OrthoMIT - Minimally invasive orthopaedic therapy
Subprojects
- Project Management (SP 1)
- Medical Specification and Evaluation (SP 2)
- Technical, Ergonomic and Economic Quality Assurance (SP 3)
- Clinical Paths (SP 4)
- Education and Training (SP 5)
- Ultrasound imaging and registration (SP 7)
- Intraoperative Multiplanar and Volumetric X-Ray Imaging (SP 8)
- Miniaturized Sensors, Instruments and Robotics (SP 11)
- Planning and Navigation Modules (SP 12)
- Integrated Surgical Workstation (SP 13)
Final Report
Funding
The OrthoMIT project was funded by the Germany Federal Ministry of Education and Research (BMBF).
(Project term: 2005-2011)
Summary
The objective of OrthoMIT is to develop an integrated platform for smart interventional therapy of bone and joint diseases in orthopaedic surgery and traumatology,as well as to demonstrate its clinical usability and cost efficiency.
Orthopaedic surgery concerns more than 1,000,000 patients in Europe per year. About 150,000 hip replacements and 8,000 knee replacement surgeries are performed in Germany per year, about 20 % of which are revision surgeries. 750,000 spinal nucleotomies are performed per year world wide. The costs for interventions on hip, knee or spine in Germany have been about 4.39 Billion Euro in 2002. The average hospital stay for orthopaedic interventions was about 12 days in Germany. Estimated 50 Million work days are lost in Europe every year after orthopaedic surgery. Any negative consequence of an intervention therefore represents a major factor in the patients quality of life and causes high costs for hospitalisation, rehabilitation and loss of working power and mobility.
With growing life expectancy, operations and consecutive risks, alongside costs, become more relevant for every patient. The development of new implants and implant materials, endoscopic procedures as well as computer assisted techniques including imaging, image processing, registration and 3D visualisation as well as planning and navigation have been the essential basis for recent progress in modern orthopaedic surgery of the major joints and spine. Today, orthopaedic surgery tends towards minimally invasive surgery offering short-term benefits such as quicker mobilisation and shorter recovery time due to less procedure related trauma, especially of soft tissue. However, minimal-access surgery procedures, which are often related to new implant concepts, require even more accuracy and surgical skills. Damage of nerves and vessels represent major complications. Unsuitable alignments and biomechanical conditions have significant impact on the longterm results and related costs of hip and knee surgery. Enhanced individualised therapeutic planning, adapted anaesthesia concepts, modular access to therapeutic options and technologies for enhanced imaging, navigation and miniaturized sensor-integrated instrumentation becomes necessary. New smart surgical strategies and the increasing complexity of information and systems consequently require optimized clinical workflows and an ergonomic design of integrated modular surgical work places.
Objectives
The objective of OrthoMIT is to reduce the time of each operation, anaesthesia, blood loss, hospitalisation time, X-ray dose delivered to patients as well as medical staff, complication rates including patient pain, traumas associated to surgery, stress of the operating team, inaccuracy of surgical procedures, variability of results between different surgeons and the global cost of interventions. This also includes aspects of postoperative care and rehabilitation. OrthoMIT will propose and evaluate an integrated demonstrator platform for smart interventional therapy with modules for hip, knee and spinal surgery enabling adapted therapeutic pathways depending on the individual situation and needs. Innovative features and modules of the OrthoMIT system will be:
- new minimally invasive surgical strategies
- new techniques for interventional ultrasound based imaging and registration, especially of MRI data and multiplanar and volumetric interventional x-ray imaging with a new electronic flat panel detector
- miniaturised sensor-integrated instruments
- enhanced knowledge based planning and navigation systems
- synergistic manipulator systems and active minirobots
- an integrated ergonomic surgical workstation
- integrated modules for case based education and training.
The industrial objective of OrthoMIT is to create a new generation of enhanced modular computer integrated and ergonomically designed surgical work places in order to strengthen the role of German industry on the global market for orthopaedic surgical products. Major German players provide latest state of the art products and know-how as a basic input for the development of innovative solutions in close cooperation with clinical partners and research institutions of the OrthoMIT consortium. SMEs participate in the project covering complementary facets of services, engineering and products.
orthoMIT Scheme
orthoMIT Navigation
Subproject 01 - Project Management
Partner
- Aachener Kompetenzzentrum Medizintechnik (AKM), SP coordinator
- Chair of Medical Engineering, Helmholtz-Insitute for Biomedical Engineering, RWTH Aachen University
- Clinic for Orthopaedics, University Hospital Aachen, RWTH Aachen University
Objectives
- successful progress of the project
- support of the cooperation of all partners
- public relations
Subproject 03 - Quality Management Technical Aspects, Ergonomics, Socio-Economics
Partner
- qcmed GmbH, Aachen, SP leader
- Synagon GmbH, Aachen
- Chair of Medical Engineering, Helmholtz-Insitute for Biomedical Engineering, RWTH Aachen University
Objectives
The work at mediTEC in this subproject focuses on the optimization of the ergonomic quality and clinical usability of the developed OrthoMIT components. To optimally support the intended users in their work, the special conditions and characteristics of both the clinical environment and the (mostly non-technical) users have to be considered throughout the whole developmental process.
To assure the usability and reliability of the OrthoMIT components, international legal directives (MDD, MPG) as well as standards have to be obeyed. According to ISO 60601-1-6 the usability of medical electrical products includes their effectiveness, efficiency, learnability and the user satisfaction related to the product.
Aproach
The usability engineering process at the orthoMIT partners institutions is supported by providing them with regulatory data, guidelines and SOPs regarding specification, design, verification and validation of usability aspects.
In this context new methods and tools are developed, model- and criteria-based as well as user-centred assessment of ergonomic quality is performed.
The mediTEC usability lab is equipped with modular tools for behavioural documentation and analysis like e.g. stationary and mobile eye-tracking, logging of physiological signals, synchronized video- and workflow-documentation and standardized questionnaires for strain assessment and other aspects.
Subproject 5 - Education and Training
Partner
- Department of Orthopaedics, University Hospital Aachen, RWTH Aachen University
- Chair of Medical Engineering, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University (mediTEC)
- Center for Audiovisual Media, University Hospital Aachen (AVMZ)
- Dept. of Orthopaedics and Trauma Surgery, University Hospital Bonn
Objectives
To support the effective, efficient and safe introduction of the new OrthoMIT components into the OR, concepts and tools for education and training of the intended users are developed in this subproject.
Based on requirements defined by the clinical partners as well as on established didactic concepts, multimedia content regarding the new OrthoMIT techniques and technologies is developed. Special databases are created allowing the integration and usage of anonymous real case data for interactive courses as well as for simulators.
The close cooperation with the SOMIT collaboration project Education and Training supports the interdisciplinary information exchange between the three SOMIT consortia (FUSION, CoHS and OrthoMIT).
Approach
The integrated OrthoMIT education and training concept for students as well as for novice and expert surgeons incorporates different modules:
- multimedia handbooks,
- interactive courses,
- online help systems,
- virtual reality simulators and
- clinical case database.
Real case data covering the whole range of OrthoMIT applications (minimally-invasive knee-, hip- and spine-surgery) is made anonymous, reviewed and stored in a case database. Out of this it can be used for interactive courses as well as to practice e.g. the planning of an intervention with a specific simulator. Hence, interested medical users can become familiar with the new OrthoMIT techniques and technologies by means of e-learning instances. The web-based architecture allows for ubiquitous and flexible learning according to the individual educational curriculum.
Subproject 07 - Intraoperative Ultrasound
Partner
- Chair of Medical Engineering Ruhr-University Bochum, Teilprojektleitung
- Institute for Neuroinformatics, Ruhr-University Bochum
- Clinic for Orthopaedics, Ruhr-University Bochum
- Clinic for Neurosurgery, Ruhr-University Bochum
- Chair of Medical Engineering, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University (HIA/mediTEC)
- Clinic for Traumatology, University Hospital, RWTH Aachen University
- Clinic for Orthopaedics, University Hospital, RWTH Aachen University
- BBraun Aesculap, Tuttlingen
Overview
Subproject 7 aims at integration of ultrasound imaging and ultrasound measurement techniques into intraoperative workflow such that image enhanced morphologic and functional information about soft tissue can be provided to the surgeon and that the physical operation site can be registered to preoperative planning data, e.g. CT and/or MRI. Furthermore, precise measurement of hard tissues such as bone and bone cement provides information for manually and similarly automatically controlled intraoperative drilling and/or milling processes. Hence, at any time pre- as well as intraoperative data can be real time updated and provided to the surgical team optimizing safety, quality as well as duration of the minimal invasive intervention.
Miniaturized 3D ultrasound geometry scanner
Objectives:
- 3D detection und reconstruction of femoral bone cement in robot guided revision hip arthroplasty
- free of X-ray radiation
- no intraoperative localizer and patient registration
Approach:
- Cement detection with intraluminal ultrasound
- integration in modular minirobot
Status:
- laboratory studies prove an accuracy comparable to computed tomography
Award:
The ultrasound based approach of intraluminal localisation and 3D-reconstruction of bone cement in RTHR using a modular Mini-Robot reveived the "Award for the Best Technical Poster Presentation" at CAOS conference in Boston (2009).
A-Mode-Ultrasound MRI-Registration
Objectives:
- MRT-based planning and registration of spherical osteotomies of the hip
- assessment of cartilage quality and constitution
- minimal invasive
Approach:
- MRT-based segmentation of the hip using level-set algorithms
- intraoperative A-Mode ultrasound to MRT-registration development of robust registration algorithms by statistical error approximation and noise compensation
Subproject 11 - Miniaturized Mechatronics
Partner
- BBraun Aesculap, Tuttlingen, SP coordinator
- Chair of Medical Engineering, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University (HIA/mediTEC)
- Institute of Materials in Electrical Engineering 1, RWTH Aachen University (IWE)
- SurgiTAIX AG, Aachen
Overview
Within subproject 11 autoclavable sensors, mechatronic surgical instruments, modular robots and hybrid 3D localizer technologies for surgical applications in hip, knee- and spine surgery are being developed to comply with safety as well as quality requirements for minimal invasive interventions.
Miniaturized, integrated sensors allow for on demand determination of physical parameters (e.g. force, pressure and strain) within tissue such as ligaments, muscles and bone to individualize the patient specific planning of the subsequent intervention. Further, miniaturized sensor integrated and in parts automated instruments benefit from synergistic effects such as using complementary sensor techniques as well as from compensation of noise artefacts increasing the safety of the minimal invasive intervention. As a consequence, reduced hospitalization times help to save costs and to increase patient comfort at the same time.
Force-Torque Sensor
Objective:
- Development of a miniaturised autoclavable Force-Torque Sensor for direct integration on surgical instrument.
Results:
- Evaluation model,
- FE analysis and structural design of the sensor model,
- Measurement- and test facility,
- First experimental results.
genALIGN
Objectives:
- Determination of the mechanical femoral axis for prosthesis alignment in Total Knee Arthroplasty
- Less invasive and more accurate than intramedullary alignment guides and lower-cost than computer assisted navigation systems
Approach:
- The surgeon applies a compressive force to the knee using the genALIGN device
- Resulting shear forces and torques are measured
- When these forces become zero the device is aligned with the mechanical femur axis
Intermediate results:
- Feasibility study under laboratory conditions: deviation from the mechanical leg axis was 0.1°±1.8° varus (Max: 3° varus) and 0.1°±1.4° anterior slope (Max.: 4° ant.)
- First cadaver study: deviations were 2.9°±1.5° valgus (Max: 5° varus) and 0.3°±2.4° anterior slope (Max.: 11° ant.)
Awards:
For the invention of genALIGN, Prof. Dr. Klaus Radermacher and Dipl.-Ing. Robert Elfring were awarded with the 3rd price in the state-wide inventors competition "patente Erfinder 2007".
SITI - Sensor Integrated Tibial Inlay
Objectives:
Measurement of intra-articular forces in the knee joint for supporting total knee arthroplasty in:
- ligament balancing, and
- rotational femoral component alignment procedures.
Approach:
- Integration of specially engineered load cells into a standard tibial trail inlay.
Intermediate results:
- Design of an operational prototype,
- First successful performance tests on a tension compression machine,
- First tests in a knee simulator.
Localizer Systems
Objectives:
- Reliable localization of tools and patient in clinical applications
- Use of electromagnetic tracking in an environment with distorting materials.
Approach:
- Development of a hybrid tracking system using optical, electromagnetic and inertial sensors.
- Correction of distortions for electromagnetic tracking ("compETE").
Miniature Robotic System
Objective:
- Development of a modular miniaturized medical robot for different surgical applications.
Intermediate Results:
- Prototype of the robot system (mechanic structure, electronic control system and of the software control- and safety system)
- First laboratory test for the application Revision total hip replacement (RTHR)
- First accuracy studies of the mechanic structure
- Prototype of the safety architecture of the control system
BCID - Bone Cement Injection Device
Objectives:
- Development of a device for the supply of acrylic bone cement.
- At the time of use, characteristics of the cement will be reproducibly adaptable for each application.
Approach:
- In a feedback control system the characteristics of the cement are manipulated using its sensitivity to certain environmental conditions.
Status:
- Design of the first prototype currently under development.
Robot-Assisted Spine Surgery
Objective:
- Development of a computer/ robotic aided system for CT-based interventions at the spine,
- X-ray radiation dose reduction for patient and physician ouser interaction and integration.
Approach:
- haptic technologies osynergistic manipulator system,
- Master/Slave architecture,
- CT- based planning and patient registration oman-machine interaction.
Subproject 12 - Planning and Navigation
Partner
- CAS Innovations AG, Erlangen, Subproject leader
- BBraun Aesculap, Tuttlingen
- SurgiTAIX AG, Aachen
- Chair of Medical Engineering, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University (HIA/mediTEC)
Objectives
This sub-project aims at developing minimal-invasive operation techniques with high precision and therefore increasing patient-safety in the field of hip-, knee- and spine-surgery. Moreover, the costs resulting of long clinical stays, additional revisions and long-term after-treatments should be reduced, as they are avoidable consequences for the society and the health-care system.
Hip resurfacing
Objective:
Computer-assisted image-based planning and navigated minimal-invasive preparation of the bony structures of the femoral head for the safe implantation of the femoral component during hip resurfacing.
Approach:
- Intra-operative tracking-based determination of a safe zone for the protection of sensitive structures during femoral head preparation on the basis of geometrical models in multiplanar calibrated X-ray projections as well as optionally palpated femoral neck regions.
- Prevention of femoral neck trauma by planning of implant position and size with respect to the boundaries of the defined safe zone.
- Free-hand navigated drilling of the Pilot K-wire which is crucial to the following safe preparation of the femoral head via the conventional instruments.
Correction Osteotomies
Objective:
Model-based computer-assisted optimal planning and navigated minimal-invasive acute correction of single- and multi-dimensional bone deformities of the lower extremities.
Approach:
- Intra-operative tracking-based definition of the bone geometry on the basis of multiplanar calibrated X-ray projections as well as kinematic data acquisition.
- Efficient Determination of optimal cutting and alignment parameters by the use of optimisation algorithms on the basis of oblique single- and double-osteotomies.
- Adaptation of a multi-body reference model on the basis of individually determined bone geometry data as well as optimally calculated correction parameters with the aim of a model-based quantitative analysis of both, the preoperative and simulated postoperative biomechanical situations.
- Free-hand navigated realisation of the optimally determined osteotom(y/ies) and bone alignment together with the following plate osteosynthesis.
Total Hip Arthroplasty: Computer Aided Revision Planning
Objectives:
- Guarantee of a firm anchorage of the new implant
- Reconstruction of suitable biomechanics
- minimally-invasive procedure
- Evaluation of the adjusting biomechanical situation before implantation of the prosthesis (e.g. estimation and evaluation of the possible implant stress
Approach:
- Anchorage planning based on computer-aided determination of the intraoperative bone morphology
- Optimization of the position of the new cup under biomechanical criteria
- Employment of modern imaging techniques and renouncement of invasive registration techniques
- Analysis of patient-specific biomechanics based on pre- and intra-operatively acquired data as well as biomechanical model knowledge
Total Hip Arthroplasty: Navigated Reimplantation
Objectives:
- Patient-specific selection of a suitable implant
- Safe fixation of the implant by optimized positioning of implant and suitable placement of screws
- Suitable positioning and orientation of the implant under biomechanical criteria
- Support of the operating surgeon by navigated implantation of the prosthesis with online-feedback concerning biomechanics and fixation
Approach:
- Fixation planning based on determination of the intra-operative bone morphology
- Optimization of the patient-specific biomechanics by choice of a suitable hip rotation center
- Computation of the optimal position and orientation of the implant by consideration of patient-specific characteristics
Subproject 13 - Integrated surgical workstation
Partner
- Chair of Medical Engineering, Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University (HIA/mediTEC), SP coordinator
- Department for Orthopaedics, University Hospital RWTH Aachen
- SurgiTAIX AG, Aachen
- BBraun Aesculap, Tuttlingen
- Trumpf Medizinsysteme GmbH, Saalfeld
- Synagon GmbH, Aachen (SP 04)
- CAS Innovations AG, Erlangen (SP 12)
- IMP, Erlangen and Siemens AG, Forchheim (SP 08)
Objectives
The essential objective of the subproject is to develop and evaluate an integrated OrthoMIT workstation with a central, consistent ergonomic user interface for the interaction of the surgeon or surgical team with the different navigation modules, the X-ray C-arm system and the operating table and other systems e.g. tele-consultation and documentation. Other objectives include the development and evaluation of a knowledge-based operating table control wizard, as well as a Zero-Dose navigation module. The operating table settings wizard supports the surgeon during the intervention for the optimal setting of the operating table. With the help of the zero-module virtual preview X-ray images are made available to the surgeon, which allows for an optimal prepositioning of the X-ray C-arm, so that unnecessary X-ray time by false images can be reduced.
Integrated Medical Workstation
Objectives:
- Development of an integration architecture which allows for a flexible, modular and open integration of medical devices
- Vendor independed integration of medical devices
- Development of a risk-management concept for an open and modular integration
- Standardization of interfaces and protocols
Approach:
- Development of an integration framework based on the SOA paradigm (Service Oriented Architecture)
- Use of existing open standards (SOAP, WSDL, XML, DICOM, HL7 etc.)
- Standardization and risk-management using the upcoming standard IEC 80001
OrthoMIT-Integration Framework - from system requirements to the integration framework
Knowledge-based OR-table positioning
Unsuitable static working postures are generally considered to be a crucial factor for most work-related musculoskeletal disorders. Also in the intraoperative clinical context the assessment and optimization of non-ergonomic working postures is subject of research as additional stress resulting from these postures leads to increased strain, fatigue and higher risk for human error during the intervention as well as â exceeding individual thresholds â long term damages.
Objectives:
- Minimization of posture-related stress and strain for the surgeon and reduction potential human-induced risks for the patient and the OR-personnel
Approach:
- Posture-improvement assistant for orthopedic surgery
- Knowledge-based system for individualised task-, surgeon- and patient-specific positioning of the OR-table
- Integration of the supporting system in conventional clinical processes
Methods:
- Simulation-based analysis under consideration of human models
- User-oriented usability tests with the help of a first labtype
- Development of further optimization strategies (concerning anthropometrical data of the patient, physician and assistant, type of invention, phase of intervention)
- Optimization of the man-machine-interaction and extension to further applications
- Assessment of the acceptance of a new computer-assisted system and analysis of potential risks and hazards
Knowledge-based OR-table positioning
Zero-Dose C-Arm Navigation
Objective:
The success and eficiency of computer assisted fluoroscopic navigation systems mainly depends on the quality of the used image data. Besides a reduction of the radiation dose, the accuracy of the images concerning defined projection of relevant antomic structures, plays an important role. In computer assisted interventions frequently more x-ray images are acquired than can be used during navigation. The question arises, wheter the virtual preview of x-ray images before acquisiton results in better image quality and less radiation dose.
Methods:
A system has been developed producing a preview of the expected x-ray iamges in realtime based on positon data of tracking systems, percutaneous palpation of anatomical landmarks and statistic deformable bone models.
Results:
An ex-vivo study has been performed on 6 human specimen to evaluate the efficiency and accuracy of the system compared to a conventional, non-navigated positioning of the c-arm. It could be shown, that the number of x-ray images could be substantially reduced by 35 percent. The required time for image acquisition was comparable in both groups.
Zero-Dose C-Arm Navigation