Luo Shi-Gan, Zhong Zhao-Ming, Zhu Si-Yuan, Chen Jian-Ting
Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou, 510515, China.
Clin Neurol Neurosurg. 2018 Aug;171:21-25. doi: 10.1016/j.clineuro.2018.04.019. Epub 2018 Apr 22.
The postoperative change in cervical sagittal alignment has an impact on health-related quality of life in adolescent idiopathic scoliosis (AIS) patients who have undergone deformity correction. However, the effect of deformity correction on sagittal cervical profile is still controversial in the literatures. The objective of this study was to investigate the postoperative change in the cervical sagittal alignment of patients with AIS.
A total of 46 AIS patients treated by posterior instrumentation and fusion with pedicle screw constructs were included in the study. Radiographs were collected preoperatively, immediate postoperatively and at the final follow-up. The C2-C7 Cobb angle and C2-C7 sagittal vertical axis (cSVA) were used to assess the cervical sagittal alignment. Spinopelvic alignment parameters, such as thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), and sagittal vertical axis (SVA), were also measured. The correlations between the cervical sagittal parameters and spinopelvic parameters were analyzed.
The incidence of cervical kyphosis was 67.4% preoperatively but increased to 87% postoperatively and 69.5% at the final follow-up. The C2-C7 Cobb angle significantly increased from pre-operation (-1.5° ± 15°) to post-operation (-5.4° ± 7.3°; P < 0.05) and spontaneously decreased to -2.9° ± 10.5° at the final follow up. The cSVA was 18.1 ± 13 mm preoperatively, 17 ± 12.3 mm after surgery and 18.5 ± 9.5 mm at the last follow-up, but the change was not statistically significant (P > 0.05). TK decreased significantly from pre-operation (17.7° ± 14.4°) to post-operation (14.2° ± 7.6°) and spontaneously improved to 16.9° ± 8.2° at the final follow-up. TK showed a significant correlation with the C2-C7 Cobb angle, but not with cSVA, in the preoperative (r = 0.709, P < 0.01), postoperative (r = 0.472, P < 0.01), and last follow-up measurements(r = 0.505, P < 0.01). Compared with patients with preoperative thoracic hypokyphosis or hyperkyphosis, patients with a normal thoracic spine had more significant postoperative changes in the C2-C7 Cobb angle and TK.
Cervical sagittal alignment after deformity correction is altered in AIS patients. An increase in cervical kyphosis after surgery is correlated with a loss of thoracic kyphosis. The change in the cervical sagittal profile may be a compensatory mechanism in response to an abnormal thoracic sagittal profile.
颈椎矢状面排列的术后变化对接受畸形矫正的青少年特发性脊柱侧凸（AIS）患者的健康相关生活质量有影响。然而，畸形矫正对颈椎矢状面形态的影响在文献中仍存在争议。本研究的目的是调查AIS患者颈椎矢状面排列的术后变化。
本研究共纳入46例接受后路器械固定及椎弓根螺钉结构融合治疗的AIS患者。在术前、术后即刻及末次随访时收集X线片。采用C2-C7 Cobb角和C2-C7矢状垂直轴（cSVA）评估颈椎矢状面排列。还测量了脊柱骨盆排列参数，如胸椎后凸（TK）、腰椎前凸（LL）、骨盆入射角（PI）、骶骨倾斜度（SS）、骨盆倾斜（PT）和矢状垂直轴（SVA）。分析颈椎矢状面参数与脊柱骨盆参数之间的相关性。
术前颈椎后凸发生率为67.4%，术后增加至87%，末次随访时为69.5%。C2-C7 Cobb角从术前的-1.5°±15°显著增加至术后的-5.4°±7.3°（P<0.05），并在末次随访时自发降至-2.9°±10.5°。术前cSVA为18.1±13mm，术后为17±12.3mm，末次随访时为18.5±9.5mm，但变化无统计学意义（P>0.05）。TK从术前的17.7°±14.4°显著降低至术后的14.2°±7.6°，并在末次随访时自发改善至16.9°±8.2°。在术前（r=0.709，P<0.01）、术后（r=0.472，P<0.01）及末次随访测量（r=0.505，P<0.01）中，TK与C2-C7 Cobb角显著相关，但与cSVA无关。与术前胸椎后凸不足或后凸过大的患者相比，胸椎正常的患者术后C2-C7 Cobb角和TK的变化更显著。
AIS患者畸形矫正后颈椎矢状面排列发生改变。术后颈椎后凸增加与胸椎后凸丢失相关。颈椎矢状面形态的变化可能是对异常胸椎矢状面形态的一种代偿机制。
