Vora Vagmin, Crawford Alvin, Babekhir Nadir, Boachie-Adjei Oheneba, Lenke Lawrence, Peskin Melissa, Charles Gina, Kim Yongjung
Penn State Milton S. Hershey Medical Center, Hershey, PA 17033-0850, USA.
Spine (Phila Pa 1976). 2007 Aug 1;32(17):1869-74. doi: 10.1097/BRS.0b013e318108b912.
Tricenter retrospective cohort study of 72 patients who underwent posterior correction of Lenke 1 adolescent idiopathic scoliosis (AIS). Each center represented a single surgeon using only one type of construct.
Compare the initial postoperative and 2-year follow-up correction of Lenke 1 AIS curves, after accounting for the preoperative flexibility of the curves.
There are multiple reports in literature of the enhanced posterior corrective ability of the pedicle screw in the treatment of AIS. Unfortunately, none of these reports took into account the preoperative flexibility of the curve. It stands to reason that rigid curves will not correct as much as flexible curves irrespective of the nature of the construct.
Groups were as follows: Group 1 (proximal and distal hooks and segmental intraspinous collar button wires), 24 patients; Group 2 (proximal hooks, distal screws, and apical sublaminar wires), 23 patients; and Group 3 (pedicle screws only), 25 patients. The postoperative correction percentage was expressed as a ratio of the preoperative flexibility and was termed Cincinnati correction index (CCI). Mathematically speaking the CCI equals (postoperative correction/preoperative erect Cobb angle) divided by (supine bending preoperative correction/preoperative erect Cobb angle). The postoperative sagittal correction was also measured.
CCI 2 (at 2-year follow-up) for Group 1 was 1.71, for Group 2 was 1.34, and for Group 3 was 1.41. The differences were not statistically significant. Within Group 1, however, there was a statistically significant difference between CCI (1.95) and CCI 2 (1.71), indicating a statistically significant loss of correction over 2 years. However, in terms of absolute values, there was only a 4 degree (average) difference between the initial and the 2-year postoperative Cobb measurement, rendering the loss off correction clinically insignificant. No such statistically or clinically significant differences were noted within Groups 2 and 3. Group 1 and Group 3 constructs further lordosed the curve by 8 degrees and 11 degrees, respectively, whereas the Group 2 construct retained or marginally increased the preoperative kyphosis.
The Group 3 (pedicle screw only) construct did not give an enhanced correction of Lenke 1 AIS, when the preoperative flexibility of the curve was considered. Also, contrary to popular belief, the pedicle screw construct has a lordosing effect on the thoracic spine. Therefore, we think that there is no significant advantage in using a relatively expensive pedicle screw construct in the correction of Lenke 1 AIS.
对72例行Lenke 1型青少年特发性脊柱侧凸（AIS）后路矫正术的患者进行三中心回顾性队列研究。每个中心由一名仅使用一种固定方式的外科医生负责。
在考虑术前侧弯柔韧性的情况下，比较Lenke 1型AIS术后即刻及2年随访时的矫正情况。
文献中有多篇报道指出椎弓根螺钉在治疗AIS时具有更强的后路矫正能力。遗憾的是，这些报道均未考虑术前侧弯的柔韧性。显而易见，无论固定方式如何，僵硬的侧弯矫正程度都不如柔韧性好的侧弯。
分组如下：第1组（近端和远端钩及节段性棘突间套环钢丝），24例患者；第2组（近端钩、远端螺钉及顶椎椎板下钢丝），23例患者；第3组（仅用椎弓根螺钉），25例患者。术后矫正百分比以术前柔韧性的比值表示，称为辛辛那提矫正指数（CCI）。从数学角度讲，CCI等于（术后矫正/术前站立位Cobb角）除以（术前仰卧位弯曲矫正/术前站立位Cobb角）。同时测量术后矢状面矫正情况。
第1组2年随访时的CCI为1.71，第2组为1.34，第3组为1.41。差异无统计学意义。然而，在第1组中，CCI（1.95）与2年随访时的CCI 2（1.71）之间存在统计学差异，表明2年内矫正度有统计学意义的丢失。不过，从绝对值来看，术后即刻与术后2年的Cobb角测量值平均仅相差4度，矫正度丢失在临床上无显著意义。第2组和第3组未观察到此类统计学及临床显著差异。第1组和第3组的固定方式分别使侧弯进一步前凸8度和1度，而第2组的固定方式维持或略微增加了术前的后凸。
在考虑术前侧弯柔韧性的情况下，第3组（仅用椎弓根螺钉）的固定方式并未增强Lenke 1型AIS的矫正效果。此外，与普遍看法相反，椎弓根螺钉固定方式对胸椎有前凸作用。因此，我们认为在矫正Lenke 1型AIS时使用相对昂贵的椎弓根螺钉固定方式并无显著优势。
