Endoprosthesis assistance system, and assistance method
Patent Information
- Application Number
- EP2023705549
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-24
- Filing Date
- 2023-02-16
- Publication Date
- 2025-01-01
AI Technical Summary
Current orthopedic navigation systems inadequately capture patient-specific kinematic joint data, leading to suboptimal selection and alignment of endoprostheses during joint replacement surgeries, as preoperative surveys lack precision and intraoperative methods alter natural joint movement, increasing patient dissatisfaction and complications.
An endoprosthesis assistance system that records kinematics before incision using patient trackers and a navigation system, allowing registration of anatomical structures post-incision, enabling precise kinematic data integration into the surgical planning process for improved implant selection and alignment.
This approach allows for more accurate and natural kinematic data capture, enhancing the precision of endoprosthesis selection and alignment, thereby improving surgical outcomes and patient satisfaction by integrating individual anatomy into the surgical planning.
Smart Images
Figure 1.1
Abstract
Description
[0001] Endoprosthesis assistance system and assistance procedures
[0002] Description
[0003] Technical area
[0004] The present disclosure relates to an endoprosthesis / implantation assistance system for assisting in the implantation of a joint replacement (endoprosthesis) in a patient, in particular during a total joint replacement operation such as a bicondylar knee endoprosthesis or hip arthroplasty. Furthermore, the present disclosure relates to an assistance method for an endoprosthesis procedure and a computer-readable storage medium according to the preambles of the independent claims.
[0005] Technical background
[0006] Orthopedic navigation systems, or navigation systems adapted for navigating instruments and implants during orthopedic surgery, have been known for many years. These orthopedic navigation systems can generally be divided into two main types or groups of navigation systems.
[0007] The first group of navigation systems is image-based and relies on a (3D) image as an anatomical system. A preoperative three-dimensional image, such as a CT scan, of the patient is created, and the patient is then registered against the preoperative CT scan, so that the real anatomy is correlated and registered with the recorded (virtual) anatomy of the scan data.
[0008] A second group of navigation systems is based on image-free navigation using a biomechanical model as an anatomical system. In this biomechanical model, the human musculoskeletal system is transferred into a simplified virtual (digital) anatomical model based on technical mechanics. In particular, bones such as the tibia or femur can be represented as lines, and joints can be simplified as joint points with correspondingly limited degrees of freedom. The biomechanical model of the patient provides a particularly good overview of the patient's kinematics. In image-free navigation, the patient, specifically the patient's bone(s), is registered intraoperatively on the biomechanical model.
[0009] Orthopedic robotic systems use similar navigation technologies, but also perform robot-assisted preparation of the bones to be treated.
[0010] With the introduction of navigation and robotics in orthopedic surgery, the resulting surgical results have become significantly more reproducible, and deviations from a desired standard have been further reduced. However, the current state of technology still poses the problem that a significant proportion of patients are dissatisfied with their postoperative results after surgery, such as knee surgery. This dissatisfaction can be attributed, in particular, to the fact that patient-specific kinematic joint data or the individual patient kinematics are not taken into account, or at least only insufficiently, when selecting implants or implant components, as well as implant alignment.
[0011] This patient-specific kinematic joint data can generally be collected either before or during surgery. If data is collected before surgery, gait laboratories / gait analysis labs are available. These labs directly record the kinematics of the patient's leg or hip via a camera, thus indirectly recording the kinematics of the bones of the joint. However, these preoperative surveys have the disadvantage that the kinematics are not recorded accurately enough, as there is no precise reference or relationship to the actual and individual bones. If a gait analysis is also performed in combination with intraoperative live X-ray images or combined with X-ray images, this problem can be partially reduced.However, such processes involving an additional X-ray image are usually very complex and very costly and require additional exposure to X-ray radiation that is harmful to the patient's health.
[0012] Further developments in orthopedic navigation or robotic systems allow the recording of the patient's bone kinematics during surgery and directly before (preparation for) processing, especially bone resection. Before recording the patient's kinematics, the joint is opened and the tissue is manipulated accordingly. In knee surgery, for example, the kneecap is usually reversed. However, this manipulation significantly influences the natural movement of the joint, as the boundary conditions of the soft tissue are significantly altered, and as a result, the kinematics can only be recorded roughly.
[0013] In summary, the current state of the art is insufficient to perform a patient kinematic assessment and cannot be used advantageously for a surgical procedure. Particularly in light of the increasingly aging population, with associated arthritic joint changes requiring joint replacement, arthroplasty faces major challenges.
[0014] Summary of the present disclosure
[0015] The objects and aims of the present disclosure are therefore to avoid or at least mitigate the disadvantages of the prior art and, in particular, to provide an endoprosthesis assistance system or implantation assistance system, as well as an assistance method and a computer-readable storage medium, which further improves implantation, in particular the selection and / or alignment of an endoprosthesis, and which even better assists and supports medical personnel such as a surgeon in order to ensure an even better endoprosthesis result. Furthermore, a further sub-objective can be seen in the even better integration of a patient's individual anatomy into endoprosthetic surgical planning in order to optimize the surgical outcome.
[0016] The objects of the present disclosure are achieved with regard to an endoprosthesis assistance system / implantation assistance system according to the invention by the features of claim 1, with regard to an assistance method according to the invention by the features of claim 9 and with regard to a computer-readable storage medium according to the invention by the features of claim 11.
[0017] The fundamental idea of the present invention is therefore to first (before an incision) acquire and record (individual) kinematics (without registration and thus, to a certain extent, without a virtual reference) via the navigation system and only then (after an incision) perform a registration. This allows natural kinematics or movement of the bones forming the joint to be preserved and used for analysis and processing. While in the prior art, the incision is made first, together with the registration, and only then, in a subsequent step, are the kinematics acquired and recorded (with a correspondingly distorted and inaccurate kinematic result), according to the present disclosure, this sequence of registration and acquisition of the kinematics is exactly reversed.
[0018] A key aspect of the present disclosure lies in particular in providing a (patient) tracker, preferably initially on the (main) bones forming the joint during a procedure on a patient for the insertion of a joint prosthesis, and in recording (natural) kinematics or (kinematic) movement of this body structure and thus of the tracked bones prior to an incision using a (tracking system of a) navigation system (via the attached patient trackers). Only after the incision and opening of the patient's anatomical structure are the real anatomical structures of the patient registered against the digital anatomical structures (anatomical system), in particular by means of a pointer / navigation pointer that palpates landmarks and / or by means of a surface scan of a surface scanner.Through this registration, the patient is registered with an anatomical system, which can be, for example, an image-based anatomical system with 3D images or an image-free anatomical system with a biomechanical model. The registration is used in particular to transfer and embed the acquired and recorded kinematics into the anatomical coordinate system of the anatomical system and then to visually provide the data to the surgeon via the display device using an assistant display, in particular with superimposed data on a dimension, a position, a torsion angle (flexion angle with simultaneous dependent rotation), and other data. Based on this provided (visually processed) data, the surgeon can then select an appropriate implant and / or optimally adjust the alignment of the implant.In this way, the endoprosthesis assistance system and the assistance procedure support the medical staff in a special way by expanding a digital anatomical system (image-based or imageless) to include the individual kinematics of the patient and this data can be used to carry out the adaptation of the implant / endoprosthesis even better.
[0019] In other words, the present invention provides, in particular, an assistance system comprising a navigation system with a tracking system, in particular with a 3D camera, and patient trackers that can be attached to the patient and are attached to each bone that defines the joint. The assistance system further comprises a navigation pointer that can record intraoperative landmarks (of the bone) via the navigation system (with the tracking system), and / or the assistance system comprises a surface scanner to capture a three-dimensional (intracorporeal) surface of the bone and register it against an anatomical model. The assistance system further comprises a display device via which the captured kinematics, registered against the anatomical system, are visually output to a user as an assistance display.to support the assessment of kinematics and the selection and alignment of an implant. In other words, an endoprosthesis assistance system for assisting a patient during a surgical endoprosthesis procedure is proposed, in particular during a total knee arthroplasty or a hip arthroplasty, comprising: a navigation system with a tracking system, which in particular has a 3D camera for tracking; at least a first and a second patient tracker, which are adapted to be rigidly attached to a first bone and a second bone of the patient, which form the movable connection of the joint; a navigation pointer, which, together with the navigation system, can detect landmarks intraoperatively via palpation and / or a 3D surface scanner, which is adapted to scan a surface and capture it three-dimensionally; a display device,In particular, a surgical monitor adapted to provide a visual display to a user; and a control unit. This control unit is specifically adapted to: capture and record the kinematics of the tracked bones via the patient trackers attached to the bones before an incision using the navigation system; perform intraoperative registration of the bone after an incision using the navigation pointer and / or the 3D surface scanner; determine a transformation of the recorded kinematics to the anatomical system based on the registration; and output an assistance display with information on the recorded kinematics relative to the anatomical system via the display device.
[0020] In particular, after attaching the patient tracker and before opening and manipulating the anatomy, a predefined movement pattern can be performed with the patient, followed by (after an incision) patient registration and conversion of the recorded kinematic data or kinematics into the patient's anatomical coordinate system (the anatomical system). Finally, the results of the kinematic analysis and assessment are transmitted to the surgeon.
[0021] In other words, a method and an (assistance) system for recording a patient's (joint) kinematics during total joint replacement surgery (e.g., a TKA - Total Knee Arthroplasty / Bicondylar Knee Endoprosthesis or a THA - Total Hip Arthroplasty) are proposed. Using a well-known navigation system, the bones defining the joint are tracked using rigid bodies attached to the bones (patient trackers). Kinematic recording and evaluation are performed before the incision and tissue manipulation. After the incision and access to the bone, the patient is registered.Registration is used to calculate the kinematics into the anatomical coordinate system (of the anatomical system) and to transmit this information to the surgeon, who can use the data to assist in selecting the correct implant components and correct implant orientation.
[0022] The term "kinematics" is well-known in the field of medical technology. In particular, the term refers to data on kinematic parameters within a patient's geometric range of motion, particularly the patient's musculoskeletal system. For example, a leg relative to a hip can only be moved within a certain range (individual interdependent parameters), which represents part of the range of motion. In particular, kinematics captures the patient's joint-specific data (varus / valgus, flexion / extension, internal / external rotation, and / or anterior / posterior displacement).
[0023] The term “kinematic movement” should be understood as a sub-term of “kinematics” and in this case means a sequence of changing arrangements of the body parts in relation to each other, for example a movement of the knee and the femur in relation to the tibia.
[0024] The term "anatomical system" in this context refers to a digitally stored anatomical model of the patient, for example, image-based using 3D images such as CT scans or imageless in the form of a biomechanical model, which can be supplemented with kinematic data and thus enriched with useful and necessary information. This transfer of the recorded kinematics is based on the registration performed. Advantageous embodiments are claimed in the subclaims and are explained in particular below.
[0025] According to a preferred embodiment, the navigation system can be embodied in the form of a surgical navigation system and / or the endoprosthesis assistance system can comprise a medical, in particular surgical, robot, and the navigation system can preferably comprise a surgical kinematics-based robot system or be embodied in the form of a surgical kinematics-based robot system. In other words, the assistance system can therefore preferably comprise a surgical navigation system and / or a surgical robot system. In particular, the at least one robot can be adapted to guide at least one medical instrument, preferably a bone saw, and to support manipulation, in particular bone processing. In particular, the navigation system can preferably be adapted to incorporate kinematics-based detection of the robot system for navigation.
[0026] According to a further preferred embodiment, the navigation system can be implemented as an image-based navigation system, and the control unit can be adapted to correlate and integrate the recorded kinematics with 3D images of the patient as an anatomical system, in particular segmented preoperative CT or MRI images. In other words, the assistance system can, in particular, comprise an image-based navigation and / or robot system.
[0027] In particular, the navigation system can also be designed as an imageless navigation system, and the control unit can be adapted to correlate and integrate the recorded kinematics with a biomechanical kinematic model of the patient as an anatomical system. In particular, the assistance system can therefore comprise an imageless navigation and / or robotic system. According to a further embodiment, the control unit can be adapted to output movement instructions stored in a memory unit, in particular in the form of moving images, to the user via the surgical monitor in order to provide the user with instructions for a predefined kinematic (movement). The assistance system can preferably use predefined movement patterns or sequences (as kinematic movements) that guide the surgeon through a specific workflow and instructions.
[0028] Preferably, the control unit can be adapted to output the recorded kinematics via the display device, in particular the surgical monitor, as a repetition (of the kinematic movement). In other words, the recorded kinematic data can be displayed, in particular, in a playback mode after the recording has been performed.
[0029] According to one embodiment, the control unit can be adapted to limit / filter a selection of a database of implant components based on an algorithm or based on a trained AI system (for example, with training data on successfully performed endoprosthesis procedures with both the selected implant(s) and an orientation of the implant) with the recorded kinematics as input data, and / or to provide a suggestion for an orientation of a given implant and to visually output it to a user via the display device. The assistance system can, in particular, have algorithms in a memory unit that provide the surgeon with recommendations for selecting implants derived from the kinematic data, in particular a recommendation for selecting the implant components and the implant orientation, in order to provide even better support to the surgeon.
[0030] According to a further embodiment, the control unit can be adapted to compare postoperative kinematics recorded via the navigation system after the end of the procedure with the preoperative kinematics recorded before the incision and, based on the comparison, to perform an evaluation and output it via the display device, in particular to perform a comparison such that postoperative kinematics follow the preoperative kinematics within a predetermined tolerance, preferably a kinematic deviation of a maximum of 10%. This postoperative kinematics (and its evaluation) is also performed with the closed joint; thus, it is first sutured and only then are the (kinematic) data recorded. This provides a direct comparison.This ensures that the implanted endoprosthesis does not adversely alter the patient's biomechanical kinematics, allowing the implant's outcome to be evaluated accordingly. The assistance system can therefore be specifically adapted to perform a kinematic assessment after implantation (after the patient's body has been closed / the anatomy has been closed, but before the patient trackers are removed) based on a comparison of the post-operative kinematics with the pre-operative kinematics.
[0031] The objects are achieved with regard to an assistance method for a surgical endoprosthetic procedure on a patient in that it comprises the steps of: preferably attaching a first and second patient tracker to a first and second bone of the patient, respectively, which form the movable connection of the joint; displaying, in particular before an incision, guided kinematics by a display device in order to provide a user, in particular a medical professional, with visual instructions; capturing, during the guided kinematics, preoperative kinematics of the tracked bones of the patient by the navigation system and providing them (as computer-readable data) to a control unit;Following an incision, performing a registration based on palpated landmarks and / or a surface alignment of an intracorporeal bone structure using the navigation system and a navigation pointer and / or a 3D surface scanner; determining, based on the registration, a transformation of the acquired kinematics into the (anatomical coordinate system of the) anatomical model using the control unit;and outputting an assistance display with information on the recorded kinematics relative to the anatomical system by the display device. Through these steps, the individual, patient-specific kinematics can be optimally incorporated into the procedure, particularly in the selection and alignment of the implant, and the final result can be improved accordingly. In particular, an optimized procedure sequence (assistance method) is disclosed that allows natural kinematics of the knee to be recorded during a navigated or robot-guided orthopedic procedure.
[0032] According to a further embodiment, the assistance method may further comprise the steps of: detecting, after closing the patient's body, postoperative kinematics of the patient using the navigation system and providing them as computer-readable data to the control unit; and comparing the detected preoperative kinematics before opening the patient with the postoperative kinematics after closing the patient's body, and determining a deviation between the detected preoperative kinematics and the detected postoperative kinematics. Furthermore, in particular after closing the patient's anatomy or body, the movement of the body section with the joint may be repeated in order to obtain a postoperative kinematic result and use it for a kinematic evaluation.
[0033] With regard to a computer-readable storage medium, the objects are achieved in that it comprises instructions which, when executed by the computer, cause the computer to carry out the method steps of the assistance method according to the present disclosure.
[0034] The assistance procedure can be used particularly in knee, hip, shoulder, or ankle surgery for partial or total joint replacement. In particular, the endoprosthesis assistance system can be adapted to support knee, hip, shoulder, or ankle surgery.
[0035] In particular, the assistance method can comprise the steps of: preferably attaching at least a first patient tracker to a first bone of the joint and a second patient tracker to a second bone of the joint; performing a movement of the first bone relative to the second bone and thus a kinematics (for a kinematics evaluation); capturing and recording the kinematics data of the tracked / tracked first and second bones in a tracker coordinate system (tracker KOS as an intermediate or recording coordinate system); preferably performing an incision, in particular by a robot, for an opening and further preferably manipulating the anatomy to obtain suitable access to the tracked bone of the joint;Performing a registration of the first and / or second bone by palpating landmarks using a navigation pointer and / or a surface mapping of the exposed first and / or second bone (or the exposed bone structure); transforming the recorded kinematics (data) into the anatomical coordinate system of the anatomical system; and outputting, in particular displaying, relevant kinematics data, in particular the kinematics of the non-manipulated anatomy, to a user such as a surgeon.
[0036] Preferably, the assistance method according to the illustration may include the performance of the actual procedure, in particular with a resection, in particular a robot-assisted procedure.
[0037] According to a preferred embodiment, the assistance method may comprise the step of a robot-guided incision after the step of detecting the kinematics by the navigation system and before the registration.
[0038] Any disclosure related to the present implantation assistance system of the present disclosure applies equally to the method according to the present disclosure and vice versa.
[0039] Short description of the characters
[0040] The present disclosure will be explained in more detail below using preferred embodiments with reference to the accompanying figures. Figure 1 shows a perspective view of an endoprosthesis assistance system according to a first preferred embodiment of the present disclosure;
[0041] Fig. 2 is a schematic view of a biomechanical model of the bones of Fig. 1 , with particularly important landmarks marked;
[0042] Figs. 3 and 4 show a schematic perspective view of a kinematic movement after attaching the patient trackers but before the incision, which can be performed by a medical professional or robotically; and
[0043] Fig. 5 is a schematic perspective view of a patient's knee joint with the patient trackers attached to the bones, the knee being opened for registration;
[0044] Fig. 6 is a schematic perspective view of a registration in the case of an imageless navigation system using a navigation pointer for palpation of the landmarks of the bone;
[0045] Fig. 7 is a schematic view of a kinematic movement and evaluation, wherein the kinematic movement step is performed after the procedure and after implantation of the knee implant and after closure of the procedure area in order to compare preoperative kinematics with postoperative kinematics;
[0046] Fig. 8 is a flowchart of an assistance method according to a preferred embodiment.
[0047] The figures are schematic in nature and are intended only to assist in understanding the present disclosure. Like elements are designated by like reference numerals. The features of the various embodiments may be interchanged.
[0048] Detailed Description of Preferred Embodiments Figs. 1 to 7 show an endoprosthesis assistance system 1 (hereinafter referred to simply as the assistance system) for assisting a patient P during a surgical endoprosthesis procedure in the form of a total knee arthroplasty according to a preferred embodiment of the present disclosure. The surgical assistance system 1 is adapted for use in total knee joint replacement operations.
[0049] Fig. 1 shows a perspective view of the assistance system 1, which has a navigation system 2 with a tracking system 4, wherein the tracking system 4 has a 3D camera 6 for tracking. Using the 3D camera and corresponding spatial detection, objects and trackers can be tracked. Specifically, the assistance system 1 further comprises a first patient tracker 8 and a second patient tracker 10 (hereinafter referred to as trackers), which are each adapted by means of screw-in systems to be rigidly screwed and fastened to the tibia as the first bone K1 of the knee joint and to the femur as the second bone K2 of the knee joint of the patient P, which accordingly form the movable connection of the joint.
[0050] In addition, the assistance system 1 (for later registration) has a navigation pointer 12 (explained in more detail below in relation to Fig. 6), which, together with the navigation system 2, can record intraoperative landmarks 14 via palpation. Alternatively or in addition to the pointer, the assistance system can also have a 3D surface scanner (not shown here) adapted to scan a surface and capture it three-dimensionally.
[0051] The assistance system 1 also has a display device 16 in the form of a
[0052] Surgical monitor to provide a visual display to medical staff.
[0053] Finally, the assistance system has a control unit 18 which, in this case, is very specifically adapted to, contrary to the prior art, first detect and record a kinematics and / or kinematic movement preoperatively via the navigation system and only after this detection and recording to carry out the registration intraoperatively, as described below under explanations of Figs. 2 to 7.
[0054] Fig. 2 schematically shows the skeleton of a left leg of patient P in a frontal and lateral view. The two trackers 8 and 10 are rigidly screwed into the femur and tibia (first and second bones K1 and K2), which form the knee joint. Navigation trackers are attached.
[0055] These attached trackers 8, 10 are tracked and spatially recorded by the 3D camera 6 of the tracking system 4 of the navigation system 2, as shown in Figs. 3 and 4. During an active movement of the leg, as indicated in Figs. 3 and 4, a kinematic movement of the bones and thus a kinematics of the bones are recorded and provided to the control unit 18 in computer-readable form. This recording of the kinematic movement or kinematics takes place preoperatively, i.e., before an incision, so that the patient's natural kinematics are recorded without a removed kneecap altering a movement or kinematics. In particular, the surgeon can perform predefined movements of the joint, and the assistance system records the movement data in the coordinate systems of the trackers. At this point in time, no anatomical data from an anatomical model can be displayed to the surgeon because the patient has not yet been registered.The movement pattern may include flexing the knee to full extension and flexion, performing a "drawer test" in which the tibia is moved forward and backward, or performing a laxity test for frontal alignment (varus / valgus loading). From a technical perspective, the human leg is a system that swings approximately like a double pendulum in the sagittal plane. The ankle joint is neglected. The femur, mounted in a nearly ideal ball-and-socket joint, swings around a fixed point in the hip. This joint has three degrees of freedom: the angles in the sagittal plane, the frontal plane, and the angle of rotation. The second joint of the leg, the knee joint, which connects the femur and tibia, is essentially a two-degree-of-freedom joint, i.e.The lower leg can be rotated relative to the thigh by the flexion angle, with simultaneous dependent rotation of the lower leg around its longitudinal axis. These possible angular ranges can be captured by kinematics with appropriate analysis.
[0056] After the movement patterns have been recorded, the incision shown in Fig. 5 is made, and access to the bony structure is prepared. In this case, the patella is usually reversed.
[0057] Fig. 6 shows a schematic of a registration process. This process involves registering the patient. In image-free navigation (especially with robots), landmarks are palpated / felt with the navigation pointer 12, or the control unit determines a center as a landmark (e.g., a hip center) by analyzing the kinematic movements. In image-based navigation or robotics, the surface of the bone is digitized using a navigation pointer and / or a 3D surface scanner.
[0058] After the registration shown in Fig. 6, the control unit 18 can determine / calculate the transformation between the tracker coordinate system and the anatomical coordinate system of an anatomical system, in particular a biomechanical model, of the patient P. In this case, the previously recorded and determined kinematic data are converted or transformed into the anatomical coordinate system(s) so that the surgeon can accurately record and measure all of the patient's kinematic parameters, for example, varus / valgus, flexion / extension, internal / external rotation, and / or anterior / posterior displacement.
[0059] The control unit 18 handles all data acquisition, calculation, and display by the display device 16. The recorded kinematic data can then be transmitted and processed without having to move the patient. The surgeon can use the information provided by the display device to select suitable implant components and / or choose a suitable implant orientation, which is then carried out with the aid of navigation and / or robotics.
[0060] As shown in Fig. 7, after implantation, the kinematics can be recorded again after the knee has been closed (sutured). Trackers 8 and 10 remain attached to bones K1 and K2 after the knee has been closed for postoperative recording of the kinematic movement and kinematics. The postoperative kinematics can be compared with the preoperative kinematics to validate the treatment goals.
[0061] Specifically, in the assistance system 1 of the present embodiment, the control unit 18 is adapted to detect and record kinematics and / or kinematic movement of the tracked bones K1, K2 preoperatively before an incision using the trackers 8, 10 attached to the bones K1, K2 using the navigation system 2, and to perform intraoperative registration of the first bone K1 and / or second bone K2 after an incision using the navigation pointer 12. Based on the registration, the control unit 18 then determines a transformation of the recorded kinematics (or kinematic movement) into an anatomical system in the form of a biomechanical model. Finally, the control device accordingly controls the surgical monitor as the display device 16 and outputs an assistance display 20. This assistance display 20 contains data or information about the kinematics of the biomechanical model as an anatomical system.Specifically, the assistance display 20 can display bone data for a possible angle of rotation from the tibia to the femur, as indicated in the table in Fig. 7, or an image sequence of the recorded kinematic movement can be played back.
[0062] The assistance display visually links data from the individually recorded, precise kinematics of the patient's knee joint with an anatomical system in the form of a biomechanical model and displays this information together in a clear and intuitive manner, allowing the surgeon to easily and effectively select an implant and its orientation. Figure 8 shows a flowchart of an assistance method according to a preferred embodiment.
[0063] In an optional first step (S1), a tracker 8, 10 in the form of a rigid body tracker is attached to the bones of the tibia and femur, respectively. Alternatively, these can simply be already attached. The femur and tibia form the movable connection of the joint.
[0064] In an optional second step S2, a guided kinematic movement is displayed by the display device 16 in order to provide the surgeon with a visual instruction of a movement sequence in order to capture the entire kinematics as far as possible.
[0065] In a step 3, before the incision and during the executed kinematic movement of the leg of the patient P, a recording of preoperative kinematics of the tibia and femur of the patient P tracked by the navigation system 2 takes place. This recorded preoperative kinematics is provided to the control unit 18 in a computer-readable manner:
[0066] Only after the kinematics have been recorded and further only after a subsequent incision does step S4 take place: performing an intraoperative registration based on palpated landmarks and / or a surface comparison of an intracorporeal bone structure of the tibia and / or the femur by the navigation system 2 and the navigation pointer 12 and / or the navigation system 2 and a 3D surface scanner.
[0067] This is followed by step S5: Based on the registration, the control unit 18 determines a transformation of the recorded kinematics and / or kinematic movement into an anatomical system. Finally, in step S6, the display device 16 outputs the assistance display 20. This assistance display comprises data of the recorded kinematics in relation to the patient's anatomical system.
[0068] In this embodiment, the assisting method further comprises the following steps.
[0069] In a step S7, a detection of postoperative kinematics of the knee of the patient P takes place by the navigation system 2, which is provided to the control unit 18 in a computer-readable manner, and only after the knee of the patient P has been closed.
[0070] In the final step S8, the recorded preoperative kinematics before opening the patient P are compared with the postoperative kinematics after closing the patient P's body, and a deviation between the recorded preoperative kinematics and the recorded postoperative kinematics is determined. The surgeon can then use this deviation to evaluate the endoprosthesis.
[0071] List of reference symbols
[0072] 1 endoprosthesis assistance system
[0073] 2 Navigation system
[0074] 4 Tracking system
[0075] 6 3D camera
[0076] 8 First patient tracker
[0077] 10 Second patient tracker
[0078] 12 navigation pointers
[0079] 14 Landmark
[0080] 16 Display device
[0081] 18 Control unit
[0082] 20 Assistant representation
[0083] 22 storage unit
[0084] P Patient
[0085] K1 First (articular) bone
[0086] K2 Second (articular) bone
[0087] 51 Step Attaching a first and second patient tracker
[0088] 52 Step Displaying a guided kinematic movement
[0089] 53 Step Recording preoperative kinematics
[0090] 54 Step Performing an intraoperative registration
[0091] 55 Step Determining a transformation between the kinematics and an anatomical system
[0092] 56 Step Outputting an Assistance Display
[0093] 57 Step Recording postoperative kinematics
[0094] 58 Step Comparing preoperative kinematics with postoperative kinematics
Claims
Claims 1. Endoprosthesis assistance system (1) for assisting in a surgical endoprosthetic procedure on a patient (P), in particular in total knee arthroplasty or hip arthroplasty, comprising: a navigation system (2) with a tracking system (4) for follow-up, which in particular includes a 3D camera (6) for follow-up; at least a first patient tracker (8) and a second patient tracker (10) which are adapted to be rigidly attached to a first bone (K1) and a second bone (K2) of the patient (P) which form the movable connection of the joint; a navigation pointer (12) which, together with the navigation system (2), can detect landmarks (14) intraoperatively via palpation and / or a 3D surface scanner which is adapted to detect a surface three-dimensionally;a display device (16), in particular an operating room monitor, adapted to output a visual display to a user; and a control unit (18) adapted to: before an incision, capture and record the kinematics of the tracked bones (K1, K2) via the patient trackers (8, 10) attached to the bones (K1, K2) using the navigation system (2); after an incision, perform an intraoperative registration of the first and / or second bone (K1, K2) using the navigation pointer (12) and / or the 3D surface scanner; determine a transformation of the recorded kinematics to an anatomical system based on the registration; and output an assistance display (20) with data on the recorded kinematics relative to the anatomical system via the display device (16).
2. Endoprosthesis assistance system (1) according to claim 1, characterized in that the navigation system (2) is designed in the form of a surgical navigation system and / or that the endoprosthesis assistance system (1) comprises a surgical robot, in particular for actuating at least one medical instrument as an end effector, and the navigation system (2) is further preferably adapted to incorporate a kinematics-based detection of the robot system for navigation.
3. Endoprosthesis assistance system (1) according to one of the above Claims, characterized in that the navigation system (2) is designed as an image-based navigation system and the control unit (18) is adapted to correlate the recorded kinematics with 3D images of the patient (P) as an anatomical system, in particular with segmented preoperative CT or MRI images.
4. Endoprosthesis assistance system (1) according to one of claims 1 or 2, characterized in that the navigation system (2) is designed as an imageless navigation system and the control unit (18) is adapted to correlate the recorded kinematics with a biomechanical kinematic model of the patient (P) as an anatomical system.
5. Endoprosthesis assistance system (1) according to one of the above Claims, characterized in that the control unit (18) is adapted to output to the user, via the operating room monitor as a display device (16), a movement instruction stored in a storage unit (22), in particular in the form of moving images, in order to provide the user with instructions for the execution of a predefined kinematic.
6. Endoprosthesis assistance system (1) according to one of the preceding claims, characterized in that the control unit (18) is adapted to output the recorded kinematics as a replay via the display device (16), in particular the operating monitor.
7. Endoprosthesis assistance system (1) according to one of the preceding claims, characterized in that the control unit (18) is adapted for this purpose, based on an algorithm or based on a trained AI system and using the recorded kinematics as input data, to restrict a selection from a database of implant components and / or to provide a suggestion for the orientation of a given implant and to output it visually to a user via the display device (16).
8. Endoprosthesis assistance system (1) according to one of the preceding claims, characterized in that the control unit (18) is adapted to compare postoperative kinematics recorded after the end of the procedure via the navigation system (2) with the preoperative kinematics recorded before the incision and to perform an evaluation based on the comparison and to output it via the display device, in particular to perform a comparison such that postoperative kinematics follow the preoperative kinematics within a predetermined tolerance, preferably a deviation of the kinematics of a maximum of 10%.
9. Assistance method for a surgical endoprosthetic procedure in a patient (P), in particular for use with an endoprosthesis assistance system (1) according to one of the preceding claims, characterized by the steps, in particular in exactly this order: Preferably attaching (S1 ) a first and second patient tracker (8, 10) to a first and second bone (K1 , K2) of the patient (P) respectively, which form the movable connection of the joint; Preferably displays (S2) prior to an incision, a guided kinematic movement by a display device (16) to provide a user with a visual instruction; Acquisition (S3), during a kinematic movement, a preoperative kinematics of the first and second bones (K1 , K2) of the patient (P) tracked by a navigation system (2) via the patient trackers (8, 10) and provision of the acquired kinematics to a control unit (18); Perform (S4), after an incision, an intraoperative registration based on palpated intracorporeal landmarks and / or a surface match of an intracorporeal bone structure of the first and / or second bone (K1 , K2) by the navigation system (2) together with a navigation pointer (12) and / or a 3D surface scanner; Determine (S5), by the control unit (18), based on the registration, a transformation of the recorded kinematics into an anatomical system; and Output (S6), through the display device (16), an assistance display (20) with data on the recorded kinematics relative to the anatomical system.
10. Assistance method according to claim 9, characterized in that the assistance method further comprises the steps: Capture (S7), after closing the patient's body (P), a postoperative kinematics of the patient (P) by the navigation system (2) and the tracked patient trackers (8,10) and provide as computer-readable data to the control unit (18); and The control unit (18) compares (S8) the recorded preoperative kinematics before opening the patient (P) with the postoperative kinematics after closing the patient's body (P) and determines any deviation between the recorded preoperative kinematics and the recorded postoperative kinematics.
11. Computer-readable storage medium comprising instructions which, when executed by the computer, cause it to perform the process steps of the assistance method according to claim 9 or 10.