Fig. 2

Inflammatory mediators contribute to non-union establishment. QRT-PCR of osteogenesis-related genes Runx2, TGF-β, osteoclastogenesis-related genes RANKL, OPG and Dcstamp and inflammatory markers TNF-α, MMP9 and MMP13. According to stainings, Runx2 levels are only impaired at early fracture healing. Interestingly, while RANKL levels are elevated throughout non-union establishment, OPG expression seems to be elevated to physiological levels of fracture healing, except for established non-union after 10 weeks. Surprisingly, low levels of Dcstamp, important for osteoclast fusion, were detected in non-union and control except for the first week after surgery, indicating excessive osteoclast formation. Inflammatory markers TNF-α, MMP9 and MMP13 as well as TGF-β showed to be enhanced 1 and 5 weeks after surgery. p-value: *< 0.05