In vivo three-dimensional kinematics of the cervical spine during head rotation in patients with cervical spondylosis.
METHODS
Kinematics of the cervical spine during head rotation was investigated using 3-dimensional (3D) magnetic resonance imaging (MRI) in patients with cervical spondylosis (CS).


OBJECTIVE
To demonstrate in vivo 3D kinematics of the spondylotic cervical spine during head rotation.


BACKGROUND
Several in vivo studies have identified kinematic differences between normal and spondylotic subjects, but only two-dimensional flexion/extension motion has been investigated. Differences of in vivo 3D cervical motion during head rotation between normal and spondylotic subjects have yet to be clarified.


METHODS
Ten healthy volunteers (control group) and 15 patients with CS (CS group) underwent 3D MRI of the cervical spine with the head rotated to 5 positions (neutral, ±45° and ±maximal head rotation). Relative motions of the cervical spine were calculated by automatically superimposing a segmented 3D MRI of the vertebra in the neutral position over images for each position using volume registration. The 3D motions of adjacent vertebra were represented with 6 degrees of freedom by Euler angles and translations on the coordinate system.


RESULTS
Compared with the control group, the CS group showed significantly decreased mean axial rotation and mean coupled lateral bending at C5-C6 and C6-C7 and significantly increased mean coupled lateral bending at C2-C3 and C3-C4, although both the groups showed the same pattern of coupled motions.


CONCLUSIONS
The in vivo 3D kinematics of the spondylotic cervical spine during head rotation was accurately depicted and compared with those of healthy cervical spines for the first time.
Nagamoto
Yukitaka
Y
Department of Orthopaedic Biomaterial Science Osaka University Graduate School of Medicine, Suita, Osaka, Japan. 7gam0to@gmail.com
Ishii
Takahiro
T
Sakaura
Hironobu
H
Iwasaki
Motoki
M
Moritomo
Hisao
H
Kashii
Masafumi
M
Hattori
Takako
T
Yoshikawa
Hideki
H
Sugamoto
Kazuomi
K
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000503:physiopathology*; D005260:Female; D019416:Head Movements; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012399:Rotation; D055009:Spondylosis / Q000503:physiopathology*; D055815:Young Adult