Abstract: Bacterial infections can destroy cartilage integrity, resulting in osteoarthritis. Goal was to develop an in vitro model with in vivo validation of acute joint inflammation. Inflammation in cocultivated human synovial fibroblasts (SFB), chondrocytes (CHDR), and mononuclear cells (MNC) was successively relieved for 10 days. Articular effusions from patients with () and without () postoperative joint infection in healthy patients (ASA 1-2) were used as model validation. Inflammation in vitro resulted in an enormous increase in IL-1 and a successive reduction in SFB numbers. CHDR however, maintained metabolic activity and proteoglycan synthesis. While concentrations of bFGF in vivo and in vitro rose consistently, the mRNA increase was only moderate. Concurring with our in vivo data, cartilage-specific IGF-1 steadily increased, while IGF-1 mRNA in the CHDR and SFB did not correlate with protein levels. Similarly, aggrecan (ACAN) protein concentrations increased in vivo and failed to correlate in vitro with gene expression in either the CHDR or the SFB, indicating extracellular matrix breakdown. Anabolic cartilage-specific BMP-7 with highly significant intra-articular levels was significantly elevated in vitro on day 10 following maximum inflammation. Our in vitro model enables us to validate early inflammation of in vivo cell- and cytokine-specific regulatory patterns. This trial is registered with MISSinG, DRKS 00003536

Zusammenfassung: Although trauma-associated mortality has fallen in recent decades, and medical care has continued to improve in many fields, the quality of life after experiencing polytrauma has attracted little attention in the literature. This group of patients suffer from persisting physical disabilities. Moreover, they experience long-term social, emotional, and psychological effects that limit/lower considerably their quality of life.We analyzed retrospective data on 147 polytraumatized patients by administering written questionnaires and conducting face-to-face interviews 6 +/- 0.8 years after the trauma in consideration of the following validated scores: Glasgow Outcome Scale, European Quality of Life Score, Short Form-36, Trauma Outcome Profile, and Beck Depressions Inventory II.Our analysis of these results reveals that polytraumatized patients suffer from persistent pain and functional disabilities after >5 years. We also observed changes in their socioeconomic situation, as well as psychological after-effects.The rehabilitation of this particular group of patients should not only address their physical disabilities. Thepsychological after-effects of trauma must be acknowledged and addressed for an even longer period of time