术前颈椎椎体CT值与颈椎前路椎间盘切除融合术后邻近椎间隙高度变化的相关性研究

Correlation between Preoperative Cervical CT Values of Hounsfield Units and Height Changes of Adjacent Intervertebral Spaces after Anterior Cervical Discectomy and Fusion

背景术前常规CT检查测量的颈椎椎体CT值可能与颈椎前路椎间盘切除融合术(ACDF)术后的邻近节段椎间隙高度丢失相关,目前有关术前颈椎椎体CT值与ACDF后并发症的相关性研究较少。目的探讨ACDF术前颈椎椎体CT值与上邻近椎间隙高度丢失之间的关系。方法选取2017年1月至2021年1月在新疆医科大学第六附属医院脊柱外科明确诊断为脊髓型或神经根型颈椎病,并接受单节段ACDF治疗的86例患者为研究对象。收集患者年龄、性别、随访时间和体质指数(BMI),并测量术前颈椎椎体CT值和术后1周与末次随访时的上邻近椎间隙高度,计算椎间隙高度丢失值。随访截至2022-02-01。依据椎间隙高度丢失值计算结果,将患者分为A组(末次随访椎间隙高度丢失值>术后1周时测量值的20%为上邻近椎间隙退变,n=15)和B组(末次随访椎间隙高度丢失值<术后1周时测量值的20%,n=71),比较两组患者的临床资料;采用二元Logistic回归分析探讨上邻近椎间隙退变的影响因素;术前颈椎椎体CT值与上邻近节段高度丢失值的相关性分析采用Pearson相关分析;绘制术前颈椎椎体CT值预测患者术后上邻近椎间隙退变的受试者工作特征曲线(ROC曲线)。结果两组患者年龄、性别、随访时间和BMI比较,差异无统计学意义(P>0.05);两组患者术前颈椎椎体CT值比较,差异有统计学意义(P<0.05);二元Logistic回归分析结果显示术前颈椎椎体CT值较低[OR=1.05,95%CI(1.02,1.08)]是上邻近椎间隙退变的危险因素(P<0.05);Pearson相关分析结果显示,患者术前颈椎椎体CT值与术后上邻近椎间隙高度丢失值呈负相关(r=-0.844,P=0.001);术前颈椎椎体CT值预测患者术后上邻近间隙退变的曲线下面积(AUC)为0.830[95%CI(0.732,0.928)],最佳截断值为329.17,灵敏度为71.8%,特异度为86.7%。结论单节段ACDF患者术前较低的颈椎椎体CT值与术后上邻近椎间隙高度丢失有关,测量术前颈椎椎体CT值有助于预测ACDF术后邻近椎间隙退变。

Background Preoperative vertebral body Hounsfield units(HU)value measured by routine CT examinations may be associated with loss of adjacent segment height after anterior cervical discectomy and fusion(ACDF).There are few studies on the relationship between preoperative HU value of the vertebral body and postoperative complications of ACDF.Objective To study the association between preoperative cervical vertebral body HU value and change of upper adjacent segment height after ACDF.Methods A retrospective study of 86 patients diagnosed with cervical spondylotic myelopathy or cervical radiculopathy and treated with single-level ACDF at Department of Spine Surgery,the Sixth Affiliated Hospital of Xinjiang Medical University from January 2017 to January 2021 was conducted.Age,gender,follow-up period,and BMI were all recorded.Preoperative vertebral HU values and Changes in upper adjacent segmental height were measured at 1 week after surgery and the last follow-up time to calculate the values of intervertebral space height loss.Follow-up was till to 2022-02-01.Patients were divided into two groups based on the results of the degeneration of upper adjacent intervertebral space:group A(last follow-up intervertebral space height loss>20%of the value measured at 1 week postoperatively was defined as upper adjacent intervertebral space degeneration,n=15)and group B(last follow-up intervertebral space height loss<20%of the value measured at 1 week postoperatively,n=71).The clinical data between the two groups were then compared.Binary logistic regression analysis was used to investigate the factors influencing the degeneration of upper adjacent intervertebral space.Pearson correlation analysis was used to correlate the preoperative vertebral HU values with the degeneration of upper adjacent intervertebral space.Receiver operating characteristic curve(ROC curve)was plotted for preoperative vertebral CT values to predict postoperative upper adjacent intervertebral space loss in patients.Results There were no significant difference in age,gender,the average follow-up time and BMI between two groups(P>0.05);There was a significant difference between the two groups in terms of preoperative vertebral HU values(P<0.05).Binary Logistic regression analysis showed that low preoperative CT value of cervical vertebra[OR=1.05,95%CI(1.02,1.08)]was a risk factor for upper and adjacent intervertebral space degeneration(P<0.05).There was a negative correlation between the HU values and upper adjacent segmental height loss(r=-0.844,P=0.001).Using receiver operating characteristic curves,the area under the curve was 0.830[95%CI(0.732,0.928)],and the most appropriate threshold of HU value was 329.17(sensitivity 71.8%,and specificity 86.7%).Conclusion Lower preoperative CT HU values are associated with loss of adjacent segment height after single-level ACDF.Preoperative measurement of cervical body HU is useful in predicting the degeneration of upper adjacent intervertebral space after ACDF.