Bone model and display system

Abstract

To facilitate checking whether a bone has been cut in conformance to a pre-operation plan after simulated surgery is performed using a bone model.SOLUTION: A bone model includes: a first member having a first cross section; a second member having a second cross section to come into contact with the first cross section; and a fixing part that fixes the first member and the second member with the first cross section and the second cross section in contact with each other.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to bone models and display systems. [Background technology]

[0002] In total hip replacement surgery, a simulated surgery is performed using a bone model before the surgery. The bone model is disclosed in, for example, Non-Patent Document 1. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Sawbones USA Pacific Research Company "Unilateral pelvis with osteoarthritis, solid form, left", [online], [Retrieved February 19, 2024], Internet <URL:https: / / www.sawbones.com / hemi-pelvis-large-left-solid-foam-osteoarthritic-hemi-pelvis-for-1301-5-full-pelvis-1294-1.html> Summary of the Invention [Problem to be solved by the invention]

[0004] To confirm whether the bone was resected according to the preoperative plan, the bone model must be divided. However, cutting the integrally formed bone model at a position suitable for confirmation is time-consuming and difficult. [Means for solving the problem]

[0005] A bone model according to one embodiment of the present disclosure includes a first member having a first cross-section, a second member having a second cross-section that contacts the first cross-section, and a fixing portion that fixes the first member and the second member while the first cross-section and the second cross-section are in contact. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, after performing a simulated surgery using a bone model, it is possible to easily confirm whether the bone cutting was performed according to the preoperative plan. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of total hip replacement surgery. [Figure 2] FIG. 1 is a schematic diagram showing an example of a bone model according to the first embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic diagram showing a state in which the bone model shown in FIG. 2 is divided. [Figure 4] FIG. 3 is a schematic diagram showing a division surface of the bone model shown in FIG. 2. [Figure 5] FIG. 10 is a schematic diagram illustrating confirmation of a bone model after bone cutting. [Figure 6] FIG. 2 is a schematic diagram showing an example of a cortical bone region and a bone marrow region of a bone model. [Figure 7] FIG. 10 is a schematic diagram illustrating a navigation surgery according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Embodiment 1] A first embodiment of the present disclosure will be described below with reference to the drawings. An example will be described below in which the bone model 10 has a shape resembling a pelvis and is used in a simulated total hip replacement surgery. However, the present disclosure is not limited to this, and the bone model 10 can be adapted to a shape compatible with any surgical procedure. For example, the bone model 10 can also be applied to simulated surgeries such as total knee replacement surgery or total shoulder replacement surgery. In this case, the bone model 10 is configured to have a shape resembling a femur, tibia, humerus, or the like.

[0009] <Summary> First, to facilitate understanding of the bone model 10 used in the simulated hip replacement surgery, a brief overview of hip replacement surgery will be provided. Hip replacement surgery is a surgery to replace a patient's hip joint with an artificial hip joint.

[0010] A hip joint is composed of a dome-shaped recessed acetabulum in the pelvis and a ball-shaped femoral head at the tip of the femur. When a hip joint is damaged due to illness or a fracture, an artificial hip joint replacement is performed to replace the damaged hip joint with an artificial hip joint. An artificial hip joint is composed of, for example, a pelvic implant attached to the acetabulum and a spherical femoral implant that engages with the pelvic implant and is attached to the femoral head.

[0011] Before hip replacement surgery, cross-sectional images of the patient's hip joint are taken using CT (Computed Tomography) or MRI (Magnetic Resonance Imaging) to create a preoperative plan. The cross-sectional image data is then imported into a computer, which then determines the size of the implant to be installed, its position, the depth and angle of the acetabular bone resection, and other factors.

[0012] In the actual surgery, the acetabulum is resected according to the preoperative plan to form a mounting surface for the implant. A pelvic implant is attached to the mounting surface of the acetabulum and engaged with a femoral implant attached to the femur, thereby functioning as the patient's hip joint.

[0013] 1 is a schematic diagram illustrating an example of total hip replacement surgery. The diagram indicated by reference numeral 100A shows a state in which an acetabulum 91 of a pelvis 9 is being resected, and the diagram indicated by reference numeral 100B shows an implant 92 attached to the acetabulum 91 as viewed from the side of the pelvis 9.

[0014] 1, an acetabulum 91 is cut using a bone cutting tool 93 to match the shape of an implant 92 to be attached, and a mounting surface 911 is formed. The implant 92 is attached to the mounting surface 911 formed on the acetabulum 91.

[0015] If the bone resection of the acetabulum 91 is performed according to the preoperative plan, the implant 92 can be attached to the acetabulum 91 in an appropriate condition, thereby reducing problems such as dislocation or revision of the artificial hip joint.

[0016] By performing a mock surgery using a bone model before surgery, the surgeon can confirm in advance how to use the bone resection tool 93, the bone resection procedure, the cutting state after the bone resection, etc. At this time, in order to properly determine whether the bone resection of the acetabulum 91 has been performed according to the preoperative plan, it is necessary to cut the bone model and check the cutting state. However, cutting the integrally formed bone model at a position suitable for checking the cutting state is time-consuming and difficult.

[0017] The bone model 10 according to the first embodiment of the present disclosure makes it possible to easily confirm whether the bone cutting was performed according to the preoperative plan after performing a simulated surgery using the bone model 10.

[0018] <Configuration of 10 bone models> The bone model 10 according to the first embodiment of the present disclosure is used in a simulated surgery for total hip replacement surgery, and includes a shape that simulates the acetabulum 91 of the pelvis 9.

[0019] 2 is a schematic diagram showing an example of a bone model 10 according to the first embodiment of the present disclosure. The view indicated by reference numeral 200A is a view from the acetabulum 101 side. The view indicated by reference numeral 200B is a view from the left side of the acetabulum 101. The view indicated by reference numeral 200C is a view from the right side of the acetabulum 101. The view indicated by reference numeral 200D is a view from the back side of the acetabulum 101.

[0020] 2, bone model 10 includes, for example, a shape that resembles one side of pelvis 9. For example, bone model 10 includes a shape that resembles acetabulum 101 that fits into the femur. The shape of bone model 10 is not limited to this, and it may be any shape that resembles the part of pelvis 9 that includes acetabulum 101 that is the target of bone resection.

[0021] The bone model 10 includes a first member 1, a second member 2, and a fixing portion 3. For example, the fixing portion 3 includes a block-shaped structure. The first member 1 includes a first dividing surface 11 (first cross section). The second member 2 includes a second dividing surface 21 (second cross section).

[0022] The bone model 10 has a shape that imitates the part of the pelvis 9 including the acetabulum 101 in a state where the first divided surface 11 and the second divided surface 21 are in contact with each other.

[0023] The fixing portion 3 fixes the first member 1 and the second member 2 so that they can be separated, with the first dividing surface 11 and the second dividing surface 21 abutting against each other. As will be described in detail later, the first member 1 and the second member 2 are fixed by the fixing portion 3 so that they can be easily separated. This allows the surgeon to perform bone resection during the simulated surgery with the members fixed and firmly joined together, and after the simulated surgery, release the fixation, separate the first member 1 and the second member 2, and check the state of the bone resection in the bone model 10.

[0024] The fixing portion 3 includes a first fixing portion 31 extending from the first member 1 and a second fixing portion 32 extending from the second member 2. For example, there is one fixing portion 3 in embodiment 1. The number of fixing portions 3 is not particularly limited, and there may be, for example, two or more fixing portions.

[0025] The first member 1 and the second member 2 have block portions (block-shaped structures). The bone model 10 is resected with the first dividing surface 11 and the second dividing surface 21 in contact with each other. By having the block portions in the bone model 10, the bone can be resected while the block portions are clamped with a vice or the like. The block portions may be, for example, a part or all of the fixing portion 3. The block portions may have a different configuration from the fixing portion 3.

[0026] Furthermore, the bone model 10 may include a marker attachment portion 102 (see FIG. 7) to which a marker 52 for detecting the position and posture of the bone model 10, which will be described later, is attached in a simulated navigation surgery for total hip replacement surgery. For example, the marker attachment portion 102 may be a mark or a depression that serves as a guide for the location where the marker is to be attached. The simulated navigation surgery will be described in detail later.

[0027] (10 divisions of bone model) 3 is a schematic diagram showing a state in which the bone model 10 has been divided. The diagram indicated by reference numeral 300A shows a state in which the bone model 10 has been joined. The diagram indicated by reference numeral 300B shows a divided second member 2. The diagram indicated by reference numeral 300C shows a divided first member 1.

[0028] 3, the first member 1 and the second member 2 are joined together with the first dividing surface 11 and the second dividing surface 21 in contact with each other. The bone model 10 can be easily divided by separating the first dividing surface 11 and the second dividing surface 21.

[0029] Fig. 4 is a schematic diagram showing the division surface of the bone model 10. As shown in Fig. 4, the first fixing portion 31 has a through-hole 311 formed by penetrating the first fixing portion 31, and the second fixing portion 32 has a through-hole 321 formed by penetrating the second fixing portion 32 and communicating with the through-hole 311.

[0030] The first member 1 and the second member 2 can be joined by inserting bolts into the through holes 311 and 321 and fastening them with nuts. Furthermore, the first member 1 and the second member 2 can be easily separated by removing the bolts and nuts. The joining method between the first member 1 and the second member 2 is not limited to this, and the first member 1 and the second member 2 may be joined by inserting, for example, a round bar-shaped member or the like into the through holes 311 and 321.

[0031] The bone model 10 is created by cutting an integrally molded object into two parts and then joining the two parts. Alternatively, the bone model 10 may be created by creating two parts separately and then joining the two parts. For example, the bone model 10 may be created by creating two parts by 3D printing and then joining the two parts. The bone model 10 may be made of, for example, a resin material or an inorganic material.

[0032] Although the bone model 10 is divided into two parts in the above example, the present invention is not limited to this. The bone model 10 may be divided into a plurality of parts, and may be divided into three or more parts.

[0033] Returning to Figure 3 for further explanation, the first divided surface 11 and the second divided surface 21 correspond to a plane that passes through the vicinity of the center of rotation of the hip joint when the first member 1 and the second member 2 are joined together. The first divided surface 11 and the second divided surface 21 correspond to a plane that is parallel to the body axis when the first member 1 and the second member 2 are joined together.

[0034] By making the first dividing surface 11 and the second dividing surface 21 correspond to a surface that passes through the vicinity of the center of rotation of the hip joint, the bone model 10 can be divided at the position where the width of the implant 92 to be attached is greatest, in other words, at the position where the thickness of the remaining bone is the thinnest. Therefore, the bone model 10 can be divided at a position suitable for checking the cutting state.

[0035] Furthermore, by making the first divided plane 11 and the second divided plane 21 correspond to a plane parallel to the body axis, the bone model 10 can be easily matched to a tomographic image of the pelvis 9 captured in a plane parallel to the body axis. This makes it easy to confirm whether the bone model 10 has been cut according to the preoperative plan.

[0036] The following description will be made with reference to Figure 4 again. As shown in Figure 4, the first divided surface 11 is configured to have at least one fitting protrusion 112 (protrusion) for alignment. On the other hand, the second divided surface 21 is configured to have at least one fitting hole 212 (hole) for alignment. When joining the first member 1 and the second member 2, the fitting protrusion 112 can be fitted into the fitting hole 212, thereby enabling the first member 1 and the second member 2 to be joined accurately. Alternatively, the first divided surface 11 may be provided with a fitting hole, and the second divided surface 21 may be provided with a fitting protrusion.

[0037] Furthermore, when dividing the bone model 10, the acetabulum 101 is also divided, so the first member 1 has a first acetabulum 15, and the second member 2 has a second acetabulum 25. As described above, the acetabulum 101 is divided along a plane that corresponds to a plane that passes through the vicinity of the center of rotation of the hip joint, so it is divided at a position that is suitable for checking the cutting state of the acetabulum 101.

[0038] The surface roughness of the divided surface 111, which is the surface of the first divided surface 11, is greater than the surface roughness of the outer surface 113, which is the surface other than the divided surface 111. The surface roughness of the divided surface 211, which is the surface of the second divided surface 21, is greater than the surface roughness of the outer surface 213, which is the surface other than the divided surface 211. This increases the friction force between the divided surfaces 111 and 211, making it difficult for the joining positions to shift. The outer surface 113 and the outer surface 213 are surfaces exposed to the outside when the first member 1 and the second member 2 are combined.

[0039] (Check cutting condition) 5 is a schematic diagram for explaining confirmation of the bone model 10 after bone cutting. The diagram indicated by reference numeral 500A is a diagram of the first member 1 before bone resection. The diagram indicated by reference numeral 500B is a diagram of the first member 1 after bone resection.

[0040] As shown in FIG. 5, when the bone model 10 is divided, the first divided surface 11 of the first member 1 can be visually confirmed. L1 in the diagram indicated by reference numeral 500A indicates the position where the first acetabulum 15 was resected by an imaginary line (see the diagram indicated by reference numeral 500B). For example, by comparing the bone thickness W1 before the resection with the bone thickness W2 after the resection, it is possible to easily confirm whether the resection was performed appropriately. Furthermore, the state of the second divided surface 21 of the second member 2 after the resection can also be confirmed.

[0041] (cortical bone and bone marrow regions) The bone model 10A may have cortical bone regions (first regions) 12, 22 and bone marrow regions (second regions) 13, 23 on the divided surfaces. The cortical bone regions 12, 22 are hard and dense regions corresponding to the areas forming the bone surface, etc., and the bone marrow regions 13, 23 are relatively soft regions corresponding to the areas forming the bone marrow inside the bone.

[0042] 6 is a schematic diagram showing an example of a cortical bone region and a bone marrow region of a bone model 10. The diagram indicated by reference numeral 600A is a schematic diagram of a first member 1A. The diagram indicated by reference numeral 600B is a schematic diagram of a second member 2A.

[0043] 6, the first member 1A has, on a first divided surface 11A, a cortical bone region 12 extending from an outer surface (external surface) 113 and a bone marrow region 13 surrounded by the cortical bone region 12. Meanwhile, the second member 2A also has, on a second divided surface 21A, a cortical bone region 22 extending from an outer surface (external surface) 213 and a bone marrow region 23. The first member 1A and the second member 2A are joined together with the bone marrow region 13 of the first member 1A and the bone marrow region 23 of the second member 2A abutting against each other.

[0044] The cortical bone regions 12 and 22 of the bone model 10A are harder than the bone marrow regions 13 and 23. This allows the simulated surgery to be performed with a feel similar to that of the patient's pelvis 9.

[0045] Furthermore, the cortical bone regions 12, 22 and the bone marrow regions 13, 23 are different in color. For example, the cortical bone regions 12, 22 are formed in a color that mimics cortical bone, such as a color close to white. For example, the bone marrow regions 13, 23 are formed in a color that mimics bone marrow, such as a color close to red. This allows the thickness of the remaining cortical bone regions 12, 22 to be visually confirmed based on the color of the divided surface of the bone model 10A, making it easy to confirm whether the bone resection is appropriate.

[0046] Although two fixing parts 3A are provided, this is not limiting. The bone model 10 may have only one fixing part 3A. The bone model 10 may have multiple fixing parts 3A. For example, the bone model 10 may have three or more fixing parts 3A.

[0047] The first fixing portions 31A1, 31A2 and the second fixing portions 32A1, 32A2 are formed with through holes 311A, 321A through which butterfly bolts or the like are inserted to join the first member 1A and the second member 2A together.

[0048] [Embodiment 2] A second embodiment of the present disclosure will be described below. For convenience of explanation, components having the same functions as those described in the first embodiment will be denoted by the same reference numerals, and the description thereof will not be repeated. The bone model 10B of the second embodiment is used in simulated navigation surgery for total hip replacement surgery.

[0049] First, a brief description will be given of navigation surgery for total hip replacement surgery. Figure 7 is a schematic diagram illustrating navigation surgery according to a second embodiment of the present disclosure. The diagram indicated by reference numeral 700A is a diagram illustrating a preoperative plan for navigation surgery, the diagram indicated by reference numeral 700B is a diagram of a marker 52 placed on the patient's hip joint, and the diagram indicated by reference numeral 700C is a diagram showing the positional relationship between the pelvis 9 and the bone resection instrument 93 displayed on the display screen 511.

[0050] As shown by the symbol 700A, before surgery, tomographic image data of the hip joint obtained by CT or the like is imported into a computer, and a three-dimensional model C of the hip joint is created using software for navigation surgery and displayed on the display screen 511 of the display device 51.

[0051] The practitioner performs preoperative examinations such as setting the position and angle of the bone resection, the size and placement position of the implant 92, etc., so that the bone resection can be performed accurately.

[0052] As shown by reference numeral 700B, during navigation surgery, markers 52 are placed on the patient's pelvis 9 and the bone resection instrument 93. The computer control unit analyzes images of the markers 52 and detects the positions and orientations of the markers 52, thereby identifying the positions and postures of the patient's pelvis 9 and the bone resection instrument 93.

[0053] As indicated by the reference symbol 700C, the control unit displays in real time the positional relationship between the pelvis 9 and the bone resection instrument 93 on the display screen 511. This makes it possible to more accurately cut the acetabulum 91, and to place the implant 92 according to the preoperative plan.

[0054] A simulated surgery can be performed as training for a surgeon to be able to perform a navigated surgery well. The simulated surgery for a navigated surgery can be performed using the display system 50.

[0055] The display system 50 includes a bone model 10B, a display device 51, a marker 52, and a computer that controls the display device 51 and the marker 52.

[0056] The bone model 10B is formed based on tomographic image data G of a deformed hip joint. The tomographic image data G is image data showing a sample example of a hip joint deformed due to, for example, an illness. The tomographic image data G is input into a computer, and three-dimensional model data C of the hip joint is generated based on the tomographic image data G. A control unit of the computer displays the generated three-dimensional model C on a display screen 511 of a display device 51.

[0057] The bone model 10B and the three-dimensional model data C are generated based on the same tomographic image data G. The three-dimensional model data C is the cross-sectional shape of the bone model 10B at the positions of the first divided surface 11B and the second divided surface 21B of the bone model 10B.

[0058] In the simulated surgery for navigation surgery, markers 52 are placed on the bone model 10B and the bone resection instrument 93. The computer control unit detects the positions and orientations of the bone model 10B and the bone resection instrument 93 by analyzing images of the markers 52.

[0059] The control unit displays the positional relationship between the bone model 10B and the bone resection tool 93 in real time on the display screen 511. The control unit also calculates the shape of the deleted bone model 10B and displays the cross-sectional shape of the bone model 10B on the display screen 511. The practitioner resects the bone model 10B while checking the data of the three-dimensional model data C displayed in real time on the display screen 511.

[0060] Since the bone model 10B and the three-dimensional model data C are generated based on the same tomographic image data G, the actual resection position of the bone model 10B can be matched with the resection position of the three-dimensional model data C displayed on the display screen 511.

[0061] Furthermore, after the simulated surgery, the surgeon can divide the bone model 10B and check whether the bone was resected according to the preoperative plan.

[0062] This allows the practitioner to receive training on how to use the navigation surgery device and how to perform bone resection in navigation surgery, and also allows the practitioner to check the state of bone resection by dividing the bone model 10B.

[0063] 〔summary〕 A bone model according to a first aspect of the present disclosure includes a first member having a first cross section, a second member having a second cross section that contacts the first cross section, and a fixing portion that fixes the first member and the second member in a state where the first cross section and the second cross section are in contact. This configuration allows the bone model to be divided and allows easy confirmation of whether the bone resection was successful as planned preoperatively.

[0064] In a bone model according to a second aspect of the present disclosure, a portion of the first member and a portion of the second member may have a block-like structure, and the fixing portion may be a portion or the entire block-like structure. With this configuration, the block-like structure can be clamped in a vise or the like to hold the entire bone model.

[0065] The bone model according to aspect 3 of the present disclosure is the bone model of aspect 1 or 2, wherein the fixing portion has a through hole and further has a bolt inserted through the through hole. According to the above configuration, the first member and the second member can be joined in a separable manner.

[0066] In the bone model according to aspect 4 of the present disclosure, in any one of aspects 1 to 3, the first cross section and the second cross section may have at least one of a projection and a hole that fit together. With this configuration, the first member and the second member can be accurately aligned and joined.

[0067] The bone model according to a fifth aspect of the present disclosure may be the bone model of the first aspect, which has a plurality of the fixing parts.

[0068] The bone model according to aspect 6 of the present disclosure is any one of aspects 1 to 5, wherein the first member and the second member have a shape that imitates the acetabulum of a pelvis when the first cross section and the second cross section are in contact with each other. According to the above configuration, the bone model can be used in simulated surgery for an artificial hip joint.

[0069] In a bone model according to aspect 7 of the present disclosure, in any one of aspects 1 to 6, the first cross section and the second cross section may be planes that pass through the vicinity of the center of rotation of the hip joint in the pelvis and correspond to planes parallel to the body axis. With this configuration, the bone model can be divided at a position suitable for checking.

[0070] In the bone model according to aspect 8 of the present disclosure, in aspect 6, the surface roughness of the first cross section and the second cross section may be greater than the surface roughness of the outer surface. With this configuration, the friction force between the first cross section and the second cross section increases, making it less likely for the bone model to shift position.

[0071] In a bone model according to a tenth aspect of the present disclosure, in the ninth aspect, the first region may be a different color from the second region. With this configuration, the state of bone resection can be more accurately and easily confirmed.

[0072] In the bone model according to aspect 11 of the present disclosure, in aspect 9 or 10, the first region may have a color that imitates cortical bone, and the second region may have a color that imitates bone marrow. This configuration makes it easy to check whether the placement position of an implant formed by bone resection is appropriate.

[0073] The bone model according to a twelfth aspect of the present disclosure is the bone model of any one of the ninth to eleventh aspects, wherein the second region of the first member and the second region of the second member may be in contact with each other.

[0074] In a bone model according to a thirteenth aspect of the present disclosure, the first region may be harder than the second region in any of the ninth to twelfth aspects. With this configuration, a simulated surgery can be performed with a feel similar to that of a patient's pelvis.

[0075] The bone model according to aspect 14 of the present disclosure is in any one of aspects 1 to 13, and includes a mounting portion for mounting a marker for detecting the posture of the bone model in a simulated surgery for navigation surgery of total hip replacement. With this configuration, the marker can be mounted at an appropriate position.

[0076] A display system according to aspect 15 of the present disclosure comprises a bone model according to aspect 1 and a display device that displays an image of a cross section of the bone model, wherein the bone model is formed based on a tomographic image of the bone, and the display device displays a cross-sectional shape of the bone model generated based on the tomographic image and at the positions of the first cross section and the second cross section.

[0077] According to the above configuration, the bone model can be used for training in navigation surgery, and the actual resection position of the bone model can be matched with the resection position of the 3D model displayed on the display device.

[0078] A display system according to aspect 16 of the present disclosure may be such that, in aspect 15, the display device detects the posture of the bone model and the surgical instrument during cutting based on markers attached to the bone model and the surgical instrument cutting the bone model, calculates the shape of the cut bone model, and displays the cross-sectional shape of the bone model.

[0079] According to the above configuration, the practitioner can resect the bone model while checking the image of the 3D model displayed in real time on the display screen, and can check on the display screen whether the bone resection was successful according to the preoperative plan.

[0080] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-described embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure. [Explanation of symbols]

[0081] 1 First member 10 bone models 102 Marker mounting part 11 1st dividing plane (1st cross section) 112 Fitting protrusion (protrusion) 12, 22 Cortical bone area (first area) 13, 23 Bone marrow area (second area) 2 Second member 21 Second dividing plane (second cross section) 212 Fitting hole (hole) 3 Fixed part 31 First fixed part (block-shaped structure) 311, 321 through holes 32 Second fixed part (block-shaped structure) 50 Display System 51 Display device 52 Marker 9 Pelvis 91 Acetabulum 93 Bone resection instruments

Claims

1. a first member having a first cross section; a second member having a second cross section in contact with the first cross section; a fixing portion that fixes the first member and the second member in a state in which the first cross section and the second cross section are in contact with each other; A bone model having

2. a portion of the first member and a portion of the second member have a block-like structure, The fixing portion is a part or the whole of the block-shaped structure. The bone model of claim 1 .

3. The fixing portion has a through hole, Further, a bolt is inserted through the through hole. The bone model of claim 1 .

4. The first cross section and the second cross section have at least one of a projection and a hole that fit together. The bone model of claim 1 .

5. A plurality of the fixing portions are provided. The bone model of claim 1 .

6. The first member and the second member have a shape that resembles an acetabulum of a pelvis when the first cross section and the second cross section are in contact with each other. The bone model of claim 1 .

7. The first cross section and the second cross section are planes that pass through the vicinity of a rotation center of a hip joint in the pelvis and correspond to a plane that is parallel to a body axis. The bone model according to claim 6.

8. The surface roughness of the first cross section and the second cross section is greater than the surface roughness of the outer surface. The bone model according to claim 6.

9. The first cross section and the second cross section each have a first region extending from an outer surface and a second region surrounded by the first region. The bone model according to claim 6.

10. The color of the first region is different from the color of the second region. The bone model according to claim 9.

11. the color of the first region is a color that simulates cortical bone; the color of the second region is a color simulating bone marrow; The bone model according to claim 10.

12. The second region of the first member and the second region of the second member are in contact with each other. The bone model according to claim 9.

13. the first region being stiffer than the second region; The bone model according to claim 9.

14. a mounting portion for mounting a marker for detecting the posture of the bone model; The bone model of claim 1 .

15. The bone model according to claim 1; a display device that displays an image of a cross section of the bone model, the bone model is formed based on a tomographic image of the bone; the display device displays a cross-sectional shape of the bone model generated based on the tomographic image and at the positions of the first cross section and the second cross section. Display system.

16. The display device includes: detecting the orientations of the bone model and the surgical instrument during cutting, based on markers attached to the bone model and the surgical instrument for cutting the bone model, calculating the shape of the cut bone model, and displaying the cross-sectional shape of the bone model; 16. The display system of claim 15.

Images