[Spinal stiffness. Differential imaging diagnosis with reference to acquired hyperostosis syndrome and spinal loading disease].

There are numerous diseases which can irreversibly stiffen the whole spine or parts of the axial skeleton. Due to didactic reasons one can distinguish 3 groups of such disorders: Paradigmatic diseases of the spine with an inherent proneness to stiffness. Rare diseases which involve a certain danger of stiffening the spine. Rigidity of the spine due to scientifically unrecognised morphologic phenomena.