双节段前路颈椎自锁式融合器融合术后矢状位影像学参数的变化

Sagittal alignment analysis on using self-locking stand-alone cages in two-level anterior cervical discectomy and fusion

中文关键词:  颈椎病  前路颈椎融合术  自锁式融合器  矢状位参数

英文关键词:Cevical spondylosis  Anterior cervical discectomy and fusion  Self-locking stand-alone cages  Sagittal alignments

中文摘要:

  【摘要】 目的：观察应用自锁式融合器行前路颈椎融合术（anterior cervical discectomy and fusion，ACDF）后矢状位影像学参数的变化。方法：回顾性分析2010年1月~2014年6月160例接受ACDF的双节段颈椎病患者，其中应用MC+融合器（单锚定组）78例，ROI-C融合器（双锚定组）82例。测量术前、术后3d、术后3个月及末次随访时颈椎侧位X线片的影像学参数，包括手术节段椎间隙高度（height of operation segment，HOS）、椎间隙角度（angle of operation segment，AOS）、C2-C7角、C2-C7矢状位轴向距离（C2-C7 sagittal vertical axis，C2-C7 SVA）及T1倾斜角（T1 slope，T1S），并应用Erk五度分级法评价术后3个月及末次随访时的植骨融合情况。采用Pearson相关性分析160例患者各时间点影像学参数间的相关性；运用独立样本t检验对比同时间点两组间各影像学参数的差异；使用配对样本t检验分别对两组组内不同时间点时各参数进行对比；两组间术后3个月及末次随访时的融合等级对比采用Mann-Whitney U检验；术后3个月及末次随访时两组组内融合等级对比运用Wilcoxon符号秩检验。结果：术后随访13.42±6.01个月（6~31个月）。术前、术后3d、术后3个月及末次随访时AOS与C2-C7角、C2-C7角与T1S、AOS与T1S、T1S与 C2-C7 SVA均呈正相关（P<0.01），C2-C7 SVA与AOS、C2-C7角均无显著相关性（P>0.01）。术后3d、3个月及末次随访时两组HOS、AOS、C2-C7角及T1S较术前均有增加（P<0.05），术后3个月及末次随访时，双锚定组AOS、C2-C7角及T1S均高于单锚定组，两组比较存在统计学差异（P<0.05）。两组术后3个月及末次随访时融合等级对比无统计学差异（P>0.05），末次随访时两组融合等级较术后3个月时下降（P<0.05）。结论：应用两种自锁式融合器行双节段ACDF均可恢复手术节段椎间隙的高度、角度以及颈椎曲度，ROI-C融合器较MC+融合器对维持术后手术节段角度及颈椎前凸更具优势。ACDF术后颈椎曲度的丢失可能引起胸椎矢状位影像学参数的变化。

英文摘要:

  【Abstract】 Objectives: To investigate changes of sagittal alignments of using self-locking stand-alone cages in anterior cervical discectomy and fusion(ACDF). Methods: A retrospect research from January 2012 to June 2014 was performed, 160 two-level cervical spondylosis patients undergoing ACDF were enrolled and divided into uni-anchored group(UAG) and bi-anchored group(BAG) according to the anchor type of self-locking stand-alone cage (MC+ and ROI-C). Cervical standing radiographs were taken at pre-operation, 3 days after operation, 3 months after operation and the last follow-up. The sagittal parameters were measured, including height of operation segment(HOS), angle of operation segment(AOS), C2-C7 angle, C2-C7 sagittal vertical axis(C2-C7 SVA) and T1 slope(T1S). Erk method was used to evaluate the fusion status of operation segment. Statistic methods, including independent t-test and paired t-test, were performed to determine the significance of difference between UAG and BAG. Correlation among the radiographic parameters of 160 patients at every check point were sought by Pearson correlation analysis. In addition, the fusion rank of two groups was compared by Mann-Whitney U test and Wilcoxon signed rank test. Results: All cases obtained the follow-up with an average of 13.42±6.01 months(range, 6 to 31 months). At pre-operation, 3 days after operation, 3 months after operation and the last follow-up, positive correlations were presented between AOS and C2-C7 angle, C2-C7 angle and T1S, AOS and T1S, T1S and C2-C7 SVA（P<0.01）. No significant difference was found between C2-C7 SVA and AOS, C2-C7 SVA and C2-C7 angle（P>0.01）. In both groups, HOS, AOS, C2-C7 angle and T1S increased after operation(P<0.05). AOS, C2-C7 angle and T1S of UAG showed a statistic lower value than BAG at 3 months after operation and the last follow-up（P<0.05）. The fusion status of both groups had no significant difference at 3 months after operation and the last follow-up(P>0.05). The fusion rank at the last follow-up was significant lower than that at 3 months after operation(P<0.05). Conclusions: The height and angle of operation segment and cervical curve can be corrected after ACDF by using both self-locking stand-alone cages. ROI-C cage can be considered as a better choice in maintaining AOS and cervical lordosis compared to MC+ cage. The thoracic radiographic sagittal parameters may be altered after ACDF following the loss of cervical curve.