Fracture of the lower cervical spine in patients with ankylosing spondylitis: Retrospective study of 19 cases.

INTRODUCTION: Controversy exists surrounding optimal treatment of cervical spine fractures secondary to ankylosing spondylitis (AS). HYPOTHESIS: The anterior approach is an effective surgical technique for these fractures and can be used to correct the AS-induced cervical-thoracic kyphosis. MATERIALS AND METHODS: This continuous, retrospective series between 1990 and 2010 included 19 patients aged 33 to 84 years who presented with a lower cervical spine fracture in the context of AS. The average follow-up was 45 months. Sixteen of these patients were surgically treated using an anterior approach and anterior fixation. In five patients without any neurological deficit, their cervical-thoracic kyphosis was corrected during the same surgery. Regional kyphosis was measured before the surgery, immediately after the surgery and at the last follow-up. RESULTS: Five deaths occurred; these were all patients with post-traumatic complete quadriplegia. Most the incomplete neurological problems improved (66%). In no cases did the neurological condition worsen. Among the 16 patients operated with the anterior approach, two patients also required an additional procedure with a posterior approach because of a persistent neurological deficit. The fractures in the operated patients who survived (14 patients) had healed within an average 4-month delay (range 3-7 months), without worsening of the kyphosis at final follow-up. In the five cases where the kyphosis was corrected, the correction averaged 26° (range 18-36°); there were no neurological complications. DISCUSSION: Based on these results, we suggest using the anterior approach to perform internal fixation as a treatment for cervical fractures secondary to AS and to correct the cervical-thoracic kyphosis in patients without neurological deficits. LEVEL OF EVIDENCE: Level IV - retrospective study.

Course of Modic 1 six months after lumbar posterior osteosynthesis.

STUDY DESIGN: A prospective study was conducted to investigate the outcome of the Modic Type 1 inflammatory signal in magnetic resonance imaging (MRI) in 17 patients with chronic low back pain 6 months after instrumented posterior lumbar arthrodesis. OBJECTIVE: To assess the course of the inflammatory signal after stabilization of a painful intervertebral segment by posterior instrumentation alone visualized on MRI systematically performed 6 months after the operation. SUMMARY OF BACKGROUND DATA: In 1988, Modic and colleagues described three degenerative stages of vertebral endplates and subchondral bone. The inflammatory stage, or Stage 1, is correlated with substantial functional disability. According to these authors, Stage 1 lesions naturally transform into Stage 2, the fatty stage. In the literature, patients with Modic 1 signal tend to have good results after arthrodesis, better than those with Modic 2 lesions. METHODS: This study included 17 patients (average age, 46 years) who had experienced chronic low back pain more than 1 year and showed Modic 1 changes in MRI and disc narrowing on plain radiographs. Every patient underwent posterior screw-rod osteosynthesis and posterolateral arthrodesis. Disc disease had occurred subsequently to discectomy (n = 7), rapidly destructive disc disease (n = 5), or spondylolisthesis resulting from spondylolysis (n = 5). Clinical results were assessed according to a visual analog scale for pain, a functional disability score for the evaluation of patients with low back pain (Eiffel), and the validated French version of the self-administered Dallas quality-of-life test (DRAD). RESULTS: Systematic MRI at 6 months showed transformation from Modic 1 to Modic 0 (normal endplate signal) in 4 patients and transformation from Modic 1 to Modic 2 in the remaining 13 patients. Clinical evaluation was performed at 6 months (at the same time as the MRI) and at 1 year. In every patient, there was improvement in the visual analog score and the functional score, which remained stable at 1 year. CONCLUSIONS: According to the literature, most Modic 1 lesions change to become Stage 2 lesions in 18 to 24 months. In this study, 17 patients with Modic Type 1 signal had changes after 6 months. It appears that posterior osteosynthesis combined with posterolateral arthrodesis accelerates the course of Modic 1 lesions, probably by correcting mechanical instability.