颈椎后路单开门椎管扩大成形术前MRI预测减压效果及评价

Effect and evaluation of MRI-based prediction of decompression outcomes before posterior cervical expansive open-door laminoplasty

中文关键词:  脊髓型颈椎病  颈椎后路单开门椎管扩大成形术  MRI预测  临床疗效

英文关键词:Cervical spondylotic myelopathy  Cervical expansive open-door laminoplasty  MRI prediction  Clinical efficacy

中文摘要:

  【摘要】 目的：探讨术前MRI预测颈椎后路单开门椎管扩大成形术的减压效果及评价。方法：回顾性分析我院2020年1月~2022年10月行颈椎后路单开门椎管扩大成形手术治疗的48例脊髓型颈椎病患者的临床资料，男35例，女13例，年龄41～78岁（59.9±9.1岁）。在术前MRI T2WI正中矢状位上测量受压节段硬膜囊中矢径；将减压节段上位椎板前下缘与下位椎板前上缘的连线定义为椎板线（LL），硬脊膜前缘至LL的中矢径即为LL模拟减压中矢径；在术后1个月的MRI T2WI正中矢状面测量减压节段硬膜囊中矢径为脊髓实际减压中矢径。对比术后1个月脊髓实际减压中矢径与LL模拟减压中矢径的相关性，经配对t检验相关性分析术前LL模拟减压中矢径与术后脊髓实际减压中矢径，两者无统计学差异（P＞0.05）定义为预测准确。对预测准确的患者评价其C2-C7 Cobb角对LL模拟减压预测价值的影响，术后12个月时采用改良日本骨科协会（modified Japanese Orthopedic Association，mJOA）评分对术后疗效进行评估。结果：受压节段硬膜囊中矢径10.1±1.5mm，LL模拟减压中矢径14.3±1.6mm，实际减压中矢径14.1±1.4mm，LL模拟减压中矢径与实际减压中矢径均较术前有统计学差异（P<0.05）；配对t检验相关性分析显示术前LL模拟减压中矢径与术后脊髓实际减压中矢径相比预测准确率为93.8%（45/48）。45例预测准确患者术前C2-C7 Cobb角为24.2°±6.7°，术后C2-C7 Cobb角为24.2°±6.3°，两者差异无统计学意义（P>0.05）。将45例预测准确患者按术前C2-C7 Cobb角分组：Cobb<20°患者16例，Cobb≥20°患者29例，Cobb≥20°患者LL模拟减压及实际减压的平均中矢径均大于Cobb<20°患者，差异有统计学意义（P<0.05）。3例预测不准确患者C2-C7 Cobb角术后较术前明显减小，术后硬膜囊实际中矢径较LL模拟减压中矢径小（P<0.05）。48例患者均获随访，随访时间12~36个月，平均22.5±7.0个月，术后12个月时mJOA评分为16.5±0.8分，较术前明显提高（P<0.05）。结论：术前应用MRI T2WI正中矢状位LL模拟减压，能较好地预测颈椎后路单开门椎管扩大成形术椎管减压效果。

英文摘要:

  【Abstract】 Objectives: To explore and evaluate the efficacy of preoperative MRI in predicting decompression outcomes in expansive open-door laminoplasty for cervical spondylosis. Methods: The clinical data of 48 patients with cervical spondylotic myelopathy(CSM) who underwent cervical expansive open-door laminoplasty in our hospital from January 2020 to October 2022 were retrospectively analyzed. There were 35 males and 13 females, aged from 41 to 78 years old(59.9±9.1 years). The midsagittal diameter of the dural sac of the compressed segment was measured on the midsagittal view of MRI T2WI before operation. The line between the anterior inferior edge of the superior lamina and the anterior superior edge of the inferior lamina was set as the lamina line(LL). The measurement of the midsagittal diameter from the anterior dural margin to the LL was the LL simulated decompression midsagittal diameter. The spinal cord′s actual decompression midsagittal diameter was measured as the dural sac midsagittal diameter at the decompressed level on the MRI T2WI mid-sagittal plane one month postoperatively. The correlation between the actual postoperative midsagittal diameter of spinal cord decompression at 1 month and the simulated decompression midsagittal diameter using LL was analyzed. The prediction was defined as accurate when there was no statistically significant difference(P>0.05) between the preoperative simulated decompression midsagittal diameter using LL and the actual postoperative decompression midsagittal diameter according to paired t test analysis. For cases predicted accurately, the effect of C2-C7 Cobb angle on the predictive value of the LL simulated decompression was assessed. The postoperative efficacy was evaluated using the modified Japanese Orthopaedic Association(mJOA) score at 12-month follow-up. Results: The spinal cord′s actual decompression midsagittal diameter after the operation was 14.1±1.4mm and the midsagittal diameter in the preoperative LL simulated decompression was 14.3±1.6mm, which were both significantly increased compared with the preoperative midsagittal diameter of the dural sac at the compressed level of 10.1±1.5mm(P<0.05). Correlation analysis showed that the predictive accuracy rate of the midsagittal diameter in LL simulated decompression was 93.8%(45/48). The preoperative C2-C7 Cobb angle of the 45 patients with accurate prediction were 24.2°±6.7°, and the postoperative C2-C7 Cobb angle was 24.2°±6.3°, and there was no statistically significant difference(P>0.05). The 45 patients with accurate predictions were grouped with preoperative C2-C7 Cobb angles into 16 patients with Cobb<20° and 29 patients with Cobb≥20°. The mean midsagittal diameter of LL simulated and actual decompression in patients with Cobb≥20° was significantly greater than that in patients with Cobb<20°(P<0.05). In the three patients with inaccurate prediction, the C2-C7 Cobb angle was significantly reduced postoperatively compared to preoperatively, and the actual midsagittal diameter of the dural sac after the operation was smaller than that in the LL simulated decompression(P<0.05). All the 48 patients were followed up for 12 to 36 months(22.5±7.0 months), and the mJOA score at 12-month postoperative follow-up was 16.5±0.8 points, which was significantly higher than that before operation(P<0.05). Conclusions: The application of MRI T2WI midsagittal LL simulated decompression before operation can well predict the effect of spinal cord decompression in cervical expansive open-door laminoplasty.