Department of Orthopaedic Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto, Nagano, 390-8621, Japan.
Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Shizuoka, Japan.
Sci Rep. 2022 Oct 10;12(1):16996. doi: 10.1038/s41598-022-21274-5.
No validated systems exist for selecting the upper instrumented vertebra (UIV) for optimal postoperative shoulder balance in Lenke type 2 adolescent idiopathic scoliosis (AIS). This study evaluated a new method for shoulder balance prediction using the modified Shinshu line (MSL) for UIV selection in AIS Lenke type 2 curves. Fifty-five consecutive AIS patients receiving posterior spinal fusion (PSF) for a Lenke type 2 AIS curve were retrospectively analyzed according to several UIV determination models. Shoulder imbalance was judged as absolute radiographic shoulder height ≥ 10 mm at the 2-year observational endpoint. The MSL was the line between the center of the spinous process of C7 and that of the lowest instrumented vertebra. The vertebral body first touched proximally by the MSL was defined as the MSL vertebra (MSLV) and recommended as the UIV. The group with the UIV matching the MSLV had a significantly lower prevalence of shoulder imbalance of 23% (odds ratio 4.08, 95% CI 1.22-13.7, P = 0.02). Setting the MSLV as the UIV in PSF for AIS Lenke type 2 may reduce the prevalence of postoperative shoulder imbalance.
在 Lenke 2 型青少年特发性脊柱侧凸（AIS）中，选择最佳术后肩部平衡的上置器械椎（UIV）尚无经过验证的系统。本研究评估了一种新的方法，即使用改良新泻线（MSL）预测 UIV 选择的肩部平衡，用于 AIS Lenke 2 型曲线。根据几种 UIV 确定模型，对 55 例连续接受后路脊柱融合术（PSF）治疗的 Lenke 2 型 AIS 患者进行回顾性分析。在 2 年观察终点，将绝对影像学肩高≥10mm 判定为肩部失衡。MSL 是 C7 棘突中心与最低置钉椎骨中心之间的连线。MSL 首先触及的椎体定义为 MSL 椎体（MSLV），并推荐作为 UIV。UIV 与 MSLV 匹配的组肩部失衡的患病率显著降低，为 23%（优势比 4.08，95%CI 1.22-13.7，P=0.02）。在 PSF 中，将 MSLV 作为 AIS Lenke 2 型的 UIV，可能会降低术后肩部失衡的患病率。
