Division of Orthopaedics, Hospital for Sick Children, Toronto, Ontario, Canada.
Division of Orthopaedic Surgery, Toronto Western Hospital, Toronto, Canada.
Spine (Phila Pa 1976). 2020 Nov 1;45(21):E1416-E1420. doi: 10.1097/BRS.0000000000003616.
Retrospective study.
To identify on early postoperative radiographs the risk factors for late distal decompensation in adolescent idiopathic scoliosis (AIS) patients undergoing posterior fusion surgery to L3.
Sparing distal fusion levels in AIS surgery is considered beneficial for postoperative mobility and outcomes; nonetheless, late distal decompensation is of concern. L3 is often advocated as lower instrumented vertebra in posterior fusion, but progressive angulation of the L3/4 disc is commonly observed.
A retrospective analysis was conducted on 78 AIS patients who underwent posterior fusion to L3 from 2007 to 2014. Patients' demographic data, early and 2-year postoperative standing radiographs by biplanar imaging system were investigated. Late decompensation was defined as progressive increase of L3-4 disc wedging angle at 2-year follow-up. Coronal, sagittal, and rotational radiographic parameters were compared between those with and without decompensation. SRS-30 scores were reviewed.
Mean age was 14.5-year, and fusion levels averaged 12.0 (range: 6-15); 43 out of 78 patients (55%) experienced progressive L3-4 disc wedging, with 6 showing wedging >5°. L3 translation from the central sacral vertical line (13.9 vs. 11.1 mm, P = 0.13) and increased pelvic tilt (13.3° vs. 8.6°, P = 0.06) on the early postoperative radiograph were associated with increased L3-4 disc wedging. Multivariate analysis revealed that larger pelvic tilt was a significant risk factor for decompensation (odds ratio = 1.1 per 1°, 95% confidence interval: 1.0-1.1, P = 0.04). SRS-30 scores did not differ significantly between the two groups (4.0 vs. 4.1, P = 0.44).
Pelvic retroversion and increased translation of L3 from the central sacral line on the early postoperative radiograph were associated with late L3-4 disc wedging in AIS fusions to L3. Careful surgical planning and correction of sagittal alignment are imperative to ensure the long-term outcomes.
回顾性研究。
在青少年特发性脊柱侧凸（AIS）患者接受后路融合至 L3 的术后早期 X 光片上，确定导致晚期远端失代偿的危险因素。
在 AIS 手术中保留远端融合节段被认为有利于术后活动度和结果；然而，晚期远端失代偿是值得关注的问题。L3 通常被认为是后路融合的下位器械椎体，但 L3/4 椎间盘的渐进性成角是常见的。
对 2007 年至 2014 年间接受后路融合至 L3 的 78 例 AIS 患者进行回顾性分析。研究患者的人口统计学数据、术后早期和 2 年站立位 X 光片（通过双平面成像系统）。晚期失代偿定义为 2 年随访时 L3-4 椎间盘楔形角进行性增加。比较有和无失代偿的患者之间的冠状位、矢状位和旋转影像学参数。审查 SRS-30 评分。
平均年龄为 14.5 岁，融合节段平均为 12.0（范围：6-15）；78 例患者中有 43 例（55%）出现 L3-4 椎间盘楔形角进行性增加，其中 6 例楔形角增加>5°。术后早期 X 光片上 L3 相对于骶骨正中垂直线的平移（13.9 毫米对 11.1 毫米，P=0.13）和骨盆倾斜度增加（13.3°对 8.6°，P=0.06）与 L3-4 椎间盘楔形角增加相关。多变量分析显示，骨盆倾斜度较大是失代偿的显著危险因素（每增加 1°，比值比为 1.1，95%置信区间：1.0-1.1，P=0.04）。两组间 SRS-30 评分无显著差异（4.0 对 4.1，P=0.44）。
术后早期 X 光片上骨盆后倾和 L3 相对于骶骨正中垂直线的平移增加与 AIS 融合至 L3 的 L3-4 椎间盘楔形角晚期增加有关。仔细的手术计划和矢状位矫正对于确保长期结果至关重要。
4 级。
