BACKGROUND CONTEXT

A previous study found that the cross-sectional area (CSA) of the preoperative cervical paraspinal extensors (CPEs) was associated with loss of cervical lordosis after laminoplasty, while a recent study found that CPE asymmetry was associated with symptoms of degenerative cervical myelopathy. Whether preoperative CPE asymmetry can predict cervical sagittal deformity (CSD) after laminoplasty is unknown.

PURPOSE

To assess whether asymmetry, degree of degeneration, and extension function of the CPE can be used as predictors of postoperative CSD in patients who undergo laminoplasty.

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

From January 2017 to December 2019, 55 patients with multilevel cord compression and myelopathic symptoms were enrolled.

OUTCOME MEASURES

The visual analog scale (VAS), neck disability index (NDI), and modified Japanese Orthopedic Association (mJOA) were used to assess cervical spinal function and quality of life.

METHODS

From January 2017 to December 2019, 55 patients undergoing modified laminoplasty were included. The following parameters were measured preoperatively and 24 months postoperatively on X-ray: (1) C0–C2 Cobb angle; (2) C2–C7 Cobb angle (CL); (3) T1 slope (T1S); (5) C2–C7 sagittal vertical axis (SVA); (6) T1S minus CL; (7) Preoperative extension function: Extension CL minus Neutral CL (EF). Preoperative global alignment parameters: (8) spino cranial angle, (9) C7-S1 sagittal vertical axis (C7 SVA), (10) pelvic incidence, (11) lumbar lordosis, (12) thoracic kyphosis. (13) Preoperative CPE parameters: Summation of bilateral total cross-sectional area (STCSA), summation of bilateral total cross-sectional area ratio (STCSAR), total cross-sectional area asymmetry, summation of bilateral functional cross-sectional area of muscle (SFCSA), summation of bilateral functional cross-sectional area of muscle ratio (FCSAR), and functional cross-sectional area of muscle asymmetry (FCSAA). The VAS, mJOA, and NDI were used to evaluate cervical spine function and quality of life. Patients were divided into the CSD group and the non-deformed group (N-CSD) group postoperatively, and the parameters between the two groups were compared. The Pearson correlation coefficient was used to evaluate the relationship between the parameters, and multiple regression analysis and ROC curve analysis were used to determine the predictors and key values.

RESULTS

Compared with functional scores, mJOA in the CSD group was significantly lower than that in the N-CSD group, while NDI and VAS were significantly higher. Postoperative CL was significantly correlated with EF, SFCSA/STCSA (C3–C6), SFCSAR (C4 and C6), STCSAR (C6), and FSCAA (C6). T1S minus CL was significantly correlated with EF, SFCSA/STCSA (C3–4 and C6), SFCSAR (C4 and C6), STCSAR (C6) and FSCAA (C6). C2–7 SVA was significantly correlated with EF, SFCSAR (C4 and C6), STCSAR (C6), and FSCAA (C6). Multiple regression analysis showed that FCSAA (C6), SFCSAR (C6), SFCSAR (C4), and EF were significant predictors of postoperative CSD. ROC curve analysis showed that the optimal cutoff points were 18.405, 2.95, 4.47, and 11.96.

CONCLUSIONS

The present study found that preoperative extension dysfunction of CPEs, asymmetry at the C6 level cervical extensors, and cervical extensor CSAs without fatty infiltration at the C4 and C6 levels were associated with cervical sagittal imbalance after modified laminoplasty. These factors can be considered when future spine surgeons formulate surgical plans.

中文翻译：

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术前颈椎椎旁伸肌的不对称性和伸展功能能否预测接受改良椎板成形术的患者术后颈椎矢状面畸形？

背景语境

之前的一项研究发现，术前颈椎椎旁伸肌 (CPE) 的横截面积 (CSA) 与椎板成形术后颈椎前凸的消失有关，而最近的一项研究发现 CPE 不对称与退行性脊髓型颈椎病的症状有关。术前 CPE 不对称是否可以预测椎板成形术后颈椎矢状面畸形 (CSD) 尚不清楚。

目的

评估 CPE 的不对称性、退化程度和伸展功能是否可用作接受椎管扩大成形术患者术后 CSD 的预测指标。

学习规划

一项回顾性研究。

患者样本

从 2017 年 1 月到 2019 年 12 月，55 名多节段脊髓受压和脊髓病症状的患者入组。

结果测量

使用视觉模拟量表 (VAS)、颈部残疾指数 (NDI) 和改良的日本骨科协会 (mJOA) 评估颈椎功能和生活质量。

方法

从 2017 年 1 月到 2019 年 12 月，55 名接受改良椎板成形术的患者被纳入。术前和术后 24 个月在 X 射线上测量了以下参数：（1）C0-C2 Cobb 角；(2) C2–C7 Cobb 角 (CL)；(3) T1斜率(T1S)；(5) C2–C7 矢状垂直轴 (SVA)；(6) T1S减去CL；(7)术前延伸函数：延伸CL减去中性CL(EF)。术前整体对齐参数：(8) 脊柱颅角，(9) C7-S1 矢状垂直轴 (C7 SVA)，(10) 骨盆入射角，(11) 腰椎前凸，(12) 胸椎后凸. (13)术前CPE参数：双侧总横截面积总和(STCSA)、双侧总横截面积比总和(STCSAR)、总横截面积不对称性、双侧肌肉功能横截面积总和( SFCSA)、双侧肌肉功能横截面积之和 (FCSAR) 和肌肉不对称功能横截面积 (FCSAA)。VAS、mJOA 和 NDI 用于评估颈椎功能和生活质量。术后将患者分为CSD组和非畸形组（N-CSD），比较两组间的参数。Pearson相关系数用于评估参数之间的关系，

结果

与功能评分相比，CSD组的mJOA明显低于N-CSD组，而NDI和VAS明显高于N-CSD组。术后 CL 与 EF、SFCSA/STCSA (C3–C6)、SFCSAR（C4 和 C6）、STCSAR (C6) 和 FSCAA (C6) 显着相关。T1S 减去 CL 与 EF、SFCSA/STCSA（C3-4 和 C6）、SFCSAR（C4 和 C6）、STCSAR（C6）和 FSCAA（C6）显着相关。C2–7 SVA 与 EF、SFCSAR（C4 和 C6）、STCSAR (C6) 和 FSCAA (C6) 显着相关。多元回归分析表明，FCSAA (C6)、SFCSAR (C6)、SFCSAR (C4) 和 EF 是术后 CSD 的重要预测因子。ROC曲线分析显示最佳截断点分别为18.405、2.95、4.47和11.96。

结论

本研究发现，CPE 术前伸展功能障碍、C6 水平颈伸肌不对称以及 C4 和 C6 水平无脂肪浸润的颈椎伸肌 CSA 与改良椎板成形术后颈椎矢状面失衡有关。未来的脊柱外科医生在制定手术计划时，可以考虑这些因素。