[Cervical fractures in ankylosing spondylitis].

In addition to general kyphoscoliosis, grotesque inclination and false positioning of the head are additional characteristics of Bekhterev's spondylitis. The causes of these changes are often fractures and are seldom of rheumatic nature. Although accidents can cause severe instability in the whole, stiffened vertebral column, minor trauma are not usually recognised. Even slight sintered fractures of the ventral vertebral area usually have a dorsal distraction component and can later increase to full dislocation. Severe deformation, which alone indicates the degree of damage, may not taken seriously until neurological changes occur. A definitive differentiation from an Anderson lesion is difficult, although this is of no relevance to the operative-therapeutic methods used. The earliest possible recognition of such a fracture or instability is of greatest prognostic significance to correct the situation without great difficulty, if necessary by using a Crutchfield clamp or a halo vest. If the fracture is found too late, such easy methods of correction are no longer possible and a more complex procedure is necessary. Whereas satisfactory stability can already be achieved via ventral access in the case of complete repositioning of the fracture, in the case of severe kyphosis and rigidity a combined dorsoventral approach involving several operations is necessary and the risk of complications is much higher.