青少年特发性脊柱侧凸患者中同样的冠状面弯型不代表同样的三维畸形：基于EOS三维影像系统的配对研究

Similar coronal curvature may not represent the same 3-dimensional deformity in adolescent idiopathic scoliosis： a matched-pair study using EOS imaging system

目的通过分析冠状面弯型匹配而矢状面胸椎后凸（TK）存在较大差异的Lenke1A型患者的术前轴状面形态及手术疗效，研究胸弯青少年特发性脊柱侧凸（AIS）患者轴状面旋转对矢状面形态和轴状面旋转对手术疗效的影响。方法回顾性分析2017年5至8月于南京鼓楼医院脊柱外科接受手术治疗的Lenke1A型右胸弯女性胸弯AIS患者。根据主胸弯Cobb角、顶椎节段、侧弯包含椎体数、Lenke分型的腰弯修正参数、Risser征进行配对，共12对冠状面弯型匹配而TK不同的AIS患者被纳入研究，分为正常TK组和TK减少组。在术前摄EOS全身影像并进行三维重建，在术后3周摄立位全脊柱正侧位x线片，在手术前后二维平片上测量影像学参数：冠状面Cobb角、TK、腰椎前凸（LL）、骨盆投射角（PI）、骨盆倾斜角（PT）。在EOS三维重建影像上得到每个椎体的旋转，并计算主胸弯平均椎体旋转（MTR）、上胸弯平均椎体旋转（PTR）和腰弯平均椎体旋转（LR）。通过配对样本t检验比较2组患者的术前、术后影像学参数情况。结果共有24例患者（12个匹配组）纳入本次研究，平均年龄（13．74-2．9）岁，两组术前主胸弯Cobb角相似（53．8°±10．2°比51．0°±11．1°，t=0．27，P=0．81）。在矢状面，正常TK组术前TK为28．2°±6．1°，而TK减小组为11．2°±5．6°（t=7．68，P〈0．01）。正常TK组MTR显著小于TK减少组（10．2°比12．7°，t=-3．74，P〈0．01），且TK与MTR之间存在显著相关性（r：0．30，P=0．03）。正常TK组LR值显著小于TK减少组（t=-2．65，P=0．002），但绝对值相似（t=-0．33，P=0．31）。胸弯与腰弯同向旋转患者的腰椎Cobb矫正率显著大于胸弯与腰弯反向旋转者（81．1％比61．9％，t=4．24，P=0．005）。结论本研究发现在控制冠状面畸形的条件下，胸椎后凸较小的患者的主胸弯轴状面椎体旋转显著大于正常胸椎后凸的患者。同时上胸椎和腰椎的旋转方向在术前手术策略的制定中也需要纳入考虑，有条件的中心也可以对AIS患者进行术前重建。

Objective To analyze the preoperative axial plane and the surgical outcomes of the Lenke type 1A patients with adolescent idiopathic seoliosis （AIS） whose coronal curve type was matched but thoracic kyphosis （TK） was different. Methods This study retrospectively reviewed a series of Lenke type 1A female AIS patients who underwent corrective surgery in the Department of Spine Surgery of Nanjing Drum Tower Hospital from May to August 2017. After matched with the Cobb angle of the main thoracic curve, the apical vertebral, the vertebra number included in the curve, the lumber modifier in the Lenke classification and Risser sign, 12 pairs of AIS patients, whose coronal curve was matched but thoracic kyphosis was different, were included in this study. The patients were divided into normal TK group and thoracic hypokyphosis group. EOS whole-body images were taken preoperatively and reconstructed by three- dimensional reconstruction. The whole spine anteroposterior X-ray was taken at 3 weeks after surgery. The radiographic parameters were measured on the preoperative and postoperative two-dimensional X-ray images： coronal Cobb angle, TK, lumbar lordosis （LL）, pelvic incidence （PI） and pelvic tilt （PT）. The vertebra rotation was obtained on the EOS three-dimensional reconstructed image, and the average vertebral rotation of the major thoracic curve （MTR）, the average vertebral rotation of the proximal thoracic curve （PTR） and the average vertebral rotation of the lumbar curve （LR） were calculated. The paired sample t test was used to compare the difference of preoperative and postoperative radiographic parameters between the groups. Results A total of 24 patients （ 12 pairs） were included in this study with an average age of （ 13.7±2. 9） years. The preoperative Cobb angle was similar in the two groups （53.8°± 10. 2° vs 51.0° ±11.1°, t = 0. 27 ,P =0. 81 ）. The average preoperative TK of the normal TK groups was 28.2°±6. 1°, while that of the thoracic hypokyphosis group was 11.2°±5.6°（ t = 7.68, P 〈 0. 01 ）. The MTR in the normal TK group was significantly smaller than that in the thoracic hypokyphosis group （ 10. 2°vs 12.7°, t = - 3.74, P 〈 0.01 ）, and there was a significant correlation between TK and MTR （ r = 0. 30, P = 0.03）. As for the lumbar curve rotation, the LR of the normal TK group was significantly smaller than that in the thoracic hypokyphosis group （t = - 2. 65, P = 0. 002）, but the absolute value of the two groups was similar （ t = - 0. 33, P = 0. 31 ）. The lumbar Cobb angle correction rate was significantly greater in patients with thoracic and lumbar curve rotating in the same direction than that in the opposite direction （81.1% vs 61.9%, t =4. 24, P= 0. 005）. Conclusions It indicated that when the coronal deformity is matched, the MTR of the patients with thoracic hypokyphosis is significantly larger than that in the patients with normal thoracic kyphosis. The direction of the thoracic and lumbar curve rotation is required to be well concerned in the preoperative surgical planning.