[Spine fractures in patients with ankylosing spondylitis: an analysis of 129 fractures after surgical treatment].

INTRODUCTION: The ankylosing spondylitis (AS) is a systemic rheumatic disease, which affects the skeleton, joints and internal organs. Attributed to the augmented rigidity of the spine and the concomitant impairment of compensatory mechanism minor force might cause spine fractures. Multilevel stabilization and dorsoventral instrumentation is a well - established procedure. This study was to evaluate the surgical outcome of 119 patients with AS associated spine fractures.

METHODS: From 07/96 to 01/10, 119 patients with 129 spine fractures due to AS were treated in our department. Data were collected retrospectively. In all patients the operative treatment of the fracture was either performed by ventral and/or dorsal spondylodesis.

RESULTS: The median age was 67 years (37-95). There were 51 cervical, 55 thoracic and 23 lumbar spine fractures. On initial presentation no fractures in 18 patients (15%) and stable fractures in 15 patients (13%) were detected, which further secondarily dislocated. Thus, in 28% of the patients the injury was assessed falsely. 47% of the fractures were preceded by a trivial trauma in domestic surrounding. 61 patients (51%) developed either an incomplete or a complete paraplegia. In 32 patients ventral instrumentation, in 82 patients dorsal and in 15 patients dorsoventral instrumentation were performed. 14% developed postoperative wound infection an in 15% revision surgery due to implant loosening or insufficient stabilization was required.

CONCLUSION: Early diagnostic of AS associated spine fractures using conventional radiographs and computed tomography scans is important for the detection and adequate treatment. A great amount of spine fractures are obviously either under diagnosed or underestimated, initially. A secondary dislocation of the fracture might result in severe neurological complications up to paraplegia.