Twin Cities Spine Center, Minneapolis, Minnesota.
Gillette Children's Specialty Healthcare, St. Paul, Minnesota.
J Bone Joint Surg Am. 2020 Nov 18;102(22):1966-1973. doi: 10.2106/JBJS.19.01485.
The selection of the lowest instrumented vertebra (LIV) in patients with adolescent idiopathic scoliosis (AIS) is still controversial. Although multiple radiographic methods have been proposed, there is no universally accepted guideline for appropriate selection of the LIV. We developed a simple and reproducible method for selection of the LIV in patients with Lenke type-1 (main thoracic) and 2 (double thoracic) curves and investigated its effectiveness in producing optimal positioning of the LIV at 5 years of follow-up.
The radiographs for 299 patients with Lenke type-1 or 2 AIS curves that were included in a multicenter database were evaluated after a minimum duration of follow-up of 5 years. The "touched vertebra" (TV) was selected on preoperative radiographs by 2 independent examiners. The LIV on postoperative radiographs was compared with the preoperative TV. The final LIV position in relation to the center sacral vertical line (CSVL) was assessed. The CSVL-LIV distance and coronal balance in patients who had fusion to the TV were compared with those in patients who had fusion cephalad and caudad to the TV. The sagittal plane was also reviewed.
In 86.6% of patients, the LIV was selected at or immediately adjacent to the TV. Among patients with an "A" lumbar modifier, those who had fusion cephalad to the TV had a significantly greater CSVL-LIV distance than those who had fusion to the TV (p = 0.006) or caudad to the TV (p = 0.002). In the groups with "B" (p = 0.424) and "C" (p = 0.326) lumbar modifiers, there were no differences among the TV groups.
We recommend the TV rule as a third modifier in the Lenke AIS classification system. Selecting the TV as the LIV in patients with Lenke type-1 and 2 curves provides acceptable positioning of the LIV at long-term follow-up. The position of the LIV was not different when fusion was performed caudad to the TV but came at the expense of fewer motion segments. Patients with lumbar modifier "A" who had fusion cephalad to the TV had greater translation of the LIV, putting these patients at risk for poor long-term outcomes.
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
在青少年特发性脊柱侧凸（AIS）患者中，选择最低固定椎（LIV）仍然存在争议。尽管已经提出了多种影像学方法，但对于 LIV 的适当选择，尚无普遍接受的指南。我们开发了一种简单且可重复的方法来选择 Lenke 1 型（主胸段）和 2 型（双胸段）曲线的 LIV，并研究了其在 5 年随访时产生 LIV 最佳定位的效果。
对至少随访 5 年的多中心数据库中 299 例 Lenke 1 型或 2 型 AIS 曲线患者的影像学资料进行评估。术前影像学上由 2 名独立的检查者选择“触及椎”（TV）。比较术后 LIV 与术前 TV。评估终末 LIV 相对于 CSA 垂线（CSVL）的位置。比较融合至 TV 的患者与融合至上位 TV 和下位 TV 的患者的 CSVL-LIV 距离和冠状平衡。也对矢状面进行了回顾。
在 86.6%的患者中，LIV 位于或紧邻 TV。在“A”型腰椎修正组中，融合至上位 TV 的患者 CSVL-LIV 距离明显大于融合至 TV（p=0.006）或下位 TV（p=0.002）的患者。在“B”型（p=0.424）和“C”型（p=0.326）腰椎修正组中，各组之间无差异。
我们建议将 TV 规则作为 Lenke AIS 分类系统的第三个修正因子。在 Lenke 1 型和 2 型曲线的患者中，将 TV 作为 LIV 选择可在长期随访中获得可接受的 LIV 定位。当融合在 TV 下位进行时，LIV 的位置没有差异，但运动节段较少。融合至上位 TV 的“A”型腰椎修正患者的 LIV 平移更大，这些患者存在长期预后不良的风险。
治疗水平 III。有关证据水平的完整描述，请参见作者说明。
