[Correlation analysis between C 7 slope and cervical sagittal parameters in short segment anterior cervical discectomy with fusion]

Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2019 Jul 15;33(7):877-882. doi: 10.7507/1002-1892.201901065.
[Article in Chinese]

Abstract

Objective: To elucidate the relationship between preoperative C 7 slope (C 7S) and sagittal parameters in anterior cervical discectomy with fusion (ACDF) by imaging.

Methods: A retrospective analysis of 54 patients (24 males and 30 females) with ACDF for cervical spondylosis between January 2012 and January 2017 was performed. The age ranged from 23 to 71 years (mean, 46.6 years). There were 29 cases of cervical spondylotic radiculopathy and 25 cases of cervical spondylotic myelopathy. The disease duration ranged from 3 to 48 months, with an average of 16.8 months. In the 55 patients, 44 were single-segment ACDF and 10 were double-segment ACDF. Sagittal parameters of cervical spine were measured on cervical X-ray films before operation and at last follow-up, including C 2-7 Cobb angle, C 2-7 sagittal vertical axis (C 2-7 SVA), C 7S, and segment Cobb angle (SCobb), and the changes of C 2-7 Cobb angle (the difference between the last follow-up and the preoperative angle) were calculated. Pearson correlation was used to analyze the correlation between the parameters before operation and at last follow-up. According to the preoperative median value of C 7S (15°), the patients were divided into group A (C 7S<15°) and group B (C 7S≥15°). The sagittal parameters before and after operation were compared between the two groups.

Results: All the 54 patients were followed up 6-45 months (mean, 15.5 months). At last follow-up, C 7S, C 2-7 Cobb angle, C 2-7 SVA, and SCobb angle were significantly improved when compared with preoperative values ( P<0.05). Correlation analysis showed that the preoperative C 7S and SCobb angles were significantly correlated with C 2-7 Cobb angle and C 2-7 SVA ( P<0.05), but there was no significant correlation between C 7S and SCobb angle ( r=0.049, P=0.724). There was a significant correlation between C 7S, C 2-7 Cobb angle, and SCobb angle at last follow-up ( P<0.05), but there was no significant correlation between C 7S and SCobb angles and C 2-7 SVA ( P>0.05). According to the median value of preoperative C 7S, 28 patients in group A had C 7S of (11.82±3.60)°, while 26 patients in group B had C 7S of (20.77±4.09)°. There was no significant difference in gender and age between the two groups ( P>0.05). The preoperative C 2-7 Cobb angle and C 2-7 SVA in group A were significantly lower than those in group B ( P<0.05). There was no significant difference between preoperative SCobb angle and group B ( t=0.234, P=0.816). There were no significant differences in C 2-7 Cobb angle, C 2-7 SVA, and SCobb angle between group A and group B at last follow-up ( P>0.05). However, the change of C 2-7 Cobb angle in group A was significantly higher than that in group B ( t=2.321, P=0.024).

Conclusion: Preoperative C 7S≥15° group has more physiological lordosis before operation, but its postoperative cervical curvature changes less, while ACDF is more conducive to correct the preoperative C 7S<15 ° cervical curvature.

目的: 通过影像学测量探讨短节段颈前路椎间盘切除融合术(anterior cervical discectomy with fusion,ACDF)中术前 C 7 倾斜角(C 7 slope,C 7S)与颈椎矢状位参数变化的关系。.

方法: 回顾分析 2012 年 1 月—2017 年 1 月收治的 54 例因颈椎病接受 ACDF 治疗的患者临床资料。其中男 24 例,女 30 例;年龄 23~71 岁,平均 46.6 岁。神经根型颈椎病 29 例,脊髓型颈椎病 25 例。病程 3~48 个月,平均 16.8 个月。单节段 ACDF 44 例,双节段 ACDF 10 例。在术前及末次随访时的颈椎 X 线片上测量颈椎矢状位参数:C 2~7 Cobb 角、C 2-7 矢状位垂直距离(C 2-7 sagittal vertical axis,C 2-7 SVA)、C 7S 和手术节段 Cobb 角(segment Cobb angle,SCobb),并计算 C 2~7 Cobb 角变化值(末次随访与术前角度的差值)。术前及末次随访时采用 Pearson 相关分析各参数之间的相关性。根据术前 C 7S 中位数(15°)分为 A 组(C 7S<15°)和 B 组(C 7S≥15°),比较两组手术前后各矢状位参数差异。.

结果: 54 例患者均获随访,随访时间 6~45 个月,平均 15.5 个月。末次随访时患者 C 7S、C 2~7 Cobb 角、C 2-7 SVA 及 SCobb 角均较术前显著改善( P<0.05)。相关性分析显示,术前 C 7S 和 SCobb 角均与 C 2~7 Cobb 角和 C 2-7 SVA 有显著相关性( P<0.05),而 C 7S 与 SCobb 角之间无显著相关性( r=0.049, P=0 .724);末次随访时,C 7S、C 2~7 Cobb 角、SCobb 角之间均有显著相关性( P<0.05),而 C 7S 和 SCobb 角与 C 2-7 SVA 之间均无显著相关性( P>0.05)。根据患者术前 C 7S 中位数分组,A 组 28 例,C 7S 为(11.82±3.60)°;B 组 26 例,C 7S 为(20.77±4.09)°;两组患者性别及年龄比较差异均无统计学意义( P>0.05)。A 组术前 C 2~7 Cobb 角和 C 2-7 SVA 显著小于 B 组( P<0.05),术前 SCobb 角与 B 组比较差异无统计学意义( t=0.234, P=0.816)。末次随访时 A、B 组间 C 2~7 Cobb 角、C 2-7 SVA 和 SCobb 角比较差异均无统计学意义( P>0.05);但 A 组 C 2~7 Cobb 角变化值显著大于 B 组( t=2.321, P=0.024)。.

结论: 术前 C 7S≥15° 者其术前有更多的生理前凸,但其术后颈椎曲度变化较小,即短节段 ACDF 更有利于矫正术前 C 7S<15° 的颈椎曲度。.

Keywords: Anterior cervical discectomy with fusion; C7 slope; cervical sagittal parameter.

MeSH terms

  • Adult
  • Aged
  • Cervical Vertebrae
  • Diskectomy*
  • Female
  • Humans
  • Lordosis* / surgery
  • Male
  • Middle Aged
  • Retrospective Studies
  • Spinal Cord Diseases / surgery*
  • Spinal Fusion*
  • Young Adult