Lee Choon Sung, Ha Jung-Ki, Kim Dae Geun, Kim Hyoungmin, Hwang Chang Ju, Lee Dong-Ho, Cho Jae Hwan
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 388-1, PungNap-2-dong, SongPa-gu, Seoul, Korea.
Department of Orthopedic Surgery, Seoul National University Hospital, Seoul National University and College of Medicine, 28-21, Yongon-dong, Jongno-gu, Seoul, Korea.
Spine J. 2015 May 1;15(5):834-40. doi: 10.1016/j.spinee.2015.01.023. Epub 2015 Jan 20.
The phenomenon of sacral slanting has not been assessed in patients with adolescent idiopathic scoliosis (AIS). It could be important in determining distal fusion level.
The purpose of this study is to clarify sacral slanting and to reveal frequency, character, and clinical importance of sacral slanting in AIS patients who underwent surgery.
STUDY DESIGN/SETTING: Retrospective review of radiographs.
The study included 389 patients who underwent surgery for AIS at a single center.
Slanted angles of sacrum, distal curve types, and postoperative decompensation were assessed in whole spine anteroposterior radiographs.
This was a retrospective case series, which included 389 AIS patients who underwent corrective surgeries. The degree of sacral slanting was defined as the angle between the horizontal line and the upper end plate of the sacrum. Distal curves were classified according to the direction of L4 tilt (L4-left type and L4-right type). The frequency, direction, and relationship with curve types were analyzed descriptively. Postoperative changes of sacral slanting were compared by paired t test. Decompensation by distal fusion level and distal curve types was analyzed descriptively. The p value of less than .05 was considered as statistically significant.
The frequency of sacral slanting was 19.5% (76 of 389), 29.6% (115 of 389), and 40.6% (158 of 389) by using criteria of 5°, 4°, and 3°, respectively. The 86.7% showed sacral slanting on the left side. The combination of L4-left type with left-sided sacral slanting was the most frequent (124 of 158, 78.7%). Slanted angles were decreased in some cases after surgery. Decompensation in the coronal plane was observed in 2 of 22 patients (9.1%) with a distal fusion level of L4 but in none of the 70 patients with a distal fusion level of L3.
Sacral slanting in patients with AIS is a unique and frequently observed finding that has never been researched to date. Most importantly, sacral slanting is a critical consideration in selecting distal fusion level when planning corrective surgery in patients with AIS.
青少年特发性脊柱侧凸（AIS）患者的骶骨倾斜现象尚未得到评估。这在确定远端融合水平方面可能很重要。
本研究的目的是阐明骶骨倾斜情况，并揭示接受手术的AIS患者中骶骨倾斜的频率、特征和临床重要性。
研究设计/地点：对X线片进行回顾性研究。
该研究纳入了在单一中心接受AIS手术的389例患者。
在全脊柱前后位X线片上评估骶骨倾斜角度、远端曲线类型和术后失代偿情况。
这是一项回顾性病例系列研究，纳入了389例接受矫正手术的AIS患者。骶骨倾斜程度定义为水平线与骶骨上端板之间的角度。远端曲线根据L4倾斜方向分类（L4左侧型和L4右侧型）。对频率、方向以及与曲线类型的关系进行描述性分析。通过配对t检验比较骶骨倾斜的术后变化。对远端融合水平和远端曲线类型导致的失代偿情况进行描述性分析。p值小于0.05被认为具有统计学意义。
分别采用5°、4°和3°的标准时，骶骨倾斜的频率分别为19.5%（389例中的76例）、29.6%（389例中的115例）和40.6%（389例中的158例）。86.7%的患者骶骨向左侧倾斜。L4左侧型与左侧骶骨倾斜的组合最为常见（158例中的124例，78.7%）。部分病例术后倾斜角度减小。在远端融合水平为L4的22例患者中有2例（9.1%）出现冠状面失代偿，而在远端融合水平为L3的70例患者中未观察到失代偿情况。
AIS患者的骶骨倾斜是一种独特且常见的发现，迄今为止从未被研究过。最重要的是，在为AIS患者规划矫正手术时，骶骨倾斜是选择远端融合水平的关键考虑因素。
