RUNX2 and hematoma: In order to assess the suitability of the bioreactor system for biological studies, we employed an established fracture hematoma model to visualize the initial phase of fracture healing in vitro.[20] Previous studies have shown that dynamic culture conditions enhance osteogenesis by improving nutrient transport, waste removal, and mechanotransduction.[29, 30] Our findings confirm this, as perfusion markedly increased cell viability and the gene expression of the osteogenic marker RUNX2, compared to static culture.