中重度僵硬型颈椎后凸畸形的形态特点与手术效果

Moderate to severe rigid cervical kyphosis: morphological characteristics and surgical treatment

中文关键词:  颈椎后凸  僵硬  形态特点  手术入路  截骨

英文关键词:Cervical kyphosis  Rigid  Morphological characteristics  Surgical approach  Osteotomy

中文摘要:

  【摘要】 目的：评估中重度僵硬型颈椎后凸的矢状位形态特征与手术效果，并分析影响手术矫形效果及神经功能转归的相关因素。方法：回顾性分析2014年1月~2021年3月在我院接受手术治疗的34例中重度僵硬型颈椎后凸畸形患者临床资料，中重度后凸定义为局部后凸角≥20°，僵硬型后凸定义为过伸位X线片示后凸柔韧性＜30%或颈椎CT示后凸节段骨性强直。患者接受手术时年龄为50.1±17.6岁（14~83岁），其中男性21例，女性13例。致畸因素包括退变性后凸18例，先天畸形5例，医源性后凸5例，强直性脊柱炎3例，创伤性后凸3例。行前路、后路或前后路联合手术分别为24例、5例及5例；其中5例行三柱截骨矫形手术。收集所有患者术前一般资料、围手术期参数和随访信息，并利用疼痛视觉模拟评分（visual analogue scale，VAS）、颈椎功能障碍指数（neck disability index，NDI）及日本骨科协会改良颈椎评分（modified Japanese Orthopaedic Association scale，mJOA）评估患者颈部疼痛和神经功能状态。通过颈椎侧位X线片测量患者术前、术后即刻及末次随访时的局部后凸角、T1倾斜角、颈椎矢状面垂直轴及颌眉垂线角，并定义畸形成角系数为局部后凸角/后凸累及节段数。根据数据分布情况选用独立样本或配对样本t检验、Mann-Whitney U检验、Wilcoxon signed-rank检验、卡方检验或Fisher精确概率检验比较上述影像学参数与评分指标在不同时间点或不同患者亚组间的分布。结果：患者局部后凸角中位数为25°（20°~100°），畸形成角系数中位数为7.5°（5°~25°）。根据mJOA评分将患者分为两组，重度颈脊髓病组患者的畸形成角系数显著大于轻中度颈脊髓病组[9.3°（5.0°~25.0°） vs 7.0°（5.3°~10.0°），P=0.016]；手术时长277±140min，中位失血量150（20~2000）ml。局部后凸角与畸形成角系数分别由术前的31.6°±19.5°与8.8°±4.2°矫正至术后2.8°±5.7°与0.9°±1.9°，差异有统计学意义（P<0.001）；经过1.0±0.8（0.3~3.1）年的影像学随访，末次随访时局部后凸角与畸形成角系数与术后即刻相比差异均无统计学意义（P>0.05）；经过3.0±1.5年的临床随访，末次随访时患者VAS、NDI及mJOA评分分别由术前的5.3±1.8分、（27.7±16.5）%及11.9±4.3分改善至1.3±1.2分、（7.7±7.1）%及14.8±2.2分，差异有统计学意义（P<0.001）。畸形成角系数的矫形幅度与mJOA评分的改善幅度呈正相关（Spearman r=0.417，P=0.018）。共有14例患者（41.2%）术后出现早期并发症，包括10例（29.4%）神经系统并发症；共有8例患者（23.5%）出现远期并发症。发生术后早期并发症的患者病程更长，最高截骨等级>2级的比例更高，手术出血量更大（P<0.05）。结论：选择恰当的手术方式治疗中重度僵硬型颈椎后凸畸形可以获得满意的临床疗效。畸形成角系数可以作为形态学评估的重要参数，并在一定程度上预测术后神经功能改善情况。

英文摘要:

  【Abstract】 Objectives: To evaluate the sagittal morphological characteristics of moderate to severe rigid cervical kyphosis, and to analyze the factors related to surgical correction effect and neurological outcome.Methods: 34 patients with moderate to severe rigid cervical kyphosis who were surgically treated at our hospital between January 2014 and March 2021 were retrospectively enrolled. The moderate to severe kyphosis was defined as regional kyphosis angle ≥20°. The rigid kyphosis was defined as flexibility <30% or segmental ankylosis visualized on CT scans. The mean age of the enrolled patients at operation was 50.1±17.6 years (range: 14-83 years), comprising 21 male patients and 13 female patients. The etiologies were degenerative kyphosis in 18 cases, congenital deformity in 5 cases, iatrogenic kyphosis in 5 cases, ankylosing spondylitis in 3 cases, and traumatic kyphosis in 3 cases. 24 cases were operated through anterior approach, 5 through posterior approach, and 5 through combined approach, respectively. Three-column osteotomy with deformity correction was performed in five patients. The baseline data, surgical parameters, and follow-up information were collected. The neck pain and neurological functional status were evaluated with visual analogue scale (VAS), neck disability index (NDI), and modified Japanese Orthopaedic Association scale (mJOA), respectively. The regional kyphosis angle, T1 slope, cervical sagittal vertical axis, and chin-brow vertical angle were measured on lateral film of cervical spine radiographs before operation, immediately after operation and at the final follow-up. The deformity angular ratio was defined as regional kyphosis angle/number of segments involved in kyphosis. According to the distribution of data, independent sample or paired sample t test, Mann-Whitney U test, Wilcoxon signed-Rank test, Chi-square test or Fisher′s exact probability test were selected to compare the distribution of the above radiographic parameters and scoring indexes at different time points or in different subgroups of patients. Results: The patients had a median regional kyphosis angle of 25° (ranged 20° to 100°) and a median deformity angular ratio of 7.5° (ranged 5° to 25°). They were divided into two groups according to mJOA score. The deformity angular ratio in patients with severe cervical myelopathy was significantly higher than that of patients with mild to moderate cervical myelopathy [9.3° (5.0°-25.0°) vs 7.0° (5.3°-10.0°), P=0.016]. The mean operation time was 277±140 minutes, and the median blood loss was 150 (20-2000)ml. The regional kyphosis angle and deformity angular ratio were corrected from 31.6°±19.5° and 8.8°±4.2° preoperatively to 2.8°±5.7°and 0.9°±1.9° postoperatively, respectively. These differences were statistically significant(P<0.001). After 1.0±0.8 (0.3-3.1) years of radiographic follow-up, there was no statistical difference in the measured values of these two sagittal parameters at the final follow-up compared with those immediately after the operation(P>0.05). The mean clinical follow-up time was 3.0±1.5 years. At the final follow-up, the VAS, NDI and mJOA scale were improved from 5.3±1.8, (27.7±16.5)% and 11.9±4.3 preoperatively to 1.3±1.2, (7.7±7.1)% and 14.8±2.2 postoperatively, respectively. These differences were statistically significant(P<0.001). The correction of deformity angular ratio was positively correlated with the improvement of mJOA(Spearman r=0.417, P=0.018). There were 14 (41.2%) patients showed early postoperative complications, including 10 (29.4%) neurological deficits, and 8 patients (23.5%) developed late complications. Patients with early postoperative complications had a longer course of disease, higher proportion of the highest osteotomy grade >2, and greater operative blood loss. Conclusions: Choosing appropriate surgical methods for the treatment of moderate to severe rigid cervical kyphosis can achieve satisfactory clinical results. The deformity angular ratio can be regarded as an important parameter for morphological evaluation, which is able to predict the postoperative improvement of neurological function to some extent.