Normal intervertebral segment rotation of the subaxial cervical spine: An in vivo study of dynamic neck motions

摘要

BackgroundAccurate knowledge of the intervertebral center of rotation (COR) and its corresponding range of motion (ROM) can help understand development of cervical pathology and guide surgical treatment.MethodsTen asymptomatic subjects were imaged using MRI and dual fluoroscopic imaging techniques during dynamic extension-flexion-extension (EFE) and axial left-right-left (LRL) rotation. The intervertebral segment CORs and ROMs were measured from C34 to C67, as the correlations between two variables were analyzed as well.ResultsDuring the EFE motion, the CORs were located at 32.4?±?20.6%, -2.4?±?11.7%, 21.8?±?12.5% and 32.3?±?25.5% posteriorly, and the corresponding ROMs were 13.8?±?4.3°, 15.1?±?5.1°, 14.4?±?7.0° and 9.2?±?4.3° from C34 to C67. The ROM of C67 was significantly smaller than other segments. The ROMs were not shown to significantly correlate to COR locations (r?=??0.243,p?=?0.132). During the LRL rotation cycle, the average CORs were at 85.6?±?18.2%, 32.3?±?25.3%, 15.7?±?12.3% and 82.4?±?31.3% posteriorly, and the corresponding ROMs were 3.5?±?1.7°, 6.9?±?3.8°, 9.6?±?4.1° and 2.6?±?2.5° from C34 to C67. The ROMs of C34 and C67 was significantly smaller than those of C45 and C56. A more posterior COR was associated with a less ROM during the neck rotation (r?=??0.583,p?