后路寰枢椎融合术后颈椎矢状面参数变化及相关因素分析

Changes and related factors of cervical sagittal parameters after posterior atlantoaxial fusion

中文关键词:  寰枢椎融合  下颈椎前凸曲度  矢状面平衡  因素分析

英文关键词:Atlantoaxial fusion  Subaxial lordosis  Cervical sagittal balance  Factor analysis

中文摘要:

  【摘要】 目的：测量后路寰枢椎融合手术对颈椎矢状面参数的变化，并对其相关影响因素进行评估。方法：回顾性研究2015年1月~2017年12月收治的寰枢椎脱位病例18例，男8例，女10例，年龄25~72岁，平均49.6±13.7岁。所有寰枢椎脱位患者均行单纯后路复位C1~C2固定融合术，随访时间为5~17个月，平均7.4±3.7个月。测量患者术前和末次随访时的枕颈角（C0~C2角）、下颈椎前凸角（C2~C7角）、颈椎前凸角（C0~C7角）、颈椎矢状面轴向垂直距离（C2-C7 sagittal vertical axis，C2-C7 SVA）、C1~C2角、T1倾斜角（T1 slope，T1S）、颈部倾斜角（neck tilt，NT）和胸廓入口角（thoracic inlet angle，TIA）等颈椎矢状面参数。在末次随访时，术后C2~C7角比术前减小的病例归为下颈椎前凸曲度减小组（5例），而术后C2~C7角比术前增加或不变的病例纳入下颈椎前凸曲度增加组（13例）。采用卡方检验做下颈椎前凸曲度减小与性别、年龄（以60岁为界限）、术前T1S（以25°为界限）、术前C2-C7 SVA（以15mm为界限）、术前TIA（以70°为界限）、术前C2-C7角（以20°为界限）、术前C0-C2角（以20°为界限）、术前C0-C7角（以45°为界限）和术后C1-C2角（以20°为界限）等临床因素相关性的单因素分析。采用Logistic回归对术后下颈椎前凸曲度减小的相关因素进行多因素分析。结果：所有患者术前和末次随访时的C0~C2角分别为21.6°±16.4°和28.3°±8.6°、C2~C7角分别为15.3°±12.9°和16.4°±11.1°、C0~C7角分别为36.8°±19.7°和44.9°±13.2°、C1~C2角分别为12.4°±17.6°和17.5°±7.3°、C2~C7 SVA分别为13.4±14.7mm和15.1±11.7mm、T1S分别为22.8°±8.2°和23.5°±7.3°、NT分别为50.8°±9.5°和51.9°±8.9°、TIA分别为73.6°±11.1°和75.4°±10.0°，以上这些颈椎矢状面参数在术前与末次随访的比较均无显著性差异（P＞0.05）。对两组患者术前和末次随访的颈椎矢状面参数进行比较，前凸减小组的术前C2~C7角明显大于前凸增加组（27.6°±10.5° vs 10.5°±10.5°，P＜0.05），余参数比较无统计学差异。单因素卡方分析显示术后下颈椎前凸曲度减小与术前C2~C7角≥20°有关（χ2=4.923，P=0.026），多因素Logistic回归分析显示术前C2~C7角≥20°并不是独立危险因素（OR=0.147，P=0.225）。结论：后路寰枢椎融合术后有可能发生下颈椎前凸曲度减小，而术前C2-C7角≥20°是术后下颈椎前凸曲度减小的危险因素。

英文摘要:

  【Abstract】 Objectives: To measure the changes of cervical sagittal parameters and evaluate the related factors after posterior atlantoaxial fusion. Methods: Eighteen patients (aged 25-72 years with mean age of 49.6±13.7 years) with atlantoaxial dislocation in Fuzhou Second Hospital Affiliated to Xiamen University between January 2015 and December 2017 were retrospectively analyzed. There were 8 males and 10 females patients. All patients with atlantoaxial dislocation underwent simple posterior reduction and C1-2 fixation. They were followed up for 5 to 17 months, with an average of 7.4±3.7 months. Cervical sagittal parameters including C0-C2 angle, C2-C7 angle, C0-C7 angle, C1-C2 angle, C2-C7 SVA, T1S, NT and TIA were measured before surgery and at the last follow-up. Chi-square test was used to analyze the relationship of lower cervical curvature lordosis and gender, age (bounded by 60 years old), preoperative T1S (bounded by 25°), preoperative C2-C7 SVA (bounded by 15mm), preoperative TIA (bounded by 70°), preoperative C2-C7 angle (bounded by 20°), preoperative C0-C2 angle (bounded by 20°), preoperative C0-C7 angle (bounded by 45°) and postoperative C1-2 angle (bounded by 20°). At the last follow-up, the subaxial lordosis loss group (5 cases) included the patients whose postoperative C2-C7 angle was reduced, and the subaxial lordosis increase group (13 cases) included the patients whose postoperative C2-C7 angle was increase. Logistic regression analysis was applied to analyze the factors related to the postoperative loss of subaxial lordosis after posterior atlantoaxial fusion. Results: The cervical sagittal parameters of preoperation and last follow-up were as follows respectively: C0-C2 angle 21.6°±16.4° and 28.3°±8.6°, C2-C7 angle 15.3°±12.9° and 16.4°±11.1°, C0-C7 angle 36.8°±19.7° and 44.9°±13.2°, C1-C2 angle 12.4°±17.6° and 17.5°±7.3°, C2-C7 SVA 13.4±14.7mm and 15.1±11.7mm, T1S 22.8°±8.2° and 23.5°±7.3°, NT 50.8°±9.5° and 51.9°±8.9°, TIA 73.6°±11.1° and 75.4°±10.0°. There was no significant difference between the preoperative and last follow-up cervical sagittal parameters(P>0.05). The cervical sagittal parameters of preoperative and final follow-up between two groups were compared, the preoperative C2-C7 angle of the subaxial lordosis loss group was bigger than the subaxial lordosis increase group(27.6°±10.5° vs 10.5°±10.5°, P<0.05), but there was no statistical difference in other parameters. Univariate chi-square analysis showed that reduction of subaxial lordosis after posterior atlantoaxial fusion was associated with preoperative C2-C7 angle ≥20° (χ2=4.923，P=0.026). However, Logistic regression analysis showed that the preoperative C2-C7 angle ≥20° was not an independent risk factor (OR=0.147，P=0.225). Conclusions: Loss of subaxial lordosis can occur after posterior atlantoaxial fusion, and preoperative C2-C7 angle ≥20° is a risk factor of postoperative loss of subaxial lordosis.