DE102022104486A1 - Endoprosthesis assistance system and assistance method - Google Patents

Abstract

The disclosure relates to an endoprosthesis assistance system (1) for assistance during a surgical endoprosthesis intervention in a patient (P), in particular in the case of a total knee arthroplasty or hip endoprosthesis, comprising: a navigation system (2) with a tracking system (4), which has in particular a 3D camera (6) for tracking; at least a first and a second patient tracker (8, 10) adapted thereto, rigidly attached to a first bone (K1) and a second bone (K2) of the patient (P) forming the mobile joint of the joint to become; a navigation pointer (12) which, together with the navigation system (2), can record landmarks (14) intraoperatively via palpation and/or a 3D surface scanner which is adapted to scan a surface and record it three-dimensionally; a display device (16), in particular an operating room monitor, which is adapted to output a visual display to a user; and a control unit (18), which is adapted for: via the patient trackers (8, 10) attached to the bones (K1, K2), before an incision, a kinematics of the bones (K1, K2) being tracked by the navigation system (2) capture and record; following an incision, intraoperatively registering 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 to output an assistance display (20) with data of the recorded kinematics to the anatomical system via the display device (16). In addition, the disclosure relates to an assistance method and a computer-readable storage medium according to the independent claims.

Description

technical field

The present disclosure relates to an endoprosthesis/implantation assistance system for assisting in an implantation in a joint replacement (endoprosthesis) in a patient, in particular in an operation for a total joint replacement such as in a bicondylar knee endoprosthesis or a hip arthroplasty. In addition, the present disclosure relates to an assistance method for an endoprosthetic intervention and a computer-readable storage medium according to the preambles of the independent claims.

Technical background

Orthopedic navigation systems or navigation systems that are adapted to navigate instruments and implants during an orthopedic intervention have been known for many years. These orthopedic navigation systems can generally be divided into essentially two types or groups of navigation systems.

A first group of navigation systems is image-based and is based on a (3D) image as an anatomical system. Here, a preoperative three-dimensional image, such as a CT image, of the patient is created and the patient is then registered with respect to the preoperative CT image, so that the real anatomy is correlated with the recorded (virtual) anatomy of the image data and registered.

A second group of navigation systems is based on imageless navigation using a biomechanical model as an anatomical system. With this biomechanical model, the human musculoskeletal system is transferred to a simplified virtual (digital) anatomical model based on technical mechanics. In particular, bones such as the tibia or the femur can be represented as lines and joints can be modeled in simplified form as joint points with correspondingly limited degrees of freedom. The biomechanical model of the patient allows a particularly good overview of the kinematics of a patient. In the case of image-free navigation, the patient, in particular the bone(s) of the patient, is registered intraoperatively on the biomechanical model.

Orthopedic robotic systems use similar navigation technologies, but also carry out robotic preparation of the bones to be processed.

With the introduction of navigation and robotics in orthopedic surgery, the results of the interventions have become significantly more reproducible and deviations from a desired standard could be further reduced. However, with the current state of the art, the problem remains that a substantial proportion of patients are not satisfied with their postoperative results after an operation, such as knee surgery. In particular, this dissatisfaction can be attributed to the fact that no or at least insufficient patient-specific kinematic joint data or the individual kinematics of the patient are taken into account when selecting implants or implant components and aligning the implant.

This patient-specific kinematic joint data can generally be collected either before the operation or during the operation. In the case of a survey prior to the operation, gait laboratories/laboratories for gait analyzes are available in which the kinematics of the patient's leg or hip are recorded directly via a camera and thus indirectly the kinematics of the bones of the joint. However, these preoperative surveys have the disadvantage that the kinematics are not recorded precisely enough, since there is no precise reference or relation to the real and individual bones. If a gait analysis is additionally performed in combination with intraoperative live X-ray images or is combined with X-ray images, this problem can be partially reduced. However, such processes with an additional X-ray exposure are usually very complex and very expensive and require an additional harmful exposure to X-ray radiation for the patient.

Orthopedic navigation or robotic systems as a further development enable the kinematics (of the bones) of the patient to be recorded during the operation and directly before (preparation for) processing, in particular resection, of the bones. Before the patient's kinematics are recorded, the joint is opened and the tissue manipulated accordingly. In knee surgery, for example, the kneecap is usually reversed. However, this manipulation significantly influences the natural movement of the joint, since the boundary conditions of the soft tissue are changed significantly, and as a result the kinematics can only be roughly recorded.

In summary, according to the prior art, a kinematics assessment of the patient can only be performed inadequately and cannot be used advantageously for an intervention. In particular before against the background of the increasingly aging population with associated arthritic joints that require joint replacement, endoprosthetics is faced with major challenges.

Summary of the present disclosure

It is therefore the objects and goals of the present disclosure to avoid or at least reduce 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 an implantation, in particular a selection and/or an alignment of an endoprosthesis is further improved and a medical personnel such as a surgeon is even better assisted and supported in order to ensure an even better result of an endoprosthesis. Furthermore, another sub-task can be seen as integrating a patient's individual anatomy even better into an endoprosthetic operation plan in order to optimize an operation result.

The objects of the present disclosure are achieved according to the invention with regard to an endoprosthesis assistance system/implantation assistance system 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.

The basic idea of the present invention is therefore first (before an incision) to capture 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/an incision). to perform registration. As a result, natural kinematics or movement of the bones forming the joint can be obtained and used for analysis and processing. So while in the prior art first the incision / incision is made together with the registration and only then, in a subsequent step, the kinematics are recorded and recorded (with a correspondingly falsified and inaccurate kinematic result), according to the present disclosure, this sequence of registration and Acquisition of the kinematics exactly the other way round.

An essential aspect of the present disclosure lies in particular in the provision of a (patient) tracker for an intervention on a patient for the use of a joint prosthesis, preferably first on the (main) bones forming the joint and before an incision (natural) kinematics or To record (kinematic) movement of this body structure and thus the tracked bones by 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 patient's real anatomical structures 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. This registration registers the patient with respect to 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 recorded and recorded kinematics in the anatomical coordinate system of the anatomical system and then to provide the data to the surgeon visually via the display device via an assistance display, in particular with data displayed for a dimension, for a Position, to a twist angle (flexion angle with simultaneous dependent rotation) and other data. On the basis of this provided (visually processed) data, the surgeon can then make a corresponding selection of an implant and/or optimally adjust an alignment of the implant. In this way, the endoprosthesis assistance system and the assistance procedure support the medical staff in a special way, in that a digital anatomical system (image-based or image-free) is expanded to include the individual kinematics of the patient and this data can be used to adapt the implant/ of the endoprosthesis even better.

In other words, the present invention provides in particular an assistance system that has a navigation system with a tracking system, in particular with a 3D camera, and has patient trackers that can be attached to the patient and are attached to each bone that defines the joint. The assistance system also has a navigation pointer that can record intraoperative landmarks (of the bone) via the navigation system (with the tracking system) and/or the assistance system has a surface scanner to detect a three-dimensional (intracorporeal) surface of the bone and compared to an anatomical one register model. The assistance system also has a display device, via which the detected and compared to the Anatomical Sys tem registered kinematics is visually output to a user as an assistance representation to support an assessment of the kinematics and a selection and alignment of an implant.

In other words, an endoprosthesis assistance system is proposed for assistance in a surgical endoprosthetic intervention in a patient, in particular in the case of a total knee arthroplasty or hip endoprosthetics, which has: a navigation system with a tracking system, which in particular uses a 3D camera for has tracking; at least a first and a second patient tracker adapted to be rigidly attached to a first bone and a second bone of the patient forming 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 detect it three-dimensionally; a display device, in particular a surgical monitor, which is adapted to output a visual display to a user; and a control unit. This control unit is specifically adapted to: acquire and record kinematics of the tracked bones via the navigation system via the patient trackers attached to the bones prior to an incision; after an incision, perform intraoperative registration via the bone 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 to output an assistance display with information about the recorded kinematics to the anatomical system via the display device.

In particular, after the patient tracker has been attached and before the anatomy is opened and manipulated, a predetermined movement pattern can be carried out with the patient, followed by (after an incision) a registration of the patient and a conversion of the recorded kinematic data or kinematics into the anatomical coordinate system (of the Anatomical System) of the patient. Finally, the results of the kinematic analysis and assessment are sent to the surgeon.

To put it another way, in particular a method and an (assistance) system for recording the (joint) kinematics of a patient during an operation for total joint replacement (e.g. in TKA - Total Knee Arthroplasty / Bicondylar Knee Prosthetics or THA - Total Hip Arthroplasty ) suggested. A known navigation system tracks the bones that define the joint with rigid bodies (patient trackers) attached to the bones. Kinematic acquisition and evaluation is performed prior to 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 (the anatomical system) and to transmit this information to the surgeon, who can use the data to assist in the selection of the correct implant components and the correct implant orientation.

The term "kinematics" is known in the field of medical technology. In particular, the term in the present case means data on kinematic parameters in a geometric movement space of the patient, in particular the skeleton of the patient's musculoskeletal system. For example, a leg relative to a hip can only be moved within a certain range (single interdependent parameters), which is part of the range of motion. In particular, joint-specific data of the patient are recorded by the kinematics (varus/valgus, flexion/extension, internal/external rotation and/or anterior/posterior displacement).

The term “kinematic movement” is to be understood as a sub-term of “kinematics” and in the present case means a sequence of changing arrangements of the body sections relative to one another, for example a movement of the knee and the femur relative to the tibia.

In the present case, the term "anatomical system" means that there is a digitally stored anatomical model of the patient, e.g necessary information can be enriched. This transmission of the recorded kinematics takes place on the basis of the registration that has been carried out.

Advantageous embodiments are claimed in the dependent claims and are explained in particular below.

According to a preferred embodiment, the navigation system can be designed in the form of a surgical navigation system and/or the endoprosthesis assistance system can have a medical, in particular surgical, robot and the navigation system can preferably be a surgical kinematics-based one Have robot system or be in the form of a surgical kinematics-based robot system. In other words, the assistance system can therefore preferably have 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 include a kinematics-based detection of the robot system for navigation.

According to a further preferred embodiment, the navigation system can be designed 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 have an image-based navigation and/or robot system.

In particular, the navigation system can also be designed as an image-free 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 have an image-free navigation and/or robot 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 kinematics (movement). The assistance system can preferably use predefined movement patterns or sequences (as kinematic movements) that guide the surgeon through a special workflow and instructions.

The control unit can preferably be adapted to output the recorded kinematics via the display device, in particular the OP monitor, as a repetition (of the kinematic movement). In other words, the captured kinematic data can be displayed in particular in a playback mode after the registration has been performed.

According to one embodiment, the control unit can be adapted for this, based on an algorithm or based on a trained AI system (e.g. with training data on successfully performed endoprosthetic interventions with both the selected implant(s) and an orientation of the implant) with the recorded kinematics as To restrict/filter input data, a selection of a database with implant components and/or to provide a suggestion for an alignment of a given implant and to output it visually to a user via the display device. In particular, the assistance system can have algorithms in a memory unit, which give the surgeon 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 support the surgeon even better.

According to a further embodiment, the control unit can be adapted to compare postoperative kinematics recorded by the navigation system after the end of the intervention with the preoperative kinematics recorded before the incision and, based on the comparison, to carry out an evaluation and output it via the display device, in particular a comparison to that effect to carry out that a postoperative kinematics follows the preoperative kinematics within a predetermined tolerance, preferably a deviation of the kinematics of at most 10%. This postoperative kinematics (and its evaluation) is also carried out with the closed joint, i.e. it is sewn up first and only then are the (kinematics) data recorded. This provides a direct comparison. This ensures that the endoprosthesis used does not adversely change the biomechanical kinematics of the patient and a result of the implant can be evaluated accordingly. The assistance system can thus be adapted in particular to carry out a kinematic evaluation after the implantation (after the patient's body has been closed again/the anatomy has been closed, but before the removal of the patient trackers) based on a comparison of the post-operative kinematics with the pre-op kinematics.

The objects are achieved with regard to an assistance method for a surgical endoprosthetic intervention in a patient in that it has the following steps: preferably attaching a first and second patient tracker to a first and second bone of the patient, which form the movable connection of the joint ; Displaying, in particular before an incision, guided kinematics by a display device to a user, in particular a medical specialist nal to provide a visual instruction; detecting, during the guided kinematics, a preoperative kinematics of the tracked bones of the patient by the navigation system and providing them (as computer-readable data) to a control unit; performing, after an incision, a registration based on palpated landmarks and/or a surface matching of an intracorporeal bone structure by the navigation system and a navigation pointer and/or a 3D surface scanner; determining, based on the registration, a transformation of the detected kinematics into the (anatomical coordinate system of the) anatomical model by the control unit; and outputting an assistance display with information about the recorded kinematics to the anatomical system by the display device. Through these steps, the individual, patient-related kinematics can be optimally included in the intervention, especially in the selection and alignment of the implant, and the end result can be improved accordingly. In particular, an optimized procedure (assistance method) is thus disclosed, which allows natural kinematics of the knee to be recorded during a navigated or robot-guided orthopedic intervention.

According to a further embodiment, the assistance method can also have the steps: after the patient's body has been closed, recording postoperative kinematics of the patient by the navigation system and providing them as computer-readable data to the control unit; and comparing the recorded pre-operative kinematics before opening the patient with the post-operative kinematics after closing the patient's body and determining a deviation between the recorded pre-operative kinematics and the recorded post-operative kinematics. Furthermore, in particular after the anatomy or the body of the patient has been closed, the movement of the body section with the joint can be repeated in order to obtain a postoperative result of the kinematics and to use this for a kinematics evaluation.

With regard to a computer-readable storage medium, the objects are achieved by comprising 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.

The assistance method can be used in particular in knee, hip, shoulder or ankle surgery for partial or complete joint replacement. In particular, the endoprosthesis assistance system can be adapted to support knee, hip, shoulder or ankle surgery.

In particular, the assistance method can have the steps: 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 kinematics (for a kinematics evaluation); Acquiring and recording the kinematic data of the tracked first and second bones in a tracker coordinate system (tracker-KOS as it were as an intermediate or recording coordinate system); Preferably making an incision, particularly by robot, for an opening and further preferably manipulating the anatomy to gain appropriate access to the tracked bone of the joint; Carrying out a registration of the first and/or second bone by palpation of landmarks using a navigation pointer and/or a surface adjustment (the so-called "surface mapping") of the exposed first and/or second bone (or the exposed bone structure; transforming the recorded ones). 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.

According to the illustration, the assistance method can preferably contain the implementation of the actual intervention, in particular with a resection, in particular a robot-assisted intervention.

According to a preferred embodiment, the assistance method can have the step of a robot-guided incision after the step of detecting the kinematics by the navigation system and before the registration.

Any disclosure in connection with the present implantation assistance system of the present disclosure also applies to the method according to the present disclosure and vice versa.

character list

• 1 eine perspektivische Ansicht eines Endoprothesen-Assistenzsystems gemäß einer ersten bevorzugten Ausführungsform der vorliegenden Offenbarung;
• 2 eine schematische Ansicht eines biomechanischen Modells der Knochen aus 1, mit eingezeichneten besonders wichtigen Landmarken;
• 3 und 4eine schematische perspektivische Ansicht einer Kinematikbewegung nach Befestigen der Patienten-Tracker aber vor der Inzision, welche durch ein medizinisches Fachpersonal oder robotergestützt durchführbar ist; und
• 5 eine schematische perspektivische Ansicht eines Kniegelenks eines Patienten mit den an die Knochen befestigten Patienten-Tracker, wobei das Knie für eine Registrierung geöffnet ist;
• 6 eine schematische perspektivische Ansicht einer Registrierung im Fall eines bildlosen Navigationssystems, das einen Navigationszeiger für eine Palpation der Landmarken des Knochens verwendet;
• 7 eine schematische Ansicht einer kinematischen Bewegung und Bewertung, wobei der Schritt der Kinematikbewegung nach dem Eingriff und nach Implantation des Knieimplantats sowie nach einem Verschließen des Eingriffsbereichs durchgeführt wird, um eine präoperative Kinematik mit einer postoperativen Kinematik zu vergleichen;
• 8 ein Flussdiagramm eines Assistenzverfahrens gemäß einer bevorzugten Ausführungsform.

The present disclosure is explained in more detail below on the basis of preferred embodiments with reference to the accompanying figures. Show it:

• 1 a perspective view of an endoprosthesis assistance system according to a first th preferred embodiment of the present disclosure;
• 2 Figure 12 shows a schematic view of a biomechanical model of the bones 1 , with marked particularly important landmarks;
• 3 and 4a schematic perspective view of a kinematic movement after attaching the patient tracker but before the incision, which can be carried out by a medical specialist or with the help of a robot; and
• 5 Figure 12 is a schematic perspective view of a patient's knee joint with the patient trackers attached to the bones, with the knee opened for registration;
• 6 Figure 12 is a schematic perspective view of registration in the case of an imageless navigation system using a navigation pointer for palpation of bone landmarks;
• 7 a schematic view of a kinematic movement and evaluation, the step of kinematic movement being performed after the intervention and after implantation of the knee implant and after closing the intervention area in order to compare pre-operative kinematics with post-operative kinematics;
• 8th a flowchart of an assistance method according to a preferred embodiment.

The figures are schematic in nature and are intended only for understanding the present disclosure. Identical elements are provided with the same reference symbols. The features of the various embodiments are interchangeable.

Detailed description of preferred embodiments

1 until 7 show an endoprosthesis assistance system 1 (hereinafter referred to only as assistance system) for assistance in a surgical endoprosthetic intervention in a patient P in the form of a total knee arthroplasty according to a preferred embodiment of the present disclosure. The surgical assistance system 1 is adapted to be used in total knee joint replacement operations.

1 shows in a perspective view 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. Objects and trackers can be tracked using the 3D camera and corresponding spatial recording. Specifically, the assistance system 1 also has a first patient tracker 8 and a second patient tracker 10 (hereinafter only referred to as a tracker), which are each adapted by means of screw-in systems 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, to be rigidly screwed in and fastened.

In addition, the assistance system 1 (for a registration to be carried out later) assigns a navigation pointer 12 (will only be assigned later 6 explained in more detail), which together with the navigation system 2 can record intraoperative landmarks 14 via palpation. As an alternative or in addition to the pointer, the assistance system can also have a 3D surface scanner (not shown here), which is adapted to scan a surface and record it three-dimensionally.

The assistance system 1 also has a display device 16 in the form of an operating room monitor in order to provide the medical specialist with a visual display.

Finally, the assistance system has a control unit 18 which, in contrast to the prior art, is very specifically adapted in the present case in order to initially detect and record a kinematics and/or kinematic movement via the navigation system preoperatively and only perform the intraoperative registration after this detection and recording , as under Explanations of 2 until 7 is described below.

2 shows schematically the skeleton of a left leg of the patient P in a front view and a side view. The two trackers 8, 10 are rigidly screwed into the femur and the tibia (first and second bones K1 and K2) which form the knee joint. Navigation trackers will be attached.

This attached tracker 8, 10, as in the 3 and 4 shown, tracked and spatially recorded by the 3D camera 6 of the tracking system 4 of the navigation system 2 and with a as in 3 and 4 indicated active movement of the leg by a kinematic movement of the bones and thus a kinematics of the bones and made available to the control unit 18 in a computer-readable manner. This detection of the kinematic movement or kinematics takes place preoperatively, ie before an incision, so that a natural kinematics of the patient is captured without a removed patella changing a movement or kinematics. In particular, the surgeon can carry out 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, the anatomical data of an anatomical model cannot 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 back and forth, or performing a laxity test for a frontal alignment (varus/valgus loading). ) be. If you look at the human leg from a technical point of view, it is a system that oscillates in the sagittal plane almost like a double pendulum. The ankle is neglected. The thigh, mounted in an almost ideal ball joint, swings around a fixed point in the hip. This joint has three degrees of freedom with the angles in the sagittal plane, the frontal plane and the angle of rotation. The second joint of the leg, the knee joint as a connection between the femur and tibia, is essentially a joint with two degrees of freedom, ie the lower leg can be rotated relative to the thigh by the flexion angle with simultaneous dependent rotation of the lower leg about its longitudinal axis. In particular, these possible angular ranges can be detected by the kinematics with a corresponding analysis.

After the movement patterns have been recorded, the in 5 shown incision made and access to the bony structure prepared. In this case, the kneecap is usually reversed.

In 6 a registration is shown schematically. Here the patient is registered. In imageless navigation (in particular with robots), landmarks are palpated with the navigation pointer/navigation pointer 12 or the control unit determines a center as a landmark (for example a hip center) by analyzing the kinematic movements. In the case of image-based navigation or robotics, the surface of the bone is digitized with a navigation pointer and/or a 3D surface scanner.

After the in 6 registration shown, 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 can be determined/calculated by the control unit 18 . Here, the previously recorded and determined kinematic data are converted or transformed into the anatomical coordinate system(s) so that the surgeon can precisely record and measure all of the patient's kinematic parameters, for example varus/valgus, flexion/ extension, internal/external rotation, and/or anterior/posterior displacement.

The control unit 18 takes over the entire data acquisition, calculation and display of the data by the display device 16. The recorded kinematic data can now be passed on and processed without having to move the patient. The surgeon can use the information provided via the display device to select suitable implant components and/or to choose a suitable implant orientation, which is then carried out with the aid of navigation and/or robotics.

As in 7 shown, after the implantation, the kinematics can be recorded again after closing (suturing) the knee. After the knee has been closed, the trackers 8, 10 remain on the bones K1, K2 for the post-operative recording of the kinematic movement and kinematics. Postoperative kinematics can be compared to preoperative kinematics to validate treatment goals.

In concrete terms, therefore, in the assistance system 1 of the present embodiment, the control unit 18 is adapted to use the trackers 8, 10 attached to the bones K1, K2 before an incision to detect a kinematics and/or kinematics movement of the tracked bones K1, K2 by the navigation system 2 preoperatively and to record and, after an incision, to register intraoperatively via the first bone K1 and/or the second bone K2 by means of 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 correspondingly controls the OP monitor as display device 16 and outputs an assistance display 20 . This assistance display 20 has data or information on the kinematics of the biomechanical model as an anatomical system. Specifically, the assistance display 20 for the bone data on a possible twist angle from the tibia to the femur can be displayed, as shown in FIG 7 indicated in the table or an image sequence of the recorded kinematic movement can also be played back.

The assistance display thus links visual data of the individually recorded, precise kinematics of the patient's knee joint with an anatomical system in the form of a biomechanical model and outputs this information together clearly and intuitively, so that the surgeon can easily and effectively select an implant and an alignment of the implant.

8th shows an assistance method according to a preferred embodiment in a flow chart.

In an optional first step S1, a tracker 8, 10 in the form of a rigid-body tracker is attached to the bones on the tibia and on the femur. Alternatively, these can simply already be attached. Femur and tibia form the flexible connection of the joint.

In an optional second step S2, a guided kinematics movement is displayed by the display device 16 in order to provide the surgeon with visual instructions for a movement sequence in order to capture the entire kinematics as far as possible.

• Erst nach der Aufzeichnung der Kinematik und ferner erst nach einer darauffolgenden Inzision, erfolgt der Schritt S4 Durchführen einer intraoperativen Registrierung auf Basis von palpatierten Landmarken und/oder eines Oberflächenabgleichs einer intrakorporalen Knochen-Struktur der Tibia und/oder des Femurs durch das Navigationssystem 2 und den Navigations-Zeiger 12 und/oder dem Navigationssystem 2 und einem 3D-Oberflächenscanner.

In a step 3, before the incision and during the performed kinematics movement of the leg of the patient P, a preoperative kinematics of the tibia and femur of the patient P tracked by the navigation system 2 is recorded. These recorded preoperative kinematics are made available to the control unit 18 in computer-readable form:

• Only after the kinematics have been recorded and then only after a subsequent incision does step S4 carry out 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.

This is followed by the step S5 determining, by the control unit 18, on the basis of the registration, a transformation of the detected kinematics and/or kinematic movement into an anatomical system.

Finally, in step S6, the assistance display 20 is output by the display device 16. This assistance display includes data of the recorded kinematics in relation to the anatomical system of the patient.

In this embodiment, the assistance method further includes the following steps.

In a step S7 , postoperative kinematics of the knee of the patient P are recorded by the navigation system 2 , specifically only after the knee of the patient P has been closed, which is made available to the control unit 18 in computer-readable form.

In the last step S8, the recorded pre-operative kinematics before the patient P is opened are compared with the post-operative kinematics after the body of the patient P is closed, and a deviation between the recorded pre-operative kinematics and the recorded post-operative kinematics is determined. The surgeon can then use this deviation to evaluate the endoprosthesis.

Reference List

1

Endoprosthesis assistance system

2

navigation system

4

tracking system

6

3D camera

8th

First patient tracker

10

Second patient tracker

12

navigation pointer

14

landmark

16

display device

18

control unit

20

assistance representation

22

storage unit

P

patient

K1

First (joint) bone

K2

Second (joint) bone

S1

Step Attach a first and second patient tracker

S2

Step Displaying a guided kinematic movement

S3

Step Acquiring a preoperative kinematics

S4

Step Carrying out an intraoperative registration

S5

Step Determining a transformation between the kinematics and an anatomical system

S6

Step Outputting an assistance representation

S7

Step Acquiring a postoperative kinematics

S8

Step Comparing the preoperative kinematics with the postoperative kinematics

Claims (11)

Endoprosthesis assistance system (1) for assistance in a surgical endoprosthetic intervention in a patient (P), in particular in the case of a total knee arthroplasty or a hip endoprosthetic, having: a navigation system (2) with a tracking system (4) for tracking, which in particular has a 3D camera (6) for tracking; at least a first patient tracker (8) and a second patient tracker (10) adapted to a first bone (K1) and a second bone (K2) of the patient (P) forming the movable joint of the joint form to be rigidly fixed; 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 a surgical monitor, which is adapted to output a visual display to a user; and a control unit (18) adapted to: prior to an incision, using the patient trackers (8, 10) attached to the bones (K1, K2), to detect and record kinematics of the tracked bones (K1, K2) by the navigation system (2); following an incision, intraoperatively registering 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 to output an assistance display (20) with data on the recorded kinematics to the anatomical system via the display device (16). 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) has a surgical robot, in particular for actuating at least one medical instrument as an end effector, and the navigation system (2) is also preferably adapted to include a kinematics-based detection of the robot system for navigation. Endoprosthesis assistance system (1) according to one of the preceding claims, characterized in that the navigation system (2) is designed as an image-based navigation system and the control unit (18) is adapted for the recorded kinematics compared to 3D images of the patient (P) as anatomical System, in particular to correlate with segmented preoperative CT or MRI images. 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 respect to a biomechanical kinematics model of the patient (P) as an anatomical system. Endoprosthesis assistance system (1) according to one of the preceding claims, characterized in that the control unit (18) is adapted to use the OP monitor as a display device (16) to display movement instructions stored in a storage unit (22), in particular in the form of moving instructions Images to output to the user to provide the user with instructions for executing predefined kinematics. 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 via the display device (16), in particular the OP monitor, as a repetition. Endoprosthesis assistance system (1) according to one of the preceding claims, characterized in that the control unit (18) is adapted for this, based on an algorithm or based on a trained AI system and with the recorded kinematics as input data, a selection of a database To limit implant components and / or to provide a proposal for an alignment of a given implant and output visually via the display device (16) to a user. 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 via the navigation system (2) after the end of the intervention with the preoperative kinematics recorded before the incision and carry out an assessment based on the comparison and output it via the display device, in particular a comparison thereto to be carried out in such a way that a postoperative kinematics follows the preoperative kinematics within a predetermined tolerance, preferably a maximum deviation of the kinematics of 10%. Assistance method for a surgical endoprosthetic intervention in a patient (P), in particular for use in 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 trackers (8, 10) to a respective first and second bone (K1, K2) of the patient (P), which form the movable connection of the joint; Preferably, prior to an incision, displaying (S2) a guided kinematic movement through a display device (16) to provide a visual instruction to a user; Detecting (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 tracker (8, 10) and providing the detected kinematics a control unit (18); Carrying out (S4), after an incision, an intraoperative registration based on palpated intracorporeal landmarks and/or a surface adjustment 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; determining (S5), by the control unit (18), on the basis of the registration, a transformation of the detected kinematics into an anatomical system; and outputting (S6), through the display device (16), an assistance display (20) with data on the recorded kinematics to the anatomical system. assistance procedure claim 9 , characterized in that the assistance method also has the steps: recording (S7), after closing the body of the patient (P), a postoperative kinematics of the patient (P) by the navigation system (2) and the tracked patient tracker (8, 10) and providing as computer readable data to the control unit (18); and comparing (S8), by the control unit (18), the detected pre-operative kinematics before opening the patient (P) with the post-operative kinematics after closing the body of the patient (P) and determining a deviation between the detected pre-operative kinematics and the recorded postoperative kinematics. Computer-readable storage medium, which includes instructions that, when executed by the computer, cause the computer to follow the process steps of the assistance process claim 9 or 10 to execute.

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