寰枢椎脱位行寰枢椎后路融合手术后的下颈椎曲度变化情况及其预测因素

Changes and predictive factors of lower cervical curvature after posterior atlantoaxial fusion for atlantoaxial dislocation

目的探讨寰枢椎脱位(atlantoaxial dislocation,AAD)患者行寰枢椎后路融合手术后的下颈椎曲度变化情况,并分析其潜在的预测因素。方法纳入本院自2012年1月~2019年3月采用寰枢椎后路固定融合手术治疗的31例AAD患者作为研究对象,统计所有患者的性别、年龄和手术前后的下颈椎曲度(C_(2)-C_(7)角)、其他颈椎矢状面参数[包括:枕颈角(C_(0)-C_(2)角),C_(1)-C_(2)角,颈椎前凸角(C_(0)-C_(7)角),颈椎矢状面轴向垂直距离(C_(2)-C_(7)sagittal vertical axis,C_(2)-C_(7)SVA),T_(1)倾斜角(T_(1)slope,T_(1)S),颈部倾斜角(neck tilt,NT)和胸廓入口角(thoracic inlet angle,TIA)]变化情况。随访观察术后C_(2)-C_(7)角变化情况,若有所减小,则视为下颈椎曲度减小(A组);若有所增加或不变者,纳入B组。对两组患者性别、年龄等人口学资料,以及手术前后的相关颈椎矢状位参数进行单因素分析;并以二分类Logistic回归分析对相关因素进行多因素分析。结果31例AAD患者均顺利完成后路寰枢椎固定融合术,术后获访9~15个月、平均(12.1±2.8)个月,术后出现下颈椎曲度减小者9(29.03%)例。单因素分析显示,术前C_(2)-C_(7)角、术后C_(1)-C_(2)角存在统计学意义(P<0.05)。多因素Logistic回归分析显示,术前C_(2)-C_(7)角≥20°(OR=8.276,P=0.001)和术后C_(1)-C_(2)角≥20°(OR=6.754,P=0.013),均是AAD患者术后下颈椎曲度减小的独立预测因素。结论下颈椎曲度减小在AAD患者行寰枢椎后路固定融合手术后并不少见,术前C_(2)-C_(7)角≥20°、术后C_(1)-C_(2)角≥20°可增加其发生风险。

Objective To investigate the changes of lower cervical curvature in patients with atlantoaxial dislocation(AAD)after posterior atlantoaxial fusion,and analyze its potential predictors.Methods From January 2012 to March 2019,31 patients with AAD who underwent posterior atlantoaxial fixation and fusion in our hospital were selected in this research.The gender,age,lower cervical curvature(C_(2)-C_(7)angle)and other parameters of cervical sagittal plane[including occipito cervical angle(C_(0)-C_(2)angle),C_(1)-C_(2)angle,cervical lordosis angle(C_(0)-C_(7)angle),C_(2)-C_(7)sagital vertical axis(SVA),T_(1)slope(T_(1)S),neck tilt(NT)and thoracic inlet angle(TIA)]were measured.The changes of C_(2)-C_(7)angle after operation were followed up.If the C_(2)-C_(7)angle decreased,it was regarded as lower cervical curvature decreased(group A);if the C_(2)-C_(7)angle increased or remained unchanged,it was included in group B.The gender,age and other demographic data of the two groups,as well as the relevant cervical sagittal parameters before and after surgery were analyzed by univariate analysis,and the related factors were analyzed by binary logistic regression analysis.Results All 31 AAD patients successfully completed posterior atlantoaxial fixation and fusion.The average follow-up period was(12.1±2.8)months(ranged 9-15 months).Univariate analysis showed that preoperative C_(2)-C_(7)angle and postoperative C_(1)-C_(2)angle had statistically significant differences(P<0.05).Multivariate logistic regression analysis showed that preoperative C_(2)-C_(7)angle≥20°(OR=8.276,P=0.001)and postoperative C_(1)-C_(2)angle≥20°(OR=6.754,P=0.013)were independent predictors of lower cervical curvature reduction in AAD patients.Conclusion Lower cervical curvature reduction is not uncommon in AAD patients after posterior atlantoaxial fixation and fusion.Preoperative C_(2)-C_(7)angle≥20°and postoperative C_(1)-C_(2)angle≥20°can increase the risk of lower cervical curvature reduction.