Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion-Extension of the Neck.
While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion-extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine.
Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 2000065, China;Department of Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114.
Yan
Y
Yu
Department of Orthopedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu, China.
Haiqing
H
Mao
College of Health and Rehabilitation Sciences, Sargent College, Boston University, Boston, MA 02215.
Jing-Sheng
JS
Li
School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
Tsung-Yuan
TY
Tsai
Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.
Liming
L
Cheng
Department of Orthopaedic Surgery, Stanford University Medical Center, Redwood City, CA 94063.
Kirkham B
KB
Wood
Department of Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, GRJ 1215, Boston, MA 02114 e-mail: guoanli12@gmail.com.
Guoan
G
Li
Department of Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114.
Thomas D
TD
Cha
D000328:Adult; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D055595:Mechanical Phenomena; D008953:Models, Anatomic; D009333:Neck / Q000503:physiopathology*; D016059:Range of Motion, Articular; D014057:Tomography, X-Ray Computed