Articles from Spine journal November 2008

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Niemelainen, Riikka ; Battie, Michele C. ; Gill, Kevin ; Videman, Tapio
The Prevalence and Characteristics of Thoracic Magnetic Resonance Imaging Findings in Men
Spine. 33(23):2552-2559, November 1, 2008.
Abstract
Study Design. A cross-sectional study of thoracic magnetic resonance image (MRI) findings.Objective. To examine the prevalence of different thoracic MRI findings for T6-T12 and their associations with age and one another by level.Summary of Background Data. There is a dearth of descriptive epidemiology of thoracic MRI findings in the general population.Methods. Thoracic MRIs of 524 men were assessed qualitatively and quantitatively for a variety of findings, including disc bulging, height and signal, vertebral deformities, endplate irregularities, osteophytes, and hemangiomas. Descriptive statistics, correlation coefficients and STATA's survey analysis were used.Results. In the lower thoracic spine, 5.4% to 9.5% of the discs, depending on level, were qualitatively assessed as moderately to severely narrowed. Anterior bulging was more common than posterior, which was relatively rare and mild when present. Signal was lower in the midthoracic than lower discs. At least 1 moderate or severe vertebral deformity was found in 6.1% of the subjects, suggesting fracture, and hemangiomas were identified in 2.3% of subjects. Disc signal correlated most highly with age (r = 0.31-0.42). Qualitatively assessed disc height narrowing (r = 0.29-0.46) and quantitative disc height (r = 0.11-0.29) were associated with disc signal. Upper and lower endplate irregularities were associated with one another (r = 0.17-0.32), as were bulging and osteophytes, anteriorly (r = 0.35-0.61) and posteriorly (r = 0.26-0.45).Conclusion. Degenerative MRI findings beyond a mild grade were not commonly observed in the thoracic spine among 35-70-year-old men. Posterior bulges, in particular, were rare. The highest correlation with age existed for disc signal. Different MRI findings were associated with one another, but the magnitude of association varied by level. The effects of individual judgments and disc level on prevalence rates were apparent.(C) 2008 Lippincott Williams & Wilkins, Inc.

Matsunaga, Shunji ; Nakamura, Kozo ; Seichi, Atsushi ; Yokoyama, Toru ; Toh, Satoshi et al
Radiographic Predictors for the Development of Myelopathy in Patients With Ossification of the Posterior Longitudinal Ligament: A Multicenter Cohort Study
Spine. 33(24):2648-2650, November 15, 2008.
Abstract
Study Design. A multicenter cohort study was performed retrospectively.Objective. To identify radiographic predictors for the development of myelopathy in patients with ossification of the posterior longitudinal ligaments (OPLL).Summary of Background Data. The pathomechanism of myelopathy in the OPLL remains unknown. Some patients with large OPLL have not exhibited myelopathy for a long periods of time. Predicting the course of future neurologic deterioration in asyptomatic patients with OPLL is difficult at their initial visit.Methods. A total of 156 OPLL patients from 16 spine institutes with an average of 10.3 years of follow-up were reviewed. Subjects underwent a plain roentgenogram, computed tomography (CT), and magnetic resonance imaging of the cervical spine during the follow-up. The trauma history of the cervical spine, maximum percentage of spinal canal stenosis in a plain roentgenogram and CT, range of motion of the cervical spine, and axial ossified pattern in magnetic resonance imaging or CT were reviewed in relation to the existence of myelopathy.Results. All 39 patients with greater than 60% spinal canal stenosis on the plain roentgenogram exhibited myelopathy. Of 117 patients with less than 60% spinal canal stenosis, 57 (49%) patients exhibited myelopathy. The range of motion of the cervical spine was significantly larger in patients with myelopathy than in those of without it. The axial ossified pattern could be classified into 2 types: a central type and a lateral deviated type. The incidence of myelopathy in patients with less than 60% spinal canal stenosis was significantly higher in the lateral deviated-type group than in the central-type group. Fifteen patients of 156 subjects developed trauma-induced myelopathy. Of the 15 patients, 13 had mixed-type OPLL and 2 had segmental-type OPLL.Conclusion. Static and dynamic factors were related to the development of myelopathy in OPLL.