Probing forces of menisci: what levels are safe for arthroscopic surgery

Purpose To facilitate effective learning, feedback on performance during arthroscopic training is essential. Less attention has been paid to feedback on monitoring safe handling of delicate tissues such as meniscus. The goal is to measure in vitro probing forces of menisci and compare them with a theoretical maximum probing force (TMPF). Method Menisci samples of ten cadavers were mounted on force platforms to measure probing forces up to 20 N in three directions. Nineteen subjects participated: six novices (experience 60 arthroscopies), and three faculty (>250 a year). All had to perform three tasks on each meniscus sample with an arthroscopic probe: push three times on the superior meniscal surface, perform one continuous run on the superior meniscal surface, and push three times on the inferior meniscal surface. The absolute maximum probing force (AMPF) was determined for each condition. A multivariable linear regression analysis was performed to assess the influence of experience on the force magnitude (P < 0.05). AMPFs were compared to the TMPF (estimated to be 8.5 N). Results The AMPF of the push task was on average 2.8 N (standard deviation (SD) of 0.8 N), of the continuous run task 2.5 N (SD 0.9 N), and of the pull task 3.9 N (SD 2.0 N). Significant difference was present between experts and novices (P < 0.05). The AMPFs are in the same order of magnitude as the TMPF. Conclusion The results indicate the necessity of using a safety level for tissue manipulation when training arthroscopy and a value for is magnitude.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin

Latent gaze information in highly dynamic decision-tasks

Die Digitalisierung durchdringt immer mehr Lebensbereiche. Aufgaben werden zunehmend digital erledigt und damit schneller, effizienter, aber auch zielorientierter und erfolgreicher erfüllt. Die rasante Entwicklung im Bereich der künstlichen Intelligenz in den letzten Jahren hat dabei eine große Rolle gespielt, denn sie hat viele hilfreiche Ansätze hervorgebracht, auf die immer weiter aufgebaut werden kann. Gleichzeitig werden die Augen, ihre Bewegungen und die Bedeutung dieser Bewegungen immer weiter erforscht. Die Verknüpfung dieser Entwicklungen hat zu spannenden Ansätzen in der Wissenschaft geführt. In dieser Dissertation stelle ich einige der Ansätze vor, an denen ich während meiner Promotion gearbeitet habe. Zunächst gebe ich einen Einblick in die Entwicklung von Modellen, die mit Hilfe künstlicher Intelligenz Verbindungen zwischen Augenbewegungsdaten und visueller Expertise herstellen. Dies wird anhand zwei verschiedener Bereiche, genauer gesagt zwei verschiedener Personengruppen, demonstriert: Sportler bei Entscheidungsfindungen und Chirurgen bei arthroskopischen Eingriffen. Die daraus resultierenden Modelle können als digitale Diagnosemodelle für die automatische Erkennung von visueller Expertise betrachtet werden. Darüber hinaus stelle ich Ansätze vor, die die Übertragbarkeit von Augenbewegungsmustern auf verschiedene Kompetenzbereiche untersuchen sowie wichtige Aspekte von Techniken zur Generalisierung. Schließlich befasse ich mich mit der zeitlichen Erkennung von Verwirrung auf der Grundlage von Augenbewegungsdaten. Die Ergebnisse legen eine Nutzung der Modelle als Zeitgeber für mögliche digitale Assistenzoptionen in der Ausbildung von Berufsanfängern nahe. Eine Besonderheit meiner Untersuchungen besteht darin, dass ich auf sehr wervolle Daten von DFB-Jugendkaderathleten sowie von langjährigen Experten in der Arthroskopie zurückgreifen konnte. Insbesondere die Arbeit mit den DFB-Daten stieß auf das Interesse von Radiound Printmedien, genauer, DeutschlandFunk Nova und SWR DasDing. Alle hier vorgestellten Beiträge wurden in international renommierten Fachzeitschriften oder auf Konferenzen veröffentlicht.Digitization is penetrating more and more areas of life. Tasks are increasingly being completed digitally, and are therefore not only fulfilled faster, more efficiently but also more purposefully and successfully. The rapid developments in the field of artificial intelligence in recent years have played a major role in this, as they brought up many helpful approaches to build on. At the same time, the eyes, their movements, and the meaning of these movements are being progressively researched. The combination of these developments has led to exciting approaches. In this dissertation, I present some of these approaches which I worked on during my Ph.D. First, I provide insight into the development of models that use artificial intelligence to connect eye movements with visual expertise. This is demonstrated for two domains or rather groups of people: athletes in decision-making actions and surgeons in arthroscopic procedures. The resulting models can be considered as digital diagnostic models for automatic expertise recognition. Furthermore, I show approaches that investigate the transferability of eye movement patterns to different expertise domains and subsequently, important aspects of techniques for generalization. Finally, I address the temporal detection of confusion based on eye movement data. The results suggest the use of the resulting model as a clock signal for possible digital assistance options in the training of young professionals. An interesting aspect of my research is that I was able to draw on very valuable data from DFB youth elite athletes as well as on long-standing experts in arthroscopy. In particular, the work with the DFB data attracted the interest of radio and print media, namely DeutschlandFunk Nova and SWR DasDing. All resulting articles presented here have been published in internationally renowned journals or at conferences

Unexpected case of ankle tuberculosis in a young professionals leading to delay in diagnosis

We report a case of a 38 year-old engineer presented with left ankle pain for 2 years and initially treated as gouty arthritis because of high serum uric acid. A year later his left ankle become swollen and plain radiograph showed soft tissue swelling around the ankle with normal articular surface and bone. An MRI investigation reported as gouty arthritis of ankle with tophi. While on treatment for gouty arthritis, he developed pus discharge from the swelling. The ankle pain also worsen and he was unable to weight bear on the affected leg. An incision and drainage shown pus from the ankle joint which grew pseudomonas aeruginosa. He was treated with intravenous followed by oral ciprofloxacin 250 mg bd. However his condition does not improved and a month after antibiotic treatment a repeated radiograph shows narrowing of joint space with irregular cortical destruction, osteopenic bone . suggestive of worsening of his septic arthritis. During this period he deny of having any fever, cough or night sweats. However he did notice some loss of weight and loss of appetite. He has worked in Africa and Russia before in petroleum industry. After 4 months of antibiotic and no sign of improvement, a biopsy and repeat culture was taken from the ankle which reveal tuberculous arthritis and positive for AFB culture. A plain chest radiograph revealed miliary tuberculosis picture. He was started on a anti TB treatment and the wound healed after a few weeks. After 4 months of treatment he was able to walk without support with reduce ankle range of motion. This case illustrate that the diagnosis was delay because tuberculosis was not suspected in a young professionals with ankle pain and elevated serum uric acid level. Further delay in diagnosis because MRI report also suggestive of gouty tophi and the pus culture and sensitivity grew pseudomonas aeruginosa

Movement Control Strategies in a Dynamic Balance Task in Children With and Without Developmental Coordination Disorder

Our study aimed to analyze movement control strategies using predefined criteria for amplitude and differences in these strategies between children with and without DCD. Children with (n = 28) and without DCD (n = 15) were included. A video-observation-tool was used to score the moving body parts during a Wii Fit slalom task over multiple time points. Two-step cluster analysis was used to extract distinct movement strategies. Two different movement strategies were identified that were independently validated by a measure of task performance and a subjective mark of quality of the movement. Initial differences between groups and changes over time toward the more successful strategy were found in both groups, albeit in a different percentage. This study shows that the more efficient movement strategy is seen in the majority of the TD children and only in a small number of children with DCD, even after practice

Novel Insights into Anterior Cruciate Ligament Injury

Anterior cruciate ligament (ACL) injury is one of the most common sports injuries of the knee. ACL reconstruction has become, standard orthopaedic practice worldwide with an estimated 175,000 reconstructions per year in the United States.6 The ACL remains the most frequently studied ligament in orthopaedic research. Hundreds of papers are published each year related to the ACL. However, the treatment options and techniques are still developing and increasing, indicating the difficulties in the treatment of this central knee ligament