EP2872065A1

EP2872065A1 - Method for generating a graphical 3d computer model of at least one anatomical structure in a selectable pre-, intra-, or postoperative status

Info

Publication number: EP2872065A1
Application number: EP12743056.9A
Authority: EP
Inventors: Lukas Kamer; Christoph Nötzli; Balazs ERDÖHELYI
Original assignee: AO Technology AG
Current assignee: AO Technology AG
Priority date: 2012-07-12
Filing date: 2012-07-12
Publication date: 2015-05-20
Also published as: JP6362592B2; JP2015530127A; WO2014008613A1; US20150227679A1; CA2878861A1

Abstract

The invention relates to a method for generating a graphical 3D computer model of anatomical structures in a selectable pre-, intra-, or postoperative status, having the following steps: A) receiving a preoperative first medical 3D image data set (10) of anatomical structures to be treated of a patient by means of a computer-assisted medical imaging method; B) generating a first graphical 3D computer model (1) of the anatomical structures to be treated in the form of a digital data set using the first medical 3D image data set (10) received in step A); C) receiving a second medical 2D or 3D image data set (20) of the anatomical structures to be treated in a pre-, intra-, or postoperative status by means of a computer-assisted medical imaging method; D) generating a second graphical 2D or 3D computer model (2) of the anatomical structures to be treated in the form of a digital data set using the second medical 2D or 3D image data set (20) received in step C); and E) carrying out an image registration process of the first graphical 3D computer model (1) using the second graphical 2D or 3D computer model (2).

Description

A method for producing a graphic 3D computer model of at least one anatomical structure in a selectable pre-, intra- or post-operative status

The invention relates to a method for producing a graphical three-dimensional (3D) computer model of at least one anatomical structure in a selectable pre-, intra- or post-operative status according to the preamble of patent claim 1.

In the surgical treatment of bone fractures and in the correction of osseous misalignments, bone fragments are anatomically repositioned and stably fixed with the appropriate osteosynthesis technique in the correct position. However, problems can result from an unrecognized misplacement of bone fragments and implants during surgery or secondary dislocation in the postoperative course. To avoid so is a faulty osteosynthesis by anatomically incorrect repositioning of bone fragments, incorrect surgical technique, unsuitable implant choice and / or their positioning.

Bone fractures and osseous deformities are routinely assessed using various radiographic imaging techniques before, during, and after surgery. Most are conventional radiographs, i. planar projection photographs. Particularly complex interventions are evaluated for diagnostic purposes with tomographic slice imaging, preferably by means of computer tomography (CT). This is done by analyzing their slice images or their three-dimensional computer models preferably preoperatively, in particular questions intra- or postoperatively.

However, the bone fragments and the osteosynthesis can not until now be assessed spatially conclusively in routine clinical operation over the entire course of therapy. This would require three-dimensional imaging such as CTs in all therapeutic steps. As mentioned, this is technically possible, but costs, radiation-hygienic reasons, generation of artefacts, personal, organizational and technical effort speak so far against a routine spatial assessment of osteosynthesis in all therapeutic stages. From US-A 2011/0082367 REGAZZONI a method for the reduction of fragments of a fractured bone is known. This known method involves generating 3D representations of bone and bone fragments based on a CT-scanned digital fractured bone dataset and a patient's contralateral healthy bone, using the 3D representation of the mirrored contralateral healthy bone as a reference model for the relative position of the 3D Representation of the reduced bone fragments serves. Subsequently, the 3D representations of the proximal and distal bone fragment are brought into agreement with the 3D representation of the reference model by means of a three-dimensional image registration and the configurations of the markers or anatomical landmarks on the proximal and distal bone fragments are extracted and transferred to the reference model. The relative positions of the markers or anatomical landmarks of the proximal and distal bone fragments transmitted to the reference model then allow to create a digital reference dataset useful for real reduction of bone fragments during surgery. From the proximal and distal bone fragment of the patient positioned on the operating table, two medical in-situ images are detected preoperatively by means of a C-Arm Fluroscope. From the two medical images, the three-dimensional positions of the markers or anatomical landmarks of the proximal and distal bone fragment relative to a local coordinate system are subsequently calculated, and therefrom the relative in-situ positions of the markers or anatomical landmarks of the proximal and distal bone fragments. Lastly, by comparing the relative in-situ positions of the markers or anatomical landmarks with the digital reference data set, a set of alignment parameters is determined.

In this known method, no image registration of the preoperatively acquired medical in-situ images with the 3D representation of the bone or bone fragments used for planning is required. However, as such image registration is not performed, surgical procedures, implants, and surgical instruments captured during planning can not be translated to the in situ situation. The adequate anatomical reduction of bone fragments along with stable osteosynthesis is a surgical guide to fracture management and corrective osteotomies. However, this is not easy to achieve, especially in difficult situations such as debris fractures with joint involvement or complex corrective osteotomies. In principle, errors can arise intraoperatively or become manifest only during the postoperative course. One possible source of error is that bone reshaping was done stably but not anatomically correct; however, this was not detected during the operation. Furthermore, although the anatomy may be conveniently restored, implants are unrecognized in a misplaced position, eg in the joint space. A biomechanically insufficient osteosynthesis with displacement of bone defects and / or osteosynthesis usually only appears in the postoperative course.

Thus, there is a need to present the osteosynthesis consisting of bone fragments and implants better preoperatively, to plan and better monitor intraoperatively as well as postoperatively, in the sense of a spatial, ie 3Dmonitoring of the osteosynthesisconstructor the entire course of therapy.

The invention is therefore based on the object, a method for producing a 3D graphic computer model, which comprises at least the surgically treated, respectively treated anatomical structures to provide in a selectable pre-, intra- or post-operative status, which for the control or monitoring a planned procedure such as is useful for orthopedic surgery. Other procedures, such as the insertion of a dental implant or neurosurgical procedures, can be monitored in the same way.

The invention achieves the stated object with a method for producing a graphic 3D computer model having the features of claim 1.

The advantages achieved by the invention are essentially to be seen in the fact that thanks to the inventive method initially generated 3D computer models of anatomical structures, such as bone by repeated registrations on the various imaging methods such as conventional preoperative X-ray images, intraoperative planar 2D C-arm, or 3D spatial C-arm images, or postoperative X-ray images are now always spatially over the entire course of therapy for presentation. A spatial representation, once and preferably generated by means of a CT preoperatively, is advantageous for various reasons: it generates a spatial representation of the region to be treated at the beginning of the therapy. This spatial information can thus be used for diagnostics and therapy planning. Furthermore, more time is available for preoperative processing and analysis than, for example, during surgery. Also, other imaging, generated by means of intraoperative 2D or 3D C-arms, is less or even inadequate for temporal and / or technical reasons to generate 3D computer models of anatomical structures such as bones. The same applies to conventional pre- and postoperative X-ray images, in which the scale representation of 3D computer models of anatomical structures such as bone fragments is not possible; certainly not without considerable additional effort. These X-ray images represent planar summation images generated from only one projection direction. But advantageous is their high image resolution.

definitions:

Medical 3D image data set: a medical 3D image data set of an anatomical structure of a patient to be treated, for example the region with fracture or with bone deformity, is preferably recorded by means of a CT. Alternatively or in addition, other three-dimensional layer imaging techniques such as Cone Beam Computed Tomography (also called digital volume tomography), magnetic resonance tomography or 3D laser scanning can be used.

Medical 2D image dataset: A medical 2D image dataset is understood to be a digital dataset which comprises the digital data of one or more digitized planar X-ray images of a patient's anatomical structure to be treated.

Graphical 3D computer model: under a graphical 3D computer model, an image that can be displayed on the screen and defined by a digital data record understood virtual model of objects, such as anatomical structures, temporary aids (eg, surgical instruments and tools) and implants. The first 3D graphical computer model may include a plurality of extractable 3D graphical submodels for separate anatomical structures, eg, bone fragments, one or more implants, and / or one or more surgical instruments. Likewise, the second graphical 2D or 3D computer model may include a plurality of extractable 3D graphical submodels for separate anatomical structures, eg, bone fragments, one or more implants, and / or one or more surgical instruments.

Implant: implants are understood to mean all solid or artificially or fully inserted or used in the human or animal body, which can be imaged by conventional X-ray images, CT or Magnetic Resonance Imaging (MRI) and limited in their shape, e.g. orthopedic implants, dental implants, pacemakers or stents.

Image registration: "Image registration" is understood in the following to mean superimposition of two or more 2D images of anatomical structures to be treated and / or of the implants used, the 2D images being compared precisely with the 3D anatomical computer model of the anatomical structures and / or implants to be treated Matched and are each defined by a digital record.

In the method according to the invention, one or more digitized medical images of the second medical 2D or 3D image data set of the anatomical structures to be treated and / or of the implants with the first 3D graphic computer model are registered by image registration, so that an updated, ie. Position of the first graphical 3D computer model adapted to the pre-, intra- or postoperative position of the anatomical structures and / or implants to be treated can be displayed on the screen of a computer.

Further advantageous embodiments of the invention can be commented on as follows: In a specific embodiment of the method, step B) additionally comprises the sub-step:

B1) introducing a 3D digital graphic submodel representing an implant into the first 3D graphic computer model.

The graphic 3D submodel of the implant may be obtained from a database, such as e.g. a CAD database into the first graphical 3D computer model.

In another embodiment of the method, step B) additionally comprises the sub-step:

B2) Introducing a 3D digital graphic submodel representing a surgical instrument into the first 3D graphical computer model. The graphical 3D submodel of the surgical instrument can also be obtained from a database, such as a database. a CAD database into the first graphical 3D computer model.

In another embodiment of the method, the preoperative first medical 3D image data record recorded in step A) comprises a plurality of anatomical structures, and the first graphical 3D computer model comprises a graphical 3D submodule for each anatomical structure and preferably for each implant and / or surgical instrument. Thus the advantage can be achieved that for the anatomical structures to be treated, such as e.g. Bone or bone fragments individually detectable graphical 3D submodels can be integrated into the first graphical 3D computer model, so that an individual analysis of certain anatomical structures is made possible. Further, the first 3D graphical computer model may include individually detectable 3D graphical submodels of implants and surgical instruments.

In a further embodiment of the method, the second graphical 2D or 3D computer model additionally comprises representations of one or more implants.

In yet another specific embodiment of the method, the second graphical 2D or 3D computer model additionally comprises representations of one or more surgical instruments. In another embodiment of the method, the second graphical 2D or 3D computer model for the anatomical structures and for each implant, and preferably also for each surgical instrument, each comprises a graphical 2D or 3D submodel.

In yet another embodiment of the method, the second graphical 2D or 3D computer model forms the reference model with which the first 3D graphical computer model is matched in performing the image registration. The second graphical 2D or 3D computer model is used as a reference model and thus defines a target model with which the first graphical 3D computer model (object model or source model) is matched. The recording of the second medical 2D or 3D image data set may include one or more digitized medical images, which are each taken at a predetermined angle of the image plane of the C-arm X-ray machine to the gravity vector, so that the positions of the anatomical structures to be treated and thus the position of the first graphical 3D computer model are defined in a fixed coordinate system with respect to the operating room.

In a further embodiment of the method, the recording (in a pre-, intra- or post-operative status) of a second medical 2D or 3D image data record in step C) comprises the acquisition of one or more digitized medical images by means of a computer-assisted medical imaging method. The inclusion of two or more digitized medical images taken at an angle relative to one another enables the generation of a 3D computer model. On the other hand, different fragments / sections of a long tubular bone can also be imaged in each one of the digitized medical images, so that intraoperatively used C-arm X-ray devices with a relatively small image section can be used to record the second medical 2D or 3D image data set. The method is characterized by the fact that at most only one X-ray image is sufficient and the known standard to the expert accounts "in two levels" omitted. Further advantages of the method are thus a reduced radiation exposure and effort. Consequently, in fracture repair and correction osteotomies entire Osteosynthesekonstrukt consisting of bone fragments, residual bone from possible bone and the implants used spatially assessed over the entire course of therapy. On the computer screen, a 3D computer model of the anatomical structure, such as the fracture or osteotomy, becomes visible, depicting the bone fragments spatially before, during or after surgery, depending on the stage of therapy. Only 3D imaging is necessary once. Once implant material becomes radiologically visible, its position can also be spatially determined and displayed by referencing its 3D computer models to the 3D computer models of the anatomical structures, such as the bone fragments.

In yet another embodiment of the method, generating the first graphical 3D computer model comprises automatic or manual identification and localization of anatomical landmarks, lines and / or regions of the anatomical structures to be treated.

In another embodiment of the method, generating the first 3D graphic computer model comprises automatic or manual identification and localization of landmarks, lines, and / or regions of each implant, and preferably each surgical instrument.

In another embodiment of the method, the generation of the second graphical 2D or 3D computer model comprises an automatic or manual re-identification and re-localization of the anatomical landmarks, lines and / or regions of the anatomical structures to be treated identified and localized in the first graphical 3D computer model. In the simplest case, therefore, the second graphical 2D or 3D computer model comprises a single digitized medical image with the re-identified and re-located anatomical landmarks. The image registration can thus be carried out with a feature-based registration method. With feature-based registration methods, a certain, as a rule, relatively small number of features, eg, of anatomical landmarks, are extracted from the images. This happens either manually or automatically. The selected anatomical features are preferably distributed over the entire image as possible and not only focus on a single region. The image registration then takes place in that the selected features, eg the selected anatomical landmarks on the object model, ie on the first graphical 3D computer model, are matched with the same anatomical landmarks on the reference, respectively target model, ie on the second graphical 2D or 3D computer model. In addition to anatomical landmarks, areas in the image which stand out clearly from surrounding areas can also be used as features as regions features or lines, respectively edges, which are present as lines themselves or as contours of regions. Lines can, for example, also be represented and extracted by their endpoints.

In a further embodiment of the method, the generation of the second graphical 2D or 3D computer model comprises an automatic or manual re-identification and re-localization of the landmarks, lines and / or regions of each implant and of each surgical instrument identified and located in the first graphical 3D computer model.

Registration of the 3D graphical submodels of the implants and / or surgical instruments can now be done in two ways:

1) First, the one or more graphical 3D submodels of the anatomical structures of the first 3D graphic computer model are registered with the one or more 3D graphical submodels of the anatomical structures of the second 3D graphic computer model and then the one or more 3D graphical submodels of the implants and / or surgical instruments of the first graphical 3D computer model with one or more graphic 3D submodels of the anatomical structures of the previously registered 3D graphical submodels of the anatomical structures of the first 3D graphical computer model and thereby the relative positions between the 3D graphical submodels of the implants and / or surgical instruments and the graphical Considers 3D submodels of the anatomical structures in the second graphical 2D or 3D computer model; or

2) First, the graphic 3D submodel (s) of the anatomical structures of the first 3D graphic computer model with the one or more graphical 3D submodels of the anatomical structures of the second and then the graphical 3D submodels of the implants and / or surgical instruments of the first graphical 3D computer model are registered with the one or more graphical 3D submodels of the implants and / or surgical instruments of the second 3D graphical computer model.

In a further embodiment of the method, step B) additionally comprises the sub-step:

computer-aided planning and execution of a virtual surgical treatment of the anatomical structures to be treated using the first medical 3D image data record taken in step A).

On the basis of the first medical 3D image data set of the anatomical structures to be treated, first of all a 3D submodel of the first graphical 3D computer model can be created, which includes the anatomical structures and serves as the initial graphic computer model for the planning and execution of the virtual surgical treatment. Further 3D submodels can subsequently be used for planned therapy steps, such as The reduction of bone fragments to the conclusion of the therapy is created and integrated into the first graphical 3D computer model.

In yet another embodiment of the method, the first graphical 3D computer model comprises a graphic 3D submodel of the anatomical structures to be treated in the form of a digital data record using the first medical 3D image data record recorded in step A).

In another embodiment of the method, the computer-aided planning comprises the integration of at least one further graphic 3D submodel of an implant into the first graphical 3D computer model. Thus, the position of implants and / or temporary aids, such as guide wires, surgical tools or instruments in each therapy step to the conclusion of the therapy can be spatially determined and displayed. This is achieved by positional alignment of corresponding 3D computer models of the implants and / or the temporary aids, which are archived and retrievable in the computer, with, firstly, the now properly positioned 3D computer models of the anatomical structures (As described above) and secondly with the visible on the X-ray images positions of the implants and / or temporary aids. The 3D computer models of the implants and / or temporary aids thus come through repeated registrations on the various imaging methods such as conventional preoperative X-ray images, intraoperative plan 2D C-arm, or 3D spatial C-arm images, or postoperative X-ray images always spatially over the entire course of therapy Presentation.

In yet another embodiment of the method, the computer-assisted planning comprises the integration of at least one further graphical 3D submodel of a temporary auxiliary device, preferably a surgical instrument, into the first 3D graphical computer model.

In a further embodiment of the method, the computer-assisted planning comprises an assessment of the biomechanical stability of the virtually surgically treated anatomical structures by means of a computer simulation, preferably by means of a finite element computer analysis. Through computer-aided analysis and planning of the operation, i. In the re-position of the anatomical structures, the nature and location of the temporary and definitive implants can be spatially displayed on the computer, virtually planned, and the biomechanical stability, e.g. an osteosynthesis by computer simulation and re-evaluated at each therapy step. Situationally, the treatment plan can then be continued or modified as needed.

In a further embodiment of the method, the first graphical 3D computer model comprises at least one graphical 3D submodule of at least one intermediate result of the anatomical structures that are virtually treated according to computer-based planning.

In another embodiment of the method, the first 3D graphic computer model comprises as a submodel an execution plan which preferably defines the exact sequence of the surgical procedure and contains corresponding control specifications. The method can be used to monitor surgical treatments. Preferably, step C) of the method first takes place in a preoperative status, so that it is possible to monitor the at least one object prior to the surgical treatment. The step C) of the method may be performed in at least one intraoperative status, so that a monitoring of the at least one object is made possible during the surgical treatment. Furthermore, the step C) can also be carried out in at least one post-operative status, so that it is possible to monitor the at least one object after the surgical treatment.

Preferably, the inventive method for quality assurance of surgical treatments is used. Another component and advantage of the method is that all data generated over the entire course of therapy can be integrated into a quality management system and thus analyzed. This in turn can have a positive effect on the type, choice and implementation of the therapy; e.g. standardize the therapy procedures according to relevant parameters.

The method can be used for the treatment of bone fractures, for the treatment of osseous malpositions and in dental implantology.

The invention and further developments of the invention are explained in more detail below with reference to the partially schematic representations of several embodiments.

Show it:

Fig. 1 is a flow diagram of an embodiment of the inventive method;

FIG. 2 is a flow chart of another embodiment of the method according to the invention; FIG. and 3 is a flowchart of an embodiment of generating a first graphical 3D computer model according to the embodiment of the inventive method according to FIG. 2.

In principle, the method according to the invention can be used for all anatomical structures which can be detected three-dimensionally by a computer-aided medical imaging method. Also, all at least partially by a computer-aided medical imaging method geometrically clearly detectable implants and intraoperatively useable surgical instruments can be used.

Example 1 :

In the following, the method according to the invention will be described by way of example for a surgical treatment of bone fractures and a correction of osseous misalignments.

The embodiments shown in FIGS. 1 and 2 differ only in that in the embodiment according to FIG. 1, a first graphical 3D computer model 1 of anatomical structures to be treated is created on the basis of a preoperative medical first 3D image data set 10, while in the FIG Embodiment according to FIG. 2, a graphic 3D computer model created analogously to the embodiment according to FIG. 1 is used as a graphical 3D submodel and generating the first graphical 3D computer model 1 additionally computer-aided planning and execution of a virtual surgical treatment of the anatomical structures to be treated using this 3D submodel includes. The embodiment of the method according to FIG. 1 can be used in particular if, for example, in emergency situations such as serious accidents, for reasons of time, no computer-aided planning of the operation is carried out. In addition, in the embodiment of the method according to FIG. 2, all pre-, intra- or postoperatively necessary image registrations for the monitoring of the entire course of therapy can be carried out using the embodiment according to FIG. 1 or the embodiment according to FIG. The embodiment of the method illustrated in FIG. 1 essentially comprises the steps:

Step 00: 3D imaging before surgery

First, a preoperative medical first 3D image data set 10 of anatomical structures of a patient to be treated is recorded by means of a computer-assisted medical imaging method. The method involves obtaining adequate image information of the surgical field prior to surgery. This provides for generating a preoperative first medical 3D image data set of an anatomical structure of a patient to be treated, for example the region with fracture or with osseous malposition, preferably by means of a CT. Alternatively or in addition, other three-dimensional layer imaging techniques such as Cone Beam Computed Tomography (also called digital volume tomography), magnetic resonance tomography or 3D laser scanning can be used. As output the preoperative first medical 3D image data set 10 is obtained in the form of a digitized 3D image data set, for example a data record in DICOM format (Digital Imaging and Communication in Medicine).

Step 101: Generation of a first graphical 3D computer model 1 of the anatomical structures to be treated in the form of a digital data record using the first medical 3D image data set 10 recorded in step 100. In particular, in this step, an identification, localization and representation of the anatomical structures is performed prior to the operation ,

Using the preoperative medical first 3D image data set 10, which was preferably created by means of a preoperative CT, the anatomical structures to be treated, such as bone fragments in fractures or bone segments in osseous misalignments identified with appropriate computer software, located and in the form of a first graphical 3D Computer models 1 stored so that they can be displayed as a 3D bone fragments, on a screen. This can be achieved by methods of identification, ie the recognition of anatomical-geometric patterns of the anatomical structures eg the bone fragments; their localization, ie the definition of their spatial position; and their representation, ie their adequate spatial representation done as a 3D computer model. This also includes techniques of image segmentation. For example, in the case of corrective osteotomies, in this step 101, two or more virtual bone fragments are already identified and localized according to the osteotomy planning, whereby a prospective cutting line is used to separate the bone fragments. Step 101 is performed automatically and / or manually on a computer prior to the operation, wherein the preoperative first medical 3D image data set 10 recorded in step 100 and computer software and methods for processing this 3D image data set, ie for identification, localization and spatial representation of 3D anatomical structures, such as bone fragments used in fractures. As output, a processed digital data set is obtained, which enables a graphical 3D representation of the anatomical structures, eg of the individual bone fragments.

The first graphical 3D computer model 1 of the anatomical structures to be treated obtained in step 101 can now be obtained by image registration with a second graphical 2D or 3D computer model 2 which comprises one or more digitized medical images of a second or further medical pre-, intra- or postoperative 2D or 3D image data set 20 can be generated, matched in terms of its spatial position. Thus, the first 3D graphic computer model 1 over the entire course of therapy, in the updated, i. in the actual pre-, intra- or postoperative position of the anatomical structures to be treated are displayed on the screen of a computer. Within a monitoring of a surgical treatment, therefore, the first graphical 3D computer model 1 can be used for positional representation of the anatomical structures to be treated preoperatively in the operating room directly before the operation, intraoperatively, after completion of the operation and / or postoperatively for follow-up. For this purpose, the steps 102 to 104 described below are executed in each case.

Alternatively, as described below under FIG. 2, the generation of the first graphic 3D computer model 1 carried out in step 201 can additionally take place computer-aided planning and execution of a virtual surgical treatment of the anatomical structures to be treated using the first medical 3D image data set 10 recorded in step 200. In this case, to monitor a surgical treatment, the image registration of the first graphic 3D computer model 1 according to one of the embodiments according to FIG. 1 or according to FIG. 2 can be carried out with one or more digitized medical images of a second or further medical procedure recorded pre-, intra- or postoperatively 2D or 3D image data set 20 are executed.

Step 102: Before the image registration of the first graphic 3D computer model 1 according to one of the embodiments according to FIG. 1 or according to FIG. 2 with a second graphic 2D or 3D computer model 2, the recording takes place - in the desired pre-, intra- or postoperative status. a second medical 2D or 3D image data set 20 comprising one or more digitized medical images 21 of the anatomical structures to be treated and / or of the implants by means of a computer-assisted medical imaging method.

Step 103: Thereafter, a second graphical 2D or 3D computer model 2 of the anatomical structures to be treated is generated in the form of a digital data set using the second medical 2D or 3D image data set 20 recorded in step 102. After the one or more digitized medical images, For example, by means of a pre-, intra- or postoperative X-ray imaging of the anatomical structures to be treated are the same anatomical landmarks (anatomical landmarks) of the anatomical structures, eg of bone fragments and bone contours of the fracture zone and the healthy bone surface including articular surface, bone gray levels and / or geometric Bone patterns on the one or more digitized medical images, or directly in the second graphical 2D or 3D computer model 2, are re-identified and re-localized to subsequently receive the first 3D graphical computer model treating anatomical structures, such as the bone fragments with the second graphical 2D or 3D computer model 2 of the pre-, intra- or postoperative situation to register. As pre-, intra- or postoperative imaging techniques are the conventional planar X-ray or X-ray images in two planes, or in the operating room immediately before surgery generated X-ray images, which were preferably generated by means of a 2D or 3D image recording method using a C-arm X-ray machine.

Step 104: Next, the image registration of the first graphic 3D computer model 1 is performed with the second graphic 2D or 3D computer model 2. Consequently, a new representation is created on which the first graphic 3D computer model 1 of the anatomical structures to be treated, e.g. the bone fragment is visible in position according to the current imaging. Possible positional shifts of the anatomical structures e.g. The bone fragments from the time of acquisition of computed tomography (CT) are therefore updated and thus compensated.

The embodiment of the method illustrated in FIG. 2 differs from the embodiment illustrated in FIG. 1 only in that the generation of the first graphic 3D computer model 1 is a computer-aided planning and execution of a virtual surgical treatment of the anatomical structures to be treated under the possible use of Implants and also may include surgical instruments.

The embodiment of the method illustrated in FIG. 2 is described by way of example at an osteosynthesis or a corrective osteotomy and essentially comprises the steps:

Step 200: 3D imaging before surgery:

First, analogously to the embodiment according to FIG. 1, the recording of a preoperative medical first 3D image data set 10 of anatomical structures of a patient to be treated is carried out by means of a computer-assisted medical imaging method.

Step 201: Subsequently, the first graphical 3D computer model 1 of the anatomical structures to be treated is generated in the form of a digital data set, wherein the generation of the first graphical 3D computer model 1 is a computer-aided planning and execution of a virtual surgical treatment of the anatomical structures to be treated using the first medical 3D image data set 10 recorded in step 100. Analogous to FIG. 1, in this step, an identification, localization and representation of the anatomical structures before the operation takes place first.

The 3D preoperative planning on the computer is shown in detail in FIG. 3, wherein the 3D preoperative planning on the computer can comprise all or only part of the steps 2011 to 2021 illustrated in FIG. In addition to the clinical examination of the patient, study of the clinical documentation including assessment of imaging, the preoperative planning of surgical treatment on the computer is now also carried out using the appropriate software. For example, anatomically correct virtual reduction of the 3D bone fragments in bone fractures is a central task (step 2012). The anatomical reduction of the 3D bone fragments also allows the visualization and analysis of a residual bone defect, if any. In osseous deformities, on the other hand, the computer virtually spatially fixes the osteotomy (step 2011) and then moves the 3D bone fragments to the planned position (step 2012). For this purpose, the above-defined 3D bone fragments are constantly redrawn or registered according to the planned position of the osteotomy.

As a further feature of this 3D preoperative planning on the computer, the fracture or the osteotomy can be analyzed virtually (step 2013). For example, it is possible to calculate the shape, size and degree of dislocation of the bone fragments and the residual defect or defect, as well as the resulting overlap of the bone fragments (important in osteotomies or bone grafting). Known fracture classifications 4, e.g. the classification AO COIAC, respectively Müller AO classification, which are stored on databases and retrievable, can be used.

Then, virtual osteosynthesis (step 2016) is planned for both fractures and osseous malocclusions by selecting computer models of temporary tools, such as surgical instruments, and definitive implants such as plates, intramedullary nails, screws, guidewires, of appropriate size and positioned in the first graphical 3D computer model as graphic 3D submodels. In case of bone defects, the planning of autologous or alloplastic material (eg, bone graft, or cement), including quantity, by virtually reconstituting the defect with corresponding virtual fillers corresponding to the volume or mechanical properties of the bone. As a further feature of step 201, an execution plan (step 2017) is defined and integrated as a submodel in the first graphical 3D computer model 1, which defines the exact sequence of the surgical procedure and contains corresponding control specifications. This determines the order of reduction of the bone fragments or osteotomies, as well as the sequence and use of temporary aids and definitive implants. The control specification includes a virtual graphical 3D computer model of the intermediate result, which can be compared to the real intermediate result during the operation.

As a further feature of step 201, the osteosynthesis created in virtual surgery planning consisting of bone fragments and implant can be virtually biomechanically tested (step 2018), e.g. using a finite element analysis.

The input used is the pre-operative medical first 3D image data record 10 recorded in step 200, on the basis of which 3D graphic submodels of the bone fragments or of the entire region can be created in the case of osseous misalignments prior to planning. The following software tools can be used to plan and execute a virtual surgical procedure:

1. Software tool for the generation of virtual osteotomies, especially in osseous deformities;

2. Software tool for virtual re-positioning of the 3D bone fragments;

3. Archived 3D computer templates of temporary aids and definitive implants such as plates, screws, intramedullary nail, Kirschner wires;

4. Software tool for analysis of components (such as number, size, geometry of bone fragments and implants) and planning operations (e.g., degree of dislocation, osteotomy angle) during planning;

5. Software tool for creating a primary execution plan and alternatives; and 6. Software tool for analyzing the biomechanical properties of osteosynthesis.

The output (output) is a first graphic 3D computer model 1 which generates the virtual surgically treated anatomical structures with the implants and / or surgical instruments according to computer-based planning, one or more graphic 3D submodels of one or more intermediate results of the computer-based planning treated anatomical structures and the computer-based planning of the osteosynthesis for the treatment of fractures, or for the correction of bony deformities may include.

Step 202: recording - in the desired pre-, intra- or postoperative status - a second medical 2D or 3D image data set 20 comprising one or more digitized medical images 21 of the anatomical structures, implants and surgical instruments to be treated by means of a computer-aided medical imaging Method analogous to FIG. 1.

Step 203: Generate a second graphical 2D or 3D computer model 2 of the anatomical structures to be treated and / or the implants in the form of a digital data set using the second medical 2D or 3D image data set 20 recorded in step 202 analogous to FIG or the plurality of digitized medical images 21, for example by means of a pre-, intra- or postoperative X-ray imaging of the anatomical structures to be treated with the implant and / or surgical instruments have been generated, anatomical landmarks (anatomical landmarks) of the anatomical structures, eg of bone fragments and Bone contours of the fracture zone and healthy bone surface including articular surface, bone gray levels and / or geometric bone patterns are re-identified and re-localized on the one or more digitized medical images 21 or directly in the second 2D or 3D graphical computer model 2 in order subsequently to register the first graphic 3D computer model 1 with the second graphical 2D or 3D computer model 2. Conventional planar radiographs or x-ray images in two planes, or in the operating room immediately before surgery, generated x-ray images, serve as preoperative imaging techniques preferably generated by means of a 2D or 3D image recording method using a C-arm X-ray machine.

Step 204: Subsequently, the image registration of the first graphic 3D computer model 1 is carried out with the second graphic 2D or 3D computer model 2. As with an image registration according to the embodiment according to FIG. 1, a new graphical representation is created on which the first graphic 3D computer model 1 of FIG to be treated anatomical structures, eg the bone fragment is visible in position according to the current imaging. Possible positional shifts of the anatomical structures e.g. The bone fragments from the time of acquisition of computed tomography (CT) are therefore updated and thus compensated. Once implants and / or surgical instruments are radiologically visible, or by other imaging, their position may be determined by referencing their 3D graphical submodels to the one or more of the 3D graphical submodels of the anatomical structures, such as the 3D model. the bone fragments are spatially determined and displayed. In addition, the entire planned implant can be visualized, including the position and its insertion direction and end position. In step 204, a prospective spatial position determination of the temporary aids and / or of the definitive implant thus takes place preoperatively. After registering all components described, the various components can be displayed or hidden on the computer as required.

The embodiments of the method according to the invention described in FIGS. 1 to 3 can subsequently be used for the three-dimensional (3D) monitoring of a surgical treatment. The 3D monitoring may include one or more of the following steps:

1) monitoring before surgery; and or

2) monitoring during the operation; and or

3) Monitoring at postoperative follow-up.

1) Monitoring before the operation: At the beginning, according to step 102 or 202, a second medical 2D or 3D image data set 20, for example a preoperative X-ray imaging of the anatomical structures to be treated is recorded. Anatomical landmarks of bone fragments and bone contours of the fracture zone and healthy bone surface including articular surface, bone gray values, and geometric bone patterns are re -identified and re-localized on the preoperative X-ray image to deliver the first 3D graphical computer model 1 of the bone fragments to the second graphical 2D or 3D computer model 2 to register. Preoperative imaging techniques are conventional plane x-ray or x-ray radiographs in two planes, or x-ray images generated in the operating room just prior to surgery, preferably generated by 2D C-arm or 3D C-arm.

A new representation thus results on which the first graphical 3D computer model 1 of the anatomical structures, e.g. the bone fragments are visible in position according to the current imaging. Any positional shifts in the bone fragments from the point in time CT acquisition are therefore updated and thus compensated.

It is now also possible to include the 3D operation planning, i. the entire planned osteosynthesis construct can be visualized including the position of implants and their insertion direction and end position. Thus, preoperatively, a prospective spatial positioning of implants takes place. After registering all components described, the various components can be displayed or hidden on the computer as required.

2) Monitoring during the operation:

There is a new X-ray image control, but now intraoperatively during surgery, preferably a 2D or 3D C-arm image control. Likewise, re-image registration is performed as described in step 204 above: anatomical landmarks of bone fragments and bone contours of the fracture zone and healthy bone surface including articular surface, bone gray levels, and geometric bone patterns are re-identified on the intraoperative X-ray image and re-localized to the first 3D graphic To register computer model 1 of the bone fragments. Intraoperatively, therefore, the The current position of the 3D bone fragments can be spatially determined or monitored. Fixing an implant to the bone at the beginning of surgery may improve or facilitate the registration process. This can be useful, in particular, in the case of corrective osteotomies, since fewer anatomical landmarks are available here which can be identified analogously in preoperative 3D imaging.

In the case of corrective osteotomies, it may be useful to perform only a partial shift in order to spatially evaluate the position of the bone fragments by means of re-identification and re-localization. Further measures can then be initiated to improve the osteotomy result. Only after checking the spatially correct position of the bone fragments does the definitive fixation take place.

As soon as implants and / or surgical instruments become visible during the operation on a further intraoperative X-ray image control, their spatial position can also be determined by registering them with the already spatially defined graphical 3D computer model 1 of the bone fragments and corresponding positioning of graphical 3D submodels of the implants and / or surgical instruments.

In turn, the 3D operation planning according to step 201 can be included again, i. The planned and instantaneous osteosynthesis, including the position of implants and / or surgical instruments and their insertion direction and end position, can be visualized, analyzed and virtually biomechanically tested.

Further X-ray image controls with re-identification and re-localization during the operation and the inclusion of information of preoperative planning and simulation help the surgeon to continue the surgery successful and three-dimensionally documented, modify and finally conclude with a control of the spatial position of the osteosynthesis.

3) Monitoring at postoperative follow-up.

There are routinely postoperative follow-up visits with X-ray controls. Optionally, the first graphical 3D computer model 1 of the bone fragments as well as the graphic 3D submodels of the implants can be re-identified and re-localized after the osteosynthesis. It can thus be determined in the postoperative X-ray checks whether or when a spatial change in position of the bone fragments or implants has taken place; especially if a postoperative change has occurred. Again, the position of the first 3D graphical computer model 1 of the bone fragments and the implants can be compared to the pre- or intraoperatively created 3D graphic computer models 1. The computerized preoperative planning can be displayed and the current situation can be simulated eg by means of Finite Element Analysis to test the biomechanical stability of the current osteosynthesis. In further follow-up checks, a re-evaluation takes place, ie it is decided based on the results shown whether the therapy should be completed or whether new diagnostic or therapeutic steps should be initiated.

If an accurate registration on only one planar X-ray image is possible, the standard X-ray documentation "in two levels" can be dispensed with. Thus, the radiation exposure and effort can be reduced.

The findings and results obtained by the embodiments of the method according to the invention shown in FIGS. 1 and 2 and one or more of the steps performed during the monitoring can be converted into a quality management system of surgical treatments.

Example 2:

In the following, the inventive method shown in FIGS. 1 to 3 is shown in a further example of applications in dental implantology. The course of therapy in the case of insertion of one or more dental implants can be monitored as follows over the course of therapy: 3D imaging of the operating area and the adjacent region, for example the adjacent teeth and / or the alveolar ridge, ie recording of a preoperative medical first 3D image data set 10 and Generate the first graphical 3D computer model 1 or a submodel thereof (steps 100 and 101 Fig. 1 or steps 200 and 201 in Fig. 2). The 3D imaging advantageously takes place by means of an optical 3D scanning method, for example by means of laser scanning. This may be done alone or in addition to preoperative CT or digital volume tomography. The monitoring of the individual therapeutic steps is now carried out by the operation area before, and then during the operation together with the Surgical instruments such as pilot drills or dental implants, as well as immediately after surgery or after incorporation of the prosthetic work (ie, a crown, or bridge) by means of optical laser scanning including the adjacent region are detected, and these generated in different Therapiestadien 3D imaging are registered. The 3D images described in the foregoing form a second and further graphical 3D computer models 2 which were generated on the basis of a second and further medical 3D image data sets 20 (steps 102 and 103 in FIG. 1 or steps 202 and 203 in FIG. 2). and registered with the first 3D graphic computer model 1 (step 104 in FIG. 1 or step 204 in FIG. 2). This registration should preferably take place on non-operated structures, for example on anatomical structures such as teeth or alveolar ridge. The registration allows the determination of the spatial position of the implants and surgical instruments. As described, steps of 3D preoperative planning (step 201 in FIG. 2) may be included in the therapy. Likewise, the result of the therapy, for example the entire dental prosthetic restoration, can be compared with the virtual planning or re-evaluated in any phase.

An advantage of this development of the invention is that laser scanning is a 3D imaging method that does not generate X-rays. This can be used as soon as surfaces of the surgical region as well as implants, surgical instruments, but also fracture segments and osteotomies become sufficiently visible and thus detectable. It is advantageous to no additional X-ray exposure of the patient in the course of therapy. Another advantage is the very detailed reproduction of surfaces such as those of the teeth or implants.

Alternatively, however, as described, conventional dental X-ray images for monitoring over the course of therapy can be used for the field of dental implantology. Although the X-ray exposure is present, it is low. If the implants or surgical instruments are not sufficiently directly visible, because they are located in the bone and / or under the mucous membrane, and thus can not be detected directly or insufficiently by laser scanning, then temporary implants with known geometry, such as an implant, can be placed on the implants or surgical instruments Healing cap, to be screwed on. If now the operated region with a clearly visible healing cap per inserted implant is scanned, then in the consequence -

26 the corresponding computer template of the healing cap including the attached computer template of the inserted implant or surgical instrument in the registration and thus their position can be clearly determined.

While various embodiments of the present invention are described above, it should be understood that the various features may be used both individually and in any combination.

This invention is therefore not limited to the above-mentioned, particularly preferred embodiments.

Claims

claims

1. A method for producing a graphic 3D computer model of at least one anatomical structure in a selectable pre-, intra- or post-operative status, comprising the steps of:

A) recording a preoperative first medical 3D image data set (10) of at least one anatomical structure of a patient to be treated by means of a computer-assisted medical imaging method;

B) generating a first graphical 3D computer model (1) of the anatomical structure to be treated in the form of a digital data set using the first medical 3D image data record (10) recorded in step A);

C) recording - in a pre-, intra- or postoperative status - a second medical 2D or 3D image dataset (20) of the anatomical structures to be treated by means of a computer-assisted medical imaging method;

D) generating a second graphical 2D or 3D computer model (2) of the anatomical structures to be treated in the form of a digital data set using the second medical 2D or 3D image data set (20) recorded in step C); and

E) performing an image registration of the first graphical 3D computer model (1) with the second graphical 2D or 3D computer model (2).

2. The method according to claim 1, characterized in that step B) additionally comprises the sub-step:

B1) introducing a 3D digital graphic submodel representing an implant into the first 3D graphical computer model (1).

3. The method according to claim 1 or 2, characterized in that the step B) additionally comprises the sub-step: B2) Introducing a 3D digital graphic submodel representing a surgical instrument into the first 3D graphical computer model (1).

4. The method according to claim 2, wherein the preoperative first medical 3D image data record (10) recorded in step A) comprises a plurality of anatomical structures and the first graphical 3D computer model (1) for each anatomical structure and preferably for each implant and / or each surgical instrument, each comprising a 3D graphical sub-model.

5. The method according to any one of claims 1 to 4, characterized in that the second graphical 2D or 3D computer model (2) additionally comprises representations of one or more implants.

6. The method according to any one of claims 1 to 5, characterized in that the second graphical 2D or 3D computer model (2) additionally comprises representations of one or more surgical instruments.

7. The method according to claim 5 or 6, characterized in that the second graphical 2D or 3D computer model (2) for the anatomical structures and for each implant, and preferably also for each surgical instrument, each comprises a graphical 2D or 3D submodel.

8. The method according to any one of claims 1 to 7, characterized in that in the execution of the image registration, the second graphical 2D or 3D computer model (2) forms the reference model, with which the first graphical 3D computer model (1) is brought into conformity.

9. The method according to any one of claims 1 to 8, characterized in that under step C) recording - in a pre-, intra- or postoperative status - a second medical 2D or 3D image data set (20) the inclusion of one or more digitized medical Images by means of a computer-aided medical imaging method.

10. The method according to any one of claims 1 to 9, characterized in that the generation of the first graphical 3D computer model (1) comprises an automatic or manual identification and localization of anatomical landmarks, lines and / or regions of the anatomical structures to be treated.

A method according to claim 10, characterized in that the generation of the first graphic 3D computer model (1) comprises an automatic or manual identification and localization of landmarks, lines and / or regions of each implant and preferably of each surgical instrument.

12. The method according to any one of claims 1 to 11, characterized in that the generation of the second graphical 2D or 3D computer model (2) an automatic or manual re-identification and re-localization of the first graphical 3D computer model (1) identified and located anatomical landmarks, lines and / or regions of the anatomical structures to be treated.

13. The method according to claim 12, characterized in that generating the second graphical 2D or 3D computer model (2) an automatic or manual re-identification and re-localization of the first graphical 3D computer model (1) identified and localized landmarks, lines and or regions of each implant and surgical instrument.

14. The method according to any one of claims 1 to 13, characterized in that the step B) additionally comprises the sub-step:

computer-aided planning and execution of a virtual surgical treatment of the anatomical structures to be treated using the first medical 3D image data set (10) taken in step A).

15. The method according to claim 14, characterized in that the first graphical 3D computer model (1) comprises a graphic 3D submodel of the anatomical structures to be treated in the form of a digital data set using the first medical 3D image data record (10) recorded in step A).

16. The method according to claim 14 or 15, characterized in that the computer-aided planning comprises the integration of at least one further graphic 3D submodel of an implant in the first graphic 3D computer model (1).

17. The method according to any one of claims 14 to 16, characterized in that the computer-aided planning, the integration of at least one further graphic 3D submodel of a temporary auxiliary means, preferably a surgical instrument in the first graphic 3D computer model (1).

18. The method according to any one of claims 14 to 17, characterized in that the computer-aided planning comprises an assessment of the biomechanical stability of the virtually surgically treated anatomical structures by means of a computer simulation, preferably by means of a finite element computer analysis.

19. The method according to any one of claims 14 to 18, characterized in that the first graphical 3D computer model (1) comprises at least one graphic 3D sub-model of at least one intermediate result of the computer-based planning virtually treated anatomical structures.

20. The method according to any one of claims 14 to 19, characterized in that the first graphic 3D computer model (1) as a submodel an execution plan (2017), which preferably defines the exact sequence of the surgical procedure and includes corresponding control instructions.

21. A method for monitoring surgical treatments using the method according to any one of claims 1 to 20.

22. The method according to claim 21, characterized in that the step C) takes place in a preoperative status, so that a monitoring of the at least one object before the surgical treatment is made possible.

23. Method according to claim 21, characterized in that step C) takes place in at least one intraoperative status, so that it is possible to monitor the at least one object during the surgical treatment.

24. The method according to any one of claims 21 to 23, characterized in that the step C) takes place in at least one postoperative status, so that a monitoring of the at least one object is made possible after the surgical treatment.

25. Use of the method according to any one of claims 21 to 24 for the quality assurance of surgical treatments.

26. Use of the method according to any one of claims 1 to 24 for the treatment of bone fractures.

27. Use of the method according to any one of claims 1 to 24 for the treatment of osseous malpositions.

28. Use of the method according to any one of claims 1 to 24 in dental implantology.