脊髓型颈椎病患者术前脊髓MRI形态特征与手术预后的相关性研究

Correlation between preoperativemodified compression ratio/spinal cord rotation angle and prognosis of cervical spondylotic myelopathy

中文关键词:  脊髓型颈椎病  改良脊髓压迫率  脊髓旋转角  脊髓功能

英文关键词:Cervical spondylotic myelopathy  Modified compression ratio  Spinal cord rotation angle  Spinal cord function recovery

中文摘要:

  【摘要】 目的：提出改良脊髓压迫率（modified compression ratio，mCR）和脊髓旋转角（spinal cord rotation angle，SCRA）的概念，探讨脊髓型颈椎病（cervical spondylotic myelopathy，CSM）患者术前脊髓形态特征与术后脊髓功能恢复情况的关系。方法：回顾性分析2017年1月~2017年6月于我院行手术治疗的98例CSM患者，其中男性62例，女性37例，年龄38~73岁（53.8±10.7岁）。在患者术前轴位T2* MRI图像上测量脊髓在受压最严重层面（maximally compressed level，MCL）的脊髓压迫率（compression ratio，CR），以椭圆拟合受压脊髓，脊髓在该椭圆短轴上的距离与椭圆长轴之比为mCR，该椭圆长轴与水平位置所成夹角为SCRA。以C2/3层面的相应形态指标为内参对MCL层面的CR、mCR和SCRA进行矫正。统计患者术前及术后3年的改良日本骨科协会（modified Japanese Orthopedic Association，mJOA）评分，并计算脊髓功能恢复率（recovery rate，RR）。以斯皮尔曼相关性分析及多因素分析形态指标（矫正CR、矫正mCR与矫正SCRA等）及临床参数（年龄、症状持续时间、术前mJOA评分等）与预后指标（术后3年mJOA评分与脊髓功能RR）的关系。结果：矫正CR为（58.31±16.71）%，矫正mCR为（49.11±16.17）%，矫正SCRA为5.09°（2.29°，10.61°）。症状持续时间12.0（4.3，36.0）个月，术前mJOA评分为13.46±1.69分，术后3年mJOA评分为16.00（14.50，16.50）分，脊髓功能RR为62.50%（33.33%，90.40%）。多因素分析显示，矫正SCRA为术后3年mJOA评分的独立预测因子[标准化系数（standardized coefficient，std.coef）=0.25，P=0.015]，矫正mCR为脊髓功能RR的独立预测因子（std.coef=0.21，P=0.038）。矫正CR与术后3年mJOA评分及脊髓功能RR无显著相关性（P>0.05）。临床参数并非术后3年mJOA评分或脊髓功能RR的独立预测因子（P>0.05）。结论：矫正mCR、矫正SCRA可用于预测术后脊髓功能恢复情况，矫正SCRA与术后3年mJOA评分、矫正mCR与脊髓功能RR呈正相关。矫正CR与术后脊髓功能恢复情况无显著性相关。

英文摘要:

  【Abstract】 Objectives: The concepts of modified compression ratio(mCR) and spinal cord rotation angle (SCRA) were proposed to discuss the relationship between pre-operative morphological character of spinal cord in patients with cervical spondylotic myelopathy(CSM) and the post-operative recovery of the patients′ spinal cord function. Methods: 98 patients with CSM [62 males and 37 females, averaged 53.80±10.7 years(38-73 years)] who underwent surgery in our hospital from January 2017-June 2017 were retrospectively analyzed. According to the pre-operative axial T2* MRI, the compression ratio(CR) of spinal cord at the maximally compression level(MCL) was measured. At the same slice, the compressed spinal cord was fitted with an ellipse. The ratio of the spinal cord length along the short axis of the ellipse to the long axis of the ellipse is defined as mCR. The angle between the long axis of the fitted ellipse and the horizontal position is defined as SCRA. Using corresponding indexes at C2/3 as internal parameters, corrected morphologic indicators were obtained. The recovery rate(RR) was measured based on pre- and post-operative scores of modified Japanese Orthopedic Association(mJOA) score. Spearman correlation analysis and multivariate analysis were used to explore the relationship between morphologic indicators (e.g., corrected CR, corrected mCR, corrected SCRA)/clinical parameters（eg., age, symptom duration, and pre-operative mJOA） and prognostic indicators(post-operative mJOA score and RR). Results: The corrected CR was (58.31±16.71)%, corrected mCR was (49.11±16.17)%, corrected SCRA was 5.09%(2.29%-10.61%), symptom duration was 12.0(4.3, 36.0) months, the pre-operative mJOA score was 13.46±1.69. At 3-year follow-up post-operative mJOA score was 16.00(14.50-16.50), RR was 62.50%(33.33%-90.40%). Multivariate analysis suggested that corrected SCRA was an independent predictor for post-operative mJOA score at 3-year follow-up[standardized coefficient(std.coef)=0.25, P=0.015] and corrected mCR was independent predictor for RR(std.coef=0.21, P=0.038). Corrected CR did not correlate to post-operative mJOA scoreand RR(P>0.05). Clinical parameters wre not independent predictors for post-operative mJOA nor RR at 3-year follow-up(P>0.05). Conclusions: Corrected mCR and corrected SCRA can predicting post-operative recovery of spinal cord function in CSM. Corrected SCRA positive correlated to 3-year follow-up post-operative mJOA and corrected mCR positive correlated to RR. Corrected CR does not significantly correlate to the post-operative recovery of spinal cord function.