[Transversal fractures in spinal ankylosis: a case series of 17 patients]

Transverse fractures of the spine are rare. They occur in ankylosed spine and may lead to neurological complications. We report a series of 18 cases observed in 17 patients with ankylosing spondylitis (AS). The objective of this study were to describe the clinical, diagnostic and therapeutic features of our series and to compare our results with those of the literature.

We conducted a retrospective study from 1975 to 2008 in the neurosurgery and rheumatology departments of the university hospital (CHU) of Clermont-Ferrand.

Eighteen transverse spine fractures were documented in 17 patients (one female patient had two fractures of the lumbar vertebrae). The 13 male and four female patients included in this series had a mean age of 57.4 ± 17.2 years and AS for a mean time of 21.3 ± 12 years (5-40). All patients had spinal ankylosis with a "bamboo" spine appearance. The reasons for hospital admission were suspicion of AS flare (n=10) and suspected traumatic fracture (n=8). Trauma, in most cases minor, was noted in 15 patients. Fourteen patients presented with mechanical spinal pain and three had both mechanical and inflammatory pain. Three patients experienced severe pain on mobilization. Two patients had pyramidal syndrome. The mean time to diagnosis of the fracture was 6.8 ± 8.4 weeks (0-22). The fracture was located in cervical spine (n=2), dorsal spine (n=8) and lumbar spine (n=8). It was transdiscal and transcorporeal in nine cases each. Standard radiographs (n=18) identified the fracture in nine cases. The fracture was demonstrated in all CT-scan (n=13). Magnetic resonance imaging (MRI) (n=6) showed the fracture in five cases and epidural hematoma in one. Eleven patients had orthopedic treatment and six underwent surgery. Outcome was favorable in 16 patients. One paraplegic patient died of pulmonary embolism.

Transverse fractures of the spine are rare and diagnosis should be considered in a patient with AS and ankylosed spine who presented mechanical spine pain following even minor trauma. If standard radiographs are normal, further investigations should be performed using MRI, CT-scan, or both.