[Spinal pseudoarthrosis in ankylosing spondylitis].

Spinal pseudoarthrosis is an uncommon complication in patients with advanced ankylosing spondylitis which consists in destruction of the discovertebral junction. Two cases of spinal pseudoarthrosis at the thoracolumbar level after a spontaneous fall are reported. Because of the neural arch involvement and the spinal cord compression a stabilization was required. Different imaging techniques are complementaries in the study of this entity, conventional radiographs and computed tomography may depicte bone abnormalities, but magnetic resonance allows a correct evaluation of spinal cord and soft tissue involvement.