Risk Factors for central canal stenosis in extension position on dynamic cervical spine Magnetic Resonance Imaging

Abstract

Objective: To find risk factors associated with central canal stenosis in extension position on dynamic cervical spine magnetic resonance imaging (MRI). Materials and methods: Of the 80 consecutive patients who underwent dynamic cervical spine MRI during the period from January 2009 to December 2010, 14 were excluded and 66 patients were analyzed. The MUS was defined as the disc level at which there was the greatest dynamic change in the spinal central canal in the flexion and extension positions. Basic imaging findings for the MUS were evaluated in the neutral position in terms of the presence of a herniated intervertebral disc (HIVD), severe disc height loss, ligamentum flavum (LF) buckling, osteophytes, posterior longitudinal ligament (PLL) thickening, facet joint hypertrophy, ankylosis or severe disc height loss at the level adjacent to the MUS, Modic-type endplate change, vertebral body dislocation, and cervical compressive myelopathy (CCM) . Results: The MUS was most common at C5/6 in both total study and patients with extension-aggravation of the MUS. At the MUS, more than 30% of patients had HIVD, disc height loss, LF buckling, osteophytes, PLL thickening, Modic-type endplate change, retrolisthesis, and CCM. Among them, osteophytes were the most common finding (86.4%) followed by HIVD (48.5%) and disc height loss (48.5%). All MRI findings assessed on neutral images did not show a significant association with the presence of extension-aggravation of the MUS. Conclusion: Osteophytes, HIVD, and disc height loss was the most significant risk factors for the MUS.