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Aseptic loosening is the primary cause of revision in cementless total knee arthroplasty (TKA), emphasizing the importance of strong initial stability for long-term implant success. Pre-clinical evaluations are crucial for understanding implant fixation mechanics and improving implant designs. Finite element (FE) analysis models often use linear elastic bone material models, which do not accurately reflect bone's mechanical behavior. Incorporating a von Mises yield model to simulate bone's plastic behavior improved predictions of primary stability but tends to overestimate fixation, potentially due to neglecting bone viscoelasticity. Stress relaxation in bone can affect primary stability by reducing press-fit forces on implants. This study aimed to include bone relaxation into FE models of femoral TKA reconstructions to investigate the impact of bone material models on primary fixation. Simulated pull-off tests were conducted using three material models: elastic, plastic, and plastic-viscoelastic. Six femoral reconstructions, previously used in another study, were included. The average pull-off force decreased (about 79%) from 31 kN with the elastic model to 6.3 kN when bone plasticity was included. Introducing stress relaxation showed a minimal effect, leading to an additional reduction in pull-off force of 0.8%. A significant positive correlation was found between bone mineral density and pull-off force across the three material models. Additionally, elastic strain energy within the femur correlated strongly with pull-off force, suggesting higher strain energy increases pull-off force. This study is the first to integrate plastic and viscoelastic bone behavior in FE simulations, offering insights into cementless implant fixation within context of realistic bone mechanics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Post/Long COVID (syndrome) is defined as a condition with symptoms persisting for more than 12 weeks after the onset of SARS-CoV-2 infection that cannot be explained otherwise. The prevalence of self-reported otorhinolaryngological Post/Long COVID symptoms is high. The aim of this review was to analyze the current literature regarding the actual prevalence, knowledge of the etiopathology, and evidence-based treatment recommendations of otorhinolaryngology-related Post/Long COVID symptoms. A systematic literature search of articles published since 2019 in PubMed and ScienceDirect was performed and resulted in 108 articles. These were the basis for this review and formed a comprehensive series of consented therapy statements on the most important of otorhinolaryngology-related Post/Long COVID symptoms. Otorhinolaryngological symptoms did not appear isolated but as part of a multi-organ syndrome. Self-reported otorhinolaryngology-related Post/Long COVID symptoms were often not confirmed by objective testing. The confirmed prevalence estimated for anosmia, dysgeusia, cough, facial palsy, hoarseness/dysphonia, acute hearing loss, tinnitus, and vertigo/dizziness was about 4%, 2%, 4-19%, 0%, 17-20%, 8%, 20%, and 5-26%, respectively. There are manifold theoretical concepts of the etiopathology of different symptoms, but there is no clear evidence-based proof. This certainly contributes to the fact that there is no effective specific treatment option for any of the symptoms mentioned. Healthcare pathways must be established so that otorhinolaryngological Post/Long COVID symptoms can be recognized and evaluated and otorhinolaryngologists can provide counseling. This would also help to establish and selectively include patients in clinical trials investigating specific therapeutic concepts.

Purpose: Synchronous esophageal (EC) and rectal carcinoma (RC) is a rare and challenging condition, particularly in curative-intended treatment. Especially locally advanced tumors may not be suitable for primary resection and require individual multimodal treatment. This review examines curative-intended management of synchronous EC and RC., Material and Methods: A systematic literature search across five electronic databases according to the PRISMA guideline was conducted. Individual patient data was analyzed, including two additional cases from our institution., Results: We identified 9 relevant cases from 1552 results. Additionally, two male patients (62 and 65 years old) from our institution were included. Both received 5-fluorouracil/cisplatin-based chemoradiotherapy (CRT) for EC. Sequential short-course radiation (SCRT) for RC was performed in one patient. After complete response (CR) in both tumors, no consecutive surgery was performed. He underwent resection for local recurrence of RC 11 months later and is currently considered as disease-free (30 months follow-up). The second patient underwent primary resection of RC and had early progression following resection of EC. We found that most patients had advanced EC (8/11), with the majority receiving neoadjuvant (5/11) or definitive treatment (3/11). Locally advanced RC was diagnosed in 5/11 patients, primarily treated with sequential resection. Pyrimidine-based systemic treatment was common. Four relapses and two deaths were reported, but median follow-up was 11 (range 1.5-30) months only., Conclusion: The review suggests that neoadjuvant multimodal approaches may offer curative potential for synchronous EC and RC, with individualized treatment protocols adapted from single-cancer protocols. Nevertheless, data on long-term outcome is limited., Competing Interests: Declarations. Ethics Approval and Informed Consent: This report was created in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Jena University Hospital (2024–3572-BO). Both patients signed informed consent regarding publishing their data and medical images. Competing interests: Martin Freesmeyer received scientific grants from Terumo and serves on an advisory board of Novartis outside of this work. All other authors declare having no conflicts of interest regarding this work., (© 2025. The Author(s).)