Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.
Department of Operation Room, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.
Clin Neurol Neurosurg. 2020 Nov;198:106247. doi: 10.1016/j.clineuro.2020.106247. Epub 2020 Sep 23.
The performance of cervical disc arthroplasty (CDA) in the spine with malalignment was unclear. The purpose of the study was to report the clinical and radiological outcomes of single-level CDA in the patients with preoperative reversible kyphosis (RK) and compare these results with a matched cohort of preoperative lordosis.
From 2014 to 2018, 36 patients with preoperative RK were matched with 229 patients with preoperative lordosis. The Japanese Orthopedic Association score, Neck Disability Index, Visual Analog Scale were used to evaluate clinical outcomes. Radiological evaluations included range of motion (ROM), C2-7 Cobb angle, shell angle (SA) at surgical level, functional spinal unit (FSU) angle and heterotopic ossification (HO).
The mean follow-up was 40.1 months. Both groups achieved significant improvements in clinical outcomes without significant intergroup differences. Before surgery, lordosis group had significantly greater C2-7 angle (9.5° vs -8.4°), SA (1.6° vs -3.7°), and FSU (2.9° vs -3.7°). After surgery, RK group experienced significant improvements in C2-7 angle and SA compared with preoperative data. In lordosis group, C2-7 angle, SA, and FSU were maintained. At the last follow-up, the intergroup difference of C2-7 angle, SA, and FSU remained significant. ROMs were preserved in both groups. The ROM of RK group was slightly lower than that of lordosis group but failing to reach a significance. Eleven patients in lordosis group and 21 patients in RK group developed HO (P = 0.127). There was a significant greater incidence of high-grade HO (grade Ⅲ, Ⅳ) in RK group (33.3 % vs 11.1 %, P = 0.034).
Both groups achieved satisfactory and comparable clinical outcomes after CDA. Despite the remarkable improvements compared with preoperative values, the cervical alignment of RK group was still significantly inferior to that of lordosis group. More HO formation occurred in RK group. Based on these results, we did not recommend CDA to the patients with preoperative RK.
颈椎间盘置换术（CDA）在脊柱失稳患者中的应用效果尚不明确。本研究旨在报告颈椎失稳患者行单节段 CDA 的临床和影像学结果，并与术前存在前凸的患者进行对比。
2014 年至 2018 年，36 例术前颈椎后凸的患者与 229 例术前存在前凸的患者相匹配。采用日本矫形协会评分（JOA）、颈椎残障指数（NDI）和视觉模拟评分（VAS）评估临床结果。影像学评估包括活动度（ROM）、C2-7 角、手术节段壳角（SA）、功能单位角（FSU）和异位骨化（HO）。
平均随访时间为 40.1 个月。两组患者的临床结果均有显著改善，但组间无显著差异。术前，前凸组 C2-7 角（9.5°对-8.4°）、SA（1.6°对-3.7°）和 FSU（2.9°对-3.7°）均明显更大。术后，后凸组 C2-7 角和 SA 较术前均有显著改善。前凸组 C2-7 角、SA 和 FSU 保持不变。末次随访时，两组间 C2-7 角、SA 和 FSU 仍有显著差异。两组 ROM 均保持良好。后凸组 ROM 略低于前凸组，但差异无统计学意义。前凸组 11 例和后凸组 21 例发生 HO（P=0.127）。后凸组发生高级别 HO（Ⅲ级、Ⅳ级）的比例明显更高（33.3%对 11.1%，P=0.034）。
CDA 后两组患者均取得了满意且相当的临床效果。尽管与术前相比有显著改善，但后凸组颈椎的排列仍明显劣于前凸组。后凸组 HO 形成更多。基于这些结果，我们不建议颈椎失稳患者行 CDA。
