颅底凹陷症患者枕颈融合术后枕颈角的变化及临床意义

Changes and clinical significance of occipito-C2 angle after occipitocervical fusion in patients with basilar invagination

中文关键词:  颅底凹陷症  枕颈融合术  枕颈角  下颈椎曲度

英文关键词:Basilar invagination  Occipitocervical fusion  Occipito-cervical angle  Subaxial cervical curvature

中文摘要:

  【摘要】 目的：观察颅底凹陷症（basilar invagination，BI）患者枕颈融合（occipito-cervical fusion，OCF）术后枕颈角（occipito-C2 angle，OC2A）的变化，分析术后OC2A变化值与OC2A术中矫正值的相关性以及对术后下颈椎的影响。方法：回顾性分析2013年9月～2019年4月我院收治的行OCF手术治疗的30例原发性BI患者的临床资料。其中男11例，女19例，年龄49.0±12.2岁（29~71岁）。固定节段：C0-C2 20例，C0-C3 8例，C0-C4 2例。在患者术前和术后7d、3个月、6个月、1年、2年时的标准颈椎侧位X线片上测量OC2A，在术后7d和术后2年时测量下颈椎椎间盘与椎体高度比（S值）、下颈椎前凸角（C2-C7角）、C4椎体中心至McGregor线垂直距离（the occiput-C4 distance，OC4D）、寰齿前间隙（atlas-dens interval，ADI）以及斜坡椎管角（clivus-canal angle，CCA）。计算术后7d与术前OC2A的差值，记为OC2A术中矫正值；计算术后2年与术后7d OC2A、S值、C2-C7角、OC4D、ADI、CCA的差值，分别记为OC2A术后丢失值、ΔS值、ΔC2-C7角、ΔOC4D、ΔADI、ΔCCA。Pearson相关分析法研究OC2A术后丢失值与OC2A术中矫正值、ΔS值、ΔC2-C7角、ΔOC4D、ΔADI、ΔCCA 之间的相关性。结果：患者术前OC2A为5.4°±7.2°，术后7d、3个月、6个月、1年、2年OC2A分别为15.8°±5.6°、13.5°±4.5°、12.4°±4.7°、11.6°±4.6°、11.2°±5.1°，术后1年与2年随访OC2A值比较差异无统计学意义（P>0.05），其余各随访时间点OC2A两两比较差异均有统计学意义（P<0.05）。术后7d和2年的S值为0.469±0.034、0.436±0.042，C2-C7角为16.5°±8.4°、10.9°±6.7°，OC4D为6.14±0.63cm、5.31±0.55cm，ADI为2.37±0.85mm、3.18±0.92mm，CCA为141.4°±21.1°、132.6°±17.5°，术后2年均较术后7d减小，差异有统计学意义（P<0.05）。OC2A术中矫正值为10.4°±9.9°，OC2A术后丢失值、ΔS值、ΔC2-C7角、ΔOC4D、ΔADI、ΔCCA分别为4.6°±4.2°、-0.033±0.018、-5.6°±5.2°、-0.83±0.48cm、-0.81±0.67mm、-8.8°±18.4°。Pearson相关分析提示OC2A术后丢失值和术中矫正值呈强负相关（r=-0.699，P<0.001），与ΔC2-C7角、ΔS值、ΔOC4D、ΔADI、ΔCCA 均呈正相关（r=0.429，r=0.413，r=0.347，r=0.296，r=0.675；P＜0.05）。结论：BI 患者术中OC2A矫正值越大，术后OC2A丢失越多，术后1年OC2A丢失趋于稳定；且OC2A丢失过多易造成下颈椎曲度发生显著改变。

英文摘要:

  【Abstract】 Objectives: To observe the changes of the occipito-C2 angle(OC2A) in basilar invagination(BI) patients after occipito-cervical fusion(OCF). The correlation between postoperative OC2A change value and intraoperative OC2A correction value and its influence on postoperative curvature of subaxial cervical was analyzed. Methods: The clinical data of 30 primary BI patients who underwent OCF surgery in our hospital from September 2013 to April 2019 were retrospectively analyzed. There were 11 males and 19 females, aged 49.0±12.2 years(29-71 years), including C0-C2 fixation in 20 cases, C0-C3 fixation in 8 cases, and C0-C4 fixation in 2 cases. The OC2A of BI patients were measured on standard lateral cervical X-rays before operation and 7 days, 3 months, 6 months, 1 year and 2 years postoperatively. Meanwhile, the heightratio of subaxial cervical disc to vertebral body(S value), the subaxial cervical angle(C2-C7 angle), the occipto-C4 distance(OC4D), atlas-dens interval(ADI) and clivus-canal angle(CCA) were measured at 7 days and 2 years after surgery. The difference of OC2A between 7 days postoperatively and pre-operation was calculated and recorded as OC2A interoperative corrected value, and the differences of OC2A, S value, C2-C7 angle, OC4D, ADI, CCA of patients between 7 days and 2 years after operation were denoted as CO2A postoperative loss value, ΔS value, ΔC2-C7 angle, ΔOC4D, ΔADI, ΔCCA, respectively. Results: The preoperative OC2A of 30 patients was 5.4°±7.2° and the OC2A values 7 days, 3 months, 6 months, 1 year, 2 years postoperatively were 15.8°±5.6°, 13.5°±4.5°, 12.4°±4.7°, 11.6°±4.6°, and 11.2°±5.1° respectively. There was no statistical difference in OC2A between 1 year and 2 years after operation(P>0.05) while the differences of OC2A between other follow-up time points were statistically significant(P<0.05). The S-values of 7 days and 2 years after operation were 0.469±0.034, 0.436±0.042, C2-C7 angle was 16.5°±8.4°, 10.9°±6.7°, OC4D was 6.14±0.63cm, 5.31±0.55cm, ADI was 2.37±0.85mm, 3.18±0.92mm, CCA was 141.4°±21.1°, 132.6°±17.5°. All of this were decrease at 2 years postoperatively compared to 7 days postoperatively, the differences was statistically significant(P<0.05). The OC2A interoperative correction value was 10.4°±9.9° and the OC2A postoperative loss value, ΔS value, ΔC2-C7 angle, ΔOC4D, ΔADI, ΔCCA were 4.6°±4.2°, 0.033±0.018, 5.6°±5.2°, -0.83±0.48cm, -0.81±0.67mm, -8.8°±18.4° respectively. Pearson correlation analysis indicated that the loss value and correction value of OC2A were strongly negatively correlated(r=-0.699, P<0.001). The postoperative OC2A loss value was positively correlated with ΔC2-C7 angle, ΔS value, ΔOC4D, ΔADI, ΔCCA respectively(r=0.429, r=0.413, r=0.347, r=0.296, r=0.675; P＜0.05). Conclusions: The greater of the correction value of OC2A in BI patients, the more OC2A loss after surgery, and the loss of OC2A tended to be stable in 1 year after surgery; and excessive loss of OC2A can easily lead to significant changes in the curvature of the subaxical cervical spine.