Department of Orthopedic Surgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, 153, Gyeongchun-ro, Guri-si 11923, South Korea.
Department of Orthopedic Surgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, 153, Gyeongchun-ro, Guri-si 11923, South Korea.
Spine J. 2018 Aug;18(8):1356-1362. doi: 10.1016/j.spinee.2017.12.006. Epub 2018 Jan 2.
Sagittal translation, a potential complication of pedicle subtraction osteotomy (PSO), can result in neurologic damage. However, few studies have been conducted on sagittal translation and its risk factors after PSO in patients with ankylosing spondylitis (AS).
We aimed to report cases of sagittal translation that developed after PSO in patients with AS with kyphotic deformity and to analyze risk factors for sagittal translation.
A retrospective case-control study was carried out.
This study included 53 patients (58 cases) with AS who underwent PSO to correct their kyphotic deformity.
The modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) was measured before the surgery. Radiological pelvic and sagittal parameters were also measured before and after surgery. Developments of sagittal translation were confirmed with intraoperative radiograph.
The subjects were grouped according to the presence (ST group) and absence (non-ST group) of sagittal translation. The demographic and radiological parameters were compared between two groups. Through multivariate logistic regression analysis, the correlations between sagittal translation and relevant parameters were analyzed for risk factor evaluation.
Sagittal translation developed in 16 patients (30.2%) [16 cases (27.6%)]. The mean lumbar lordosis angle and sagittal vertical axis of both ST group and non-ST group were successfully corrected. In a comparison of two groups, the ST group (58.2±13.3) showed a significantly higher mSASSS than the non-ST group (33.9±11.9) (p<.001). The ST group (50.4°±7.8°, 16.9°±6.8°) also showed a significantly higher preoperative pelvic incidence and sacral slope than the non-ST group (45.3°±7.2°, 11.0°±7.7°) (p=.026, p=.011). No significant differences were observed between the two groups for the rest of radiological parameters. In multivariate analysis, only mSASSS was positively correlated with sagittal translation (odds ratio 1.16, p=.001).
The incidence of sagittal translation after PSO was closely related with severity of ankylosis in patients with AS. Therefore, surgeons must consider sagittal translation, which could induce neurologic complications, when PSO is performed for patients with AS with severe ankylosis.
经椎弓根截骨术（PSO）后矢状面平移是一种潜在的并发症，可导致神经损伤。然而，很少有研究关注强直性脊柱炎（AS）患者 PSO 后矢状面平移及其危险因素。
报告 AS 伴后凸畸形患者行 PSO 后出现矢状面平移的病例，并分析矢状面平移的危险因素。
回顾性病例对照研究。
本研究纳入了 53 例（58 例）接受 PSO 矫正后凸畸形的 AS 患者。
手术前测量改良 Stoke 强直性脊柱炎脊柱评分（mSASSS）。还测量了手术前后骨盆和矢状位参数。术中 X 线片证实了矢状面平移的发展。
根据是否存在（ST 组）和不存在（非 ST 组）矢状面平移对患者进行分组。比较两组患者的人口统计学和影像学参数。通过多变量 logistic 回归分析，分析矢状面平移与相关参数的相关性，以评估危险因素。
16 例（30.2%）患者出现矢状面平移[16 例（27.6%）]。ST 组和非 ST 组的腰椎前凸角和矢状垂直轴均得到成功矫正。与非 ST 组相比，ST 组（58.2±13.3）的 mSASSS 显著更高（p<.001）。ST 组（50.4°±7.8°，16.9°±6.8°）的骨盆入射角和骶骨倾斜角也显著高于非 ST 组（45.3°±7.2°，11.0°±7.7°）（p=.026，p=.011）。两组间其余影像学参数无显著差异。多变量分析显示，只有 mSASSS 与矢状面平移呈正相关（优势比 1.16，p=.001）。
AS 患者 PSO 后矢状面平移的发生率与关节融合的严重程度密切相关。因此，当对严重融合的 AS 患者行 PSO 时，外科医生必须考虑可能导致神经并发症的矢状面平移。
