AbstractRATIONALE AND OBJECTIVES.
The authors determine the dynamic changes of the spinal canal during flexion and extension in patients with cervical spondylosis.METHODS.
Forty-six patients were studied inside a wholebody magnetic resonance (MR) scanner with between 50° of flexion and 30° of extension, using a positioning device. At neutral position (0°) and maximum flexion and extension sagittal T2-weighted turbo spin echo sequences were acquired.RESULTS.
A significant (P ≤ 0.05) increase of spinal stenosis was found at extension (48%, 22 of 46 patients) when compared with flexion (24%, 11 of 46). Cervical cord compression was diagnosed at flexion in 5 patients (11%) and at extension in 9 patients (20%). Concerning the number of patients with cervical cord compression at flexion and extension, significant differences (P ≤ 0.05) were found in patients with degenerative changes at four segments compared with patients with one segment involvement.CONCLUSIONS.
Magnetic resonance imaging identified a significant percentage of increased spinal stenosis at flexion and, especially, at extension, which was not observed at neutral position(0°). Flexion and extension MR imaging demonstrates additional information using a noninvasive technique concerning the dynamic factors in the pathogenesis of cervical spondylotic myelopathy.