according to the present invention, which assists in the formation of a screw insertion hole in the right portion of the second sacral vertebra S2, may have a projection that can be inserted into a screw insertion hole formed in the left portion of the first sacral vertebra S1, instead of a projection that can be inserted into a screw insertion hole formed in the right portion of the first sacral vertebra S1. Similarly, the screw insertion hole forming guide according to the present invention, which assists in the formation of a screw insertion hole in the left portion of the second sacral vertebra S2, may have a projection that can be inserted into a screw insertion hole formed in the right portion of the first sacral vertebra S1, instead of a projection that can be inserted into a screw insertion hole formed in the left portion of the first sacral vertebra S1.
[0059] Furthermore, the screw insertion hole formation guide according to the present invention does not necessarily have to have multiple contact surfaces that contact the surface of the first sacral vertebra S1 and multiple contact surfaces that contact the surface of the second sacral vertebra S2. In other words, the screw insertion hole formation guide according to the present invention only needs to have at least one contact surface that contacts the surface of the first sacral vertebra S1, or at least one contact surface that contacts the surface of the second sacral vertebra S2. Reducing the number of contact surfaces that contact the surface of the second sacral vertebra S2 greatly contributes to minimally invasiveness, but whether such a design is possible naturally depends on the bone shape of the patient.
[0060] Furthermore, the screw insertion hole forming guide according to the present invention may include a support portion having a shape other than a substantially hemisphere.
[0061] Furthermore, the guide body provided in the screw insertion hole forming guide according to the first and second embodiments is merely an example. The screw insertion hole forming guide according to the present invention may include any guide body that can determine the positional relationship between the guide cylinder, the projection, and the support portion. [Explanation of Symbols]
[0062] 10 Guide for forming screw insertion holes 11 Right-side guide tube 12 Left-side guide tube 13 Base 14 1st connection part 15 2nd connection part 16a~16g Support part 16a'~16g' Contact surface 20 Guide for forming screw insertion holes 21 Guide tube 22 Protrusion 23 1st overhang 24 Second overhang 25a~25e Support part 25a'~25e' Contact surface 30 Guide for forming screw insertion holes 31 Guide tube 32 Protrusion 33 1st overhang 34 Second overhang 35a~35e Support part 35a'~35e' Contact surface 40 Guide for forming screw insertion holes 41 Guide tube 42 Right protrusion 43 Left side protrusion 44 1st overhang 45 Second overhang 46 Left and right connection section 47a~47g Support part 47a'~47g' Contact surface 50 Guide for forming screw insertion holes 51 Guide tube 52 Right protrusion 53 Left protrusion 54 1st overhang 55 Second overhang 56 Third overhang 57 Left and right connection part 58a~58g Support part 58a'~58g' Contact surface
Claims
1. A screw insertion hole forming guide used in spinal fusion surgery to form a screw insertion hole in a target area located on the right or left side of the second sacral vertebra S2 after forming a screw insertion hole in the right and / or left side of the first sacral vertebra S1, The guide body and A guide tube provided on the guide body, having a proximal open end that is close to the target area during use and a distal open end located on the opposite side, One or a pair of projections provided on the guide body that can be inserted into screw insertion holes formed on the right and / or left side of the first sacral vertebra S1, The guide body is provided with at least one support portion and Equipped with, The at least one support portion has a contact surface shaped to match the surface shape of the first sacral vertebra S1 and / or the second sacral vertebra S2. A guide for forming screw insertion holes, characterized by the following features.
2. The target area is located on the right side of the second sacral vertebra S2. The aforementioned projection consists of a right-side projection that can be inserted into a screw insertion hole formed in the right-side portion of the first sacral vertebra S1. The guide for forming a screw insertion hole according to feature 1.
3. The projection further includes a left-side projection that can be inserted into a screw insertion hole formed in the left side of the first sacral vertebra S1. The guide for forming a screw insertion hole according to feature 2.
4. The target area is located on the left side of the second sacral vertebra S2. The aforementioned projection consists of a left-side projection that can be inserted into a screw insertion hole formed in the left side of the first sacral vertebra S1. The guide for forming a screw insertion hole according to feature 1.
5. The projection further includes a right-side projection that can be inserted into a screw insertion hole formed in the right-side portion of the first sacral vertebra S1. The guide for forming a screw insertion hole according to feature 4.