Journal of Spine

Investigation of Cervical Intervertebral Discs before and after Surgery for Adolescent Idiopathic Scoliosis

Abstract

Kosuke Takimura, Noriaki Kawakami, Tetsuya Ohara, Taichi Tsuji, Yoshitaka Suzuki, Toshiki Saito, Ayato Nohara, Ryoji Tauchi, Tsuneo Takebayashi and Toshihiko Yamashita

Objective: The aim of this study was to assess the changes in MRI signal intensities of cervical intervertebral discs following corrective surgery in patients with Adolescent Idiopathic Scoliosis (AIS) who were postoperatively followed up for longer than 10 years. Introduction: Sagittal alignment of the cervical spine secondarily may change after corrective surgery in patients with AIS. No previous studies have evaluated MRI images to investigate postoperative changes in cervical intervertebral discs considering cervical alignment that may be influenced by surgical intervention for AIS.

Methods: Eighty-nine patients with AIS who underwent MRI scans preoperatively and 10 years postoperatively following surgery. Control group of volunteers with no neck pain underwent MRI on the cervical spine. Both groups were evaluated the signal intensity and morphology of intervertebral discs (nucleus pulposus) on sagittal T2- weighted MRI images of the C2/3 to C7/T1 discs. Nucleus pulposus signal intensity was assessed using that of the spinal cord as reference and classified as "normal" (N), dehydration (DH), degeneration (DG), and "intermediate" (IM).

Results: The AIS group included 89 cases and the control group included 35 cases. Comparison of pre- and postoperative signal intensity in the AIS group indicated that signal intensity significantly decreased postoperatively for all intervertebral discs (P<0.01) except for the C7/T1 disc. On the other hand, decreased signal intensity accounted for over half of the discs in the control group, except for the C7/T1 disc; however, no statistically significant differences were observed between the postoperative and the control groups.

Conclusion: Postoperative cervical disc intensity had significantly reduced in comparison with preoperative values. However, no statistically significant differences were observed between the control and postoperative group with regard to reduced signal intensity. Pre-to postoperative sagittal cervical alignment changes may have affected the changes in signal intensity.