Only dysplastic (congenital) spondylolisthesis can lead to the complete picture of spondyloptosis. Its therapies are still con troversially discussed today. The therapeutic palette ranges from therapeutic nihilism to fusion in situ, to complete reduc tion of the lumbo-sacral junction. The goal of the symposium, which is presented in this book, was to demonstrate the anatomical and biomechanical funda mental principles which are significant for the selection of the appropriate therapy. With regard to the choice of therapeutic options, no unanimous opinion could be achieved. However, it clearly...