Department of Orthopedic Surgery, Graduate School, College of Medicine, Kyung Hee University, Seoul, Korea.
PLoS One. 2021 Jul 19;16(7):e0254381. doi: 10.1371/journal.pone.0254381. eCollection 2021.
In this study, we evaluated factors affecting changes in cervical lordosis after deformity correction and during follow-up period in adult spinal deformity (ASD) patients with severe sagittal imbalance.
Seventy-nine patients, with an average age of 71.6 years, who underwent long-segment fixation from T10 to S1 with sacropelvic fixation were included. We performed a comparative analysis of the radiographic parameters after surgery (Post) and at the last follow-up (Last). We calculated the Pearson's correlation coefficient and performed multilinear regression analysis to predict independent parameters for Post and Last cervical lordosis (CL), T1 slope (T1S), and thoracic kyphosis (TK).
Hyperlordotic changes of -23.3° in CL before surgery was reduced to -7° after surgery, and Last CL had increased to -15.3°. T1S was reduced from 27° before surgery to 14.4° after surgery and had increased to 18.8° at the last follow-up. Through multilinear regression analysis, we found that Post CL and T1S were more significantly affected by the amount of LL correction (p = .045 and .049). The effect of Last T1S was significantly associated with the Last CL; the effect of Last TK, with the Last T1S; and the effect of Post PI-LL, with the Last TK (p < .05).
The postoperative kyphotic change in CL in ASD patients with preoperative cervical hyperlordosis is not permanent and is affected by drastic LL correction and SVA restoration. To achieve spinopelvic harmony proportional to the difference in LL relative to PI, TK becomes modified over time to increase T1S and CL, in an effort to achieve optimal spine curvature.
本研究旨在评估严重矢状面失衡的成人脊柱畸形（ASD）患者在畸形矫正后和随访期间颈椎前凸（CL）变化的影响因素。
共纳入 79 例患者，平均年龄 71.6 岁，均行 T10 至 S1 长节段固定并骨盆固定。我们对术后（Post）和末次随访（Last）的影像学参数进行了对比分析。我们计算了 Pearson 相关系数，并进行了多元线性回归分析，以预测 Post 和 Last 颈椎前凸（CL）、T1 斜率（T1S）和胸椎后凸（TK）的独立参数。
术前 CL 由 23.3°的过伸变为术后的-7°，末次随访时 CL 增加至-15.3°。T1S 从术前的 27°减少到术后的 14.4°，末次随访时增加到 18.8°。通过多元线性回归分析，我们发现 Post CL 和 T1S 受 LL 矫正量的影响更为显著（p =.045 和.049）。末次 T1S 的影响与末次 CL 显著相关；末次 TK 的影响与末次 T1S 显著相关；Post PI-LL 的影响与末次 TK 显著相关（p <.05）。
术前颈椎过伸的 ASD 患者术后 CL 的后凸变化并非永久性的，而是受到剧烈的 LL 矫正和 SVA 恢复的影响。为了使脊柱骨盆达到与 LL 相对于 PI 的差异相匹配的比例，TK 会随着时间的推移而发生改变，以增加 T1S 和 CL，从而实现最佳的脊柱曲率。
