[Fractures of the axis organ in ankylosing spondylitis (author's transl)].

Fractures of the axis organ in ankylosing spondylitis display special features resulting from the peculiar underlying osteopathy. Depending on the localisation und extent of the vertebral ossification process, the mechanical load situations are different from case to case. Besides the disease-specific metaplastic-productive development, it is also possible that the peculiar destructive-absorptive component dominates in the overall pattern of the fracture, leading to false interpretations such as "non-typical fracture", "persistent pseudoarthrosis", specific spondylitis, stress fracture, suspected tumour, etc. Eight observations by the author demonstrate the risks, problems, differential diagnostic difficulties and the experience collected from observations of the course of the disease: four fractures of the cervical vertebral column (following mild traumas) were mainly flexion, luxation (compression) fractures at C 5/6 with partly extensive spondylodiscitic destruction, conservative treatment being sufficient in the absence of severe neurological symptoms (with one exception). A transvertebral fracture (after trauma) had occurred at the eleventh thoracic vertebral body with extremely protracted healing. Two stress fractures in which healing tendency was absent, were seen in a lumbar vertebral column sigment with spondylo-arthritically stiffened vertebral arch components, being probably a post-traumatic spondylolisthesis in segment L 5/S 1.