A method for planning knee replacement surgery, an electronic device, and a storage medium.
By collecting and mapping the contact point trajectory between the femur and tibia during knee replacement surgery, the surgeon can adjust the position of the prosthesis and spacer, thus solving the problem that the contact trajectory between the prosthesis and spacer affects the postoperative efficacy after knee replacement surgery, and improving the reliability of the surgery and the lifespan of the prosthesis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING TINAVI MEDICAL TECH
- Filing Date
- 2023-08-23
- Publication Date
- 2026-07-17
AI Technical Summary
In existing technologies, after knee replacement surgery, the contact trajectory between the prosthesis and the spacer affects the postoperative efficacy during knee flexion and extension, resulting in poor patient satisfaction in about 20% of cases and increasing the joint revision rate, thus affecting the lifespan of the prosthesis.
By collecting the contact points between the femur and tibia at different flexion angles, the contact point trajectory is generated and mapped to a custom surgeon's surgical view coordinate system. The osteotomy planning results are then output, and the positions of the prosthesis and spacer are adjusted until they meet the preset target, thus achieving closed-loop prediction and trial molding.
This effectively avoids the influence of the contact trajectory between the prosthesis and the spacer during postoperative knee flexion and extension, reduces the postoperative revision rate, and extends the service life of the joint prosthesis.
Smart Images
Figure CN117017485B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of artificial intelligence technology, specifically to a method for planning knee replacement surgery, an electronic device, and a storage medium. Background Technology
[0002] Knee replacement surgery is a procedure that replaces part of a patient's knee joint with an artificial component. When there are problems with the knee joint, pain, swelling, stiffness, or difficulty in normal movement can occur. Knee joint problems can be caused by a variety of different conditions, one of the most common being osteoarthritis. Knee replacement surgery effectively reduces knee pain and improves how the knee joint functions, and has become a commonly used orthopedic procedure.
[0003] The surface of the human knee joint is covered with cartilage. As we age, the cartilage gradually wears down, and the bones and ligaments around the knee joint also degenerate, eventually causing knee pain, deformity, and limited mobility. Many people have a misconception that knee replacement surgery involves replacing the entire knee, but this is not the case. Knee replacement surgery mainly replaces the worn-out, pitted cartilage on the surface of the knee joint with a metal prosthesis and a wear-resistant polyethylene pad.
[0004] Types of artificial knee replacement include total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA).
[0005] Total knee arthroplasty (TKA) is a surgical procedure that replaces a knee joint deformed due to osteoarthritis or rheumatoid arthritis with artificial materials (see attached). Figure 1 As shown in the image, this is an effective surgical method for treating end-stage knee osteoarthritis caused by various factors.
[0006] Unicompartmental knee arthroplasty (UKA) involves replacing only the surface of the affected area, and is currently mainly used for medial condyle replacement (as shown in the attached image). Figure 2 (As shown). Unicompartmental knee arthroplasty has a narrow scope of application, mainly used for patients with early-stage osteoarthritis (OA) and localized cartilage damage within a single compartment, without patellofemoral joint involvement. However, compared to total knee replacement, unicompartmental knee replacement has the following advantages: ① The surgery only removes the diseased articular surface, thus removing much less bone than in total knee replacement; ② Fewer foreign bodies are implanted (including metals, polyethylene, and bone cement); ③ Shorter operation time, less surgical trauma and complications, and faster postoperative recovery.
[0007] Total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) are effective surgical procedures for treating end-stage knee osteoarthritis. Postoperative joint mobility and stability are crucial indicators of surgical success. The contact point trajectory between the femur and tibia can be used to assess joint stability and freedom of movement. Manual surgery lacks precision and heavily relies on the surgeon's individual skill. Digital and visualized trajectory prediction data can compensate for insufficient experience and expand the capabilities of specialists. However, current manual surgery techniques cannot collect contact point data, lacking this trajectory data for knee replacement surgery. Due to the lack of femoral and tibial contact point trajectory prediction data, approximately 20% of TKA patients currently experience poor postoperative satisfaction. The contact trajectory between the prosthesis and spacer during knee flexion and extension affects postoperative outcomes and may even increase revision rates, thus impacting prosthesis lifespan. Summary of the Invention
[0008] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a knee replacement surgery planning method, electronic device and storage medium to solve the technical problem in the related art that the contact trajectory between the prosthesis and the pad during knee flexion and extension affects the postoperative efficacy.
[0009] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:
[0010] According to a first aspect of the present invention, a method for planning a knee replacement surgery is provided, comprising:
[0011] Step S1: Register the points on the femoral and tibial images with the points on the actual patient location to establish the relationship between the image coordinate system and the patient coordinate system.
[0012] Step S2: Collect the contact points between the femur and tibia at different flexion angles of the patient;
[0013] Step S3: Based on the relationship between the image coordinate system and the patient coordinate system, map the collected contact points to the image coordinate system to generate contact point trajectories;
[0014] Step S4: Map the contact point trajectory to a custom coordinate system, which is the image coordinate system from the surgeon's perspective.
[0015] Step S5: Based on the distribution of inner and outer contact points on all contact point trajectories, output the surgical planning results for osteotomy.
[0016] Preferably, the method further includes:
[0017] Step S6: Based on the surgical planning results output in step S5, simulate the installation of the prosthesis and spacer in the software, and obtain the contact point trajectory after the simulated installation of the prosthesis and spacer.
[0018] Step S7: Adjust the position of the prosthesis and pad until the contact point trajectory matches the preset surgical plan target;
[0019] Step S8: Based on the position of the prosthesis and pad corresponding to the contact point trajectory that meets the preset surgical planning target, perform osteotomy and trial molding on the patient;
[0020] Step S9: Each time a trial model is performed, return to step S2 and re-collect the contact point trajectory between the femur and tibia at different flexion angles until the distribution of medial and lateral contact points on all contact point trajectories meets the preset surgical planning target.
[0021] Step S10: Based on the trial molding results, install the prosthesis and pad at the corresponding part of the patient's body.
[0022] Preferably, in step S2, the contact points between the femur and tibia are collected at different flexion angles, including:
[0023] Calculate the direction of the force line on the femur relative to the tibia, and the point on each femur that is closest to the transverse section of the tibia.
[0024] The nearest point is determined as the lowest point of the medial and lateral condyles, and the lowest point is determined as the contact point between the femur and tibia.
[0025] Preferably, after mapping the acquired contact points to the image coordinate system according to the correlation between the image coordinate system and the patient coordinate system in step S3, the method further includes:
[0026] Calculate the pose matrix of the femoral image coordinates in the tibial coordinate system;
[0027] The generation of the contact point trajectory is specifically as follows:
[0028] Based on the pose matrix, the contact point at each flexion angle is projected onto the XY plane of the tibial coordinate system to obtain the contact point trajectory at different flexion angles. The contact point trajectory at each flexion angle is the line connecting the contact point at that flexion angle projected onto the XY plane.
[0029] In this system, the Z-axis of the tibial coordinate system coincides with the tibial force line, and the Y-axis coincides with the Akagi line, with the origin located at the proximal end of the tibial force line; the Akagi line is the line connecting the center of the posterior cruciate ligament insertion point and the inner edge of the tibial tuberosity; the tibial force line is the line connecting the center of the proximal tibia and the midpoint of the medial and lateral malleoli of the ankle.
[0030] Preferably, calculating the pose matrix of the femoral image coordinates in the tibial coordinate system includes:
[0031] Real-time acquisition of the pose matrix of the femoral tracker in the camera coordinate system Where T represents the transformation matrix, whose value is output by the optical camera; C represents the optical camera, used to acquire the spatial position and orientation information of the femoral tracker and the tibial tracker; F represents the femoral tracker, used to acquire the spatial position and orientation of the femur; the femoral tracker is fixed to the patient's femur by bone pins, and its position remains unchanged;
[0032] Real-time calculation of the pose matrix of the femoral image coordinates in the camera coordinate system : I represents a femoral image;
[0033] Real-time acquisition of the pose matrix of the tibia tracker in the camera coordinate system T represents a tibial tracker, used to acquire the spatial position and orientation of the tibia; the tibial tracker is fixed to the patient's tibia by bone pins and its position remains unchanged;
[0034] Real-time calculation of the pose matrix of the tibia image coordinates in the camera coordinate system : I2 represents the image of the tibia;
[0035] Calculate the pose matrix of the femoral image coordinates in the tibial coordinate system. : =invert( ) .
[0036] Preferably, in step S4, mapping the contact point trajectory to a custom coordinate system specifically involves:
[0037] The coordinates of the first location point and the second location point on the patient's tibia were collected using probes.
[0038] Based on the relationship between the image coordinate system and the patient coordinate system established in step S1, the coordinates of the first position point and the second position point are mapped onto the tibial image. A custom two-dimensional coordinate system is established with the line connecting these two points as the X-axis and the midpoint of the line connecting these two points as the origin.
[0039] Preferably, in step S5, based on the distribution of the inner and outer contact points on all contact point trajectories, the surgical planning result for osteotomy is output, including:
[0040] If the outer trajectory point on the contact point trajectory is within the preset safe zone, osteotomy of the lateral tibia is performed according to the current surgical plan;
[0041] If the outer trajectory point on the contact point trajectory exceeds the preset safety zone on both sides, the surgical planning result of reducing the amount of lateral tibial osteotomy is output.
[0042] If the outer trajectory point on the contact point trajectory only exceeds the preset safety zone on the front side, the surgical planning result of reducing the anterolateral osteotomy of the tibia and increasing the posterolateral osteotomy of the tibia is output.
[0043] If the outer trajectory point on the contact point trajectory exceeds the preset safety zone only on the posterior side, the surgical planning result of increasing the anterolateral osteotomy amount of the tibia and decreasing the posterolateral osteotomy amount of the tibia is output.
[0044] If the outer trajectory points on the contact point trajectory are concentrated within the preset safe zone, the surgical planning result of increasing the amount of lateral tibial osteotomy is output.
[0045] Preferably, the method further includes:
[0046] If the inner trajectory point on the contact point trajectory is within the preset safe zone, osteotomy of the medial side of the tibia is performed according to the current surgical plan;
[0047] If the front and rear sides of the inner trajectory point on the contact point trajectory both exceed the preset safety zone, output the surgical planning result of reducing the amount of inner osteotomy.
[0048] If the inner trajectory point on the contact point trajectory exceeds the preset safety zone only on the front side, the surgical planning result of reducing the amount of anteromedial osteotomy and increasing the amount of posteromedial osteotomy is output.
[0049] If the inner trajectory point on the contact point trajectory exceeds the preset safety zone only on the rear side, the surgical planning result of increasing the anteromedial osteotomy amount and decreasing the posteromedial osteotomy amount is output.
[0050] If the inner trajectory points on the contact point trajectory are concentrated within the preset safe zone, the surgical planning result of increasing the amount of inner osteotomy is output.
[0051] Preferably, in step S1, registering points on the femoral and tibial images with points on the actual patient location includes:
[0052] Coarse registration calculation: Based on the location of coarse registration points in the surgical plan, collect the patient's coarse registration points; based on the bony landmarks in the surgical plan, collect the position of the corresponding bony landmarks in the camera coordinate system using a probe.
[0053] Using a rigid registration algorithm, the minimum positional error matrix between the patient's coarse registration point and the surgical plan's coarse registration point is calculated, and the minimum error matrix is used as the original registration matrix.
[0054] Fine registration calculation: Multiple scattered points are selected on the bone surface of the patient's surgical area using a probe, and the fine registration matrix is calculated using an iterative nearest point algorithm;
[0055] Transform the original point cloud data pi to obtain the new point cloud target point p'i: p'i = Rpi + t, where pi represents the acquired registration point, R represents the rotation matrix of the registration matrix, and t represents the translation matrix of the registration matrix; the rotation matrix R and the translation matrix t are the fine registration matrix;
[0056] Convert the fine registration matrix to 4 4. Homogeneous transformation matrix to obtain femoral registration matrix Where T represents the transformation matrix, F represents the femoral tracker, and I represents the femoral image. This represents the pose of the femoral image coordinates in the patient coordinate system; and the tibial registration matrix. Where T represents the transformation matrix, I2 represents the tibia tracker, and I2 represents the tibia image. This indicates the pose of the tibia image coordinates in the patient coordinate system.
[0057] According to a second aspect of the present invention, a knee replacement surgery planning device is provided, comprising:
[0058] The registration module is used to register points on the femoral and tibial images with points on the actual patient location to establish the relationship between the image coordinate system and the patient coordinate system.
[0059] The acquisition module is used to acquire the contact points between the femur and tibia at different flexion angles of the patient;
[0060] The mapping module is used to map the acquired contact points to the image coordinate system based on the relationship between the image coordinate system and the patient coordinate system, thereby generating the contact point trajectory.
[0061] It is also used to map the contact point trajectory to a custom coordinate system, which is the image coordinate system from the surgeon's perspective.
[0062] The planning module is used to output the surgical planning results of osteotomy based on the distribution of inner and outer contact points on all contact point trajectories.
[0063] According to a third aspect of the present invention, an electronic device is provided, comprising:
[0064] The processor, communication interface, memory, and communication bus are connected, with the processor, communication interface, and memory communicating with each other via the communication bus.
[0065] Memory, used to store computer programs;
[0066] The processor implements the above method when executing programs stored in memory.
[0067] According to a fourth aspect of the present invention, a non-transitory computer-readable storage medium is provided storing computer instructions for causing a computer to perform the methods described above.
[0068] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:
[0069] By collecting the contact point trajectory between the femur with the implanted prosthesis and the tibia with the implanted spacer, the corresponding surgical planning results are output, which helps doctors correct the position of the prosthesis and spacer. This avoids the problem of the contact trajectory between the prosthesis and spacer affecting the postoperative efficacy during knee flexion and extension, reduces the postoperative revision rate, and extends the service life of the joint prosthesis.
[0070] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description
[0071] Figure 1 This is a flowchart of total knee arthroplasty (TKA) as shown in the background art;
[0072] Figure 2 This is a flowchart illustrating a unicompartmental knee arthroplasty (UKA) based on the background art.
[0073] Figure 3 This is a flowchart illustrating a knee replacement surgery planning method according to an exemplary embodiment;
[0074] Figure 4 This is a schematic diagram illustrating the effect of acquiring the trajectory of the contact point between the femur and tibia according to an exemplary embodiment;
[0075] Figure 5A This is a schematic diagram of a tibial coordinate system according to an exemplary embodiment;
[0076] Figure 5B This is a schematic diagram of the femoral coordinate system according to an exemplary embodiment;
[0077] Figures 6A-6E This is a schematic diagram illustrating the positional relationship between the outer trajectory point on the contact point trajectory and the preset safety zone, according to an exemplary embodiment.
[0078] Figures 7A-7E This is a schematic diagram illustrating the positional relationship between the inner trajectory point on the contact point trajectory and the preset safety zone, according to an exemplary embodiment.
[0079] Figure 8This is a flowchart illustrating a knee replacement surgery planning method according to another exemplary embodiment;
[0080] Figure 9 This is a schematic block diagram of a knee replacement surgery planning device according to an exemplary embodiment;
[0081] Figure 10 This is a schematic block diagram illustrating an electronic device in an exemplary embodiment. Detailed Implementation
[0082] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0083] As described in the background section, in related technologies, after knee replacement surgery, there is a technical problem where the contact trajectory between the prosthesis and the spacer during knee flexion and extension affects the postoperative efficacy.
[0084] In order to effectively solve the problems in related technologies, the present invention provides a method for planning knee replacement surgery, an electronic device and a storage medium, which are described in detail below.
[0085] Example 1
[0086] Figure 3 This is a flowchart illustrating a knee replacement surgery planning method according to an exemplary embodiment, see [link to flowchart]. Figure 3 The method includes:
[0087] Step S1: Register the points on the femoral and tibial images with the points on the actual patient location to establish the relationship between the image coordinate system and the patient coordinate system.
[0088] Step S2: Collect the contact points between the femur and tibia at different flexion angles of the patient;
[0089] Step S3: Based on the relationship between the image coordinate system and the patient coordinate system, map the collected contact points to the image coordinate system to generate contact point trajectories;
[0090] Step S4: Map the contact point trajectory to a custom coordinate system, which is the image coordinate system from the surgeon's perspective.
[0091] Step S5: Based on the distribution of inner and outer contact points on all contact point trajectories, output the surgical planning results for osteotomy.
[0092] It should be noted that, in practice, the technical solution provided in this embodiment runs in the controller of the medical device, or is loaded into an electronic device connected to the controller. The controller of the medical device executes the corresponding method by calling the program stored in the electronic device.
[0093] It is understood that the technical solution provided in this embodiment, by collecting the contact points between the femur and tibia at different flexion angles of the patient, generates the contact point trajectory, and outputs the corresponding surgical planning results, assists the doctor in visually predicting and judging the amount of osteotomy in different parts during knee replacement surgery. This avoids the problem of the contact trajectory between the prosthesis and the pad affecting the postoperative efficacy during the knee flexion and extension process, reduces the postoperative revision rate, and extends the service life of the joint prosthesis.
[0094] Furthermore, the method also includes:
[0095] Step S6: Based on the surgical planning results output in step S5, simulate the installation of the prosthesis and spacer in the software, and obtain the contact point trajectory after the simulated installation of the prosthesis and spacer.
[0096] Step S7: Adjust the position of the prosthesis and pad until the contact point trajectory matches the preset surgical plan target;
[0097] Step S8: Based on the position of the prosthesis and pad corresponding to the contact point trajectory that meets the preset surgical planning target, perform osteotomy and trial molding on the patient;
[0098] Step S9: Each time a trial model is performed, return to step S2 and re-collect the contact point trajectory between the femur and tibia at different flexion angles until the distribution of medial and lateral contact points on all contact point trajectories meets the preset surgical planning target.
[0099] Step S10: Based on the trial molding results, install the prosthesis and pad at the corresponding part of the patient's body.
[0100] Understandably, after each osteotomy, re-collecting the contact point trajectory between the femur and tibia at different flexion angles helps the doctor determine whether the osteotomy location and amount are appropriate. If not, adjustments are made. Therefore, the technical solution provided in this embodiment can achieve closed-loop prediction, continuously reminding the doctor that the placement of the prosthesis and spacer during the trial molding will not affect postoperative knee flexion and extension, thus improving the reliability of the surgery.
[0101] Further, in step S2, the contact points between the femur and tibia are collected at different flexion angles (including but not limited to varus, valgus, and hyperextension), including:
[0102] Calculate the direction of the force line on the femur relative to the tibia, and the point on both femurs closest to the transverse section of the tibia;
[0103] The nearest point is determined as the lowest point of the medial and lateral condyles, and the lowest point is determined as the contact point between the femur and tibia.
[0104] After mapping the acquired contact points to the image coordinate system according to the correlation between the image coordinate system and the patient coordinate system in step S3, the method further includes:
[0105] Calculate the pose matrix of the femoral image coordinates in the tibial coordinate system;
[0106] The generation of the contact point trajectory is specifically as follows:
[0107] Based on the pose matrix, the contact point at each flexion angle is projected onto the XY plane of the tibial coordinate system to obtain the contact point trajectory at different flexion angles. The contact point trajectory at each flexion angle is the line connecting the contact point at that flexion angle projected onto the XY plane.
[0108] Wherein, the tibial coordinate system (e.g.) Figure 5A The Z-axis (as shown) coincides with the tibial force line, and the Y-axis coincides with the Akaggi line, with the origin located at the proximal end of the tibial force line; the Akaggi line is the line connecting the center of the posterior cruciate ligament insertion point and the inner edge of the tibial tuberosity; the tibial force line is the line connecting the center of the proximal tibia and the midpoint of the medial and lateral malleoli of the ankle.
[0109] The femoral image coordinates mentioned in this embodiment are image coordinates in the femoral coordinate system. (See femoral coordinate system). Figure 5B As shown): The X-axis coincides with the condylar line; the Z-axis is the femoral force line; the Y-axis is perpendicular to the condylar line and the force line, pointing forward of the body; the origin is located at the midpoint of the condylar line.
[0110] Understandably, projecting the contact point between the femur and tibia onto the XY plane of the tibial coordinate system allows for a better understanding of the current position of the prosthesis and spacer, and the resulting contact point trajectory can affect postoperative knee flexion and extension.
[0111] Specifically, the calculation of the pose matrix of the femoral image coordinates in the tibial coordinate system includes:
[0112] Real-time acquisition of the pose matrix of the femoral tracker in the camera coordinate system Where T represents the transformation matrix, whose value is output by the optical camera; C represents the optical camera, used to acquire the spatial position and orientation information of the femoral tracker and the tibial tracker; F represents the femoral tracker, used to acquire the spatial position and orientation of the femur; the femoral tracker is fixed to the patient's femur by bone pins, and its position remains unchanged;
[0113] Real-time calculation of the pose matrix of the femoral image coordinates in the camera coordinate system : I represents a femoral image;
[0114] Real-time acquisition of the pose matrix of the tibia tracker in the camera coordinate system T represents a tibial tracker, used to acquire the spatial position and orientation of the tibia; the tibial tracker is fixed to the patient's tibia by bone pins and its position remains unchanged;
[0115] Real-time calculation of the pose matrix of the tibia image coordinates in the camera coordinate system : I2 represents the image of the tibia;
[0116] Calculate the pose matrix of the femoral image coordinates in the tibial coordinate system. : =invert( ) .
[0117] Preferably, in step S4, mapping the contact point trajectory to a custom coordinate system specifically involves:
[0118] The coordinates of the first location point and the second location point on the patient's tibia were collected using probes.
[0119] Based on the relationship between the image coordinate system and the patient coordinate system established in step S1, the coordinates of the first position point and the second position point are mapped onto the tibial image. A custom two-dimensional coordinate system is established with the line connecting these two points as the X-axis and the midpoint of the line connecting these two points as the origin.
[0120] It should be noted that the custom coordinate system is an auxiliary function; the system defaults to the tibial coordinate system defined above. However, the output contact point trajectory in the tibial coordinate system may not conform to the surgeon's viewpoint. From the surgeon's viewpoint, if the contact point trajectory distribution is not symmetrical with the Akag line, two points can be selected on the tibia using a probe to redefine the X-axis direction. These two points are used to define the X-axis, and the Y-axis of the coordinate system will no longer be in the Akag line direction.
[0121] In practice, an optical camera can be used to capture the spatial position of the probe. Whether the probe captures the inner or outer point is determined by the doctor. Two points define a straight line, and the two points selected by the doctor are mapped onto the image coordinate system. The direction of this straight line becomes the new X-axis direction.
[0122] It should be noted that the image coordinate system (tibial coordinate system) established earlier was customized by the software for modeling. However, for the convenience of surgery, doctors may think that the image coordinate system customized by the software is not convenient for observing the surgical situation. Therefore, doctors will collect two points on the patient as the X-axis, select the origin, and re-establish a coordinate system that they think is more suitable for observing the surgical situation.
[0123] The two points selected from the surgeon's perspective are generally the center point of the inner platform and the center point of the outer platform. The X-axis is defined by these two points, and the trajectory of the contact point in a custom coordinate system is easier for the surgeon to view, thus assisting in the osteotomy.
[0124] In this embodiment, the medial side refers to the side relatively close to the human body's central axis (which is the extension of the axis of symmetry of the human face), and the medial platform refers to the medial tibial plane. In this embodiment, the lateral side refers to the side relatively far from the human body's central axis, and the lateral platform refers to the lateral tibial plane.
[0125] Furthermore, in step S5, based on the distribution of the inner and outer contact points on all contact point trajectories, the surgical planning results for osteotomy are output, including:
[0126] like Figure 6A As shown, if the outer trajectory point on the contact point trajectory is within the preset safe zone, osteotomy of the lateral tibia is performed according to the current surgical plan;
[0127] like Figure 6B As shown, if the outer trajectory point on the contact point trajectory exceeds the preset safety zone on both sides, the surgical planning result of reducing the amount of lateral tibial osteotomy is output.
[0128] like Figure 6C As shown, if the outer trajectory point on the contact point trajectory only exceeds the preset safety zone on the front side, the surgical planning result of reducing the anterolateral osteotomy of the tibia and increasing the posterolateral osteotomy of the tibia is output.
[0129] like Figure 6D As shown, if the outer trajectory point on the contact point trajectory only exceeds the preset safety zone on the rear side, the surgical planning result of increasing the anterolateral osteotomy of the tibia and decreasing the posterolateral osteotomy of the tibia is output.
[0130] like Figure 6E As shown, if the outer trajectory points on the contact point trajectory are concentrated within the preset safe zone, the surgical planning result of increasing the amount of lateral tibial osteotomy is output.
[0131] like Figure 7A As shown, if the inner trajectory point on the contact point trajectory is within the preset safe zone, osteotomy of the medial side of the tibia is performed according to the current surgical plan;
[0132] like Figure 7B As shown, if the front and rear sides of the inner trajectory point on the contact point trajectory both exceed the preset safety zone, the surgical planning result of reducing the amount of inner osteotomy is output.
[0133] like Figure 7C As shown, if the inner trajectory point on the contact point trajectory only exceeds the preset safety zone on the front side, the surgical planning result of reducing the amount of osteotomy on the front medial side and increasing the amount of osteotomy on the back medial side is output.
[0134] like Figure 7D As shown, if the inner trajectory point on the contact point trajectory only exceeds the preset safety zone on the rear side, the surgical planning result of increasing the anteromedial osteotomy amount and decreasing the posteromedial osteotomy amount is output.
[0135] like Figure 7E As shown, if the inner trajectory points on the contact point trajectory are concentrated within the preset safe zone, the surgical planning result of increasing the amount of inner osteotomy is output.
[0136] It should be noted that the preset safety zones can be adjusted according to the doctor's clinical needs. The default areas are: the inner safety zone, a circular area not exceeding 1 / 2 of the distance between the center and the inner edge of the inner platform; and the outer safety zone, a circular area not exceeding 2 / 3 of the distance between the center and the outer edge of the outer platform.
[0137] In practice, step S1 involves registering points on the femoral and tibial images with points on the patient's actual body location, including:
[0138] Coarse registration calculation: Based on the location of coarse registration points in the surgical plan, collect the patient's coarse registration points; based on the bony landmarks in the surgical plan, collect the position of the corresponding bony landmarks in the camera coordinate system using a probe.
[0139] Using a rigid registration algorithm, the minimum positional error matrix between the patient's coarse registration point and the surgical plan's coarse registration point is calculated, and this minimum error matrix is used as the original registration matrix.
[0140] Fine registration calculation: Multiple scattered points are selected on the bone surface of the patient's surgical area using a probe, and the fine registration matrix is calculated using an iterative nearest point algorithm;
[0141] Transform the original point cloud data pi to obtain the new point cloud target point p'i: p'i = Rpi + t, where pi represents the acquisition and registration point, R represents the rotation matrix of the registration matrix, and t represents the translation matrix of the registration matrix; the rotation matrix R and the translation matrix t are the fine registration matrix;
[0142] Convert the fine registration matrix to 4 4. Homogeneous transformation matrix to obtain femoral registration matrix Where T represents the transformation matrix, F represents the femoral tracker, and I represents the femoral image. This represents the pose of the femoral image coordinates in the patient coordinate system; and the tibial registration matrix. Where T represents the transformation matrix, I2 represents the tibia tracker, and I2 represents the tibia image. This indicates the pose of the tibia image coordinates in the patient coordinate system.
[0143] Example 2
[0144] Figure 8 This is a flowchart illustrating a knee replacement surgery planning method according to another exemplary embodiment, see [link to flowchart]. Figure 8 The method includes:
[0145] Step S21: Register the points on the femoral and tibial images with the points on the actual patient location to establish the relationship between the image coordinate system and the patient coordinate system.
[0146] Step S22: Collect the contact points between the femur and tibia at different flexion angles of the patient;
[0147] Step S23: Based on the relationship between the image coordinate system and the patient coordinate system, map the collected contact points to the image coordinate system to generate contact point trajectories;
[0148] Step S24: Map the contact point trajectory to a custom coordinate system, which is the image coordinate system from the surgeon's perspective.
[0149] Step S25: Output the surgical planning results based on the distribution of inner and outer contact points on all contact point trajectories;
[0150] Step S26: Based on the surgical planning results output in step S25, simulate the installation of the prosthesis and spacer in the software, and obtain the contact point trajectory after the simulated installation of the prosthesis and spacer.
[0151] Step S27: Adjust the position of the prosthesis and pad until the contact point trajectory matches the preset surgical plan target;
[0152] Step S28: Perform osteotomy and trial molding on the patient according to the position of the prosthesis and pad corresponding to the contact point trajectory that meets the preset surgical planning target;
[0153] Step S29: Each time a trial model is performed, return to step S22 and re-collect the contact point trajectory between the femur and tibia at different flexion angles until the distribution of medial and lateral contact points on all contact point trajectories meets the preset surgical planning target.
[0154] Step S30: Based on the trial molding results, install the prosthesis and pad at the corresponding part of the patient's body.
[0155] It should be noted that, in practice, the technical solution provided in this embodiment runs in the controller of the medical device, or is loaded into an electronic device connected to the controller. The controller of the medical device executes the corresponding method by calling the program stored in the electronic device.
[0156] It is understood that the technical solution provided in this embodiment, by collecting the contact points between the femur and tibia at different flexion angles of the patient, generates the contact point trajectory, and outputs the corresponding surgical planning results, assists the doctor in visually predicting and judging the amount of osteotomy in different parts during knee replacement surgery. This avoids the problem of the contact trajectory between the prosthesis and the pad affecting the postoperative efficacy during the knee flexion and extension process, reduces the postoperative revision rate, and extends the service life of the joint prosthesis.
[0157] Example 3
[0158] Figure 9 This is a schematic block diagram of a knee replacement surgery planning device 100 according to an exemplary embodiment. See also: Figure 9 The device includes:
[0159] The registration module 101 is used to register points on the femoral and tibial images with points on the actual patient location to establish the relationship between the image coordinate system and the patient coordinate system.
[0160] The acquisition module 102 is used to acquire the contact points between the femur and tibia at different flexion angles of the patient;
[0161] The mapping module 103 is used to map the acquired contact points to the image coordinate system according to the relationship between the image coordinate system and the patient coordinate system, and generate the contact point trajectory.
[0162] It is also used to map the contact point trajectory to a custom coordinate system, which is the image coordinate system from the surgeon's perspective.
[0163] The planning module 104 is used to output the surgical planning results of osteotomy based on the distribution of inner and outer contact points on all contact point trajectories.
[0164] It should be noted that, in practice, the technical solution provided in this embodiment runs in the controller of the medical device, or is loaded into an electronic device connected to the controller. The controller of the medical device executes the corresponding method by calling the program stored in the electronic device.
[0165] The implementation methods and beneficial effects of each module are described in the relevant steps of the above embodiments, and will not be repeated in this embodiment.
[0166] It is understood that the technical solution provided in this embodiment, by collecting the contact points between the femur and tibia at different flexion angles of the patient, generates the contact point trajectory, and outputs the corresponding surgical planning results, assists the doctor in visually predicting and judging the amount of osteotomy in different parts during knee replacement surgery. This avoids the problem of the contact trajectory between the prosthesis and the pad affecting the postoperative efficacy during the knee flexion and extension process, reduces the postoperative revision rate, and extends the service life of the joint prosthesis.
[0167] Example 4
[0168] See Figure 10 An electronic device according to an exemplary embodiment includes:
[0169] The processor 701, communication interface 702, memory 703, and communication bus 704 are provided, wherein the processor 701, communication interface 702, and memory 703 communicate with each other through the communication bus 704.
[0170] Memory 703 is used to store computer programs;
[0171] The processor 701 implements the above method when executing a program stored in memory.
[0172] It is understood that the technical solution provided in this embodiment, by collecting the contact points between the femur and tibia at different flexion angles of the patient, generates the contact point trajectory, and outputs the corresponding surgical planning results, assists the doctor in visually predicting and judging the amount of osteotomy in different parts during knee replacement surgery. This avoids the problem of the contact trajectory between the prosthesis and the pad affecting the postoperative efficacy during the knee flexion and extension process, reduces the postoperative revision rate, and extends the service life of the joint prosthesis.
[0173] Example 5
[0174] An exemplary embodiment illustrates a non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the methods described above.
[0175] It is understood that the technical solution provided in this embodiment, by collecting the contact points between the femur and tibia at different flexion angles of the patient, generates the contact point trajectory, and outputs the corresponding surgical planning results, assists the doctor in visually predicting and judging the amount of osteotomy in different parts during knee replacement surgery. This avoids the problem of the contact trajectory between the prosthesis and the pad affecting the postoperative efficacy during the knee flexion and extension process, reduces the postoperative revision rate, and extends the service life of the joint prosthesis.
[0176] Of course, those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.). The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The storage medium can be a memory, magnetic disk, optical disk, etc.
[0177] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A method for planning knee replacement surgery, characterized in that, include: Step S1: Register the points on the femoral and tibial images with the points on the actual patient location to establish the relationship between the image coordinate system and the patient coordinate system. Step S2: Collect the contact points between the femur and tibia at different flexion angles of the patient; Step S3: Based on the relationship between the image coordinate system and the patient coordinate system, map the collected contact points to the image coordinate system to generate contact point trajectories; Step S4: Map the contact point trajectory to a custom coordinate system, which is the image coordinate system from the surgeon's perspective. Step S5: Based on the distribution of the inner and outer contact points on all contact point trajectories, output the surgical planning results for osteotomy; After mapping the acquired contact points to the image coordinate system according to the correlation between the image coordinate system and the patient coordinate system in step S3, the method further includes: Calculate the pose matrix of the femoral image coordinates in the tibial coordinate system; The generation of the contact point trajectory is specifically as follows: Based on the pose matrix, the contact point at each flexion angle is projected onto the XY plane of the tibial coordinate system to obtain the contact point trajectory at different flexion angles. The contact point trajectory at each flexion angle is the line connecting the contact point at that flexion angle projected onto the XY plane. In this system, the Z-axis of the tibial coordinate system coincides with the tibial force line, and the Y-axis coincides with the Akagi line, with the origin located at the proximal end of the tibial force line; the Akagi line is the line connecting the center of the posterior cruciate ligament insertion point and the inner edge of the tibial tuberosity; the tibial force line is the line connecting the center of the proximal tibia and the midpoint of the medial and lateral malleoli of the ankle.
2. The method according to claim 1, characterized in that, Also includes: Step S6: Based on the surgical planning results output in step S5, simulate the installation of the prosthesis and spacer in the software, and obtain the contact point trajectory after the simulated installation of the prosthesis and spacer. Step S7: Adjust the position of the prosthesis and pad until the contact point trajectory matches the pre-planned surgical target.
3. The method according to claim 1, characterized in that, In step S2, the contact points between the femur and tibia are collected at different flexion angles, including: Calculate the direction of the force line on the femur relative to the tibia, and the point on both femurs closest to the transverse section of the tibia; The nearest point is determined as the lowest point of the medial and lateral condyles, and the lowest point is determined as the contact point between the femur and tibia.
4. The method according to claim 1, characterized in that, The calculation of the pose matrix of the femoral image coordinates in the tibial coordinate system includes: Real-time acquisition of the pose matrix of the femoral tracker in the camera coordinate system Where T represents the transformation matrix, whose value is output by the optical camera; C represents the optical camera, used to acquire the spatial position and orientation information of the femoral tracker and the tibial tracker; F represents the femoral tracker, used to acquire the spatial position and orientation of the femur; the femoral tracker is fixed to the patient's femur by bone pins, and its position remains unchanged; Real-time calculation of the pose matrix of the femoral image coordinates in the camera coordinate system : I represents a femoral image; Real-time acquisition of the pose matrix of the tibia tracker in the camera coordinate system T represents a tibial tracker, used to acquire the spatial position and orientation of the tibia; the tibial tracker is fixed to the patient's tibia by bone pins and its position remains unchanged; Real-time calculation of the pose matrix of the tibia image coordinates in the camera coordinate system : I2 represents the image of the tibia; Calculate the pose matrix of the femoral image coordinates in the tibial coordinate system. : =invert( ) .
5. The method according to claim 1, characterized in that, In step S4, the contact point trajectory is mapped to a custom coordinate system, specifically as follows: The coordinates of the first location point and the second location point on the patient's tibia were collected using probes. Based on the relationship between the image coordinate system and the patient coordinate system established in step S1, the coordinates of the first position point and the second position point are mapped onto the tibial image. A custom two-dimensional coordinate system is established with the line connecting these two points as the X-axis and the midpoint of the line connecting these two points as the origin.
6. The method according to claim 1, characterized in that, In step S5, based on the distribution of the inner and outer contact points on all contact point trajectories, the surgical planning results for osteotomy are output, including: If the outer trajectory point on the contact point trajectory is within the preset safe zone, osteotomy of the lateral tibia is performed according to the current surgical plan; If the outer trajectory point on the contact point trajectory exceeds the preset safety zone on both sides, the surgical planning result of reducing the amount of lateral tibial osteotomy is output. If the outer trajectory point on the contact point trajectory only exceeds the preset safety zone on the front side, the surgical planning result of reducing the anterolateral osteotomy of the tibia and increasing the posterolateral osteotomy of the tibia is output. If the outer trajectory point on the contact point trajectory exceeds the preset safety zone only on the posterior side, the surgical planning result of increasing the anterolateral osteotomy amount of the tibia and decreasing the posterolateral osteotomy amount of the tibia is output. If the outer trajectory points on the contact point trajectory are concentrated within the preset safe zone, the surgical planning result of increasing the amount of lateral tibial osteotomy is output.
7. The method according to claim 6, characterized in that, Also includes: If the inner trajectory point on the contact point trajectory is within the preset safe zone, osteotomy of the medial side of the tibia is performed according to the current surgical plan; If the front and rear sides of the inner trajectory point on the contact point trajectory both exceed the preset safety zone, output the surgical planning result of reducing the amount of inner osteotomy. If the inner trajectory point on the contact point trajectory exceeds the preset safety zone only on the front side, the surgical planning result of reducing the amount of anteromedial osteotomy and increasing the amount of posteromedial osteotomy is output. If the inner trajectory point on the contact point trajectory exceeds the preset safety zone only on the rear side, the surgical planning result of increasing the anteromedial osteotomy amount and decreasing the posteromedial osteotomy amount is output. If the inner trajectory points on the contact point trajectory are concentrated within the preset safe zone, the surgical planning result of increasing the amount of inner osteotomy is output.
8. The method according to any one of claims 1 to 7, characterized in that, Step S1 involves registering points on the femoral and tibial images with points on the actual patient location, including: Coarse registration calculation: Based on the location of coarse registration points in the surgical plan, collect the patient's coarse registration points; based on the bony landmarks in the surgical plan, collect the position of the corresponding bony landmarks in the camera coordinate system using a probe. Using a rigid registration algorithm, the minimum positional error matrix between the patient's coarse registration point and the surgical plan's coarse registration point is calculated, and the minimum error matrix is used as the original registration matrix. Fine registration calculation: Multiple scattered points are selected on the bone surface of the patient's surgical area using a probe, and the fine registration matrix is calculated using an iterative nearest point algorithm; Transform the original point cloud data pi to obtain the new point cloud target point p'i: p'i = Rpi + t, where pi represents the acquired registration point, R represents the rotation matrix of the registration matrix, and t represents the translation matrix of the registration matrix; the rotation matrix R and the translation matrix t are the fine registration matrix; Convert the fine registration matrix to 4 4. Homogeneous transformation matrix to obtain femoral registration matrix Where T represents the transformation matrix, F represents the femoral tracker, and I represents the femoral image. This represents the pose of the femoral image coordinates in the patient coordinate system; and the tibial registration matrix. Where T represents the transformation matrix, I2 represents the tibia tracker, and I2 represents the tibia image. This indicates the pose of the tibia image coordinates in the patient coordinate system.
9. A knee replacement surgery planning device, characterized in that, The knee replacement surgery planning method according to any one of claims 1 to 8, wherein the device comprises: The registration module is used to register points on the femoral and tibial images with points on the actual patient location to establish the relationship between the image coordinate system and the patient coordinate system. The acquisition module is used to acquire the contact points between the femur and tibia at different flexion angles of the patient; The mapping module is used to map the acquired contact points to the image coordinate system based on the relationship between the image coordinate system and the patient coordinate system, thereby generating the contact point trajectory. It is also used to map the contact point trajectory to a custom coordinate system, which is the image coordinate system from the surgeon's perspective. The planning module is used to output the surgical planning results of osteotomy based on the distribution of inner and outer contact points on all contact point trajectories.
10. An electronic device, characterized in that, include: The processor, communication interface, memory, and communication bus are connected, with the processor, communication interface, and memory communicating with each other via the communication bus. Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the method described in any one of claims 1 to 8.
11. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to perform the method according to any one of claims 1-8.