Zhao Yiwei, Du You, Yang Yang, Zhang Haoran, Li Chenkai, Sun Dihan, Li Ziquan, Zhang Jianguo, Wang Shengru
Department of Orthopedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
Clin Orthop Relat Res. 2025 Mar 21. doi: 10.1097/CORR.0000000000003448.
Abnormal cervical sagittal alignment (CSA), typically cervical kyphosis, is more common in patients with adolescent idiopathic scoliosis (AIS) than in teenagers without AIS. Changes in CSA after posterior spinal fusion for AIS have been observed and may be associated with patient-reported clinical outcomes and age-related cervical disc degeneration. Previous studies have shown inconsistent postoperative reciprocal changes in CSA in patients with single structural thoracolumbar/lumbar (TL/L) AIS (Lenke 5C classification). However, little is known about the medium-term reciprocal changes in CSA after selective posterior TL/L fusion surgery.
QUESTIONS/PURPOSES: We sought to determine the following: (1) What proportion of patients with Lenke 5C AIS have abnormal CSA before surgery? (2) What were the changes in CSA after selective posterior TL/L fusion surgery in the overall Lenke 5C AIS cohort and in subgroups classified by thoracic kyphosis? (3) What global sagittal parameters were associated with CSA preoperatively and at the latest follow-up? (4) What is the correlation between CSA and Scoliosis Research Society Outcomes Questionnaire (SRS-22) scores?
We queried our institutional database and identified 186 patients diagnosed with Lenke 5C AIS who underwent selective posterior TL/L fusion surgery from April 2010 to February 2018. Of these, 13% (25) of patients were lost to follow-up before 5 years, and 8% (15) of patients were excluded based on exclusion criteria, leaving 79% (146) of patients for analysis in this retrospective study. During this period, we typically offered selective posterior TL/L fusion surgery to patients with Lenke 5C AIS when the main TL/L Cobb angle exceeded 35°. All patients who were offered surgery for this diagnosis opted to have the procedure. Briefly, the surgical procedure consisted of pedicle screw insertion, multiple-level Ponte osteotomy, and segmental direct vertebral body derotation to correct the deformity. Ninety percent (132 of 146) of the patients were female, with a mean ± SD age of 15 ± 2 years. The mean follow-up time was 7 ± 1 years. All patients had a single structural TL/L curve, with a mean preoperative main TL/L Cobb angle of 43° ± 9°. Radiologic measurements included coronal deformity parameters, cervical sagittal parameters, and global sagittal parameters. SRS-22 scores were used to evaluate clinical outcomes. The preoperative cervical sagittal parameters were analyzed to assess the abnormal CSA proportion. Cervical sagittal parameters were compared preoperatively, postoperatively, and at the latest final follow-up. Based on the degree of thoracic kyphosis, patients were classified into a hypokyphotic group (thoracic kyphosis < 20°) and a normokyphotic group (thoracic kyphosis ≥ 20°), with further comparison of CSA within subgroups. Multiple linear regression analysis was performed to assess the correlation between CSA and global sagittal parameters. Finally, the SRS-22 scores at the latest follow-up were compared between cervical lordosis (defined as CSA > 0°) and cervical kyphosis (defined as CSA < 0°).
Fifty-eight percent (84 of 146) of patients with Lenke 5C AIS had cervical kyphosis before surgery. After selective posterior TL/L fusion surgery, we observed an increase in cervical lordosis (from 5° ± 13° before surgery to 2° ± 12°, mean difference 4° [95% confidence interval (CI) 2° to 5°]; p < 0.001), thoracic kyphosis (from 19° ± 9° before surgery to 28° ± 10°, mean difference -9° [95% CI -11° to -8°]; p < 0.001), and lumbar lordosis (from -48° ± 11° before surgery to -51° ± 14°, mean difference 3° [95% CI 1° to 6°]; p = 0.005) at 5 years of follow-up. Subgroup analysis revealed an increase in CSA in the hypokyphotic group, while no increase was observed in the normokyphotic group. At the preoperative stage, after controlling for potentially confounding variables such as the C2-7 sagittal vertical axis and lumbar lordosis, a correlation was observed between thoracic kyphosis (β = -1.27 [95% CI -1.50 to -1.03]; p < 0.001) and the preoperative CSA. At the latest follow-up, after controlling for potentially confounding variables such as thoracic kyphosis, a correlation was observed between global thoracic kyphosis (β = -0.46 [95% CI -0.85 to -0.08]; p = 0.02) and the follow-up CSA. When we compared patients with cervical kyphosis at the most recent follow-up to those with cervical lordosis, we found no between-group differences in SRS-22 scores between those groups.
In light of our findings, surgeons should pay particular attention to preoperative CSA in these patients. For patients with cervical kyphosis and cervical discomfort, if there is concurrent reduction in thoracic kyphosis, it can be communicated that both CSA and thoracic kyphosis are likely to improve postoperatively. Future studies should use more specific outcome measures to assess the correlation between CSA changes and patient-reported clinical outcomes.
Level III, therapeutic study.
颈椎矢状面排列异常（CSA），典型的是颈椎后凸，在青少年特发性脊柱侧凸（AIS）患者中比在无AIS的青少年中更常见。已观察到AIS患者后路脊柱融合术后CSA的变化，且可能与患者报告的临床结果及年龄相关的颈椎间盘退变有关。先前的研究表明，单一结构性胸腰段/腰段（TL/L）AIS（Lenke 5C分类）患者术后CSA的相互变化不一致。然而，对于选择性后路TL/L融合手术后CSA的中期相互变化知之甚少。
问题/目的：我们试图确定以下几点：（1）Lenke 5C型AIS患者术前CSA异常的比例是多少？（2）在整个Lenke 5C型AIS队列以及按胸椎后凸分类的亚组中，选择性后路TL/L融合手术后CSA有哪些变化？（3）术前及最新随访时，哪些整体矢状面参数与CSA相关？（4）CSA与脊柱侧凸研究学会结局问卷（SRS-22）评分之间的相关性如何？
我们查询了机构数据库，并确定了186例2010年4月至2018年2月期间接受选择性后路TL/L融合手术的Lenke 5C型AIS患者。其中，13%（25例）患者在5年之前失访，8%（15例）患者根据排除标准被排除，在这项回顾性研究中留下79%（146例）患者进行分析。在此期间，当主要TL/L Cobb角超过35°时，我们通常为Lenke 5C型AIS患者提供选择性后路TL/L融合手术。所有因该诊断而接受手术的患者均选择进行该手术。简而言之，手术过程包括椎弓根螺钉置入、多级Ponte截骨术以及节段性直接椎体去旋转以纠正畸形。90%（146例中的132例）患者为女性，平均年龄±标准差为15±2岁。平均随访时间为7±1年。所有患者均有单一结构性TL/L曲线，术前主要TL/L Cobb角平均为43°±9°。放射学测量包括冠状面畸形参数、颈椎矢状面参数和整体矢状面参数。SRS-22评分用于评估临床结果。分析术前颈椎矢状面参数以评估CSA异常比例。比较术前、术后及最新最终随访时的颈椎矢状面参数。根据胸椎后凸程度，将患者分为低后凸组（胸椎后凸<20°）和正常后凸组（胸椎后凸≥20°），并进一步比较亚组内的CSA。进行多元线性回归分析以评估CSA与整体矢状面参数之间的相关性。最后，比较最新随访时颈椎前凸（定义为CSA>0°）和颈椎后凸（定义为CSA<0°）患者的SRS-22评分。
Lenke 5C型AIS患者中58%（146例中的84例）术前存在颈椎后凸。选择性后路TL/L融合手术后，我们观察到在5年随访时颈椎前凸增加（从术前的5°±13°增加到2°±12°，平均差值4°[95%置信区间（CI）2°至5°]；p<0.001），胸椎后凸增加（从术前的19°±9°增加到28°±10°，平均差值-9°[95%CI -11°至-8°]；p<0.001），腰椎前凸增加（从术前的-48°±11°增加到-51°±14°，平均差值3°[95%CI 1°至6°]；p = 0.005）。亚组分析显示低后凸组CSA增加，而正常后凸组未观察到增加。在术前阶段，在控制了如C2-7矢状垂直轴和腰椎前凸等潜在混杂变量后，观察到胸椎后凸（β=-1.27[95%CI -1.50至-1.03]；p<0.001）与术前CSA之间存在相关性。在最新随访时，在控制了如胸椎后凸等潜在混杂变量后，观察到整体胸椎后凸（β=-0.46[95%CI -0.85至-0.08]；p = 0.02）与随访时的CSA之间存在相关性。当我们将最新随访时颈椎后凸的患者与颈椎前凸的患者进行比较时，我们发现两组之间SRS-22评分无组间差异。
根据我们的研究结果，外科医生应特别关注这些患者的术前CSA。对于有颈椎后凸和颈部不适的患者，如果同时存在胸椎后凸减小，可以告知其CSA和胸椎后凸术后都可能改善。未来的研究应使用更具体的结局指标来评估CSA变化与患者报告的临床结果之间的相关性。
III级，治疗性研究。
