ABSTRACT
INTRODUCTION: Traumatic peroneal nerve injury (PNI) caused by ski or snowboard edges is a severe but scarcely reported accident. METHODS: In a 20-year retrospective study, all skiers and snowboarders with this injury treated surgically at the Department of Plastic, Reconstructive and Aesthetic Surgery at the Medical University of Innsbruck, Austria, were included, covering a period from 1999/2000 to 2018/2019. RESULTS: In total, 34 patients were included in this study (30 males (88.2%) and 4 (11.8%) females). Of these 34 injured skiers or snowboarders, 33 (97.1%) were recreational athletes and Non-Austrian citizens, and 21 (61.8%) patients sustained accidental injuries without collision. All of the injuries under investigation, i.e., open lacerations, most often with complete transection, were the patients' main injuries. Surgery was performed with direct coaptation in 24 patients (70.6%), and with a suralis nerve graft in the other 10 patients (29.4%). CONCLUSION: Traumatic laceration of the peroneal nerve at the knee level by sharp ski or snowboard edges is a rare but severe injury. Causes for this injury may be multifactorial. Recommendations to reduce the risk of such an injury may follow general instructions and warnings to skiers and snowboarders regarding equipment, familiarity with the region, as well as appropriate skills and training.
ABSTRACT
The fate of human adipose tissue stem cells (ASCs) is largely determined by biochemical and mechanical cues from the extracellular matrix (ECM), which are sensed and transmitted by integrins. It is well known that specific ECM constituents influence ASC proliferation and differentiation. Nevertheless, knowledge on how individual integrins regulate distinct processes is still limited. We performed gene profiling of 18 alpha integrins in sorted ASCs and adipocytes, identifying downregulations of RGD-motif binding integrins integrin-alpha-V (ITGAV) and integrin-alpha-5 (ITGA5), upregulation of laminin binding and leukocyte-specific integrins and individual regulations of collagen and LDV-receptors in differentiated adipocytes in-vivo. Gene function analyses in in-vitro cultured ASCs unraveled differential functions of ITGA5 and ITGAV. Knockdown of ITGAV, but not ITGA5 reduced proliferation, caused p21(Cip1) induction, repression of survivin and specific regulation of Hippo pathway mediator TAZ. Gene knockdown of both integrins promoted adipogenic differentiation, while transgenic expression impaired adipogenesis. Inhibition of ITGAV using cilengitide resulted in a similar phenotype, mimicking loss of pan-ITGAV expression using RNAi. Herein we show ASC specific integrin expression patterns and demonstrate distinct regulating roles of both integrins in human ASCs and adipocyte physiology suggesting a negative impact of RDG-motif signaling on adipogenic differentiation of ASCs via ITGA5 and ITGAV.