Post-traumatic spinal hematoma in ankylosing spondylitis.

PURPOSE: The purpose of this study is to examine the incidence, location, and magnetic resonance imaging (MRI) features of spinal epidural hematoma (SEH) and spinal subdural hematoma (SSH) in post-traumatic ankylosing spondylitis (AS) patients. METHODS: A total of 2256 consecutive referrals for urgent and emergency MRI scans of the spine over a period of eight years and nine months were manually reviewed for any mentions indicating axial ankylosis and post-traumatic spinal hematoma. We found 164 patients with ankylosed spines complicated by spinal fracture, of whom 32 had AS. Of the 132 excluded patients, 80 had diffuse idiopathic skeletal hyperostosis (DISH). The primary outcome was the presence of spinal hematoma, and the secondary outcome was spinal canal narrowing and spinal cord impingement. Two musculoskeletal radiologists and one fellow in musculoskeletal radiology reviewed the images for the presence of spinal hematoma and related signal characteristics, blinded to one another and initial reports. RESULTS: Of 28 post-traumatic AS patients, 19 had SEHs and five had spinal SSHs. There was a statistically significant difference between Frankel grades before and after surgery in respect of neurological improvement (p = 0.008). Patients who had radiologically proven spinal cord impingement showed more severe neurological deficits (p = 0.012). Hematomas with T1 heterogeneity showed a significantly increased delay (p = 0.047) between injury and imaging, while other signal characteristics were only approximate. CONCLUSIONS: Both SEH and SSH are common complications in post-traumatic AS patients. Patients benefit from surgery, but the relevance of spinal hematoma as a separate factor causing neurological deficit remains unclear.

Prevalence of vertebral compression fractures and associated factors in children and adolescents with severe juvenile idiopathic arthritis.

OBJECTIVE: Vertebral fractures occur in patients with juvenile idiopathic arthritis (JIA), but data on their frequency and causes are scarce. Our cross-sectional study evaluated prevalence of compression fractures and associated factors in a high-risk pediatric population with severe JIA. METHODS: Children and adolescents with a history of treatment-resistant polyarticular-course JIA for ≥ 5 years or systemic arthritis for ≥ 3 years were recruited. Clinical examination, dietary recall, laboratory measurements, bone mineral density (BMD) measurement by dual-energy X-ray absorptiometry, and spinal radiography were performed. RESULTS: Our study included 50 patients (41 girls), of whom 6 (12%) had systemic arthritis, with a median age of 14.8 years (range 7.0-18.7 yrs) and median disease duration of 10.2 years (range 3.9-16.8 years). Ninety-four percent had used systemic glucocorticoids (GC); the median total duration of GC treatment was 7.1 years (range 0-15.5 yrs). The median weight-adjusted cumulative GC dose for the preceding 3 years was 72 mg/kg (range 0-911 mg/kg). The median bone age-corrected lumbar spine and whole-body areal BMD Z-scores were -0.8 and -1.0, respectively. Twenty-two percent had vertebral fractures, mostly thoracic. Compression fractures were associated with high disease activity, high body mass index (BMI), and high recent cumulative GC dose, but not with disease duration or BMD. Thirty percent had sustained at least 1 peripheral low energy fracture. Twenty-six percent were deemed to have significantly compromised bone health. CONCLUSION: Severe JIA is associated with a significant risk of vertebral compression fractures. Associated factors include high disease activity, high BMI, and high recent GC exposure. Further studies are needed to establish optimal prevention and treatment guidelines.