Periodic Reporting for period 2 - CuraBone (Predictive models and simulations in bone regeneration: a multiscale patient-specific approach)
Reporting period: 2019-04-01 to 2021-03-31
Thanks to the current advances in image-based technologies, the patients' bone shape can be replicated with a 3D-model and even 3D-printed. Using imaging techniques like CT or MRI helps to visualize the actual inner structures of a patient. Well-fitted 3D-models of implants or scaffolds can be designed directly on the patients' actual surface of his/her broken bone. Although, it is not possible to predict the outcome of different treatments (bone ingrowth into the implant, healing and regeneration). In fact, surgeons, clinical engineers and industry should develop the implant together to ensure the best outcome.
CuraBone aimed to bridge the gap between research and Industry, focusing on three main orthopaedic applications: knee and shoulder joints and cranio-maxillofacial surgery and additionally evaluated different bioresorbable and non-resorbable scaffold solutions. To accomplish this aim, CuraBone has comprised three objectives. First, musculoskeletal patient-specific models were created. These models used individual patient data like bone geometries or muscle attachment locations to calculate the loads acting on the bone-implant-composition. Second, a computational-based platform was developed to simulate the impact of therapeutic treatment, optimizing the design of implants and providing personalized rehabilitation therapies. Finally, a systematic methodology was implemented to validate the developed computational models. A quantitative comparison between clinical and numerical results was conducted resulting in accurate personalized predictive models for each situation.
The three objectives were successfully achieved during CuraBone development. Using computer simulation technologies CuraBone has achieved optimized, patient-specific treatments of bone injuries and rehabilitation therapies. We based the processes on image analysis to define a predictive methodology in order to meet every patients' needs to its best. In short, CuraBone has focused on the development of a predictive computer-based platform for the creation of patient-fitted implants for cranio-maxillofacial (CMF) applications and knee and shoulder joints.
To achieve a successful total joint arthroplasty, implants have to be mechanically fixated to the bone, its stability is highly dependent on the interaction between the implant and bone tissue. The long-term fixation of a porous implant is mainly regulated by the relative micro-motion between prosthesis and host bone. Therefore, Jonathan Pitocchi developed a method for automatically generating a finite element model (FEM) of a shoulder implant, which predicts the micro-motion for a custom reverse shoulder implant (Fig.2) [1]. The methodology also incorporates a novel tool that combines scapular bone shape and cortical morphology in a statistical shape model [2]. In addition, a musculoskeletal model was created by means of an automated method for accurately measuring muscle elongations during the preoperative planning of shoulder arthroplasty [3]. This numerical platform can be easily adapted to analyze different bones and prostheses in the future. It may have important applications in the design and planning of custom implants, calculating the results and guaranteeing low computational costs.
Reverse shoulder implants have a 3D-printed customized glenoid component where bone ingrowth is fundamental for the long-term success of the fixation. Gabriele Nasello developed a mechano-driven algorithm implemented in a FEM based approach which was validated using goat in-vivo experiments [4]. This predictive tool will guide future bone regeneration after surgical interventions [5]. Validation of bone regeneration algorithms was achieved through the creation of novel microfluidic-based in-vitro cell cultures where Gabriele Nasello recreated bone formation under controlled conditions [6,7] (Fig.3).
In addition, Antoine Vautrin and Maria Hilvert developed a computer-based methodology for the personalized design of bioresorbable implants for cranio-maxillofacial applications (Fig.4) [8]. Currently, preoperative planning is already used to supply the surgeon with patient-specific plates (non-resorbable). To develop bioresorbable solutions for this application, different materials have been evaluated for the different applications. CMF plates have been computationally evaluated, considering plate degradation and bone healing process.
Finally, one of the main challenges of these bioreasorbable plates was to characterize the dynamics of material degradation under different conditions. Therefore, Simone Russo has designed and fabricated a new bioreactor that provides the possibility to apply different fluid flow conditions and that has been conceived to evaluate material degradation over time (Fig.5).
Additionally, CuraBone has created a new generation of researchers able to manage new ideas, design, development, testing, validation and protection of new products and also able to be part of highly skilled research and professional teams. They have started very promising careers: Maria Paz Quilez is a partnership R&D Project manager in Biocartis (BE); Jonathan Pitocchi continues in Materialise (BE) as Shoulder Research Coordinator; Maria Hilvert is Innovation Manager in RWTH Innovation GmbH (DE); Gabriele Nasello got a post-doc position in KULeuven (BE); Simone Russo is Project Coordinator in Medpace (BE), David Leandro Dejtiar continues as a Research Engineer in Materialise and finally Antoine Vautrin has a research position in AO Foundation (CH).