Department of Neurosurgery, Dongguk University Ilsan Hospital, Ilsan, South Korea.
Department of Neurosurgery, Seoul National University College of Medicine, Seoul, South Korea.
PLoS One. 2020 Feb 25;15(2):e0228628. doi: 10.1371/journal.pone.0228628. eCollection 2020.
We reviewed charts and radiologic studies of 30 patients operated upon by ADR with Mobi-C® in single level since 2006. All patients had healthy cervical facet joints (less than or equal to grade 1 according to grading systems for cervical facet joint degeneration) preoperatively. We assessed clinical outcomes with NDI and VAS on neck and arm over follow-up and also measured ROM at implanted segment on dynamic radiographs during follow-up. The mean follow-up period was 42.4 ± 15.9 months. We then assessed the linearity of changes in ROM at implanted segment through linear mixed model. All patients showed significantly improved clinical outcomes. ROMs at implanted segment were maintained at slightly increased levels until 24 months postoperatively (P = 0.529). However, after 24 months, ROMs at implanted segment decreased significantly until last follow-up (P = 0.001). In addition, the decreasing pattern after 24 months showed a regular regression (P = 0.001). This decline was correlated with decline of extension angle at implanted segment. Based on this regular regression, we estimated that ROMs at implanted segments would be less than 2 degrees at 10.24 years postoperatively. Even though implanted segment maintains its motion for some length of time, we could assume that an artificial disc would have limited life expectancy correlated with the decline of extension angle.
我们回顾了自 2006 年以来，30 例接受 ADR 与 Mobi-C®单节段手术患者的图表和影像学研究。所有患者术前颈椎关节突关节均健康（根据颈椎关节突关节退变分级系统，分级≤1）。我们通过随访时的 NDI 和颈部及手臂 VAS 评估临床结果，并在随访时通过动态 X 线片测量植入节段的 ROM。平均随访时间为 42.4±15.9 个月。然后，我们通过线性混合模型评估植入节段 ROM 变化的线性。所有患者的临床结果均显著改善。植入节段的 ROM 在术后 24 个月内保持略微增加的水平（P=0.529）。然而，24 个月后，植入节段的 ROM 显著下降，直至最后一次随访（P=0.001）。此外，24 个月后的下降模式呈规则回归（P=0.001）。这种下降与植入节段伸展角度的下降相关。基于这种规则回归，我们估计术后 10.24 年，植入节段的 ROM 将小于 2 度。即使植入节段在一定时间内保持运动，我们也可以假设人工椎间盘的预期寿命有限，与伸展角度的下降相关。
