[Pathologies of joint endoprostheses : Histopathological diagnostics for endoprosthetic centers]

Joint endoprosthetics is one of the most successful surgical-orthopedic procedures worldwide, enabling pain reduction and complete restoration of mobility. In the Federal Republic of Germany, around 400,000 joint endoprostheses, hip and knee joints are currently implanted every year ( https://www.eprd.de/de ) and around 30,000 replacement operations or revisions are carried out. Although there is constant optimization in the various technical and medical sectors of material development, construction, antibiotic therapy strategies, and surgical methodology of surgical joint replacement, factors that reduce service life and a variety of prosthesis-associated pathologies still exist. For implant revisions, the SLIM consensus classification, which is internationally accepted in the scientific literature, should be applied. The revised version of the SLIM consensus classification defines a comprehensive etiological spectrum of local joint endoprosthesis-associated pathologies histopathologically using nine types. In addition, this includes particle characterization and differentiation from endogenous particles. The analysis of the removed explant is the task of technical disciplines. Their mechanical and physical tests can provide information on the cause of the damage. For example, an examination of the fracture surface can determine whether the fracture occurred over a longer period of time (fatigue fracture, sustained fracture) or whether it occurred suddenly (forced fracture). It is therefore important to note that this diagnosis is carried out in an interdisciplinary manner, particularly in the context of peri-implant, mostly bacterial infections, and in the case of primarily functional and material-related causes. This interdisciplinary approach is particularly necessary for complex endoprosthesis pathologies, which require precise causal and technology-based damage analysis. In addition to histopathology, definitive diagnosis is only possible in a clinical-orthopedic, microbiological, laboratory medicine-related, radiological, nuclear medicine-related, material-technical and, in particular, biomechanical-technical context.