Unicompartmental prosthesis planning method, device and computer equipment

Abstract

The embodiments of the present application are applicable to the field of computer-assisted medical treatment and surgical planning technology, and provide a method, apparatus, and computer equipment for prosthesis planning for unicompartmental surgery, the method comprising: obtaining parameter information of a prosthesis to be planned, the parameter information including the amount of osteotomy; determining the placement position of the prosthesis in a pre-constructed three-dimensional model based on the parameter information; calculating the coverage ratio between the prosthesis cross section and the corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position; determining a target prosthesis from a plurality of prostheses to be planned based on the coverage ratio, and performing preoperative planning for unicompartmental surgery based on the target prosthesis. By adopting the above method, the prosthesis posture can be automatically planned according to the amount of osteotomy of the prosthesis, and then the best prosthesis can be selected for preoperative planning by calculating the coverage ratio of the prosthesis cross section, thereby ensuring the accuracy and safety of prosthesis planning for unicompartmental surgery.

Description

Technical Field

[0001] The embodiments of the present application belong to the technical field of computer-assisted medical treatment and surgical planning, and in particular, relate to a method, apparatus, and computer equipment for planning a unicompartmental prosthesis. Background Art

[0002] Unicompartmental knee arthroplasty (UKA) is a procedure that treats damage or degeneration in a specific area of the knee joint. By removing the affected cartilage and some bone and implanting a prosthesis, patients can regain functional function. Preoperative prosthesis planning can provide an accurate surgical plan for the replacement.

[0003] In existing technologies, prosthesis planning for unicompartmental knee replacement surgery is mainly based on iterative closest point (ICP) registration to determine the placement of the prosthesis. This is not only time-consuming, but the planning process does not fully consider the characteristics of the prosthesis itself, which may lead to planning errors and affect the surgical outcome. Summary of the Invention

[0004] In view of this, the embodiments of the present application provide a method, device and computer equipment for planning a unicompartmental knee surgery prosthesis, which can automatically plan the prosthesis posture according to the amount of bone resection of the prosthesis, and then select the best prosthesis for preoperative planning by calculating the coverage rate of the prosthesis cross-section, thereby ensuring the accuracy and safety of unicompartmental knee surgery prosthesis planning.

[0005] A first aspect of an embodiment of the present application provides a prosthesis planning method for unicompartmental knee surgery, comprising:

[0006] Acquiring parameter information of a prosthesis to be planned, wherein the prosthesis includes a femoral prosthesis and a tibial prosthesis, and the parameter information includes an amount of osteotomy;

[0007] Determining a placement position of the prosthesis in a pre-constructed three-dimensional model based on the parameter information;

[0008] calculating a coverage ratio between a cross section of the prosthesis and a corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position, the coverage ratio representing a proportion of an intersection plane of the prosthesis cross section and the bone cross section in the bone cross section;

[0009] According to the coverage, a target prosthesis is determined from a plurality of prostheses to be planned, and preoperative planning of unicompartmental surgery is performed based on the target prosthesis.

[0010] A second aspect of the embodiments of the present application provides a prosthesis planning device for unicompartmental knee surgery, comprising:

[0011] A parameter information acquisition module is used to acquire parameter information of the prosthesis to be planned, wherein the prosthesis includes a femoral prosthesis and a tibial prosthesis, and the parameter information includes an osteotomy amount;

[0012] a placement position determination module, configured to determine a placement position of the prosthesis in a pre-constructed three-dimensional model based on the parameter information;

[0013] a coverage calculation module, configured to calculate a coverage ratio between a cross section of the prosthesis and a corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position, wherein the coverage ratio represents a proportion of an intersection plane of the prosthesis cross section and the bone cross section in the bone cross section;

[0014] A preoperative planning module is used to determine a target prosthesis from a plurality of prostheses to be planned according to the coverage rate, and perform preoperative planning of unicompartmental surgery based on the target prosthesis.

[0015] A third aspect of an embodiment of the present application provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the computer device implements the method described in the first aspect above.

[0016] A fourth aspect of the embodiments of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a computer, the method described in the first aspect above is implemented.

[0017] A fifth aspect of the embodiments of the present application provides a computer program product, including a computer program, which, when executed, enables the method described in the first aspect to be executed.

[0018] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0019] In an embodiment of the present application, by obtaining parameter information of the prosthesis to be planned, including the amount of osteotomy, the computer device can determine the placement position of the prosthesis in a pre-constructed three-dimensional model based on the parameter information of the prosthesis. In this way, the computer device can calculate the coverage ratio between the prosthesis cross section and the corresponding bone cross section when the prosthesis is placed in the above-mentioned placement position, and thus determine the target prosthesis adapted to the patient based on the coverage ratio. The computer device can perform preoperative planning of unicompartmental surgery based on the target prosthesis to obtain the best surgical plan. In an embodiment of the present application, by automatically setting the initial position of the prosthesis and adjusting the posture of the prosthesis based on parameters such as the amount of osteotomy, the shape of the prosthesis to be implanted and the amount of osteotomy can be fully considered in the preoperative planning stage, thereby determining the optimal prosthesis model, improving the speed and accuracy of prosthesis planning for unicompartmental surgery, and improving the safety of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0021] Figure 1 Schematic diagram of a prosthesis planning method for unicompartmental knee surgery provided in an embodiment of the present application;

[0022] Figure 2 Schematic diagram of a possible implementation of S102 in a prosthesis planning method for unicompartmental knee surgery provided in an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of a femoral landmark provided in an embodiment of the present application;

[0024] Figure 4 is a schematic diagram of a tibial landmark point provided in an embodiment of the present application;

[0025] Figure 5 Schematic diagram of a possible implementation of S1023 in a prosthesis planning method for unicompartmental knee surgery provided in an embodiment of the present application;

[0026] Figure 6 is a schematic diagram of a femoral prosthesis and a tibial prosthesis provided in an embodiment of the present application;

[0027] Figure 7 is a schematic diagram of a prosthesis placement position provided in an embodiment of the present application;

[0028] Figure 8 Schematic diagram of a prosthesis planning process for unicompartmental knee surgery provided in an embodiment of the present application;

[0029] Figure 9 Schematic diagram of a prosthesis planning device for unicompartmental surgery provided in an embodiment of the present application;

[0030] Figure 10 This is a schematic diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obstructing the description of the present application with unnecessary details.

[0032] The technical solution of this application is described below through specific embodiments.

[0033] Reference Figure 1 , shows a schematic diagram of a prosthesis planning method for unicompartmental knee surgery provided by an embodiment of the present application, which may specifically include the following steps:

[0034] S101. Obtain parameter information of a prosthesis to be planned, where the prosthesis includes a femoral prosthesis and a tibial prosthesis, and the parameter information includes an amount of osteotomy.

[0035] It should be noted that this method can be applied to a computer device, that is, the execution subject of the embodiments of this application can be a computer device. By executing the various steps of the planning method provided in the embodiments of this application, the computer device can fully consider information such as the shape of the prosthesis and the amount of osteotomy before surgery, determine the optimal prosthesis for use during surgery, and use it for preoperative planning, thereby obtaining an accurate preoperative planning plan.

[0036] The computer device can be any type of electronic device capable of performing preoperative planning, such as computer-assisted medical equipment or other desktop computers, laptop computers, etc. capable of carrying out corresponding functions. The embodiment of the present application does not limit the type of computer device.

[0037] The scenario to which this method is applicable may be the preoperative planning stage of unicompartmental knee replacement surgery, so the surgeries mentioned in the embodiments of this application all refer to unicompartmental knee replacement surgery. During unicompartmental knee replacement surgery, the doctor needs to remove the diseased cartilage and part of the bone at the patient's knee joint, and implant a prosthesis at the resection site. The preoperative planning stage is to plan and determine the prosthesis to be used and how to implant the prosthesis, etc., to form a complete planning plan to guide the doctor in performing the surgery. The prostheses required for unicompartmental knee replacement surgery include femoral prostheses and tibial prostheses. Among them, the femoral area that is resected during the operation needs to be implanted with a femoral prosthesis to replace the resected femur, and the tibial area that is resected needs to be implanted with a tibial prosthesis. Unless otherwise specified, the prostheses mentioned in the embodiments of this application all include femoral prostheses and tibial prostheses.

[0038] In the embodiments of the present application, the prosthesis to be planned can be one of multiple available models. By executing the present method, the computer device can determine the most suitable prosthesis for intraoperative use, i.e., the target prosthesis, from among the multiple models, and perform preoperative planning of the surgical plan based on the target prosthesis. In other words, the computer device can evaluate multiple prosthesis models, determine the most suitable target prosthesis, and plan how to implant the target prosthesis intraoperatively.

[0039] During the preoperative planning stage, the computer device can obtain parameter information of the prosthesis to be planned. Usually, for a usable prosthesis, the manufacturer of the prosthesis can provide the user with various parameter information of the prosthesis of this model after completing the production of the prosthesis of this model. These parameter information may include the coordinate system of the prosthesis itself, that is, the prosthesis coordinate system, the position information of each landmark point on the prosthesis, each cross-section of the prosthesis and its normal vector direction, the recommended amount of osteotomy when using the prosthesis for surgery, etc. These parameter information can be organized into a readable file for use by the computer device when performing preoperative planning. Specifically, the computer device can read the parameter information of the femoral prosthesis and tibial prosthesis currently to be planned or evaluated from the readable file.

[0040] S102: Determine the placement position of the prosthesis in the pre-constructed three-dimensional model according to the parameter information.

[0041] In an embodiment of the present application, preoperative planning can be performed based on a pre-constructed 3D model, which can be a 3D model of the patient's surgical site. For example, before surgery, an imaging device can be used to scan the patient and obtain a medical image of the surgical site, i.e., the patient's knee joint. A 3D model of the knee joint can be constructed through 3D reconstruction. In one example, the 3D model can specifically be a 3D model of the femur and tibia at the knee joint.

[0042] After obtaining the parameter information of the prosthesis, the computer device can determine the placement position of the prosthesis in the pre-constructed three-dimensional model based on the parameter information. Since the prosthesis in the embodiment of the present application includes a femoral prosthesis and a tibial prosthesis, the computer device can determine the placement position of the femoral prosthesis and the placement position of the tibial prosthesis in the three-dimensional model based on the parameter information of the femoral prosthesis and the parameter information of the tibial prosthesis, respectively.

[0043] In an embodiment of the present application, a computer device may determine an initial position and place the prosthesis at the initial position during the planning phase. The computer device may then move the prosthesis from the initial position to the final position based on parameter information such as the prosthesis shape and amount of osteotomy. The final position after the movement is the actual implantation position of the prosthesis during surgery, as determined by planning.

[0044] In a possible implementation of the embodiment of the present application, as Figure 2 As shown, in S102, the placement position of the prosthesis in the pre-built three-dimensional model is determined according to the parameter information, which may specifically include the following steps S1021-S1023:

[0045] S1021. Establish a coordinate system based on the selected landmark points.

[0046] In an embodiment of the present application, in order to achieve accurate preoperative planning, a computer device can establish corresponding coordinate systems for the patient's knee joint surgical site, namely a femoral coordinate system and a tibial coordinate system. The computer device can establish the femoral coordinate system and the tibial coordinate system based on selected landmark points. Specifically, the computer device can establish the femoral coordinate system based on the selected femoral landmark point and establish the tibial coordinate system based on the selected tibial landmark point.

[0047] In an embodiment of the present application, the above-mentioned landmark points can be manually selected by the doctor in the three-dimensional model after the computer device completes the reconstruction of the three-dimensional model of the femur and tibia; or, the computer device can automatically select the various landmark points that can be used to construct the coordinate system by identifying the three-dimensional model. This embodiment of the present application is not limited to this.

[0048] like Figure 3 and Figure 4 The following are schematic diagrams of a femoral landmark point and a tibial landmark point provided by the embodiments of the present application. Figure 3 The femoral landmark points shown may include the femoral head center point 301, the lateral epicondyle point 302, the medial epicondyle point 303, the distal femoral lateral point 304, the distal femoral medial point 305, the posterior femoral condyle lateral point 306, the posterior femoral condyle medial point 307 and the distal femoral center point 308, etc. Figure 4 The tibial landmark points shown may include the tibial lateral condyle point 401, the tibial medial condyle point 402, the tibial plateau center point 403, the tibial tuberosity point 404, the PCL insertion center point 405, the tibial plateau lateral point 406 and the tibial plateau medial point 407. Figure 3 and Figure 4 The positions of the landmarks shown are only examples. The actual positions of the landmarks on the femur and tibia may vary. Figure 3 or Figure 4 The following describes the establishment process of the femoral coordinate system and the tibia coordinate system.

[0049] The femoral coordinate system can be established by following steps 1.1-1.4:

[0050] 1.1 Calculate the midpoint of the line connecting the medial epicondyle and the lateral epicondyle as , set the center point of the femoral head as F, and obtain the Y-axis vector of the femoral coordinate system as ;

[0051] 1.2 Point and vector Create a point-based plane ;

[0052] 1.3 Assume that the medial point of the posterior femoral condyle is on the plane The projection point on , the lateral point of the posterior femoral condyle is set on the plane The projection point on , get the X-axis vector of the femoral coordinate system and set it as It should be noted that if the surgical side is the right side, the direction of the above X-axis vector is reversed;

[0053] 1.4 With the above vector Cross product vector Get the Z-axis vector of the femoral coordinate system , completing the construction of the femoral coordinate system.

[0054] The tibial coordinate system can be established by following steps 2.1-2.4:

[0055] 2.1 Let the center point of PCL be The tibial tuberosity is , and get the vector ;

[0056] 2.2 Calculate the midpoint of the line connecting the lateral tibial condyle and the medial tibial condyle. The center point of the tibial plateau is , get the Y-axis vector of the tibia coordinate system ;

[0057] 2.3 With the above vector Cross product vector Get the X-axis vector of the tibia coordinate system ;

[0058] 2.4 With the above vector Cross product vector Get the Z-axis vector of the tibia coordinate system , completing the construction of the tibia coordinate system.

[0059] S1022: Determine the initial position of the prosthesis in the pre-constructed three-dimensional model according to the coordinate system.

[0060] In the embodiment of the present application, the initial positions of the femoral prosthesis and the tibial prosthesis can be determined respectively. Specifically, the computer device can first determine the prosthesis origin. Among them, for the femoral prosthesis, its prosthesis origin It can be the distal point of the femur on the surgical side; for tibial prosthesis, the origin of the prosthesis It can be the tibial plateau side point.

[0061] It should be noted that during the operation, the surgical side can be divided into the inner side or the outer side, or can also be divided into the left side or the right side. The distal femoral point on the surgical side can be determined as the medial femoral distal point or the lateral femoral distal point according to the actual situation; accordingly, it serves as the origin of the tibial prosthesis. The surgical side point of the tibial plateau can be determined as the medial point or the lateral point of the tibial plateau according to actual conditions.

[0062] Then, the computer device can establish a first rotation matrix based on the distal point of the femur on the surgical side and the femoral coordinate system. , and according to the first rotation matrix Determine the initial position of the femoral prosthesis in the 3D model. The initial position of the femoral prosthesis in the 3D model can be represented by the femoral prosthesis pose matrix, which is:

[0063]

[0064] The initial position of the femoral prosthesis represented by the femoral prosthesis pose matrix may mean that the computer device can place the femoral prosthesis at a certain position in the three-dimensional model so that the femoral prosthesis has the pose represented by the pose matrix. In this way, the current position of the femoral prosthesis is also the initial position of the femoral prosthesis.

[0065] On the other hand, the computer device can establish a second rotation matrix based on the tibial plateau side point and the tibial coordinate system , and according to the second rotation matrix Determine the initial position of the tibial prosthesis in the 3D model. Similar to the placement of the femoral prosthesis, the initial position of the tibial prosthesis in the 3D model can be represented by the tibial prosthesis pose matrix, which is:

[0066]

[0067] The initial position of the tibial prosthesis represented by the tibial prosthesis pose matrix may mean that the computer device can place the tibial prosthesis at a certain position in the three-dimensional model so that the tibial prosthesis has the pose represented by the pose matrix. In this way, the current position of the tibial prosthesis is also the initial position of the tibial prosthesis.

[0068] S1023: After placing the prosthesis at the initial position, move the prosthesis according to the osteotomy amount in the parameter information to obtain a placement position of the prosthesis in the three-dimensional model.

[0069] In an embodiment of the present application, after the femoral and tibial prostheses are placed in their initial positions, the computer device can move the femoral and tibial prostheses based on the amount of osteotomy, allowing the planning process to fully consider the amount of osteotomy. The placement positions determined after moving the femoral and tibial prostheses based on the amount of osteotomy are the actual planned implant positions of the femoral and tibial prostheses during the surgical procedure.

[0070] In a possible implementation of the embodiment of the present application, as Figure 5 As shown, in step S1023, the prosthesis is moved according to the osteotomy amount in the parameter information to obtain the placement position of the prosthesis in the three-dimensional model, which can specifically include the following steps S1231-S1233. Among them, S1231-S1232 introduce the specific process of moving the femoral prosthesis, and S1233 introduces the specific process of moving the tibial prosthesis.

[0071] S1231. For the femoral prosthesis, displace the femoral prosthesis along the normal vector direction of the distal cross-section of the prosthesis so that the distance from the distal point of the femur on the surgical side to the distal cross-section of the prosthesis is equal to the distal osteotomy amount of the femoral prosthesis.

[0072] Specifically, for a femoral prosthesis, the computer device may first shift the distal cross-section of the femoral prosthesis such that the distance between the distal femoral point on the prosthesis's surgical side and the distal cross-section equals the distal osteotomy of the femoral prosthesis. Depending on whether the surgical side is medial or lateral, the distal femoral point on the surgical side may be either the distal lateral point or the distal medial point. For example, when the surgical side is medial, the distal femoral point on the surgical side is the distal medial point; when the surgical side is lateral, the distal femoral point on the surgical side is the distal lateral point.

[0073] S1232. Displace the femoral prosthesis along the direction of the first normal vector so that the distance from the posterior condyle point on the surgical side to the posterior condyle section of the prosthesis is equal to the posterior condyle osteotomy amount of the femoral prosthesis; wherein, the first normal vector is obtained by cross-multiplying the normal vector of the distal section of the prosthesis by the second normal vector, and the second normal vector is obtained by cross-multiplying the normal vector of the posterior condyle section of the prosthesis by the normal vector of the posterior oblique section of the prosthesis.

[0074] Specifically, the computer device can determine a second normal vector obtained by cross-producting the normal vector of the posterior condyle section of the femoral prosthesis and the normal vector of the posterior oblique section of the prosthesis. Then, the normal vector of the distal section of the prosthesis and the second normal vector can be calculated The result of the cross product is the first normal vector The computer device moves along the first normal vector The femoral prosthesis was displaced in the direction of the operation so that the distance from the posterior condyle point on the surgical side to the posterior condyle section of the prosthesis was equal to the amount of posterior condyle osteotomy of the femoral prosthesis.

[0075] It should be noted that the data such as the distal osteotomy amount, posterior condyle osteotomy amount and normal vector of each cross section of the femoral prosthesis currently to be planned can be obtained from the parameter information of the femoral prosthesis. The above-mentioned distal cross section of the prosthesis is a cross section located near the distal point of the femoral prosthesis. Depending on the surgical side, the above-mentioned distal point of the femoral prosthesis is the medial point of the distal femur or the lateral point of the distal femur. The posterior condyle cross section of the prosthesis is a cross section located near the superior posterior condyle point of the femoral prosthesis. Similarly, depending on the surgical side, the above-mentioned posterior condyle point is the medial point of the posterior femoral condyle or the lateral point of the posterior femoral condyle. The cross section between the distal point and the posterior condyle point is the posterior oblique cross section of the prosthesis.

[0076] S1233. For the tibial prosthesis, displace the tibial prosthesis along the normal vector direction of the tibial prosthesis cross section so that the distance from the non-operative side tibial plateau point to the tibial prosthesis cross section is equal to the osteotomy amount of the tibial prosthesis.

[0077] For the femoral prosthesis, the computer device can displace the tibial prosthesis in the direction of the normal vector of the tibial prosthesis cross section so that the distance from the non-operative side tibial plateau point to the moved tibial prosthesis cross section is equal to the amount of osteotomy of the tibial prosthesis. The above-mentioned non-operative side tibial plateau point can be a landmark point on the other side opposite to the operative side tibial plateau point. For example, when the operative side is the medial side, the operative side tibial plateau point is the medial point of the tibial plateau, so the non-operative side tibial plateau point is the lateral point of the tibial plateau; when the operative side is the lateral side, the operative side tibial plateau point is the lateral point of the tibial plateau, so the non-operative side tibial plateau point is the medial point of the tibial plateau. The above-mentioned data such as the amount of osteotomy of the tibial prosthesis can be obtained from the parameter information of the tibial prosthesis.

[0078] The distal osteotomy amount, posterior condylar osteotomy amount, and tibial osteotomy amount of the femoral prosthesis represent the specific thickness of the osteotomy, that is, the thickness of the bone area that needs to be cut or resected during the implantation of the corresponding prosthesis. In the embodiments of the present application, referring to the specific osteotomy amount when planning the implanted prosthesis ensures that the thickness of the bone cut in all directions is consistent with the thickness of the implanted prosthesis, thereby improving the accuracy of the surgery.

[0079] After the femoral prosthesis and tibial prosthesis are displaced according to the above steps, the current positions of the femoral prosthesis and tibial prosthesis are their final placement positions. Figure 6 The figures show examples of a femoral prosthesis and a tibial prosthesis provided in the embodiments of the present application. Figure 6 Part (a) shows a schematic diagram of a femoral prosthesis 610. Figure 6 Part (b) in FIG. 1 shows a schematic diagram of a tibial prosthesis 620. Figure 6 Based on the femoral and tibial prostheses shown, see Figure 7 , are schematic diagrams of the placement of the prosthesis provided in the embodiments of the present application. Figure 7Part (a) shows the placement of the femoral prosthesis, which is about to Figure 6 Part (a) of FIG. 1 is a schematic diagram of a femoral prosthesis 610 placed in a three-dimensional model of the femur. Figure 7 Part (b) shows the placement of the tibial prosthesis, which is about to be Figure 6 Part (b) of FIG. 1 shows a schematic diagram of the tibial prosthesis 620 placed in the tibial three-dimensional model. Figure 7 In part (a), the points marked 711 and 712 are the medial epicondyle and lateral epicondyle of the femoral landmarks, the points marked 713 and 714 are the medial point of the distal femur or the lateral point of the distal femur, and the points marked 715 and 716 are the medial point of the posterior femoral condyle or the lateral point of the posterior femoral condyle. Figure 7 In part (b), the point marked 721 is the medial point of the tibial plateau among the tibial landmark points, and the point marked 722 is the center point of the tibial plateau.

[0080] S103: Calculate the coverage between the prosthesis cross section and the corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position.

[0081] In an embodiment of the present application, the coverage ratio between the prosthesis cross section and the corresponding bone cross section in the three-dimensional model can be used to represent the proportion of the intersection plane of the prosthesis cross section and the bone cross section in the bone cross section. Specifically, since the placement position of the prosthesis determined in the aforementioned steps is the position where the prosthesis needs to be implanted when the prosthesis of this model is used during surgery, that is, the prosthesis needs to be placed at the above-mentioned placement position determined during the operation. Therefore, in the preoperative planning stage, the area where the prosthesis cross section and the corresponding bone interface are relative or overlapping when the prosthesis is simulated and placed at this position can be determined. This area is the intersection plane of the two. The computer device can calculate the area of the intersection plane and compare it with the area of the corresponding bone cross section. The ratio of the two is the coverage ratio of the prosthesis cross section to the corresponding bone cross section. The coverage ratio should be a value less than or equal to 100%. From the perspective of surgical accuracy and safety, the greater the coverage ratio, the better. The greater the coverage ratio, the more closely the prosthesis used matches the patient's knee joint surgical site.

[0082] In the embodiment of the present application, since the cross-sections of the femoral prosthesis and the tibial prosthesis are different, when calculating the coverage rate of the prosthesis cross-section, it can be performed separately for the femoral prosthesis and the tibial prosthesis.

[0083] Specifically, for a femoral prosthesis, since its prosthetic cross-section includes a distal femoral cross-section, a posterior femoral condyle cross-section, and a posterior femoral oblique cross-section, the bone cross-sections corresponding to these cross-sections in the three-dimensional model also include the distal femoral cross-section, the posterior femoral condyle cross-section, and the posterior femoral oblique cross-section. Therefore, the computer device can first calculate the first area of the distal femoral cross-section, the posterior femoral condyle cross-section, and the posterior femoral oblique cross-section relative to the corresponding distal femoral cross-section, the posterior femoral condyle cross-section, and the posterior femoral oblique cross-section in the three-dimensional model. This first area is the sum of the areas of the intersection planes formed by the three prosthetic cross-sections and the corresponding bone cross-sections relative to or overlapping with each other. The computer device can also calculate the second area of the distal femoral cross-section, the posterior femoral condyle cross-section, and the posterior femoral oblique cross-section. This second area is the sum of the areas of the three bone cross-sections. By calculating the ratio of the first area to the second area, the coverage rate of the femoral prosthesis can be obtained.

[0084] For the tibial prosthesis, a third area can be calculated between the cross section of the tibial prosthesis and the corresponding cross section of the tibial bone in the three-dimensional model. This third area is the area of the intersection plane formed by the intersection of the cross section of the tibial prosthesis and the corresponding cross section of the tibial bone. After calculating the fourth area of the cross section of the tibial bone, the computer device calculates the ratio of the third area to the fourth area to obtain the coverage rate of the tibial prosthesis.

[0085] In this way, the evaluation process of a certain model of femoral prosthesis and tibial prosthesis is completed, and the coverage rate of the femoral prosthesis and tibial prosthesis is obtained.

[0086] S104: Determine a target prosthesis from the multiple prostheses to be planned according to the coverage rate, and perform preoperative planning of unicompartmental surgery based on the target prosthesis.

[0087] In the embodiment of the present application, steps S101-S103 describe the process of evaluating a specific prosthesis model to be planned. The evaluation results include data on the coverage rate of the prosthesis model. The computer device can evaluate multiple prostheses to be planned in the same manner, obtain the coverage rate of each prosthesis model, and determine a target prosthesis based on the coverage rate. This target prosthesis is the prosthesis that can be used in the actual surgery.

[0088] In one possible implementation of an embodiment of the present application, a threshold may be set. After the prosthesis is evaluated according to the aforementioned steps to obtain corresponding coverage data, if the coverage is greater than the set threshold, the computer device may use it as a target prosthesis and perform subsequent preoperative planning.

[0089] In another possible implementation of the present embodiment, the computer device can also determine the prosthesis with the highest coverage from among multiple prostheses to be planned as the target prosthesis and perform subsequent preoperative planning. The target prostheses include a femoral target prosthesis and a tibial target prosthesis. In this way, based on the patient's actual condition, the prosthesis that best matches the patient can be determined from a variety of available prostheses and used in preoperative planning, further improving the accuracy of preoperative planning.

[0090] In an embodiment of the present application, after the target prosthesis is determined, the process of using the target prosthesis by the computer device for preoperative planning can refer to the process of planning how to guide the doctor to implant the target prosthesis into the corresponding position during the operation. In one example, the planning result may include information on determining the initial position of the target prosthesis and how to displace the target prosthesis so as to place the target prosthesis in the final determined placement position. For the determined target prosthesis, the process of determining its placement position described in S101-S102 above is also part of the specific process of preoperative planning.

[0091] In an embodiment of the present application, by obtaining parameter information of the prosthesis to be planned, including the amount of osteotomy, the computer device can determine the placement position of the prosthesis in the pre-constructed three-dimensional model based on the parameter information of the prosthesis. In this way, the computer device can calculate the coverage rate between the prosthesis cross section and the corresponding bone cross section when the prosthesis is placed in the above-mentioned placement position, and thus determine the target prosthesis adapted to the patient based on the coverage rate. The computer device can perform preoperative planning of unicompartmental surgery based on the target prosthesis to obtain the best surgical plan. By automatically setting the initial position of the prosthesis and adjusting the posture of the prosthesis based on parameters such as the amount of osteotomy, the embodiment of the present application can fully consider the shape of the prosthesis to be implanted and the amount of osteotomy in the preoperative planning stage, thereby determining the optimal prosthesis model, improving the speed and accuracy of prosthesis planning for unicompartmental surgery, and improving the safety of the operation.

[0092] It should be noted that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0093] For ease of understanding, the unicompartmental prosthesis planning method provided in an embodiment of the present application is introduced below with reference to a complete example.

[0094] like Figure 8 The figure is a schematic diagram of a unicompartmental prosthesis planning process provided by an embodiment of the present application. Figure 8 The entire planning process mainly includes the following steps S801-S806:

[0095] S801: Acquire a medical image and segment the femur and tibia.

[0096] In this step, an imaging device may be used to scan the patient's knee joint to obtain a medical image of the knee joint, and a segmentation algorithm may be used to segment the femur and tibia.

[0097] S802. Establish femur and tibia models based on three-dimensional reconstruction.

[0098] In this step, a three-dimensional reconstruction method can be used to respectively establish a femur three-dimensional model and a tibia three-dimensional model.

[0099] S803. Mark the femoral landmark point and the tibial landmark point.

[0100] In this step, the doctor may manually mark the femoral landmark points and the tibial landmark points in the reconstructed three-dimensional model.

[0101] Among them, femoral landmarks can include Figure 3 The femoral head center point, lateral epicondyle point, medial epicondyle point, distal femoral lateral point, distal femoral medial point, posterior femoral condyle lateral point, posterior femoral condyle medial point and distal femoral center point are shown in FIG; tibial landmark points may include Figure 4 The lateral tibial condyle point, medial tibial condyle point, tibial plateau center point, tibial tuberosity point, PCL insertion center point, tibial plateau lateral point and tibial plateau medial point are shown in the figure.

[0102] S804: Establish a femoral coordinate system and a tibia coordinate system based on the landmark points.

[0103] In this step, the process of establishing the femoral coordinate system can be:

[0104] A.1) Calculate the midpoint of the line connecting the medial epicondyle and the lateral epicondyle as , let the center point of the femoral head be F, and the Y-axis vector of the femoral coordinate system be ;

[0105] A.2) Point and vector Create a point-based plane ;

[0106] A.3) Assume that the medial point of the posterior femoral condyle is on the plane The projection point on , the lateral point of the posterior femoral condyle is set on the plane The projection point on , get the X-axis vector of the femoral coordinate system and set it as It should be noted that if the surgical side is the right side, the direction of the above X-axis vector is reversed;

[0107] A.4) With the above vector Cross product vector Get the Z-axis vector of the femoral coordinate system , completing the construction of the femoral coordinate system.

[0108] The process of establishing the tibia coordinate system can be:

[0109] B.1) Let the center of the PCL insertion point be The tibial tuberosity is , and get the vector ;

[0110] B.2) Calculate the midpoint of the line connecting the lateral tibial condyle and the medial tibial condyle as The center point of the tibial plateau is , get the Y-axis vector of the tibia coordinate system ;

[0111] B.3) With the above vector Cross product vector Get the X-axis vector of the tibia coordinate system ;

[0112] B.4) With the above vector Cross product vector Get the Z-axis vector of the tibia coordinate system , completing the construction of the tibia coordinate system.

[0113] S805: Place the femoral prosthesis and the tibial prosthesis at corresponding positions based on parameter information such as the prosthesis osteotomy amount.

[0114] In this step, the placement position of the prosthesis can be determined based on the selected landmark points, the constructed coordinate system, and the prosthesis parameter information including the amount of osteotomy, and the prosthesis is placed at the position.

[0115] The procedure for placing a femoral prosthesis can be:

[0116] C.1) Set the origin of the prosthesis For the distal point of the femur on the surgical side, a rotation matrix is established using the X, Y, and Z axes of the femoral coordinate system , that is, the first rotation matrix in the aforementioned embodiment . Assume that the femoral prosthesis posture matrix is

[0117]

[0118] And place the femoral prosthesis at the initial position corresponding to the posture matrix.

[0119] C.2) Displace the femoral prosthesis along the normal vector of the distal section of the prosthesis so that the distance from the distal point of the femur on the surgical side to the distal section of the prosthesis is equal to the distal osteotomy of the femoral prosthesis.

[0120] C.3) Calculate the cross product of the normal vector of the posterior condyle section of the femoral prosthesis and the normal vector of the posterior oblique section of the prosthesis to obtain the vector , that is, the second normal vector in the aforementioned embodiment Then multiply the normal vector of the distal section of the prosthesis by the second normal vector , and get the vector , that is, the first normal vector in the aforementioned embodiment .

[0121] C.4) At the first normal vector The femoral prosthesis is displaced upward so that the distance from the posterior condyle point on the surgical side to the posterior condyle section of the prosthesis is equal to the posterior condyle osteotomy of the femoral prosthesis. At this point, the placement of the femoral prosthesis is planned.

[0122] The procedure for placing a tibial prosthesis can be:

[0123] D.1) Set the origin of the tibial prosthesis The rotation matrix is established based on the X, Y and Z axes of the tibial coordinate system for the tibial plateau point on the surgical side. , that is, the second rotation matrix in the aforementioned embodiment . Assume that the tibial prosthesis posture matrix is

[0124]

[0125] The tibial prosthesis is placed at the initial position corresponding to the posture matrix.

[0126] D.2) Displace the tibial component in the direction of the normal vector of the tibial component cross section so that the distance from the non-operative tibial plateau to the tibial component cross section equals the amount of osteotomy. At this point, the planned placement of the tibial component is determined.

[0127] S806. Based on the current placement positions, plan and select the femoral prosthesis and tibial prosthesis with the greatest coverage, and complete the surgical planning.

[0128] In this step, the computer device can traverse and place all prostheses and plan to obtain the optimal femoral prosthesis and tibial prosthesis. Specifically, this step includes femoral prosthesis planning and tibial prosthesis planning. Among them:

[0129] The femoral prosthesis planning process can be:

[0130] E.1) Go through all femoral components and determine the placement of each femoral component according to the previous steps and place the femoral component at that location.

[0131] E.2) Determine the distal cross-section of the prosthesis, the posterior condyle cross-section of the prosthesis, and the posterior oblique cross-section of the prosthesis, as well as the distal cross-section of the femur, the posterior condyle cross-section of the femur, and the posterior oblique cross-section of the femur in the 3D model.

[0132] E.3) Based on the femoral prosthesis cross-sections and the corresponding femoral cross-sections in the 3D model, calculate the area of the intersection planes of each corresponding cross-section. Specifically, calculate the area of the intersection planes where the distal prosthesis cross-sections lie opposite or overlap with the corresponding distal femoral cross-sections, the area of the intersection planes where the posterior condyle prosthesis cross-sections lie opposite or overlap with the corresponding posterior femoral condyle cross-sections, and the area of the intersection planes where the posterior oblique prosthesis cross-sections lie opposite or overlap with the corresponding posterior oblique femoral cross-sections.

[0133] E.4) Based on the sum of the areas of all intersecting planes (the first area in the aforementioned embodiment), calculate the ratio of the sum of the areas of all intersecting planes to the sum of the areas of all femoral cross sections (the second area in the aforementioned embodiment). This ratio is the coverage of the femoral prosthesis.

[0134] E.5) Select the femoral component with the greatest coverage for preoperative planning.

[0135] The tibial prosthesis planning process can be:

[0136] F.1) Go through all tibial components and determine the placement of each tibial component according to the previous steps and place the tibial component in that location.

[0137] F.2) Determine the cross section of the tibial prosthesis and the corresponding cross section of the tibial bone in the three-dimensional model, and calculate the area of the intersection plane between the two (the third area in the aforementioned embodiment).

[0138] F.3) Based on the area of the intersection plane, the ratio of the intersection plane to the tibial cross section in the three-dimensional model (the area of the tibial cross section is the fourth area in the aforementioned embodiment) is calculated. This ratio is the coverage rate of the tibial prosthesis.

[0139] F.4) Select the tibial component with the greatest coverage for preoperative planning.

[0140] The unicompartmental prosthesis planning method provided in the embodiments of this application can automatically set the prosthesis position based on selected landmarks and the amount of prosthesis bone resection. By calculating the coverage of the prosthesis cross section, the optimal prosthesis model is selected, making unicompartmental prosthesis planning faster, more accurate, and safer.

[0141] Reference Figure 9 , shows a schematic diagram of a prosthesis planning device for unicompartmental surgery provided by an embodiment of the present application, which may specifically include a parameter information acquisition module 901, a placement position determination module 902, a coverage calculation module 903, and a preoperative planning module 904, wherein:

[0142] Parameter information acquisition module 901 is used to acquire parameter information of the prosthesis to be planned, wherein the prosthesis includes a femoral prosthesis and a tibial prosthesis, and the parameter information includes the amount of osteotomy;

[0143] A placement position determination module 902 is configured to determine the placement position of the prosthesis in the pre-constructed three-dimensional model based on the parameter information;

[0144] a coverage calculation module 903 for calculating a coverage ratio between a cross section of the prosthesis and a corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position, wherein the coverage ratio represents a proportion of an intersection plane of the prosthesis cross section and the bone cross section in the bone cross section;

[0145] The preoperative planning module 904 is configured to determine a target prosthesis from the plurality of prostheses to be planned according to the coverage rate, and perform preoperative planning of unicompartmental surgery based on the target prosthesis.

[0146] In the embodiment of the present application, the placement position determination module 902 may be specifically configured to:

[0147] Establish a coordinate system based on the selected landmark points;

[0148] determining an initial position of the prosthesis in a pre-constructed three-dimensional model according to the coordinate system;

[0149] After the prosthesis is placed in the initial position, the prosthesis is moved according to the osteotomy amount in the parameter information to obtain the placement position of the prosthesis in the three-dimensional model.

[0150] In the embodiment of the present application, the coordinate system may include a femoral coordinate system and a tibia coordinate system, and the placement position determination module 902 may also be used to:

[0151] Determine the prosthesis origin; wherein, the prosthesis origin of the femoral prosthesis is the distal point of the femur on the surgical side, and the prosthesis origin of the tibial prosthesis is the point of the tibial plateau on the surgical side;

[0152] establishing a first rotation matrix based on the distal end of the operated-side femur and the femoral coordinate system, and determining an initial position of the femoral prosthesis in the three-dimensional model according to the first rotation matrix; and

[0153] A second rotation matrix is established based on the tibial plateau lateral point and the tibial coordinate system, and an initial position of the tibial prosthesis in the three-dimensional model is determined according to the second rotation matrix.

[0154] In a possible implementation of the embodiment of the present application, the placement position determination module 902 may also be used to:

[0155] For the femoral prosthesis, displacing the femoral prosthesis along the normal vector direction of the distal cross-section of the prosthesis so that the distance from the distal point of the femur on the surgical side to the distal cross-section of the prosthesis is equal to the distal osteotomy amount of the femoral prosthesis;

[0156] The femoral prosthesis is displaced along the direction of the first normal vector so that the distance from the posterior condyle point on the surgical side to the posterior condyle section of the prosthesis is equal to the posterior condyle osteotomy amount of the femoral prosthesis; wherein the first normal vector is obtained by cross-multiplying the normal vector of the distal section of the prosthesis by the second normal vector, and the second normal vector is obtained by cross-multiplying the normal vector of the posterior condyle section of the prosthesis by the normal vector of the posterior oblique section of the prosthesis.

[0157] In another possible implementation of the embodiment of the present application, the placement position determination module 902 may also be used to:

[0158] For the tibial prosthesis, the tibial prosthesis is displaced along the normal vector direction of the tibial prosthesis cross section so that the distance from the non-operative side tibial plateau point to the tibial prosthesis cross section is equal to the osteotomy amount of the tibial prosthesis.

[0159] In the embodiment of the present application, the coverage calculation module 903 may be specifically used to:

[0160] For the femoral prosthesis, calculating first areas of a distal femoral cross-section, a posterior femoral condyle cross-section, and a posterior femoral oblique cross-section relative to the corresponding distal femoral cross-section, posterior femoral condyle cross-section, and posterior femoral oblique cross-section in the three-dimensional model; and second areas of the distal femoral cross-section, the posterior femoral condyle cross-section, and the posterior femoral oblique cross-section; calculating a ratio of the first area to the second area to obtain a coverage rate of the femoral prosthesis;

[0161] For the tibial prosthesis, a third area of the tibial prosthesis cross section relative to the corresponding tibial cross section in the three-dimensional model is calculated; and a fourth area of the tibial cross section is calculated; and a ratio of the third area to the fourth area is calculated to obtain the coverage rate of the tibial prosthesis.

[0162] In the embodiment of the present application, the preoperative planning module 904 may be specifically used to:

[0163] The prosthesis with the largest coverage rate is determined from the multiple prostheses to be planned as the target prosthesis; the target prosthesis includes a femoral target prosthesis and a tibial target prosthesis.

[0164] The present invention provides a prosthesis planning device for unicompartmental surgery, which can be a computer device or a functional module in a computer device capable of implementing the steps in the aforementioned method embodiments. The device can be used to implement the steps in the aforementioned method embodiments.

[0165] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiment part.

[0166] Reference Figure 10, shows a schematic diagram of a computer device provided by an embodiment of the present application. Figure 10 As shown, the computer device 1000 in the embodiment of the present application includes: a processor 1010, a memory 1020, and a computer program 1021 stored in the memory 1020 and executable on the processor 1010. When the processor 1010 executes the computer program 1021, the steps of each embodiment of the above-mentioned unicompartmental prosthesis planning method are implemented, such as Figure 1 Alternatively, when the processor 1010 executes the computer program 1021, the functions of the modules / units in the above-mentioned device embodiments are realized, for example, Figure 9 Functions of modules 901 to 904 are shown.

[0167] Exemplarily, the computer program 1021 may be divided into one or more modules / units, which are stored in the memory 1020 and executed by the processor 1010 to complete the present application. The one or more modules / units may be a series of computer program instruction segments capable of performing specific functions, which may be used to describe the execution process of the computer program 1021 in the computer device 1000. For example, the computer program 1021 may be divided into a parameter information acquisition module, a placement position determination module, a coverage calculation module, and a preoperative planning module, with the specific functions of each module being as follows:

[0168] A parameter information acquisition module is used to acquire parameter information of the prosthesis to be planned, wherein the prosthesis includes a femoral prosthesis and a tibial prosthesis, and the parameter information includes an osteotomy amount;

[0169] a placement position determination module, configured to determine a placement position of the prosthesis in a pre-constructed three-dimensional model based on the parameter information;

[0170] a coverage calculation module, configured to calculate a coverage ratio between a cross section of the prosthesis and a corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position, wherein the coverage ratio represents a proportion of an intersection plane of the prosthesis cross section and the bone cross section in the bone cross section;

[0171] A preoperative planning module is used to determine a target prosthesis from a plurality of prostheses to be planned according to the coverage rate, and perform preoperative planning of unicompartmental surgery based on the target prosthesis.

[0172] The computer device 1000 may be a device capable of performing each step in the aforementioned method embodiments. The computer device 1000 may be a desktop computer, a cloud server, or other devices. For example, the computer device 1000 may be a computer-assisted medical device. The computer device 1000 may include, but is not limited to, a processor 1010 and a memory 1020. Those skilled in the art will appreciate that Figure 10 This is only an example of the computer device 1000 and does not constitute a limitation of the computer device 1000. The computer device 1000 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device 1000 may also include input and output devices, network access devices, buses, etc.

[0173] The processor 1010 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0174] The memory 1020 can be an internal storage unit of the computer device 1000, such as a hard drive or memory of the computer device 1000. The memory 1020 can also be an external storage device of the computer device 1000, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped on the computer device 1000. Furthermore, the memory 1020 can include both an internal storage unit of the computer device 1000 and an external storage device. The memory 1020 is used to store the computer program 1021 and other programs and data required by the computer device 1000. The memory 1020 can also be used to temporarily store data that has been output or is about to be output.

[0175] An embodiment of the present application further discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the methods described in the aforementioned embodiments are implemented.

[0176] An embodiment of the present application further discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed by a computer, the methods described in the aforementioned embodiments are implemented.

[0177] An embodiment of the present application further discloses a computer program product, including a computer program. When the computer program is run on a computer, the computer is caused to execute the methods described in the aforementioned embodiments.

[0178] The above embodiments are intended only to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the above embodiments or replace some of the technical features therein with equivalents; and such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application and should be included within the scope of protection of the present application.

Claims

1. A method for planning a unicompartmental prosthesis, characterized in that: include: Acquiring parameter information of a prosthesis to be planned, wherein the prosthesis includes a femoral prosthesis and a tibial prosthesis, and the parameter information includes an amount of osteotomy; establishing a coordinate system based on the selected landmark points, determining an initial position of the prosthesis in the pre-constructed three-dimensional model according to the coordinate system, and after placing the prosthesis in the initial position, moving the prosthesis according to the amount of osteotomy in the parameter information to obtain a placement position of the prosthesis in the three-dimensional model; calculating a coverage ratio between a cross section of the prosthesis and a corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position, the coverage ratio representing a proportion of an intersection plane of the prosthesis cross section and the bone cross section in the bone cross section; determining a target prosthesis from a plurality of prostheses to be planned according to the coverage rate, and performing preoperative planning of unicompartmental surgery based on the target prosthesis; The step of moving the prosthesis according to the amount of osteotomy in the parameter information to obtain a placement position of the prosthesis in the three-dimensional model includes: For the femoral prosthesis, the femoral prosthesis is displaced along the normal vector direction of the distal cross-section of the prosthesis so that the distance from the distal point of the femur on the surgical side to the distal cross-section of the prosthesis is equal to the distal osteotomy amount of the femoral prosthesis; the femoral prosthesis is displaced along the first normal vector direction so that the distance from the posterior condyle point on the surgical side to the posterior condyle cross-section of the prosthesis is equal to the posterior condyle osteotomy amount of the femoral prosthesis; wherein the first normal vector is obtained by cross-multiplying the normal vector of the distal cross-section of the prosthesis by the second normal vector, and the second normal vector is obtained by cross-multiplying the normal vector of the posterior condyle cross-section of the prosthesis by the normal vector of the posterior oblique cross-section of the prosthesis; For the tibial prosthesis, the tibial prosthesis is displaced along the normal vector direction of the tibial prosthesis cross section so that the distance from the non-operative side point of the tibial plateau to the tibial prosthesis cross section is equal to the osteotomy amount of the tibial prosthesis.

2. The method according to claim 1, characterized in that The coordinate system includes a femoral coordinate system and a tibial coordinate system, and determining the initial position of the prosthesis in the pre-constructed three-dimensional model according to the coordinate system includes: Determine the prosthesis origin; wherein, the prosthesis origin of the femoral prosthesis is the distal point of the femur on the surgical side, and the prosthesis origin of the tibial prosthesis is the point of the tibial plateau on the surgical side; establishing a first rotation matrix based on the distal end of the operated-side femur and the femoral coordinate system, and determining an initial position of the femoral prosthesis in the three-dimensional model according to the first rotation matrix; and A second rotation matrix is established based on the tibial plateau lateral point and the tibial coordinate system, and an initial position of the tibial prosthesis in the three-dimensional model is determined according to the second rotation matrix.

3. The method according to claim 1 or 2, characterized in that Calculating the coverage between the prosthesis cross section and the corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position includes: For the femoral prosthesis, calculating first areas of a distal femoral cross-section, a posterior femoral condyle cross-section, and a posterior femoral oblique cross-section relative to the corresponding distal femoral cross-section, posterior femoral condyle cross-section, and posterior femoral oblique cross-section in the three-dimensional model; and second areas of the distal femoral cross-section, the posterior femoral condyle cross-section, and the posterior femoral oblique cross-section; calculating a ratio of the first area to the second area to obtain a coverage rate of the femoral prosthesis; For the tibial prosthesis, a third area of the tibial prosthesis cross section relative to the corresponding tibial cross section in the three-dimensional model is calculated; and a fourth area of the tibial cross section is calculated; and a ratio of the third area to the fourth area is calculated to obtain the coverage rate of the tibial prosthesis.

4. The method according to claim 3, characterized in that Determining a target prosthesis from a plurality of prostheses to be planned according to the coverage rate includes: The prosthesis with the largest coverage rate is determined from the multiple prostheses to be planned as the target prosthesis; the target prosthesis includes a femoral target prosthesis and a tibial target prosthesis.

5. A prosthesis planning device for unicompartmental surgery, characterized in that: include: A parameter information acquisition module is used to acquire parameter information of the prosthesis to be planned, wherein the prosthesis includes a femoral prosthesis and a tibial prosthesis, and the parameter information includes an osteotomy amount; a placement position determination module, configured to establish a coordinate system based on selected landmark points, determine an initial position of the prosthesis in a pre-constructed three-dimensional model according to the coordinate system, and after placing the prosthesis in the initial position, move the prosthesis according to the osteotomy amount in the parameter information to obtain a placement position of the prosthesis in the three-dimensional model; a coverage calculation module, configured to calculate a coverage ratio between a cross section of the prosthesis and a corresponding bone cross section in the three-dimensional model when the prosthesis is in the placement position, wherein the coverage ratio represents a proportion of an intersection plane of the prosthesis cross section and the bone cross section in the bone cross section; a preoperative planning module, configured to determine a target prosthesis from a plurality of prostheses to be planned according to the coverage rate, and perform preoperative planning of unicompartmental surgery based on the target prosthesis; Wherein, the placement position determination module is specifically used to: For the femoral prosthesis, the femoral prosthesis is displaced along the normal vector direction of the distal cross-section of the prosthesis so that the distance from the distal point of the femur on the surgical side to the distal cross-section of the prosthesis is equal to the distal osteotomy amount of the femoral prosthesis; the femoral prosthesis is displaced along the first normal vector direction so that the distance from the posterior condyle point on the surgical side to the posterior condyle cross-section of the prosthesis is equal to the posterior condyle osteotomy amount of the femoral prosthesis; wherein the first normal vector is obtained by cross-multiplying the normal vector of the distal cross-section of the prosthesis by the second normal vector, and the second normal vector is obtained by cross-multiplying the normal vector of the posterior condyle cross-section of the prosthesis by the normal vector of the posterior oblique cross-section of the prosthesis; For the tibial prosthesis, the tibial prosthesis is displaced along the normal vector direction of the tibial prosthesis cross section so that the distance from the non-operative side point of the tibial plateau to the tibial prosthesis cross section is equal to the osteotomy amount of the tibial prosthesis.

6. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the computer device is caused to implement the method according to any one of claims 1 to 4.

7. A computer program product comprising a computer program, characterized in that When the computer program is executed, the method according to any one of claims 1 to 4 is performed.

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