经关节突环形减压术治疗胸椎后纵韧带骨化症的疗效及神经功能恶化危险因素分析

Transarticular osteotomy and circumferential decompression through a single posterior approach for ossification of thoracic posterior longitudinal ligament: outcomes and risk factors of transient postoperative neurologic deterioration

中文关键词:  后纵韧带骨化症  胸椎  经关节突截骨术  环形减压术  疗效

英文关键词:Ossification of the posterior longitudinal ligament  Thoracic  Transarticular osteotomy  Circumferential decompression  Outcome

中文摘要:

  【摘要】 目的：回顾性分析后路经关节突脊髓环形减压术治疗胸椎后纵韧带骨化症（ossification of posterior longitudinal ligament，OPLL）的临床疗效，探讨导致术后短暂神经功能损害加重的相关危险因素。方法：2015年8月~2018年9月，共有29例胸椎OPLL患者在我院行后入路经关节突脊髓环形减压手术，男18例，女11例。年龄27～80岁（52.8±14.6岁）；20例为孤立型，5例为连续型，4例为混合型（孤立+连续）。所有患者环形减压均为1个节段，平均椎板减压3个节段。随访30.0±11.7个月（13～50个月），利用JOA评分（11分法）分别评价患者术前及末次随访时的神经功能，根据Harabayashi法计算神经功能改善率。根据术后是否出现即刻肌力减退将患者分为肌力减退组和无肌力减退组，收集两组患者的年龄、性别比、体重指数（BMI）、病程、术前JOA评分、OPLL位置和类型、手术时间、术中出血量、术中平均动脉压和术前与术中平均动脉压差，比较两组的差异，将存在统计学差异的指标和文献中报道可能导致短暂神经功能损害加重的因素进行二元Logistic回归分析。结果：29例患者均完成手术，手术时间80～354min（170.7±74.1min），出血量150～3500ml（1097.9±788.7ml）。术后6例（20.7%）发生脑脊液漏；6例（20.7%）术后即刻出现肌力减退；1例肋间神经痛。术前JOA评分为5.3±2.1分（2～10分），术后末次随访时为8.9±1.6分（5～11分），有统计学差异（P<0.001），术后神经功能较术前明显改善，神经功能改善率为16.7%～100%[（64.2±21.4）%]，其中优9例，良16例，一般3例，无变化1例，优良率86.2%，末次随访无一例出现症状恶化情况。术后即刻肌力减退组与无肌力减退组比较术中出血量、术前与术中平均动脉压差有统计学差异（P<0.05）。二分类Logistic回归分析显示术中平均动脉压降低是导致术后短暂神经功能损害加重的危险因素（OR＝1.27，P=0.026，95%CI 1.01～1.57），术中平均动脉压较术前每降低1mmHg，发生术后肌力减退的风险增加27%。结论：后入路经关节突脊髓环形减压术治疗胸椎OPLL可取得理想的临床疗效，将术中平均动脉压维持在与术前一致的水平可有效降低术后短暂神经功能损害加重的风险。

英文摘要:

  【Abstract】 Objectives: To retrospectively evaluate the clinical efficacy of posterior transarticular osteotomy and circumferential decompression for thoracic ossification of posterior longitudinal ligament(OPLL), and to explore the risk factors of transient postoperative neurologic deterioration. Methods: A total of 29 patients with thoracic OPLL underwent posterior transarticular osteotomy and circumferential decompression from August 2015 to September 2018, including 18 males and 11 females. The age ranged from 27 to 80 years old, with an average age of 52.8±14.6 years. 20 patients were beaked type OPLL, 5 patients were continuous type and 4 patients were mixed type. All patients underwent 1 level of circumferential decompression and an average of 3 level of laminectomy. The average follow-up time was 30.0±11.7 months(range 13-50 months). A modified Japanese Orthopedic Association(JOA) scale for thoracic spine was used to evaluate neurologic status at pre-operation and post-operation respectively, and final recovery rates were assessed according to Hirabayashi system. The patients were divided into 2 groups based on the absence or presence of transient postoperative paralysis. The following items were compared between two groups: age, sex, body mass index, the duration of disease(from first symptom to operation), the preoperative JOA score, location of the OPLL, type of the OPLL, operation time, the blood loss, mean arterial pressure, difference value of pre-operative and intraoperative mean arterial pressure. And then, items with statistical difference and risk factors reported in the previous literature that may lead to transient postoperative paralysis were selected for binary Logistic regression analysis. Results: All patients underwent surgery. The average operation time was 170.7±74.1min(range 80-354min). The mean blood loss was 1097.9±788.7ml(range 150-3500ml). Surgical complications included dural tear in 6 patients(20.7%), intercostal neuralgia in 1 patient(3.4%), and transient postoperative neurologic deterioration in 6 patients(20.7%). The average JOA score was significantly improved from 5.3±2.1 before surgery to 8.9±1.6 at the final follow-up(P<0.001). The mean recovery rate was (64.2±21.4)%(range 16.7%-100%), and excellent and good rate was 86.2%: 9 patients were excellent, 16 patients were good, 3 patients were fair and 1 patient was poor. None had suffered neurological deterioration at the final follow-up. The blood loss, the difference value of pre-operative and intraoperative mean arterial pressure were significantly different between two groups(P<0.05). When included in a binary Logistic regression model, difference value of pre-operative and intraoperative mean arterial pressure was associated with the transient postoperative neurological deterioration(OR＝1.27, P=0.026, 95%CI 1.01-1.57). For every 1mmHg decrease compared with the preoperative mean arterial pressure, the risk of transient postoperative neurological deterioration increased by 27 percents. Conclusions: Posterior transarticular osteotomy and circumferential decompression seemed to be effective for the thoracic ossification of posterior longitudinal ligament. Maintaining intraoperative mean arterial pressure at a consistent preoperative level can significantly reduce the risk of transient postoperative neurologic deterioration.