颈椎前路椎体次全切除植骨融合术后钛网沉降的危险因素

Risk factors of titanium mesh subsidence after anterior cervical corpectomy and fusion

中文关键词:  脊髓型颈椎病  颈椎前路椎体次全切术  钛网沉降  危险因素  椎体间撑开距离

英文关键词:Cervical spondylotic myelopathy  Anterior cervical corpectomy and fusion  Titanium mesh subsidence  Risk factor  Intervertebral distraction distance

中文摘要:

  【摘要】 目的：分析颈椎前路椎体次全切除植骨融合术（anterior cervical corpectomy and fusion，ACCF）后钛网（titanium mesh cages，TMC）沉降的发生率及其危险因素。方法：回顾性分析北京大学第三医院骨科脊柱组2019年1月～2021年12月期间实施ACCF手术的82例脊髓型颈椎病患者，其中男性44例，女性38例，年龄52.4±10.1岁（34~76岁），随访时间26.6±12.5个月（6~42个月）。根据术后3个月时融合节段高度下降是否超过2.0mm将患者分为沉降组和未沉降组。在术前、术后1d、术后3个月颈椎侧位X线片上测量C2/C7 Cobb角、手术节段Cobb角、椎体间撑开距离、融合节段高度；在术前颈椎CT上测量手术节段近端及远端椎体的CT值，评估骨质疏松情况，记录术前、末次随访的JOA评分，计算JOA评分改善率；将各变量进行单因素分析，将P＜0.1的变量及有临床意义的危险因素纳入Logistic回归分析，通过受试者工作特征（receiver operating characteristic，ROC）曲线评价危险因素预测钛网沉降的风险，根据约登指数最大的原则寻找临界点。结果：58例患者（70.7%）发生了钛网沉降。沉降组与未沉降组的性别、年龄、住院时间无统计学差异（P＞0.05）。沉降组与未沉降组C2/C7 Cobb角及手术节段Cobb角术后1d较术前均显著增加（P＜0.05），术后3个月两组手术节段Cobb角及未沉降组C2/C7 Cobb角较术前均明显增加（P＜0.05）。两组同时间点C2/C7 Cobb角及手术节段Cobb角无统计学差异（P＞0.05）。沉降组术后椎间撑开距离明显大于未沉降组（3.82±1.93mm vs 2.37±1.98mm，P=0.003）。术后3个月融合节段椎体间高度未沉降组显著大于沉降组（P＜0.05）。两组术前近、远端椎体的CT值无统计学差异（近端364.6±102.2HU vs 389.2±102.3HU，P=0.325；远端305.2±82.4HU vs 341.1±84.6HU，P=0.086）。末次随访时两组JOA评分改善率无统计学差异（P=0.442）；两组轴性症状发生率无统计学差异（6.9% vs 12.5%，P=0.409）。Logistic回归分析结果显示，椎体间撑开距离的比值比1.496[95%置信区间（1.107，2.022），P=0.009]；椎体间撑开距离预测钛网沉降的ROC曲线下面积为0.717，椎体间撑开距离临界值为1.8mm。结论：ACCF术中椎体间过度撑开是钛网沉降的独立危险因素，术中椎体间撑开距离超过1.8mm显著增加钛网沉降的发生风险。

英文摘要:

  【Abstract】 Objectives: To investigate the incidence and potential risk factors of titanium mesh cages(TMC) subsidence after anterior cervical corpectomy and fusion(ACCF). Methods: The data of 82 patients underwent ACCF between January 2019 and December 2021 at the Spine group of Department of Orthopaedics, Peking University Third Hospital were retrospectively analyzed. There were 44 males and 38 females, aged 52.4±10.1 years (range: 34-76 years), and they were followed up for 26.6±12.5 months(range: 6-42 months). The patients were divided into subsidence group and non-subsidence group according to whether the height of the fusion segment decreased ≥2.0mm at postoperative 3 months. C2/C7 Cobb angle, Cobb angle of the operative segment, intervertebral distraction distance and fusion segment height were measured on lateral cervical X-ray films before operation, on postoeprative 1d and at 3 months after operation. The preoperative CT values of proximal and distal vertebral bodies of operative segments were measured to estimate osteoporosis; The Japanese Orthopaedic Association(JOA) score was recorded preoperatively and at the final follow-up, and the JOA score recovery rate was also documemted. Univariate analysis was performed on each variable, and variables with P<0.1 and risk factors with clinical significance were included in logistic regression analysis. Receiver operating characteristic(ROC) curve was employed to evaluate the risk factors and predict TMC subsidence, and the cut-off point was determined according to the principle of the maximum Jordon index. Results: 58 patients(70.7%) developed TMC subsidence. There was no statistical difference between subsidence group and non-subsidence group in gender, age, length of hospital stay(P>0.05). The C2/C7 Cobb angle and Cobb angle of operative segment in both groups were all significantly increased on postoperative 1d compared with before operation(P<0.05). The C2/C7 Cobb angle in the non-subsidence group and Cobb angle of operative segment in both groups were significantly increased 3 months after operation compared with before operation(P<0.05). There was no statistically significant difference in C2/C7 Cobb angle and Cobb angle of operative segment between the two groups at the same time point(P>0.05). The postoperative intervertebral distraction distance in the subsidence group was significantly larger than that in the non-subsidence group(3.82±1.93mm vs 2.37±1.98mm, P=0.003). At 3 months after operation, the intervertebral height at fusion segments in the non-subsidence group were significantly higher than that in the subsidence group(P<0.05). No statistical difference was found in the CT values of proximal and distal vertebral bodies between the subsidence group and non-subsidence group(Proximal 364.6±102.2HU vs 389.2±102.3HU, P=0.325; Distal 305.2±82.4HU vs 341.1±84.6HU, P=0.086). There was no significant difference in the improvement rate of JOA score between the two groups(P=0.442). There was no significant difference in the incidence of axial symptoms between subsidence group and non-subsidence group(6.9% vs 12.5%, P=0.409). The logistic regression analysis results showed that the odds ratio of the intervertebral distraction distance was 1.496[95%CI(1.107, 2.022), P=0.009]. The area under the ROC curve to predict TMC subsidence based on the intervertebral distraction distance was 0.717. The cut-off value of the intervertebral distraction distance was 1.83mm when the Jordan index was the maximum. Conclusions: The excessive intervertebral distraction during ACCF is an independent risk factor for TMC subsidence, and the risk of TMC subsidence is significantly increased when the distance of intervertebral distraction is more than 1.8mm during operation.