Personalized winged acetabular cup for artificial total hip revision and design method thereof

Abstract

The invention belongs to the field of acetabular cups, and particularly discloses a winged acetabular cup for personalized artificial total hip revision and a design method thereof.The winged acetabular cup comprises a winged acetabular cup body, and a biological curved surface matched with acetabular residual bone anatomy of a patient is arranged on the outer surface of the winged acetabular cup body; the positioning mark group comprises at least one positioning bulge which is arranged on the biological curved surface and is distributed in a non-coplanar manner, and the contact surface of the positioning bulge and a remaining skeleton anatomical mark of the acetabulum form a unique space matching relationship; the screw hole is formed in the positioning bulge in a penetrating manner; golden angle positioning can be automatically achieved through direct attachment in an operation by means of the unique space matching relation between the positioning protrusion and the bone anatomical marker, and personal errors are thoroughly eliminated; the biological curved surface optimization algorithm ensures that the contact area of the prosthesis and the residual bone meets the requirement, the gradient porous structure is combined, the matching degree and osseointegration efficiency of a bone defect area are remarkably improved, the dislocation rate is reduced, and meanwhile the operation time is shortened.

Description

Technical Field

[0001] This invention belongs to the field of acetabular cups, specifically relating to a winged acetabular cup for personalized total hip arthroplasty revision surgery and its design method. Background Technology

[0002] Total hip arthroplasty includes femoral prosthesis replacement and acetabular prosthesis replacement. Technical parameters in acetabular prosthesis replacement include the anteversion angle, abduction angle, and compression fit of the acetabular cup to the bone.

[0003] In current technologies, many factors influence the anteversion and abduction angles, including patient position, surgical field exposure, surgeon's subjective feelings, and experience.

[0004] Therefore, the placement of the acetabular prosthesis's anteversion and abduction angles during surgery is often less than ideal. This is especially true for patients undergoing revision total hip arthroplasty, where the implanted prosthesis has already failed. During this failure process, the prosthesis wears down against the patient's own bone, leading to osteolysis and bone loss. This process presents three problems:

[0005] 1. Disruption of the anatomical structure of the skeleton makes it difficult to find bony landmarks during surgery, thus making it difficult to accurately place the acetabular cup;

[0006] 2. After bone loss, the acetabular bone is difficult to completely cover and adhere to the prosthesis, thus affecting the stability of the acetabular cup;

[0007] 3. During the surgery, objective factors such as patient position and physical differences (body mass index, development, etc.) may lead to unclear markings for the placement of the acetabular cup, which may affect the postoperative prosthesis position (anteversion angle, abduction angle). Summary of the Invention

[0008] The purpose of this invention is to provide a personalized total hip arthroplasty revision surgery with a winged acetabular cup and its design method, in order to solve the problem mentioned in the background art that the placement of the acetabular cup in traditional total hip arthroplasty depends on the doctor's subjective judgment and is affected by the patient's position and surgical field exposure, which can easily lead to prosthesis loosening and dislocation.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A personalized total hip arthroplasty revision surgery winged acetabular cup includes: a winged acetabular cup body, the outer surface of which is provided with a bio-shaped curved surface that matches the anatomy of the patient's acetabular residual bone; a positioning marker group, including at least one non-coplanar positioning protrusion disposed on the bio-shaped curved surface, the contact surface of the positioning protrusion forming a unique spatial matching relationship with the remaining anatomical markers of the acetabulum; and a screw hole penetrating inside the positioning protrusion.

[0011] Preferably, the height of the positioning protrusion is 1.5-2mm and the diameter is 2-3mm.

[0012] Preferably, when the positioning protrusion fits seamlessly with the corresponding retained skeletal anatomical landmark, the forward tilt angle of the winged acetabular cup body is 15°-25° and the abduction angle is 40°-45°.

[0013] Preferably, the preserved skeletal anatomical landmarks include at least one of the ischial tuberosity, iliopectineal eminence, acetabular notch, pubic ramus, and iliac arcuate line.

[0014] Preferably, the surface of the winged acetabulum body is provided with a porous coating with a pore size of 50-500μm.

[0015] A method for designing a winged acetabular cup for personalized total hip arthroplasty revision surgery includes:

[0016] S1. Obtain CT scan data of the patient's acetabular region;

[0017] S2. Establish a three-dimensional model of the remaining bone fragments using the CT scan data, and identify the remaining anatomical landmarks of the bones;

[0018] S3. Calculate the plane normal vector of the ideal implantation plane using the anterior tilt angle of 15°-25° and the abduction angle of 40°-45° as inputs, and determine the ideal implantation plane of the acetabular cup model based on the plane normal vector;

[0019] S4. Position the standard acetabular cup model to the ideal implantation plane and optimize the bio-shaped surface;

[0020] S5. Based on the identified anatomical landmarks of the skeletal remains, generate at least one positioning protrusion point in the area where the distance between the anatomical landmarks of the skeletal remains and the bio-type curved surface is less than 1 mm.

[0021] S6. Generate a three-dimensional model of the positioning protrusion based on the location point of the positioning protrusion, ensuring that the contact surface of the positioning protrusion conforms to the retained skeletal anatomical landmarks.

[0022] S7. Output a 3D model of the acetabular cup with positioning protrusions.

[0023] Preferably, the optimized biological surface includes:

[0024] Discretize the surface of the acetabular cup model into a set of grid points;

[0025] Calculate the target porosity for each point in the grid set;

[0026] Gradient porous structures are generated based on porosity.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention achieves automatic golden angle positioning by directly fitting the protrusion with the anatomical landmark of the bone during surgery, thus eliminating human error to the greatest extent. The biological curved surface optimization algorithm ensures that the contact area between the prosthesis and the residual bone meets the requirements. Combined with the gradient porous structure, it significantly improves the matching degree and bone integration efficiency of the bone defect area, reduces the dislocation rate and shortens the operation time. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0030] Figure 1 This is a schematic diagram of the matching structure between the winged acetabular cup body and the skeleton of the present invention. Figure 2 This is a front view of the winged acetabular cup body matching the skeleton of the present invention.

[0031] In the diagram: 1. The main body of the acetabular cup with wings; 2. The positioning protrusion; 3. The screw hole. Detailed Implementation

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0035] As attached Figure 1 As shown:

[0036] Example 1: This example provides a winged acetabular cup for personalized total hip arthroplasty revision surgery, including: a winged acetabular cup body 1, the outer surface of which is provided with a bio-shaped curved surface that matches the anatomy of the patient's acetabular residual bone; a positioning marker group, including at least one non-coplanar positioning protrusion 2 set on the bio-shaped curved surface, the contact surface of the positioning protrusion 2 forming a unique spatial matching relationship with the remaining anatomical markers of the acetabulum; and a screw hole 3, which is disposed through the interior of the positioning protrusion 2.

[0037] The winged acetabular cup body 1 is fixed to the bone by passing screws through screw holes 3, thereby improving the anti-dislodgement performance.

[0038] Specifically, the height of the positioning protrusion 2 is 1.5-2mm, and the diameter is 2-3mm.

[0039] Specifically, when the positioning protrusion 2 fits seamlessly with the corresponding remaining anatomical landmark of the bone, the forward tilt angle of the winged acetabular cup body 1 is 15°-25° and the abduction angle is 40°-45°.

[0040] Specifically, the remaining skeletal anatomical landmarks include at least one of the following: ischial tuberosity, iliopectineal eminence, acetabular notch, pubic ramus, and iliac arcuate line.

[0041] Specifically, the surface of the winged acetabulum body 1 is provided with a porous coating with a pore size of 50-500μm.

[0042] By setting a positioning protrusion 2 on the winged acetabular cup body 1, and pre-customizing the winged acetabular cup body 1 and the positioning protrusion 2 according to the patient's bones, the contact surface of the positioning protrusion 2 forms a unique spatial matching relationship with the remaining anatomical landmarks of the acetabulum. During the pressing process, the positioning protrusion 2 fits tightly with the remaining anatomical landmarks of the bones, and the acetabular area of ​​the winged acetabular cup body 1 fits tightly. This indicates that the winged acetabular cup body 1 has been assembled and that the anteversion angle and abduction angle meet the requirements. There is no need for medical staff to make subjective judgments during the operation, and it is not affected by the patient's position, acetabular development and bone defects, which greatly improves the efficiency and accuracy of the operation.

[0043] Example 2: A method for designing a winged acetabular cup for personalized total hip arthroplasty revision surgery, comprising:

[0044] S1. Obtain CT scan data of the patient's acetabular region;

[0045] S2. Establish a three-dimensional model of the remaining bone fragments using CT scan data and identify anatomical landmarks of the remaining bones;

[0046] S3. Calculate the plane normal vector of the ideal implantation plane using the anterior tilt angle of 15°-25° and the abduction angle of 40°-45° as inputs, and determine the ideal implantation plane of the acetabular cup model based on the plane normal vector;

[0047] The formula for calculating the plane normal vector is as follows:

[0048]

[0049] Where α is the forward tilt angle, ranging from 15° to 25°, and β is the abduction angle, ranging from 40° to 45°. The unit normal vector of the ideal implantation plane.

[0050] S4. Position the standard acetabular cup model to the ideal implantation plane and optimize the bio-shaped surface;

[0051] S5. Based on the identified anatomical landmarks of the skeletal remains, generate at least one positioning protrusion 2 location point in the area where the distance between the anatomical landmarks of the skeletal remains and the bio-type curved surface is <1mm.

[0052] S6. Generate a three-dimensional model of positioning protrusion 2 based on the location point of positioning protrusion 2, and ensure that the contact surface of positioning protrusion 2 conforms to the retained skeletal anatomical landmarks.

[0053] S7. Output the 3D model of the acetabular cup with positioning protrusion 2.

[0054] Specifically, optimizing biological-type surfaces includes:

[0055]

[0056] Where H(x) is the unit step function: δ is the allowable gap threshold, with a value of 0.5 mm. Let be the position vector of a point on the surface of the acetabular cup. Let dS be the position vector of the nearest point on the surface of the residual bone, and dS be the area of ​​the biomorphic surface element. total This represents the total surface area of ​​the acetabular cup.

[0057] Specifically, in the three-dimensional model of positioning protrusion 2 generated with the location point of positioning protrusion 2 as the reference, the center coordinates of each positioning protrusion 2 satisfy the vector constraint equation.

[0058] The formula for calculating vector constraint equations is as follows:

[0059]

[0060] Where i is the number of the positioning protrusion 2. Let be the position vector of the center of the i-th positioning protrusion 2 in the pelvic coordinate system. Let be the position vector of the geometric center of the acetabulum in the pelvic coordinate system. The plane normal vector is the plane that is ideally placed into the plane.

[0061] Definition of pelvic coordinate system:

[0062] Origin point: Midpoint of the pubic symphysis;

[0063] Z-axis: Perpendicular to the sagittal plane of the human body, pointing to the right side of the patient;

[0064] Y-axis: perpendicular to the coronal plane, pointing towards the patient's ventral side;

[0065] X-axis: Perpendicular to the cross-section, pointing towards the patient's head.

[0066] Example 3: A method for manufacturing an acetabular cup, comprising:

[0067] Import the model obtained in Example 2 into the 3D printing equipment;

[0068] Titanium alloy powder is selected for laser melting and forming. Process parameters:

[0069] Laser power 200-300W;

[0070] Scanning speed: 800-1200 mm / s.

[0071] Specifically, the optimized biological-type surface includes:

[0072] The surface of the acetabular cup model is discretized into a grid point set p = p1, p2, ..., p n ;

[0073] For each point p in the grid point set i Calculate the target porosity ρtarget(p) i );

[0074] A gradient porous structure, PoreDiameter(pi), is generated based on porosity.

[0075] The formula for calculating porosity is as follows:

[0076]

[0077] Wherein, ρtarget(p i ) represents the target porosity at each point in the mesh set of the acetabular cup model, ρbase is the base porosity fixed at 70%, and D(x,y,z) is the bone mineral density (g / cm³) converted from CT values ​​(HU). 3 ), D max The patient's maximum bone mineral density value in the acetabular region (g / cm²) 3 ), where k is the compensation coefficient (ranging from 0.3 to 0.6, calibrated through finite element simulation);

[0078] CT value to solid density conversion was based on the clinical calibration model in Medical Physics, Vol. 41, pp. 031907.

[0079] Generate gradient porous structures:

[0080]

[0081] Where d min 50μm, d max It is 500μm;

[0082] Mechanical safety thresholds: ρmin is 60%, ρmax is 85%.

[0083] Bone density compensation is achieved by spraying a porous coating onto the acetabular cup according to the bone density gradient after 3D printing.

[0084] Bone resorption area: Bone mineral density D < 0.5 g / cm³ 3 Increased porosity leads to increased pore size, which in turn increases the space for bone ingrowth.

[0085] Sclerotic bone area: Bone mineral density D > 1.2 g / cm³ 3 Decreased porosity leads to decreased pore size, which in turn increases local stiffness.

[0086] It is especially suitable for patients who have undergone multiple surgeries or have severe bone defects requiring revision surgery.

[0087] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0088] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0089] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0090] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A personalized total hip arthroplasty revision surgery with a winged acetabular cup, characterized in that, include: A winged acetabular cup body (1) has a bio-shaped curved surface on its outer surface that matches the anatomy of the patient's acetabular remnant bone. The positioning marker group includes at least one non-coplanar positioning protrusion (2) disposed on the bio-type curved surface, wherein the contact surface of the positioning protrusion (2) forms a unique spatial matching relationship with the anatomical landmark of the acetabulum. The screw hole (3) is provided through the inside of the positioning protrusion (2).

2. The personalized total hip arthroplasty revision surgery with a winged acetabular cup according to claim 1, characterized in that, The positioning protrusion (2) has a height of 1.5-2mm and a diameter of 2-3mm.

3. The personalized total hip arthroplasty revision surgery with a winged acetabular cup according to claim 1, characterized in that, When the positioning protrusion (2) fits seamlessly with the corresponding anatomical landmark of the bone, the forward tilt angle of the winged acetabular cup body (1) is 15°-25° and the abduction angle is 40°-45°.

4. The personalized total hip arthroplasty revision surgery with a winged acetabular cup according to claim 1, characterized in that, The remaining skeletal anatomical landmarks include at least one of the ischial tuberosity, iliopectineal eminence, acetabular notch, pubic ramus, and arcuate line of the ilium.

5. A personalized total hip arthroplasty revision surgery with a winged acetabular cup according to claim 1, characterized in that, The surface of the winged mortis cup body (1) is provided with a porous coating with a pore size of 50-500μm.

6. A method for designing a winged acetabular cup for personalized total hip arthroplasty revision surgery according to any one of claims 1-5, characterized in that, include: S1. Obtain CT scan data of the patient's acetabular region; S2. Establish a three-dimensional model of the remaining bone fragments using the CT scan data, and identify the remaining anatomical landmarks of the bones; S3. Calculate the plane normal vector of the ideal implantation plane using the anterior tilt angle of 15°-25° and the abduction angle of 40°-45° as inputs, and determine the ideal implantation plane of the acetabular cup model based on the plane normal vector; S4. Position the standard acetabular cup model to the ideal implantation plane and optimize the bio-shaped surface; S5. Based on the identified anatomical landmarks of the skeletal remains, generate at least one positioning protrusion (2) location point in the area where the distance between the anatomical landmarks of the skeletal remains and the bio-type curved surface is <1mm. S6. Generate a three-dimensional model of the positioning protrusion (2) based on the location point of the positioning protrusion (2) to ensure that the contact surface of the positioning protrusion (2) conforms to the existing skeletal anatomical landmarks; S7. Output the 3D model of the acetabular cup with positioning protrusion (2).

7. The design method of a winged acetabular cup for personalized total hip arthroplasty revision surgery according to claim 6, characterized in that, The optimized bio-type surface includes: Discretize the surface of the acetabular cup model into a set of grid points; Calculate the target porosity for each point in the grid set; Gradient porous structures are generated based on porosity.

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