Acetabular cover prosthesis and manufacturing method thereof

Abstract

The present invention discloses an acetabular cover prosthesis and a manufacturing method thereof, belonging to the technical field of prosthesis replacement. The acetabular cover prosthesis comprises an acetabular top and an acetabular side portion integrally arranged with the acetabular top, the acetabular top has an arcuate groove concave inwardly and conforming to the femoral head, the acetabular side portion has a joint surface conforming to the outer surface of the hip bone, the acetabular side portion is provided with a screw through hole for fixing with the hip bone, the acetabular top and the acetabular side portion are both porous tantalum structures using 3D printing, and a through-hole reinforcement structure is provided in the screw through hole. 3D printing is combined with femoral head plastic surgery to adjust the concentric circle relationship between the acetabulum and the femoral head, so the surgical indications of this procedure are wider than PAO; at the same time, the method is simple to operate, and a high degree of fit with the femur or acetabulum can be achieved without trimming and osteotomy, and has the advantages of short operation time, less bleeding, and low risk; in addition, the present invention adopts a porous tantalum structure, which is conducive to bone growth to form a reliable connection and improves the bonding strength.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to an acetabular cover prosthesis and a manufacturing method thereof. Background Art

[0002] The hip joint is composed of the femoral head and the acetabulum. It is a ball-and-socket joint and a typical bar-and-acetabulum joint. Hip arthritis usually refers to a type of osteoarthritis caused by long-term uneven weight bearing on the hip joint surface, resulting in degeneration of the articular cartilage or changes in bone structure. Its main manifestations include pain in the lateral buttocks, groin and other parts (which may radiate to the knee), swelling, joint effusion, cartilage wear, bone spur hyperplasia, joint deformation, limited internal rotation and extension of the hip, inability to walk or even bedridden, etc.

[0003] The most classic surgical method for severe hip joint diseases is the Bern periacetabular osteotomy (PAO) first reported by Ganz et al. This procedure increases the coverage of the acetabulum on the femoral head by adjusting the direction of the acetabulum after osteotomy, provides more mechanical support for the femoral head, and reconstructs the mechanical structure, which can effectively stop or prevent the progression of osteoarthritis.

[0004] However, PAO surgery requires bone harvesting from the human body, and requires osteotomy and trimming to achieve a concentric relationship with the femur or acetabulum. The operation is complex, traumatic, risky, and has a long learning curve. The complication rate is as high as 15%, which has serious physiological and psychological effects on patients.

[0005] Therefore, it is necessary to develop an acetabular cover prosthesis to replace human bones, so that the operation no longer requires bone removal, significantly reducing surgical wounds and pain, and through special manufacturing methods, it can be highly matched with the femur or acetabulum without trimming, with a high degree of matching, and the use of special materials can have a strong level of bonding with human bones, creating conditions for improving the success rate of surgery and reducing surgical risks for patients with hip joint diseases. Summary of the invention

[0006] In view of this, an object of the present invention is to provide an acetabular cover prosthesis and a manufacturing method thereof.

[0007] One of the purposes of the present invention is achieved through the following scheme:

[0008] An acetabular cover prosthesis comprises an acetabular top and an acetabular side portion integrally arranged with the acetabular top, the acetabular top having an arcuate groove which is concave inwardly and conforms to the femoral head, the acetabular side portion having a joint surface which conforms to the outer surface of the hip bone, the acetabular side portion being provided with a screw through hole for fixing with the hip bone, the acetabular top and the acetabular side portion being both porous tantalum structures printed by 3D printing, and a through-hole reinforcement structure being provided in the screw through hole.

[0009] Furthermore, the via reinforcement structure is a solid wall.

[0010] Furthermore, the thickness of the solid wall is 0.3-0.6 mm.

[0011] Furthermore, the mesh size of the porous tantalum structure is 400-600 μm.

[0012] Furthermore, there are three screw through holes in total, and the three screw through holes are arranged on the side of the acetabulum at intervals and not parallel to each other.

[0013] Furthermore, the diameter of the screw through hole is 4-6 mm.

[0014] The second object of the present invention is achieved by the following scheme

[0015] The above-mentioned method for manufacturing an acetabular cover prosthesis comprises the following steps:

[0016] 1) Establish a hip joint model: Use CT or MRI technology to extract hip joint data information, and reversely generate a three-dimensional mathematical model based on the hip joint data information;

[0017] 2) Establishing the acetabular cover model:

[0018] I. Determine the acetabular cover layout area based on a three-dimensional mathematical model;

[0019] II. extracting the hip surface curve in the acetabular cover arrangement area, that is, forming the acetabular side curve;

[0020] III. Determine the acetabular surface and its center;

[0021] IV. Determine the spherical surface of the femoral head and its center;

[0022] V. Adjust the center of the acetabulum surface and the center of the femoral head sphere to the same point;

[0023] VI. The spherical surface of the femoral head is equidistant and level with the acetabular surface. Then the equidistant surface is intercepted through the acetabular cover layout area to form the acetabular top curved surface.

[0024] VII. Smoothly fit the lateral curved surface of the acetabulum and the top curved surface of the acetabulum into a whole piece, that is, to form the overall curved surface of the acetabulum cover.

[0025] VIII. The overall curved surface of the acetabular cover is 4-6 mm apart to form an acetabular cover model;

[0026] VIIII. Punch screw holes on the acetabular cover model, thus completing the establishment of the acetabular cover model;

[0027] 3) Establishing the acetabular cover printing model:

[0028] The acetabular cover model was generated into a porous structure with a mesh size of 400-600 μm using three-dimensional software;

[0029] 4) Prepare the printing program: import the STL file of the printing model into the 3D printing device, perform slicing, obtain the cross-sectional graphics that need to be printed, and design the plane printing path according to the cross-sectional graphics;

[0030] 5) Print:

[0031] I. Toner preparation: After the tantalum powder is mixed into a particle ratio, it is loaded into the toner storage area and connected to the toner nozzle through the conveying system;

[0032] II. Printing: In an argon atmosphere, the first layer is printed on the printing table along the printing path, and then the laser or electron beam is used to heat and melt the fusion layer and consolidate it; then, on the basis of the first consolidated layer, the second consolidated layer and the third consolidated layer are stacked until the prosthesis is formed; during this process, the heat preservation device in the printing table is turned on to keep the contact surface with the prosthesis at the same temperature as the prosthesis;

[0033] 6) Cooling: After printing is completed, the printing table is rotated for air cooling;

[0034] 7) After cooling, remove the prosthesis and printing is completed.

[0035] Furthermore, the acetabular cover arrangement area is set based on the following: at least two rows of screw holes can be set in the top of the acetabular cover prosthesis and the combined inclusion area 3 / 4-4 / 5 of the acetabular cover for the anterior-posterior position of the femoral head and the side of the acetabular cover prosthesis.

[0036] Furthermore, the acetabular cover arrangement area is set based on: the angle between the line from the edge of the acetabular cover prosthesis to the center of the femoral head and the line from the side of the hip bone to the center of the femoral head is 30-35°.

[0037] Furthermore, in step 3), the solid wall of the screw hole should be kept with a thickness of 0.3-0.6 mm.

[0038] The beneficial effects of the present invention are:

[0039] The present invention uses 3D personalized customization to make the top of the acetabulum have an arc-shaped groove that is concave inward and conforms to the femoral head, and the side of the acetabulum has a joint surface that conforms to the outer surface of the hip bone, so that the head and acetabulum match very well. 3D printing combined with femoral head plasty is used to adjust the concentric circle relationship between the acetabulum and the femoral head. Therefore, the surgical indications of this procedure are wider than PAO; at the same time, the method is simple to operate, and a high degree of fit with the femur or acetabulum can be achieved without trimming and osteotomy. Compared with PAO, it has the advantages of short operation time, less bleeding, and low risk; in addition, the present invention adopts a porous tantalum structure, and the porous tantalum has good affinity with human bones, which is conducive to bone ingrowth to form a reliable connection, thereby improving the bonding strength and increasing the success rate of the operation.

[0040] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0042] Figure 1 A three-dimensional schematic diagram of an acetabular cover prosthesis according to the present invention;

[0043] Figure 2 It is a schematic diagram of another direction of an acetabular cover prosthesis of the present invention;

[0044] Figure 3 The printed finished product diagram of the present invention;

[0045] Figure 4 This is a schematic diagram of the present invention after being combined with human bones;

[0046] Figure 5 It is a schematic diagram of another direction after the present invention is combined with human bone;

[0047] Figure 6 It is the overall surface diagram of the acetabular cover;

[0048] Figure 7 This is a CT scan of the hip joint;

[0049] Figure 8 A three-dimensional schematic diagram of the hip joint;

[0050] Fig. 9 A three-dimensional schematic diagram of the hip joint in another direction;

[0051] Fig.10 Schematic diagram of the triangular patch of the hip joint;

[0052] Fig.11 is a schematic diagram of a hip joint;

[0053] Fig.12 To determine the schematic diagram of the acetabular surface and its center;

[0054] Fig.13 To determine the schematic diagram of the spherical surface of the femoral head and its center;

[0055] Fig.14 Set up a schematic diagram for the acetabular cover layout area;

[0056] Fig.15 Setting another schematic diagram for the acetabular cover placement area;

[0057] Fig.16 These are the X-rays before and after surgery for the first patient;

[0058] Fig.17 These are the X-rays of the second patient before and after surgery;

[0059] Fig.18 These are the X-rays before and after surgery for the third patient;

[0060] Fig.19 These are the X-rays before and after surgery for the fourth patient;

[0061] Fig. 20 These are the X-rays before and after surgery for the fifth patient;

[0062] Fig.21 These are the X-rays before and after surgery for the sixth patient;

[0063] Fig. 22 These are the X-rays of the seventh patient before and after surgery. DETAILED DESCRIPTION

[0064] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0065] like Figure 1-15 As shown, an acetabular cover prosthesis 9 of the present invention comprises an acetabular top 1 and an acetabular side 2, the acetabular top and the acetabular side are integrally arranged, and both are porous tantalum structures using 3D printing:

[0066] The top of the acetabulum has an arc-shaped groove 3 which is concave inward and conforms to the femoral head 7. The arc-shaped groove forms a rotational fit with the femoral head to achieve joint connection, increase the coverage of the acetabulum on the femoral head, provide more mechanical support for the femoral head, rebuild the mechanical structure, and effectively stop or prevent the progression of osteoarthritis.

[0067] The acetabulum side has a joint surface 4 that conforms to the outer surface of the hip bone 8. The joint surface fits the hip bone, which can improve the combination level between the prosthesis and the hip bone and enhance the stability of fixation.

[0068] In this embodiment, in order to further improve the reliability of fixation, a screw through hole 5 is provided on the side of the acetabulum, and the screw is passed through the screw through hole and fixed with the hip bone thread, and its binding force is greatly improved;

[0069] In addition, a solid wall 6 with a thickness of 0.3-0.6 mm is provided in the screw hole. The bearing capacity of the solid wall is much higher than that of the porous structure. Therefore, the solid wall can enhance the structural rigidity of the screw hole and reduce the risk of damage to the screw hole.

[0070] As an improvement of this embodiment, the mesh size of the porous tantalum structure is 400-600 μm.

[0071] As an improvement of this embodiment, three screw through holes are provided in total, and the three screw through holes are provided on the side of the acetabulum at intervals and not parallel to each other, that is, the three screw through holes are not on the same straight line, thereby improving the overall structural level.

[0072] As an improvement of this embodiment, the diameter of the screw through hole is 4-6 mm.

[0073] The present invention also provides a method for manufacturing an acetabular cover prosthesis, comprising the following steps:

[0074] 1) Establish a hip joint model: Use CT or MRI technology to extract hip joint data information, and reversely generate a three-dimensional mathematical model based on the hip joint data information, such as Figure 7-Figure 11 As shown,

[0075] 2) Establishing the acetabular cover model:

[0076] I. Determine the acetabular cover layout area based on the three-dimensional mathematical model; the acetabular cover layout area is set based on: the combined inclusion area of ​​the acetabular cover prosthesis acetabular top and the acetabular cover to the femoral head in the anteroposterior position is 3 / 4-4 / 5, that is, the sum of the acetabular cover prosthesis acetabular top and the femoral head in the anteroposterior position and the acetabular cover and the femoral head in the anteroposterior position is 3 / 4-4 / 5 of the total anteroposterior area of ​​the femoral head. Fig.15 As shown, the coverage level is ensured; in addition, it is also necessary to ensure that at least two rows of screw holes can be set on the acetabular side of the acetabular cover prosthesis. Through the two rows of screw holes, the level of integration with the human bone can be improved, and the reliability of fixation can be further improved.

[0077] II. extracting the hip surface curve in the acetabular cover arrangement area, that is, forming the acetabular side curve;

[0078] III. Determine the acetabular surface and its center, such as Fig.12 As shown;

[0079] IV. Determine the spherical surface of the femoral head and its center, such as Fig.13 As shown;

[0080] V. Adjust the center of the acetabulum surface and the center of the femoral head sphere to the same point;

[0081] VI. The spherical surface of the femoral head is equidistant and level with the acetabular surface. Then the equidistant surface is intercepted through the acetabular cover layout area to form the acetabular top surface, such as Figure 6 As shown;

[0082] VII. Smoothly fit the lateral curved surface of the acetabulum and the top curved surface of the acetabulum into a whole piece, that is, to form the overall curved surface of the acetabulum cover. The transition must be smooth and without edges and corners;

[0083] VIII. The overall curved surface of the acetabular cover is 4-6 mm apart to form an acetabular cover model;

[0084] VIIII. Punch screw holes on the acetabular cover model, thus completing the establishment of the acetabular cover model;

[0085] 3) Establishing the acetabular cover printing model:

[0086] Use 3D software, such as the lattice command in UG, to generate a porous structure with a mesh size of 400-600 μm from the acetabular cover model; during this process, the solid wall with a screw hole thickness of 0.3-0.6 mm needs to be maintained;

[0087] 4) Prepare the printing program: import the STL file of the printing model into the 3D printing device, perform slicing processing, obtain the cross-sectional graphics that need to be printed, and design the plane printing path according to the cross-sectional graphics;

[0088] 5) Print:

[0089] I. Toner preparation: After the tantalum powder is mixed into a particle ratio, it is loaded into the toner storage area and connected to the toner nozzle through the conveying system;

[0090] II. Printing: In an argon atmosphere, the first layer is printed on the printing table along the printing path, and then the laser or electron beam is used to heat and melt the fusion layer and consolidate it; then, on the basis of the first consolidated layer, the second consolidated layer and the third consolidated layer are stacked until the prosthesis is formed; during this process, the heat preservation device in the printing table is turned on to keep the contact surface with the prosthesis at the same temperature as the prosthesis;

[0091] 6) Cooling: After printing is completed, the printing table is rotated for air cooling;

[0092] 7) After cooling, remove the prosthesis. Figure 3 As shown, printing ends.

[0093] Furthermore, the acetabular cover layout area is set based on: the angle between the line from the edge of the acetabular cover prosthesis to the center of the femoral head and the line from the side of the hip bone to the center of the femoral head is 30-35°. Fig.14 In this way, the edge of the acetabular cover prosthesis can be restricted to prevent it from being too long, which may interfere with the femur and affect the movement during joint movement.

[0094] Using the above scheme, a total of 10 cases were completed clinically from September 2018 to September 2019. Figure 16-22 A total of seven cases were shown, with an average age of 18 years old. A high degree of fit with the femur or acetabulum was achieved without trimming and osteotomy, the average operation time was reduced by 30%, and the success rate was 100%.

[0095] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for manufacturing an acetabular cover prosthesis, the acetabular cover prosthesis comprising an integrally arranged acetabular top and acetabular side, both of which are 3D-printed porous tantalum structures, the acetabular top having an arc-shaped groove that is concave inward and conforms to the femoral head, the acetabular side having a joint surface that conforms to the outer surface of the hip bone, the acetabular side having a screw through hole for fixing with the hip bone, a through hole reinforcement structure being arranged in the screw through hole, the through hole reinforcement structure being a solid wall, the acetabular top being located on a side of the acetabular side away from the hip bone, the method comprising the following steps: 1) Establish a hip joint model: Use CT or MRI technology to extract hip joint data information, and reversely generate a three-dimensional mathematical model based on the hip joint data information; 2) Establishing the acetabular cover model: I. Determine the acetabular cover layout area based on the three-dimensional mathematical model, based on: The sum of the top of the acetabular cover prosthesis and the anterior-posterior wrapping area of ​​the acetabular cover and the femoral head is 3 / 4-4 / 5 of the total anterior-posterior area of ​​the femoral head. At least two rows of screw holes are arranged on the side of the acetabulum of the acetabular cover prosthesis, and the angle between the line connecting the edge of the acetabulum top away from the hip bone to the center of the femoral head and the line connecting the side of the hip bone and the center of the femoral head is 30-35 degrees; II. extracting the hip surface curve in the acetabular cover arrangement area, that is, forming the acetabular side curve; III. Determine the acetabular surface and its center; IV. Determine the spherical surface of the femoral head and its center; V. Adjust the center of the acetabulum surface and the center of the femoral head sphere to the same point; VI. The spherical surface of the femoral head is equidistant and level with the acetabular surface. Then the equidistant surface is intercepted through the acetabular cover layout area to form the acetabular top curved surface. VII. Smoothly fit the lateral curved surface of the acetabulum and the top curved surface of the acetabulum into a whole piece, that is, to form the overall curved surface of the acetabulum cover. VIII. The overall curved surface of the acetabular cover is 4-6 mm apart to form an acetabular cover model; VIIII. Punch screw holes on the acetabular cover model, thus completing the establishment of the acetabular cover model; 3) Create a printed model of the acetabular cover: The acetabular cover model was generated into a porous structure with a mesh size of 400-600 μm using three-dimensional software; 4) Prepare the printing program: import the STL file of the printing model into the 3D printing device, perform slicing, obtain the cross-sectional graphics that need to be printed, and design the plane printing path according to the cross-sectional graphics; 5) Print: I. Toner preparation: After the tantalum powder is mixed into a particle ratio, it is loaded into the toner storage area and connected to the toner nozzle through the conveying system; II. Printing: In an argon atmosphere, the first layer is printed on the printing table along the printing path, and then the laser or electron beam is used to heat and melt the fusion layer and consolidate it; then, on the basis of the first consolidated layer, the second consolidated layer and the third consolidated layer are stacked until the prosthesis is formed; during this process, the heat preservation device in the printing table is turned on to keep the contact surface with the prosthesis at the same temperature as the prosthesis; 6) Cooling: After printing is completed, the printing table is rotated for air cooling; 7) After cooling down, remove the prosthesis and printing is completed.

2. The method according to claim 1, characterized in that: In step 3), the solid wall of the screw hole with a thickness of 0.3-0.6mm should also be maintained.

3. The method according to claim 1, characterized in that: There are three screw through holes in total, and the three screw through holes are arranged on the side of the acetabulum at intervals and not parallel to each other.

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