Kanie Yuya, Takenaka Shota, Kitahara Takayuki, Furuya Masayuki, Ukon Yuichiro, Fujimori Takahito, Okada Seiji, Kaito Takashi
Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
Department of Orthopaedic Surgery, Japan Community Heath Care Organization Osaka Hospital, Osaka, Japan.
J Spine Surg. 2024 Jun 21;10(2):255-263. doi: 10.21037/jss-23-138. Epub 2024 Jun 13.
Although pelvic obliquity (PO) is a risk factor for postoperative coronal decompensation in corrective surgery in adolescent idiopathic scoliosis (AIS), especially Lenke 5C, methods of measuring PO are controversial. This study aimed to establish an appropriate measurement method using multiplanar reconstructed computed tomography (MPR-CT) images instead of standing posteroanterior (PA) whole-spine radiographs to evaluate PO in patients with Lenke 5C AIS.
This study was a retrospective cross-sectional study. Twenty-five patients who underwent corrective surgery for AIS in Osaka University Hospital from August 2014 to February 2023 were included. Cobb angle, L5 tilt, C7 plumb line to center sacral vertebral line (C7PL-CSVL), and leg length discrepancy (LLD) were measured on standing PA whole-spine radiographs preoperatively. Sacral obliquity (SO), the slope of the upper endplate of S1, and iliac obliquity (IO), the tilt of the line connecting the iliac crests, were measured on standing PA whole-spine radiographs and MPR-CT (SO/IO-X-ray, SO/IO-CT, respectively). S1 angle and S2 angle were measured on CT.
The mean age of the patients was 18.7±3.9 years and all of them were females. SO-X-ray and SO-CT were larger than IO-X-ray and IO-CT, respectively. SO-X-ray was highly correlated with SO-CT (r=0.838, P<0.001). L5 tilt had higher correlation with SO-CT (r=0.884, P<0.001) than with SO-X-ray (r=0.726, P=0.001) and IO-CT (r=0.550, P=0.22). L5 tilt was correlated poorly with IO-X-ray (r=0.104, P=0.69). The S1 angle was 4.5±3.5° meanwhile the S2 angle was 1.2±2.1°, the sacral deformity was mainly due to the S1 vertebral wedging.
Given the asymmetric sacral morphology, SO is more appropriate pelvic parameter than IO to represent the sacral tilt of Lenke 5C AIS, especially when measured using CT images to overcome the poor visibility on PA whole-spine radiographs.
尽管骨盆倾斜（PO）是青少年特发性脊柱侧凸（AIS）矫正手术，尤其是Lenke 5C型术后冠状面失代偿的一个危险因素，但PO的测量方法仍存在争议。本研究旨在建立一种合适的测量方法，使用多平面重建计算机断层扫描（MPR-CT）图像而非站立位后前位（PA）全脊柱X线片来评估Lenke 5C型AIS患者的PO。
本研究为回顾性横断面研究。纳入2014年8月至2023年2月在大阪大学医院接受AIS矫正手术的25例患者。术前在站立位PA全脊柱X线片上测量Cobb角、L5倾斜度、C7铅垂线至骶骨中心椎体线（C7PL-CSVL）以及下肢长度差异（LLD）。在站立位PA全脊柱X线片和MPR-CT上分别测量骶骨倾斜度（SO），即S1上终板的斜率，以及髂骨倾斜度（IO），即连接双侧髂嵴的线的倾斜度（分别为SO/IO-X线、SO/IO-CT）。在CT上测量S1角和S2角。
患者的平均年龄为18.7±3.9岁，均为女性。SO-X线和SO-CT分别大于IO-X线和IO-CT。SO-X线与SO-CT高度相关（r = 0.838，P < 0.001）。L5倾斜度与SO-CT的相关性（r = 0.884，P < 0.001）高于与SO-X线（r = 0.726，P = 0.001）和IO-CT（r = 0.550，P = 0.22）的相关性。L5倾斜度与IO-X线的相关性较差（r = 0.104，P = 0.69）。S1角为4.5±3.5°，而S2角为1.2±2.1°，骶骨畸形主要由于S1椎体楔形改变。
鉴于骶骨形态不对称，SO比IO更适合作为代表Lenke 5C型AIS骶骨倾斜度的骨盆参数，尤其是在使用CT图像测量时，可克服PA全脊柱X线片上显示不佳的问题。
