The intervertebral discs are soft tissues of the spine that are between vertebrae. In the healthy condition they allow smooth motion. In case of degeneration, the patient experiences severe pain and motion is hindered. Percutaneous Cement Discoplasty is a surgical technique that has recently been developed to relieve pain in highly degenerated intervertebral discs in patients that cannot undergo major surgery. Little is currently known about the biomechanical effects of discoplasty.
This study aimed at investigating the effects of discoplasty surgery and measuring its impact over the specimen geometry and mechanical behaviour. Tests were performed on porcine specimens in three conditions for each specimen: with intact disc, after simulating disc degeneration, and after discoplasty. An optical system (3D Digital Image Correlation, DIC) was used to measure the surface displacements and strains.
The posterior disc height, range of motion (ROM), and stiffness were measured at the peak load. The specimens were scanned with medical imaging (Computed Tomography, CT) to confirm that the cement distribution was acceptable. Discoplasty recovered the height loss caused by disc degeneration with respect to the intact condition, but it did not impact significantly either the ROM or the stiffness. The strains over the disc surface increased after nucleotomy, while discoplasty concentrated the strains on the endplates.
In conclusion, this preliminary study has shown that discoplasty has the potential of restoring the intervertebral height, opening the neuroforamen as clinically observed, without compromising the spine mobility. This study confirms that this in vitro approach can be used to further investigate discoplasty.
Chloé Techens, Marco Palanca, Peter Endre Éltes, Áron Lazáry, Luca Cristofolini, Testing the impact of discoplasty on the biomechanics of the intervertebral disc with simulated degeneration: An in vitro study, Medical Engineering & Physics, Volume 84, (2020), Pages 51-59, ISSN 1350-4533. https://doi.org/10.1016/j.medengphy.2020.07.024
The number of patients with iatrogenic spinal deformities is increasing with the global increase in the number of instrumented spinal operations. Correcting such a deformity could prove to be challenging due to the complex anatomical structure of the spine caused by previous surgeries. For these cases, extensive preoperative planning and proper implementation of the surgical plan are vital for surgical success.
The aim of this study was to generate a virtual and 3D printed patient-specific model to understand the complex anatomical-geometrical problem presented in a patient with severe sagittal and coronal malalignment due to repetitive surgical interventions over a 39-year period; and to develop the optimal plan for the deformity correction.
A patient-specific virtual geometry was defined using segmentation based on the preoperative CT scan. A 3D virtual plan was created with a cut out wedge shape of the L4 vertebrae to simulate a 3-column pedicle subtraction osteotomy (PSO) surgery with 20° of correction in the sagittal plane. In parallel, the developed virtual geometry was printed using a fused deposition modelling device to help the surgeon visualize deformed spine and provide guidance in the preoperative planning phase but also aid the surgeon in understanding the complex anatomy of the surgery.
The surgery was performed successfully, and no complications were registered. Using the preoperative and 6-month follow-up x-ray scans, the spinopelvic parameters were measured to calculate the amount of correction the surgery provided. The sagittal vertical axis decreased by 7cm, while the distance between the C7 plumb line and the sacral vertical line in the coronal plane was reduced by 4cm. A 30° correction was achieved for the lumbar lordosis following the PSO at the L4 vertebrae.
Fayad Jennifer, Turbucz Mate, Hajnal Benjamin, Bereczki Ferenc, Bartos Marton, Bank Andras, Lazary Aron, Eltes Peter Endre (2021). Complicated Postoperative Flat Back Deformity Correction with the Aid of Virtual and 3D Printed Anatomical Models: Case Report. Frontiers in Surgery, 8, 157.
At the end of April, Spinner held its third training event. In response to the current travel restrictions this was held online, over five mornings. The focus of the training was modelling and simulation and involved:
An introduction to the parsimonious approach to deep learning by Adagos, illustrated with a workshop using their NeurEco neural network package.
An introduction to reduced order modelling by Ansys, illustrated with a workshop using their Twin Builder.
Pedicle screw fixation is extensively performed to treat spine injuries. Post-operative complications may arise from this surgery leading to back pain or revisions. Finite element (FE) models could be used to predict the outcomes of surgeries and test the effect of different screw’s sizes.
The aim of this study was to generate patient-specific Computed Tomography (CT)-based FE models of human vertebrae with two pedicle screws, verify the models, and use them to evaluate the effect of the screws’ size and geometry on the mechanical properties of the screws-vertebra structure.
We found that changes in screw’s length resulted in significantly lower differences in peak stress in the screws, mean strain in the bone around the screw and maximum deflection of the structure with respect to changes in screw’s diameter. In addition, the maximum deflection predicted with realistic or simplified screws correlated very well, while the peak stress in screws with realistic or simplified design correlated well but simplified models underestimated the peak stress.
In conclusion, the results showed that the diameter of the screw has a major role on the mechanics of the screw-vertebral structure for each patient. Simplified screws can be used to estimate the mechanical properties of the implanted vertebrae, but the systematic underestimation of the peak stress should be considered when interpreting the results from the FE analyses.
Sensale, M., Vendeuvre, T., Schilling, C., Grupp, T., Rochette, M., & Dall’Ara, E. (2021). Patient-specific finite element models of posterior pedicle screw fixation: effect of screw’s size and geometry. Frontiers in Bioengineering and Biotechnology, 9, 175.
In January (12th – 15th), together with other two Spinner fellows (Jennifer Fayad and Cameron James), I spent an intense week in Sheffield for a non-standard workshop: Modelathon.
Modelathon is an event that brings together researchers in bioengineering to challenge a clinical burden through computational modelling. The focus was on osteoarthritis, an ageing-associated disease characterised by the degradation of the cartilage, and its surgical treatments. The goal of the workshop was to develop a multi-scale model to study the effects of osteoarthritis on the biomechanics of the knee and to compare a total knee replacement with an osteocondral plug. Five teams challenged each other in an amazing venue, the futuristic computer room at the Diamond (University of Sheffield). After two days only one team won, having provided the best scientific and technical answer according to a panel of experts.
As a PhD student based in industry, I am learning how coordination and harmony in a team are essential to achieve goals. The Modelathon gave me the possibility to put into practice those soft skills that are essential to start and deliver a project. In fact, in my team it was challenging to optimise the distribution of tasks according to everyone’s backgrounds and motivations. When you have 48 hours to start a project from scratch and to deliver it, everyone must bring his/her best skills and expertise and perform on his/her strengths more than weaknesses. In this sense, communication represented an important factor that influenced the performance of the team, which was composed of six researchers that have met there for the first time. It was amazing to try to keep the motivation high and create a positive work environment in a team with six different nationalities and ways of doing.
was such a constructive experience to practice project management skills and to
acquire insights about how a multi scale approach and the best software on the
market could provide a model to study a pathology that is an economic burden in
our ageing society. Participating in these workshops and trainings is what
makes doing a Phd a unique experience.
The SPINNER project received its funding from the European Union’s Horizon 2020 research and innovation programme; that makes me, Cameron James, a publicly funded researcher. As a publicly funded researcher, I have a responsibility to share my work with the public, to engage with them in conversation and to demonstrate the public-value of my work. However, living inside the bubble of academia, it can be an incredibly daunting task to reach out and start that conversation. At the SPINNER “Public Engagement and Media Training Event”, I took my first steps in tackling that challenge, by discovering the opportunities and developing the skills that will assist me in disseminating my research to the public.
“Improving the public understanding of science is an investment in the future, not a luxury to be indulged in if and when resources allow.”
The opening activity of the day was a workshop on public engagement events, where we were tasked, as a team, to develop a plan for a SPINNER outreach event. The workshop was delivered by Fran Marshall, from the UoS’s ‘Partnerships and Regional Engagement’ team, who was able to share her experiences in organising public engagement events ranging from Pint of Science to the Festival of the Mind. With Fran’s guidance, we learned the importance of clearly defining the objective of the event, tailoring the event to this objective and evaluating the success of this objective; above all else, the most important thing is to know what message we are trying to deliver to the public, and to know how we plan to deliver it.
In addition to learning from Fran’s experience as an event organiser, we also had the opportunity to talk with Dr. Enrico Dall’Ara, a member of the SPINNER staff and supervisor of ESR5, about his experiences as a participant in Pint of Science (centre-right).
Our final speaker of the morning was Dr. Sam Pashneh-Tala, who told his own story of how engaging with media influenced the path of his research career. Starting with the On-Screen Talent Market at Sheffield Doc/Fest, Sam’s media journey has taken him to the One Show, Sunday Brunch and Dear Lovejoy, so he speaks from experience when he emphasises the importance of being proactive and strategic in approaching potential media platforms or collaborators. In fact, one of the take-home messages from Sam’s presentation was to never underestimate the power of a well-crafted tweet; a point he proved with an anecdote of how one single tweet, mentioning how he used FormLab’s products in his research, led to him becoming one of their ‘international 3D printing ambassadors’.
“Craft your posts carefully”
Dr. Sam Pashneh-Tala
In the afternoon session, Hannah Postles and Sean Barton, from the UoS’s media team, arrived to coach us on media interaction. We began the session by focussing on press releases and had fun trying to come up with catchy, jargon-free headliners to describe our research. After press releases, we began to look at opinion pieces, with a particular focus on The Conversation, an independent news source for academics to report on current affairs that relate to their area of research.
For the grand finale, we were each placed in front of the camera for some hands-on interview practice. From his safe space behind the camera, Sean opened the interview with a simple “So could you start by telling me who you are and a little bit about your research?”; but what started off as a gentle conversation quickly became a game of fielding and countering questions on ethical and technical issues, all while trying to remember the tips and tricks they taught me about controlling my body language and the direction of conversation. Although it felt like much longer, the ‘trial by fire’ lasted only a few minutes and while watching the recording afterwards I was actually proud of the confidence with which I delivered my answers. It has to be said that my interview technique is in no way perfect, but at least I now have an idea of how I need to improve.
The SPINNER “Public Engagement and Media Training Event” was an excellent learning opportunity. When I arrived at the start of the day, I may already have understood why I needed to engage with the public and media, but I was lacking in the knowledge of how to initiate that conversation. The day’s activities impressed on me the importance of being proactive in reaching out to the public and media, and have helped me to develop the essential skills for participating in these activites.
“The day was awesome. I loved the interviews… mainly watching the others!”
Chloé Techens, ESR 3
On behalf of the SPINNER ESRs, I would like to thank the speakers for sharing their time and their expertise; I sincerely hope that we can put your advice to good use over the coming months.
Spinner is pleased to announce that RBF Morph has joined the project as a partner. RBF Morph are pioneers in providing reliable and high-performance mesh-morphing-based technology for CAE multiphysics modelling and optimisation.
RBF Morph will work with Spinner Fellow, Marco Senale, who is based in Ansys, Lyon, to use their technology to develop in silico models of the spine.
One of SPINNER’s key objectives is the making of integrated, user-friendly, in silico models of the mechanics of damaged and reconstructed spinal segments that can be used for predictive design, patient-specific analysis and surgical navigation.
With RBF Morph’s RBF Morph ACT Extension, they will contribute to the development of the medical digital twin. Thanks to mesh morphing the Finite Element Analysis model of the vertebra and the parametric shape of the implanted screws can be squeezed into a reduced-order models (ROM) that allows real time interaction thus enabling a precise and accurate positioning and dimensioning of the correction.
Welcome to the SPINNER ESR Blog. Over the project the Spinner Fellows will reflect on their research and training experiences, giving an insight to their research project and the processes of doing research in their fields.
Host by the University of Bologna and Fin-ceramica SPA, Faenza, Italy
18th – 22nd February 2019
In February, the fellows attended their second training, hosted by Luca
Cristofolini at the University of Bologna.
On the first day, the fellows observed a spine surgery led by Prof Cesare
Faldini at the Istituto Ortopedico Rizzoli.
On the second day, Carla Pegoraro from the PLoS One journal and
Insigneo’s former Director, Marco Viceconti, now at the University of Bologna,
explained how to write scientifically from a publishing and academic
perspectives. Luca gave a tour of the Biomechanics Laboratory. Vittorio Colombo
from the University of Bologna give a workshop on Intellectual Properties.
On the third day, the Fellows had an opportunity to present their
progress to the group. In the afternoon, Claudia Mazzà, University of Sheffield
talked about Research Ethics.
Over the course of the week, the Fellows learnt about Project Management
from three different industrial perspectives: Michel Rochette, Ansys, as a
large software house, Mathieu Causse, as a start-up software company and Christopher
Schilling, Aesculap in the development of an implantable device.
Finceramica in Faenza, a biomaterials company that synthesises materials
for bone and joint repair, hosted the final day. They providing an insight into
their products and materials and the development of implantable products.
By day, the Fellows experienced Bologna la dotta, the learned,
through their technical and professional development and arguable Bologna la
rossa, the red, observing the surgery. By night, they experienced Bologna la
grassa, the fat, exploring the medieval, porticoed centre to feast in the
shelter of the twin, leaning towers, on the cured meats, cheeses, fresh pasta,
of course beef ragú, the famous Bolgnese sauce.
Denata said: “Being able to observe a spinal surgery in person was not only fascinating but gave me a better idea of what is realistic and what not when designing a bone graft which could later be possibly used by the surgeons for spinal repair.”
Another Fellow said “The event was excellent and included some great activities. The scheduling achieved a really good balance between the more inolved activities (tours etc.) and the presentations, so that no single day was spent entirely in a lecture environment.”
In early December,
the Spinner Fellows and their supervisors journeyed to town of Tuttlingen in
the state of Baden-Württemberg in the South West of Germany, close to the Swiss
border. This is the home for the headquarters of Aesculap AG, a medical device
company with a broad range of devices, including implants and surgical equipment
for spinal implants and related interventions. Tuttlingen also houses
Aesculap’s purpose built Aesculap Academy, the venue for Spinner’s first
On the first
afternoon, Prof Dr Thomas Grupp, the Principal Expert Engineer, Research and Development
for Biomechanics, Orthopaedics and Spine, hosted the event and welcomed the
Spinner delegation by providing an introduction to Aesculap AG, which had just
celebrated its 150 year anniversary in 2017, and B. Braun, its parent company.
The Spinner Research Fellows then introduced themselves and their research
projects to each other. Christoph Schilling, Aesculap AG, then introduced the
range of spinal implants and surgical tools that had been developed and
manufactured by Aesculap.
Dinner was at a Hirsch micro-brewery in the neighbouring town of Wurmlingen, where a sample of range of the local beers from a light white beer to a darker Christmas beer was a popular choice to accompany the solid meals of steak or stew.
The second day
began with a hands-on workshop demonstrating the spinal plates and fixtures on
plastic models of the cervical and lumbar spines. This provided an invaluable
grounding of the practical application of the Spinner Fellows research
In the afternoon the spine surgeons, Pavel Barsa, Regional Hospital, Liberec, Áron Lazáry and Peter Eltes, National Centre for Spinal Disorders, Budapest, provided detailed case studies, with photographs and medical images of surgical interventions, which drew out issues of corrective surgery, the importance of balance in the spine and preservation of spine curvature, and the use of cement reinforcement and spine fixation.
Dinner was at a restaurant local to Tuttlingen, where Christmas Beer was a popular accompaniment to the rumpsteaks and fried onions.
The third day began with a tour Aesculap’s Benchmark manufacturing plant, where the production, quality measurement and sterilisation of a variety of medical devices, including the spinal wedges and the fixations devices and well as knee and hip prosthesis. After more cases studies on advanced spine surgery, the Spinner Fellows had an opportunity to meet with their supervisory teams.
The visit finished with a tour of the Biomechanical Research Laboratory, which demonstrated the involved testing regimes developed to recreate authentic usage and wear conditions for medical devices. The Spinner Fellows appreciated the warm welcome and practical introduction into the application their research areas provided by Thomas and his team at Aesculap and case studies provided by the spine surgeons.
Here is what some of the participants had to say:
Denata Syla: “The training event changed my point of view to the project completely. Before I went to the event I thought I had an idea, but now I know that I do not really have an idea about how to apply my project. This makes me think it over and make significant changes, so it was very helpful for me.”
Marco Sensale: “The TE1 at Aesculap provided an intensive training about spinal surgical procedures. It was a unique opportunity to learn from international experts and to have insights in Aesculap’s specialisation in spinal devices. The hands-on workshops with surgeons to simulate operations were the best part of the training.”
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This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 766012
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