"Curiosity leads to new knowledge"

The János Bolyai Research Fellowship was established by the Hungarian Academy of Sciences to drive and recognize outstanding achievements in research and development. This year's winners include Gusztáv Fekete, a mechanical engineer who has been researching knee biomechanics since his undergraduate days at ELTE. What happens inside the knee while walking or running? How can we slow down knee wear and make life easier for people who suffer from it? The associate professor at ELTE Savaria University Centre in Szombathely returns to Belgium regularly, where he received his Ph.D. He has been teaching in China for years, while in Szombathely he is planning to start a hospital laboratory with his doctoral students.

As a mechanical engineer, you are working on the wear of knee joints. Did you have a particular reason for pursuing this?

To get to the reason, let me first share my motivation. When I was a mechanical engineering student at Szent István University (now known as the Hungarian University of Agriculture and Life Sciences) in Gödöllő, my plan was that after graduating in mechanical engineering, I would go back to my old high school, Boronkay György Technical High School, and teach there. My teachers Kálmán Kovács and Gábor Bermann, were role models. I looked up to them and wanted to be a teacher just like them.

That was the plan. And then Béla M. Csizmadia entered my first statistics class in a white coat, elegant and with impressive knowledge. You should know that the professor taught applied mechanics, which is as difficult and important for a mechanic as anatomy for a doctor. After his lectures, a new goal slowly began to take shape in front of my eyes, namely that I would like to hold lectures at a university... and the lecture would be applied mechanics. After two years, and having passed the mechanics exam, I took a deep breath, went to Professor Csizmadia’s office, and asked him if I could join one of the department’s research projects. Although I was not among the top students in terms of grades, the professor put his trust in me and suggested three topics to me, one of them being research on knee biomechanics. This one seemed the most interesting: it is interdisciplinary and requires knowledge of several fields. It seems to me that

every major event in life is linked to a person coming into your life.

In this case, it was because of the professor that I changed my path.

And how did you get the necessary knowledge for working on a technical solution to a medical problem?

What algorithm can lead us to new knowledge? I usually tell a student or a novice researcher, to start with going through the literature. I often get the response, "Professor, this is such a new topic, that no one has written about it yet", and then when we sit down in front of my computer, we find at least 20 pieces of literature on the subject. Once we have the literature, we can start "adding to the brief knowledge that we have on the subject" by looking for the unanswered questions. Here you need to filter out what other researchers have missed or have not found. Here is an example! Everyone ignores the effect of friction in sliding-rolling knee joint modelling because it has a low value...but what if it does have an effect? Or even the sliding-rolling coefficient itself, which is usually used as a constant, but changes as the knee bends! These are all questions that have interested me, and others have studied. Curiosity leads to new knowledge.

You are looking for the most effective way to replace the knee joint. What is problematic in this area?

I think the only difficulty is when you have no ideas. The perfect research system and the innovation ecosystem that might follow it must be conceived as a mathematical description of a phenomenon using the laws of nature and verified by experiments. This ideal system is only moderately accessible to most researchers, including me, as experiments require laboratories, experimental test equipment, etc., which are usually extremely expensive. If this is not available,

the researcher is left with theory and modelling, which is not a tragedy, it is a challenge.

As János Bolyai wrote to his father in Timișoara, "out of nothing I have created a strange new universe" („Semmiből egy új más világot teremtettem”), so we must take our ideas and theoretical results to the point where we have the confidence to take on bigger research tasks. I believe that with perseverance, I can get to the point where we can build a biomechanics laboratory together with the Faculty of Informatics of ELTE and the Teaching Hospital Markusovszky, in Szombathely. There is space and will on both sides, and my task is to get the resources through my scientific achievements.

What is the current status of the case?

To set up the lab, I first contacted Tamás De Jonge, Head of the Department of Orthopaedic Surgery at Markusovszky Hospital and a renowned expert in knee replacement. I remember being surprised at first by his name, he sounded Belgian or Dutch. When we met in person, it turned out that he had distant Dutch ancestry, so we exchanged a few words in Dutch, which I had learned in Belgium. Dr. De Jonge was very positive about the idea of a lab, and soon freed up a space within the hospital for me and my PhD students to start work. I currently have three Chinese PhD students and two more will arrive in September, so the human resource is ensured. As far as funding is concerned, I am constantly applying for funding, and I am very confident that I will eventually be able to get the support needed.

You defended your doctoral thesis on this topic at Ghent University and your work has been published in a book. How has your relationship with Belgian researchers developed since then?

I have been in contact with three researchers at three universities since I moved back to Hungary. I usually visit Professor Magd Abdel Wahab at Ghent University and Bernardo Innocenti Université Libre de Bruxelles, and I visited him this summer as part of an Erasmus+ programme. I have a close professional relationship with Professor Innocenti, we have a common biomechanical research and interest in the knee joint. One of our goals is to investigate the effect of prosthesis size on wear using a theoretical wear model that we have devised. The professor has a well-equipped biomechanics laboratory at the BEAMS department, so we conducted experiments during the two weeks we spent at ULB. My friend Péter Pokreisz from Diószeg, who I met at the Belgian Club of Hungarian Scientists, works at the University of Leuven.

Examination at Ningbo No. 9 Hospital. A joint Hungarian-Chinese research laboratory is planned to be launched in the future at the Teaching Hospital Markusovszky in Szombathely

You also have a long-standing professional relationship with Ningbo University in China. How do these experiences contribute to your achievements?

One of the greatest events of my life was when, 5 years ago, I was invited by Yaodong Gu, then Vice Dean, now Dean and friend, to their research institute, the Research Academy of Grand Health (which belongs to Ningbo University), of which I have been an official collaborator since 2017. Alongside my Chinese colleagues, I am also learning a lot myself, as I have had to broaden my research focus from just the knee joint to the biomechanics of the lower limb and sports injury prevention. What does this involve? Due to the multifaceted nature of sports injuries, we are researching different sports and everyday movements (such as running, jogging, or walking) while wearing different sports shoes. Before designing footwear, it is also an important aspect to study individual-dependent parameters such as the effect of fatigue of sports on the symmetry of kinematic and kinetic parameters of the lower limbs. The relationship between fatigue and symmetry (e.g., shortening of the bending angles of one lower limb) is significant because these parameters significantly increase the risk of sports injury. These

basic findings will help to understand the mechanisms of injuries associated with long-distance running,

and provide a basis for designing sports shoes and footwear. In the case of sports injuries, rehabilitation options must also be addressed. Here's an example. In the case of an Achilles tendon rupture, it was found through experiments and numerical methods (musculoskeletal modelling) that the trajectory of the center of pressure of the foot was laterally displaced during different movements on the injured side, which increased the forces acting on the knee, and thus the knee adduction torque. On the one hand, this causes bowlegs (genu-varum), leads to knee arthritis in the long-term, and on the other hand, it increases the risk of ankle sprains. Our results can be used to distinguish between different pathogenesis-induced abnormal gait patterns, providing a basis for clinicians to decide on the treatment of abnormal and pathological gait patterns and for engineers to design sports equipment and sports shoes.

You came to the Szombathely campus in 2014 with international relationships behind you, what motivated you?

I have to go back to the words of János Bolyai again, because I was motivated by the creation of "something out of nothing". At that time, the Szombathely campus was part of the University of West Hungary and they decided to create a mechanical engineering program to serve the industrial needs of the city and the region. I was the very first person to arrive and take up the job in May 2014 and I felt I was part of something significant. This is an opportunity that comes along very rarely, and I am grateful to God for bringing me here and for the opportunity to work here.

What do you hope to achieve during your fellowship?

I have two major goals for the fellowship period. The first relates to a controversial issue in the competition between knee implants that allow full physiological motion and "hinge" implants. The hypothesis is that if the implant allows local relative displacement between its surfaces, such as rotation, the implant will wear faster and become unusable sooner. There is no rotation when it comes to the "hinge" implant. Since it is not known how wear is affected by implant rotation, our studies

determine how much of the wear is due to rotational movement,

and whether this movement should be limited, kept within an optimal range, or is simply negligible. The second objective is connected to the effect of implant size on wear, as several authors have shown the contradiction that larger implants (with better pressure distribution) suffer more wear than smallerones. To answer this question, I will determine the magnitude of the theoretical wear during each movement cycle depending on the size of the implant. This results in an approximate function between wear and knee implant size. I will address these objectives using multi-body dynamic models, including a previous model, during the squatting motion. The execution of this movement will include the whole functional flexing (0-120 degrees) and the magnitude of the forces acting in the joint will be close to maximum. My internal expectation for myself is to be able to apply for the title of Doctor of the Hungarian Academy of Sciences.

Picture: Gábor Cseh / VAOL

In your spare time you ride your motorbike. Why do you enjoy riding a motorcycle?

When I was still a PhD student, my colleague István Oldal (who also taught me to box on an amateur level) took me for a ride on his bike. I decided then to get a driving license and buy a second-hand bike. In 2008, I bought my first bike, a 250cc Honda Rebel, which I toured Hungary with. Why did I enjoy riding a motorcycle back then? Maybe it was the fact that from then on, I could go down to my parents' garage and go anywhere. The feeling of freedom. Of course, there was also the fact that riding a motorbike was cool and I always liked to take someone with me so that others could experience it too. Thankfully, my wife also likes this hobby, she likes to come with me if there is someone to look after our children. We have three children, so I don't get to ride my bike as often these days, but the feeling of freedom still comes over me when I turn the key on my 750cc Honda and ride down the highway...