UWE VIEWEG is Head of the Department of Spine Surgery, Leopoldina Hospital, Schweinfurt, Germany. He is specialized in minimally invasive spine surgery, non-fusion technology, corrections of degenerative scoliosis and high-grade spondylolisthesis as well as quality control of different spine procedures. FRANK GROCHULLA is Head of the Department of Spine Surgery, EuromedClinic, Fürth, Germany.