双切线夹角对寰枢椎脱位评估的初步研究

preliminary study on the assessment role of bitangent angle in atlantoaxial dislocation

目的初步探讨双切线夹角在寰枢椎脱位临床评估中的作用。方法回顾性纳入2010年3月至2015年4月郑州市第一人民神经外科及骨科行手术治疗的非外伤性寰枢椎脱位患者66例(患病组),以及同时期因脑血管疾病行头颈部CT血管成像(CTA)检查者336例(对照组)。在CT图像上测量两组的双切线夹角,比较两组及手术前、后双切线夹角的差异。采用Nurick评分评估临床病变程度,并分析手术前、后双切线夹角与临床病变程度的相关性。结果对照组双切线夹角为121.1°~176.9°,平均(152.2±8.9)°。患病组术前双切线夹角为72.3°~134.9°,平均(102.4±20.1)°;术后3个月为69.6°~167.2°,平均(131.9±23.9)°。患病组术前、术后的双切线夹角与对照组比较,差异均有统计学意义(均P<0.01);术前、术后的双切线夹角比较,差异亦有统计学意义(P<0.01);患病组术前、术后的Nurick评分比较,差异有统计学意义(Z=-2.421,P<0.05)。Spearman相关性分析显示,术前双切线夹角与Nurick评分呈负相关(r=-0.79,P<0.01),术后3个月二者的相关性明显下降(r=-0.51,P<0.01)。结论初步研究结果显示,寰枢椎脱位患者双切线夹角变小,其与临床症状具有一定的相关性。

Objective To conduct preliminary study on the assessment role of bitangent angle in atlantoaxial dislocation. Methods A total of 66 case of non-traumatic atlantoaxial dislocation underwent operation at Department of Neurosurgery and Orthopedics, Zhengzhou First People′s Hospital from March 2010 to April 2015 and were classified into illness group. During the same study period, a total of 336 patients with cerebrovascular disease underwent head-neck CT angiography (CTA) examination and were categorized into normal group. The bitangent angle in the 2 groups were measured in CT image, and the difference of bitangent angles between 2 groups was analyzed. The Nurick score was used as evaluation tool for severity of clinical symptoms and was used for correlation analysis with the bitangent angle. Results The bitangent angle range in normal group was 121.1-176.9°, with an average of 152.2±8.9°. In the illness group, the bitangent angle range prior to operation was 72.3-134.9°, with an average of 102.4±20.1°. The bitangent angle range post operation was 69.6-167.2°, with an average of 131.9±23.9°. There was significant difference between 2 groups both preoperatively and postoperatively concerning bitangent angle (P<0.01) and also between preoperative and postoperative conditions (P<0.01). In the illness group, the difference in Nurick score between preoperation and postoperation was significant (P=0.015). Based on Spearman correlation analysis, the bitangent angle and Nurick score had negative correlation before the operation (r=-0.79, P<0.01), while the correlation was attenuated obviously after the operation (r=-0.51, P<0.01). Conclusion The preliminary results have suggested that the bitangent angle is decreased in patients with atlantoaxial dislocation, which might be correlated with clinical symptoms.