ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Background & objectives: Porous tantalum has been exten- sively used in orthopaedic surgery, including uncemented total knee arthroplasty (TKA). We aimed to analyse possible causes for unexpected medial tibia bone loss resulting in porous tanta- lum tibia component fracture necessitating early revision after primary TKA. Methods: Retrieved tissue samples collected at revision surgery under- neath the tibial baseplate were histologically analysed and scanned with 3 MeV focused proton beam for Proton-Induced X-ray Emission (micro-PIXE) elemental analysis. Fractographic and microstructural analysis were performed by stereomicroscopy. A full 3D finite-element model was made for numerical analysis of stress-strain conditions of the tibial baseplate. Results: The 65-year old patient was revised 44 months after primary TKA because of suddenly increased pain. His right knee radiographs depicted fracture and displacement of the tibial base- plate. Histological examination of tissue underneath the broken medial part of the tibial baseplate revealed dark stained metal debris, which was confirmed by micro-PIXE to consist of Tan- talum and Titanium. Fractographic analysis and tensile testing showed that the failure of the tibial baseplate fulfilled the crite- ria of a typical fatigue fracture. Microstructural analysis of the contact surface revealed signs of bone ingrowth in 22.5% of the surface only and was even less pronounced in the medial half of the tibial baseplate. Conclusion: This case details the second known report of failure of a modern cementless modular, trabecular metal (Porous Tan- talum™) tibial baseplate in a TKA. Further studies are needed to confirm the responsibility of metal debris for an increased bone absorption leading to catastrophic tibial baseplate failure. PS-20-002 Characterisation of primary cilium by an ultrastructural study in actinic keratosis and squamous cell carcinoma A. Sanz Zorrilla*, F. Leiva-Cepas, M.J. Gálvez Medina, R. Ortega Salas, I. Cantarero Carmona *Reina Sofía University Hospital in Córdoba, Spain Background & objectives: The primary cilium (PC) is an organelle that plays an essential role in cellular signalling, its aberrant activa- tion is related to an uncontrolled cell division. By an ultrastructural study, we characterised it in relation to squamous cell carcinoma and actinic-keratosis. Methods: The samples were obtained by a dermatologist, consist- ing of human skin with suspicion of actinic-keratosis (AK) and/ or squamous-cell-carcinoma (SCC). Half of the biopsy was used for diagnosis and the other half for ultrastructural study. The other hemisection was fixed in glutaraldehyde, and then stored in PBS. The sample sections were cut by an ultramicrotome and examined under electron microscope (EM). Results: From each sample, we got a hematoxylin and eosin (H&E) histological slice and immunohistochemistry: CD31, beta-eosin and immunohistochemistry: CD31, beta- catenin, ki67, vimentin, PTEN, catenin, ki67, vimentin, PTEN, e--cadherin, p63 cadherin, p63 and p53. As for EM, we collected almost 20 images of each sample. We observed a decrease of the cells which expressed the PC in SCC and a gradual loss of AK in their differ- ent grades of dysplasia. Conclusion: We have shown that PC participates in the malignancy process of AK up to SCC. The decreased expression of the PC appears to be directly proportional to the AK grade, which could help to predict the progression to SCC. PS-21 | Poster Session History of Pathology PS-21-001 Epidemics in an Atlantic Archipelago R. Henriques De Gouveia*, I. Álvares Furtado *1 Histology and Pathological Anatomy, Faculty of Life Sciences of the University of Madeira; 2 LANA - Clinical Analysis and Pathological Anatomy Laboratory, Portugal Background & objectives: Islands, in their natural isolation, are pro- tected from nefarious external influences. Yet, when people and goods movements occur, danger of infectious diseases increases. The authors aim to study epidemics’ outbursts throughout History in an Atlantic Archipelago from the XV century. Methods: A retrospective search for information on infectious diseases / epidemics was performed through Historical, Medical, Literary, Journalistic and Photographic archives and databases of various Institutions of the Archipelago. An analysis of the data, according to the current infectious pathology knowledge, was done. Results: From the XVth to the XXIst centuries, 9 epidemics’ out- breaks occurred and were officially reported at the Archipelago. They were: 1521-1538 – Plague, 1751 – Measles, 1815 – Smallpox, 1856 – Cholera, 1873 – Smallpox, 1905/6 – Bubonic Plague, 1910- 1911 – Cholera, 1919-1920 – Pneumonic (Spanish) Influenza, 2020-… – Covid-19. Popular, medical, institutional, governmen- tal and religious interventions tried to overcome each catastrophe; yet, they led to thousands or millions of deaths, sequelae in the survivors and unspeakable suffering. Conclusion: In a period of seven centuries, 9 major epidemics happened. In an Archipelago where tourism and trade exchanges have been relevant throughout the centuries, the occurrence of epidemics’ outbursts are explained. Yet, it is important to understand the socio- economic and medico-sanitary contexts of each outbreak, which may provide data and knowledge to be used / adapted to new – present or future – epidemics, both as preventive and curative measures. PS-21-002 Smallpox and skin models R. Henriques De Gouveia*, T. Ferreira, V. Sousa, L. Carvalho *1 Histology and Pathological Anatomy, Faculty of Life Sciences of the University of Madeira; 2 LANA - Clinical Analysis and Pathological Anatomy Laboratory, Portugal Background & objectives: In pandemic times, science looks back to History trying to learn lessons from the past. Smallpox was among major historical epidemics and was an example in vaccination history. The authors aim to present Variole skin lesions to young medical generations. Methods: To attain the objective, a search was performed in the collection of the Anatomical Pathology Museum – Medical Fac- ulty, Coimbra University. It is a museum from the XIXth century, UNESCO’s World Heritage since 2013, that houses thousands of objects of various natures [from books, photographs, scientific equipment, anatomo-pathological specimens in glass containers with fixative liquid, to artificial (clay, wax) models]. Results: Among the 161 wax models of skin pathology in the Museum, 2 expose Smallpox (Variole) cutaneous lesions. Dat- ing from the XIXth century, acquired in Paris, handcrafted by the French modeler Vasseur, they correspond to human arms with umbilicated vesico-pustular papules. These wax models are three- dimensions representations and present not only anatomic but also pathological accuracy; since they were executed facing the real victims or copied from an original model. S159