Bony defects are a common problem in musculoskeletal surgery. Replacement with autologous bone grafts is limited by availability of transplant material. Sterilized cancellous bone, while being osteoconductive, has limited osteoinductivity. Nanofiber scaffolds are currently used for several purposes due to their capability of imitating the extracellular matrix. Furthermore, they allow modification to provide functional properties. Previously we showed that electrospun nanofiber scaffolds can be used for bone tissue regeneration. While aiming to use the osteoinductive capacities of collagen type-I nanofibers we saw reduced scaffold pore sizes that limited cellular migration and thus colonization of the scaffolds. Aim of the present study was the incorporation of mesenchymal stem cells into the electrospinning process of a nanofiber scaffold to produce cell-seeded nanofiber scaffolds for bone replacement. After construction of a suitable spinning apparatus for simultaneous electrospinning and spraying with independently controllable spinning and spraying devices and extensive optimization of the spinning process, in vitro and in vivo evaluation of the resulting scaffolds was conducted. Stem cells isolated from rat femora were incorporated into PLLA (poly-l-lactide acid) and PLLA-collagen type-I nanofiber scaffolds (PLLA Col I Blend) via simultaneous electrospinning and-spraying. Metabolic activity, proliferation and osteoblastic differentiation were assessed in vitro. for in vivo evaluation scaffolds were implanted into critical size defects of the rat scull. After 4 weeks, animals were sacrificed and bone healing was analyzed using CT-scans, histological, immunhistochemical and fluorescence evaluation. Successful integration of mesenchymal stem cells into the scaffolds was achieved by iteration of spinning and spraying conditions regarding polymer solvent, spinning distance, the use of a liquid counter-electrode, electrode voltage and spinning duration. In vivo formation of bone tissue was achieved. Using a PLLA scaffold, comparable results for the cell-free and cell-seeded scaffolds were found, while the cell-seeded PLLA-collagen scaffolds showed significantly better bone formation when compared to the cell-free PLLA-collagen scaffolds. These results provide support for the future use of cell-seeded nanofiber scaffolds for large bony defects. Bony defects are a common problem in musculoskeletal surgery e.g. after tumor resection, infection, revision arthroplasty or trauma. In general, studies have shown that the physiological process of fracture healing is disturbed in 5-30% which results in delayed or incomplete recovery, depending on the treatment 1. To treat such defects, adequate bone replacement is needed. As this affects approximately 500,000 surgeries in Europe and approximately 2.2 million surgeries per year worldwide, bone is the second most transplanted tissue 2,3. Although replacement with autologous bone is the "golden standard", this procedure is limited by availability of transplant material and ster...
Introduction While overcrowding of emergency departments was often reported in the recent years, during the early phase of the pandemic, a reduction in patient numbers was seen. The aim of the current study was to describe the orthopedic trauma patient cohort presenting to the emergency department (ED) during the early pandemic period as compared to the cohort from the analogue time period 2019. Materials and methods A single-center case–control study was performed. All the consecutive orthopedic trauma patients > 12 years presenting to the ED were included. Patients in the same time period in 2019 served as the control group. Results Compared to 2019, in 2020, 33% less patients presented in the emergency department. Patients treated in 2020 were significantly older, significantly more often brought to ED by emergency medical services and significantly more often admitted. The number of fractures and diagnoses requiring surgical treatment decreased only slightly and the proportion of these patients among all the patients was significantly higher during the pandemic than in the control period. Furthermore, a higher percentage of polytrauma patients could be found in 2020 as well. Analysis of Manchester Triage System showed significantly less not urgent patients in 2020. Conclusion The present study shows a significant decline in the number of patients treated in the ED during the pandemic period but at the same time almost identical numbers of patients with fractures or diagnoses requiring surgical treatment. In the context of an overall decline in patient numbers, a stronger concentration on level 1 trauma centers seems to be evident during the pandemic.
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