Computer-aided design of personalized lumbar interbody fusion device and its design and production method

Abstract

The present invention belongs to the field of osteotomy orthotics in orthopedics, and in particular relates to a computer-aided design of a personalized lumbar intervertebral fusion device and a design and manufacturing method thereof, which includes reconstructing a patient's lumbar vertebrae model, measuring the position parameters of the intervertebral fusion device to be implanted and the parameters of the vertebral body under the fusion device in the patient's lumbar vertebrae model; using modeling software, taking the normal vertebral body shape as a reference, and taking the measured intervertebral size parameters of the patient as a standard, designing the shape parameters of the intervertebral fusion device body; designing positioning wings on the fusion device body in combination with the size parameters of the vertebral body under the fusion device position; designing two nail holes on the intervertebral fusion device body and the positioning wings, respectively, and fixing the fusion device without notches; the main body adopts a mesh structure and a solid structure arranged in an alternating manner; and adopting 3D printing technology to manufacture the device. The present invention has the following beneficial effects: the lumbar intervertebral fusion device manufactured by the present invention has a moderate volume, and its position and fixing method are accurate and reliable, and the incision insertion of posterior pedicle screws is avoided, thereby realizing minimally invasive, precise, low-cost and short recovery time surgery.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices, and in particular relates to a computer-aided design of a personalized lumbar intervertebral fusion device and a design and manufacturing method thereof. Background Art

[0002] The most common site of lumbar disc herniation is the L4-5 intervertebral disc, accounting for 58%-62%; L5-S1 is the second, accounting for 38%-44%, and a very small number of discs occur above L3-4, and 5%-10% of cases occur in two intervertebral discs at the same time. The L5-S1 intervertebral disc is the two intervertebral discs at the bottom of the entire spine, which is the most concentrated part of the body's stress and bears the greatest pressure. The lumbar spine has a large range of motion, and the pulling force on the lower intervertebral disc, especially the fiber ring, is the greatest when the spine moves in various directions. Because the sacrum is fixed and does not participate in spinal movement, the sacrum does not produce corresponding coordinated buffering movements when the spine moves, and the activities of the upper segments of the spine are ultimately concentrated on the two lowest active segments. Therefore, the L4-5 intervertebral disc has the greatest chance of injury.

[0003] Lumbar fusion has a history of nearly 100 years. In 1911, ALBEE and HIBBS reported the method of posterior spinal fusion. With the continuous improvement and development of surgical approaches, instruments and bone graft materials, lumbar fusion has been continuously developed and improved, and has become a basic technology for the treatment of spinal degenerative diseases, deformities, trauma, tuberculosis and tumors. After years of clinical verification, it is generally believed that its efficacy is satisfactory.

[0004] At present, the fusion devices used in clinical practice are classified into horizontal cylindrical, square, vertical cylindrical, bullet-shaped, etc. according to their shapes. The commonly used surgical procedures include posterolateral (intertransverse process) vertebral fusion, posterior intervertebral fusion, transforaminal intervertebral fusion, anterior lumbar intervertebral fusion, 360° fusion, etc. Although there are various fusion procedures and fusion devices, the ideal lumbar fusion should try to meet the following requirements: simple approach, good surgical field exposure; high fusion rate, easy to restore intervertebral height, maintain the physiological curvature of the spine; convenient internal fixation, stable and reliable; good surgical effect.

[0005] However, the commonly used intervertebral fusion devices currently have a distraction function. After implantation, pedicle screws need to be inserted from the posterior approach to complete fixation, which cannot maintain the physiological curvature of the spine. The fixation is inconvenient and the stability and reliability are poor. In addition, since the spinal canal contains multiple nerves and blood vessels, the fixation risk is extremely high. Summary of the invention

[0006] To solve the problem of anterior placement of intervertebral fusion devices in the prior art and the fact that the current general lumbar intervertebral fusion devices are fixed in size and must be fixed with pedicle screws during implantation, which causes great trauma and slow recovery. The present invention provides a personalized lumbar intervertebral fusion device and a design and production method thereof, which is based on three-dimensional reconstruction of the patient's lumbar CT data, and measures the intervertebral length, width and height of the implanted fusion device, as well as the length, width and height of the normal vertebral body at the upper or lower end of the fusion device. The scope of surgery is determined according to the specific characteristics of the disease, and a personalized intervertebral fusion device is designed. Aiming at the anatomical characteristics of the patient's lumbar spine and surrounding soft tissues, combined with computer-aided design and 3D printing technology, a lumbar intervertebral fusion device that is completely consistent with the patient's individual size and shape is designed, and the guide holes reserved in the fusion device are used for screw fixation to avoid the risk of damaging the spinal canal and the posterior pedicle fixation incision, thereby achieving minimally invasive precision treatment.

[0007] The technical solution of the present invention is a method for designing and manufacturing a computer-aided personalized lumbar intervertebral fusion device, which is characterized by comprising the following steps:

[0008] Step 1: Reconstruct the patient's lumbar spine model, including the abnormal vertebral body and the upper and lower vertebral body models;

[0009] Step 2: Measure the position parameters of the intervertebral fusion cage to be implanted and the vertebral parameters under the fusion cage in the patient's lumbar spine model;

[0010] Step 3: Using modeling software, taking the normal vertebral shape as a reference and the measured intervertebral size parameters of the patient as a standard, design the main body shape parameters of the intervertebral fusion device;

[0011] Step 4: Design positioning wings on the fusion cage body based on the size parameters of the vertebral body under the fusion cage position;

[0012] Step 5: Design two nail holes on the intervertebral fusion device body and the positioning wing, respectively, and the two nail holes are arranged in a cross manner;

[0013] Step 6: The fusion device is fixed with a non-notch design to avoid damage to the surrounding soft tissue;

[0014] Step 7: The main body of the fusion device is designed with a mesh structure and a solid structure interlaced;

[0015] Step 8: 3D printing technology is used in production, and the material is metal.

[0016] Preferably, the patient's lumbar spine model reconstructed in step 1 also includes a sacrum model, specifically by collecting tomographic CT data of the patient's complete lumbar spine, storing it in DICOM image format, and establishing a three-dimensional lumbar spine model through three-dimensional reconstruction software.

[0017] Preferably, the patient's lumbar spine model reconstructed in step 1 also includes a sacrum model.

[0018] Preferably, the position parameters of the intervertebral fusion device to be implanted in the patient's lumbar spine model measured in step 2 include intervertebral length, width and height;

[0019] The parameters of the intervertebral fusion cage to be implanted in the patient's lumbar spine model were measured, including the length, width and height of the vertebral body under the cage.

[0020] Preferably, the modeling software in step 3 adopts mimics reconstruction software.

[0021] Preferably, in step 3, the intervertebral fusion cage body shape parameters are designed such that the cage length and width are 5-10 mm smaller than the intervertebral length and width, respectively, and the height range of the high fusion cage can fluctuate by 3 mm based on the measured height dimension.

[0022] Preferably, in step 8, the metal is titanium alloy.

[0023] A computer-aided design personalized lumbar intervertebral fusion device is characterized in that it includes an intervertebral fusion device body and a positioning wing, wherein the upper end of the positioning wing is connected to the lower end of the fusion device body, and the lower end of the positioning wing is attached to the surface of the lower vertebral body; two nail holes are designed on the intervertebral fusion device body and the positioning wing, and the two nail holes are respectively arranged in a cross manner.

[0024] Preferably, the center of the fusion device body adopts a hollow structure, and the outer surface of the fusion device body adopts a mesh structure and a solid structure arranged alternately;

[0025] Preferably, the mesh structure adopts a polygonal grid.

[0026] Preferably, the polygonal mesh is a mesh with an even number of edges;

[0027] Preferably, the entity structures are respectively arranged on both sides and upper and lower ends of the fusion device body;

[0028] Preferably, the nail cap position of the nail hole adopts a non-notch structure, and the non-notch structure adopts a countersunk hole;

[0029] Preferably, the intervertebral fusion device body and the positioning wings are provided with one or more pairs of nail holes;

[0030] Preferably, the intervertebral fusion device body is provided with auxiliary fixation holes;

[0031] Preferably, the positioning wing is provided with an auxiliary fixing hole.

[0032] The beneficial effects of the present invention are as follows: the lumbar intervertebral fusion device manufactured by the present invention has a moderate size, and its position and fixation method are accurate and reliable, and the incision insertion of posterior pedicle screws is avoided, thereby achieving minimally invasive surgery, low cost, short recovery time, and relatively few complications. The outer surface adopts a staggered design of a mesh structure and a solid structure to ensure the strength of the fusion device, and the mesh structure facilitates the growth of bone tissue and strengthens the fixation of the fusion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 2 is a schematic structural diagram of Embodiment 1 of the computer-aided design of a personalized lumbar intervertebral fusion device according to the present invention;

[0034] Figure 2 yes Figure 1 Rear view of

[0035] Figure 3 yes Figure 1 A top view of

[0036] Figure 4 yes Figure 1 Right view of;

[0037] Figure 5 It is a structural schematic diagram of Example 2 of the computer-aided design of a personalized lumbar intervertebral fusion device according to the present invention;

[0038] Figure 6 is a structural schematic diagram of Example 3 of the computer-aided design of a personalized lumbar intervertebral fusion device according to the present invention;

[0039] Figure 7 is a structural schematic diagram of Example 4 of a computer-aided design personalized lumbar intervertebral fusion device according to the present invention;

[0040] Figure 8 is a structural schematic diagram of Example 5 of the computer-aided design of a personalized lumbar intervertebral fusion device according to the present invention;

[0041] Fig. 9 Yes Yes Figure 8 Right view of .

[0042] In the figure, 1. intervertebral fusion device body, 2. positioning wing, 3. nail hole, 4. through hole, 5. mesh structure, 6. solid structure, 7. auxiliary fixation hole. DETAILED DESCRIPTION

[0043] A specific embodiment of the present invention is described below in conjunction with the accompanying drawings. A computer-aided design and manufacturing method for a personalized lumbar intervertebral fusion device comprises the following steps:

[0044] Step 1: Reconstruct the patient's lumbar spine model, including the abnormal vertebral body and the upper and lower vertebral body models;

[0045] Step 2: Measure the position parameters of the intervertebral fusion cage to be implanted and the vertebral parameters under the fusion cage in the patient's lumbar spine model;

[0046] Step 3: Using modeling software, taking the normal vertebral shape as a reference and the measured intervertebral size parameters of the patient as a standard, design the main body shape parameters of the intervertebral fusion device;

[0047] Step 4: Design positioning wings on the fusion cage body based on the size parameters of the vertebral body under the fusion cage position;

[0048] Step 5: Design two nail holes on the intervertebral fusion device body and the positioning wing, respectively, and the two nail holes are arranged in a cross manner;

[0049] Step 6: The fusion device is fixed with a non-notch design to avoid damage to the surrounding soft tissue;

[0050] Step 7: The main body of the fusion device is designed with a mesh structure and a solid structure interlaced;

[0051] Step 8: 3D printing technology is used in production, and the material is metal.

[0052] The patient's lumbar spine model reconstructed in step 1 also includes a sacrum model. Specifically, the tomographic CT data of the patient's complete lumbar spine is collected, stored in a DICOM image format, and a three-dimensional lumbar spine model is established through three-dimensional reconstruction software.

[0053] The patient's lumbar spine model reconstructed in step 1 also includes a sacrum model.

[0054] In step 2, the position parameters of the intervertebral fusion device to be implanted in the patient's lumbar spine model are measured, including the intervertebral length, width and height;

[0055] The parameters of the intervertebral fusion cage to be implanted in the patient's lumbar spine model were measured, including the length, width and height of the vertebral body under the cage.

[0056] In step 3, the modeling software used is mimics reconstruction software.

[0057] In step 3, the external shape parameters of the intervertebral fusion device are designed. Specifically, the length and width of the device are 5 to 10 mm smaller than the length and width of the intervertebral space, respectively. The height range of the device can fluctuate up and down by 3 mm based on the measured height dimension.

[0058] In step 8, the metal is titanium alloy.

[0059] A computer-aided design personalized lumbar intervertebral fusion device is characterized in that it includes an intervertebral fusion device body 1 and a positioning wing 2, the intervertebral fusion device body 1 and the positioning wing 2 are integrally formed, the upper end of the positioning wing 2 is connected to the lower end of the fusion device body 1, and the lower end of the positioning wing 2 is attached to the surface of the lower vertebral body; nail holes 3 are set on the intervertebral fusion device body 1 and the positioning wing 2.

[0060] The center of the fusion device body 1 adopts a hollow structure, and a through hole 4 is arranged at the center of the fusion device body 1 .

[0061] The outer surface of the fusion device body is provided with a mesh structure 5 and a solid structure 6 arranged alternately.

[0062] The nail holes 3 are arranged in pairs, and the pairs of nail holes 3 are arranged in a cross manner.

[0063] The mesh structure 5 adopts a polygonal mesh.

[0064] The polygon mesh has an even number of edges.

[0065] The entity structure 6 is respectively arranged on both sides and the upper and lower ends of the fusion device body.

[0066] The nail cap position of the nail hole 3 adopts a non-notch structure, and the non-notch structure adopts a countersink.

[0067] One or more pairs of nail holes are arranged on the intervertebral fusion device body 1 and the positioning wings 2 .

[0068] The intervertebral fusion device body 1 is provided with auxiliary fixation holes 7 , and the auxiliary fixation holes 7 are used to assist in fixation of the intervertebral fusion device body 1 .

[0069] The positioning wing 1 is provided with an auxiliary fixing hole 7, which is used to assist in fixing the positioning wing 1 to the lower vertebral body.

[0070] Example 1

[0071] A computer-aided design method for designing and manufacturing a personalized lumbar intervertebral fusion device, characterized by comprising the following steps:

[0072] Step 1: Reconstruct the patient's lumbar spine model, including the abnormal vertebra and the upper and lower vertebrae, and the sacrum if necessary;

[0073] Step 2: Measure the position parameters of the intervertebral fusion cage to be implanted in the model, including the intervertebral length, width and height, and also measure the length, width and height of the vertebral body under the cage;

[0074] Step 3: Using modeling software, with the normal vertebral shape as a reference and the patient's intervertebral dimension parameters measured as a standard, the main body shape of the intervertebral fusion device is designed. The length and width of the fusion device are 5-10mm smaller than the intervertebral length and width respectively, and the height range can fluctuate up and down by 3mm based on the measured height dimension;

[0075] Step 4: Based on the size parameters of the vertebral body under the fusion device, design the fusion device positioning wing to achieve the position fixation during vertebral implantation, wherein the upper end of the positioning wing is connected to the fusion device, and the lower end is attached to the surface of the lower vertebral body;

[0076] Step 5: Design two nail holes on the main body and positioning wings of the intervertebral fusion device, respectively, in a cross-shaped manner, and require that the nail holes penetrate the pedicles without damaging the spinal canal;

[0077] Step 6: The fusion device is fixed with a non-notch design to avoid damage to the surrounding soft tissue;

[0078] Step 7: The main body of the fusion device is designed with a mesh structure and a solid structure in an alternating manner. The solid structure ensures the strength of the fusion device, and the mesh structure facilitates the growth of bone tissue and strengthens the fixation of the fusion device.

[0079] Step 8: 3D printing technology is used during processing, and the material is metal titanium alloy.

[0080] A computer-aided design personalized lumbar intervertebral fusion device is characterized in that it includes an intervertebral fusion device body 1 and a positioning wing 2, the intervertebral fusion device body 1 and the positioning wing 2 are integrally formed, the upper end of the positioning wing 2 is connected to the lower end of the fusion device body 1, and the lower end of the positioning wing 2 is attached to the surface of the lower vertebral body; nail holes 3 are set on the intervertebral fusion device body 1 and the positioning wing 2.

[0081] The center of the fusion device body 1 adopts a hollow structure, and a through hole 4 is arranged at the center of the fusion device body 1 .

[0082] Example 2

[0083] In addition to the technical solution of embodiment 1, the following technical solutions are also included:

[0084] The outer surface of the fusion device body is provided with a mesh structure 5 and a solid structure 6 arranged alternately.

[0085] The nail holes 3 are arranged in pairs, and the pairs of nail holes 3 are arranged in a cross manner.

[0086] The mesh structure 5 adopts a polygonal mesh;

[0087] The polygon mesh has an even number of edges.

[0088] The entity structure 6 is respectively arranged on both sides and the upper and lower ends of the fusion device body.

[0089] Example 3

[0090] In addition to the technical solution of Example 2, the following technical solutions are also included:

[0091] The nail cap position of the nail hole 3 adopts a non-notch structure, and the non-notch structure adopts a countersink.

[0092] A pair of nail holes are arranged on the intervertebral fusion device body 1 and the positioning wings 2 .

[0093] The positioning wing 1 is provided with a pair of auxiliary fixing holes 7 .

[0094] Example 4

[0095] In addition to the technical solution of Example 2, the following technical solutions are also included:

[0096] The nail cap position of the nail hole 3 adopts a non-notch structure, and the non-notch structure adopts a countersink.

[0097] A pair of nail holes are arranged on the intervertebral fusion device body 1 and the positioning wings 2 .

[0098] The intervertebral fusion device body 1 is provided with a pair of auxiliary fixing holes 7 .

[0099] Example 5

[0100] This embodiment is a personalized lumbar intervertebral fusion device used in cases of lumbar sacral tuberculosis.

[0101] 1. Use mimics reconstruction software to reconstruct the lumbar sacral model between L4 and sacrum;

[0102] 2. Measure the parameters of L5 eroded by tuberculosis, namely the size of the sacral endplate and the residual L5 vertebral body. The length of the sacral endplate is 42mm, the width is 28mm, the height is 27mm in the front and 19mm in the back.

[0103] 3. The length of the contact surface between the fusion device and the sacrum is designed to be 32mm, with a 5mm gap between the two ends and the upper end plate of the sacrum; the width is designed to be 22mm, that is, the front side is flush with the front side of the upper end plate of the sacrum, and the back side is 5mm; the height is designed according to the actual height of the gap between L5 and the sacrum, that is, the front height is 27mm and the back height is 19mm;

[0104] 4. The upper end of the fusion device positioning wing is connected to the main body, and the inner side is attached to the anterior surface of the sacrum. The length is 27mm and the thickness is 2mm.

[0105] 5. Two screw holes are designed on the main body of the fusion device, and the holes avoid the position of the tapered holes, so that the screws can be inserted crosswise and implanted into the pedicles respectively; two screw holes are designed on the positioning wings to assist fixation, and the screws are also implanted into the pedicles;

[0106] 6. The nail cap position adopts a non-notch design to avoid the nail cap protruding and abrading the soft tissue;

[0107] 7. The center of the fusion device is hollow, and the outer surface is staggered with mesh and solid structures. The solid structure ensures the strength of the fusion device, and the mesh structure facilitates the growth of bone tissue and strengthens the fixation of the fusion device.

[0108] 8. 3D printing technology is used during processing, and the material is metal titanium alloy.

[0109] A computer-aided design personalized lumbar intervertebral fusion device is characterized in that it includes an intervertebral fusion device body 1 and a positioning wing 2, the intervertebral fusion device body 1 and the positioning wing 2 are integrally formed, the upper end of the positioning wing 2 is connected to the lower end of the fusion device body 1, and the lower end of the positioning wing 2 is attached to the surface of the lower vertebral body; nail holes 3 are set on the intervertebral fusion device body 1 and the positioning wing 2.

[0110] The center of the fusion device body 1 adopts a hollow structure, and a through hole 4 is arranged at the center of the fusion device body 1 .

[0111] The outer surface of the fusion device body is provided with a mesh structure 5 and a solid structure 6 arranged alternately.

[0112] The nail holes 3 are arranged in pairs, and the pairs of nail holes 3 are arranged in a cross manner.

[0113] The mesh structure 5 adopts a polygonal mesh;

[0114] The polygon mesh has an even number of edges.

[0115] The entity structure 6 is respectively arranged on both sides and the upper and lower ends of the fusion device body.

[0116] The nail cap position of the nail hole 3 adopts a non-notch structure, and the non-notch structure adopts a countersink.

[0117] A pair of nail holes are arranged on the intervertebral fusion device body 1 and the positioning wings 2 .

[0118] The intervertebral fusion cage body 1 is provided with auxiliary fixing holes 7 .

[0119] The positioning wing 1 is provided with an auxiliary fixing hole.

[0120] Compared with the prior art, the lumbar intervertebral fusion device designed and manufactured using the present invention has a moderate size, and its position and fixation method are accurate and reliable, avoiding the incision placement of posterior pedicle screws, realizing minimally invasive surgery, low cost, short recovery time, and relatively few complications. The outer surface adopts a staggered design of a mesh structure and a solid structure to ensure the strength of the fusion device, and the mesh structure facilitates the growth of bone tissue and strengthens the fixation of the fusion device.

Claims

1. A method for designing and manufacturing a computer-aided personalized lumbar intervertebral fusion device, characterized in that: The following steps are involved: Step 1: Reconstruct the patient's lumbar spine model, including the abnormal vertebral body and the upper and lower vertebral body models, and also the sacrum model. Specifically, the tomographic CT data of the patient's complete lumbar spine is collected, stored in the DICOM image format, and a three-dimensional lumbar spine model is established through three-dimensional reconstruction software; Step 2: Measure the position parameters of the intervertebral fusion cage to be implanted and the vertebral parameters under the fusion cage in the patient's lumbar spine model; Step 3: Using modeling software, taking the normal vertebral shape as a reference and the measured intervertebral size parameters of the patient as a standard, design the main body shape parameters of the intervertebral fusion device; Step 4: Design positioning wings on the fusion cage body based on the size parameters of the vertebral body under the fusion cage position; Step 5: Two nail holes are designed on the intervertebral fusion device body and the positioning wings, and the two nail holes are arranged in a cross manner; the personalized lumbar intervertebral fusion device prosthesis includes an intervertebral fusion device body and positioning wings, the upper end of the positioning wings is connected to the lower end of the fusion device body, the lower end of the positioning wings is attached to the surface of the lower vertebral body, and the inner side is attached to the anterior surface of the sacrum; the intervertebral fusion device body and the positioning wings are designed in pairs, and the paired nail holes are arranged in a cross manner; Step 6: The fusion device is fixed with a non-notch design to avoid damage to the surrounding soft tissue; Step 7: The main body of the fusion device is designed with a mesh structure and a solid structure interlaced; Step 8: 3D printing technology is used in production, and the material is metal.

2. The method for designing and manufacturing a computer-aided personalized lumbar intervertebral fusion device according to claim 1, characterized in that: In step 2, the position parameters of the intervertebral fusion device to be implanted in the patient's lumbar vertebrae model include the intervertebral length, width and height; the parameters of the intervertebral fusion device to be implanted in the patient's lumbar vertebrae model include the length, width and height of the vertebral body under the fusion device.

3. The method for designing and manufacturing a computer-aided personalized lumbar intervertebral fusion device according to claim 1, characterized in that: In step 3, the modeling software used is mimics reconstruction software.

4. The method for designing and manufacturing a computer-aided personalized lumbar intervertebral fusion device according to claim 3, characterized in that: In step 3, the external shape parameters of the intervertebral fusion device are designed. Specifically, the length and width of the device are 5 to 10 mm smaller than the length and width of the intervertebral space, respectively. The height range of the device can fluctuate up and down by 3 mm based on the measured height dimension.

5. The method for designing and manufacturing a computer-aided personalized lumbar intervertebral fusion device according to claim 1, characterized in that: In step 8, the metal is titanium alloy.

6. A prosthesis using the computer-aided design and manufacturing method of a personalized lumbar intervertebral fusion device according to claims 1 to 5, characterized in that: It includes an intervertebral fusion device body and a positioning wing, wherein the upper end of the positioning wing is connected to the lower end of the fusion device body, and the lower end of the positioning wing is attached to the surface of the lower vertebral body; two nail holes are designed on the intervertebral fusion device body and the positioning wing, and the two nail holes are arranged in a cross manner.

7. The computer-aided design personalized lumbar intervertebral fusion device according to claim 6, characterized in that: The center of the fusion device body adopts a hollow structure, and the outer surface of the fusion device body adopts a mesh structure and a solid structure arranged alternately; the mesh structure adopts a polygonal grid; the solid structure is respectively arranged on both sides and the upper and lower ends of the fusion device body; the nail cap position of the nail hole adopts a non-notch structure, and the non-notch structure adopts a countersunk hole.

8. The computer-aided design personalized lumbar intervertebral fusion device according to claim 7, characterized in that: The intervertebral fusion device body is provided with an auxiliary fixation hole; and / or the positioning wing is provided with an auxiliary fixation hole.

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