Efficacy of Dynamic Radiographs in Routine Evaluations for Degenerative Cervical Spine Disease

ABSTRACT

Objectives@#To analyze the usefulness of flexion-extension radiographs in the diagnosis of degenerative cervical disease.Summary of Literature ReviewThere is little information about the efficacy of flexion-extension radiographs in the diagnosis of degenerative cervical disease. @*Methods@#and MaterialsWe analyzed 1,062 patients with cervical degenerative disease who underwent flexion-extension radiographs and computed tomography (CT) or magnetic resonance imaging (MRI). The range of motion of the cervical joints was measured. Segmental instability was evaluated using the sagittal translation (≥3.5 mm) between C2 and T1, the sagittal angulation (≥3.5°), the vertebral slip angle (≥ 10°), and the dynamic spinal canal stenosis (≤12 mm). The relationship between canal compromise on CT or MRI and radiological instability was also evaluated. @*Results@#Cervical range of motion was 36.45°±17.63° (range, 2.1°–106.6°). Segmental instability was observed in 484 patients (nine cases of sagittal translation, 79 cases of sagittal plane rotation, 415 cases of a vertical slip angle, and 21 cases of dynamic spinal stenosis). Segmental instability was related with pathology in 218 patients with available CT or MRI (42%, including five cases of sagittal translation, 32 cases of sagittal plane rotation, 171 cases of vertical slip angle, and 10 cases of dynamic spinal stenosis. @*Conclusions@#Flexion-extension radiographs of the cervical spine were useful in diagnosing and evaluating subaxial segmental instability.