Hu Ziang, He Dengwei, Gao Jiawei, Zeng Zhongyou, Jiang Chao, Ni Weiyu, Yik Jasper H N, Zhao Xing, Fan Shunwu
Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
Department of Orthopaedic Surgery, Lishui Hospital; Zhejiang University School of Medicine, Lishui Municipal Central Hospital, Lishui, Zhejiang, China.
Global Spine J. 2023 Jan;13(1):97-103. doi: 10.1177/2192568221992098. Epub 2021 Mar 9.
A retrospective study of prospectively collected radiographic and clinical data.
This study aims to investigate the relationship between endplate morphology parameters and the incidence of cage subsidence in patients with mini-open single-level oblique lateral lumbar interbody fusion (OLIF).
We included 119 inpatients who underwent OLIF from February 2015 to December 2017. A total of 119 patients with single treatment level of OLIF were included. Plain anteroposterior and lateral radiograph were taken preoperatively, postoperatively, and during follow-up. The correlation between disc height, endplate concave angle/depth, cage position and cage subsidence were investigated. Functional rating index (Visual Analogue Scale for pain, and Roland Morris Disability Questionnaire) were employed to assess clinical outcomes.
Cage subsidence was more commonly seen at the superior endplates (42/119, 35.29%) than at the inferior endplates (6/119, 5.04%) (p < 0.01). More importantly, cage subsidence was significantly less in patients with superior endplates that were without concave angle (3/20, 15%) than with concave angle (37/99, 37.37%) (p < 0.05). Cage subsidence correlated negatively with preoperative anterior disc height (r = -0.21, p < 0.05), but positively with disc distraction rate (r = 0.27, p < 0.01). Lastly, the distance of cage to the anterior edges of the vertebral body showed a positive correlation (r = 0.26, p < 0.01).
This study for the first time demonstrated that endplate morphology correlates with cage subsidence after OLIF. Since relatively flat endplates with smaller concave angle significantly diminish the incidence of subsidence, the morphology of cage surface should be taken into consideration when designing the next generation of cage. In addition, precise measurement of the disc height to avoid over-distraction, and more anteriorly placement of the cage is suggested to reduce subsidence.
对前瞻性收集的影像学和临床数据进行回顾性研究。
本研究旨在探讨小切口单节段斜外侧腰椎椎间融合术（OLIF）患者终板形态参数与椎间融合器下沉发生率之间的关系。
纳入2015年2月至2017年12月接受OLIF手术的119例住院患者。共纳入119例单节段OLIF治疗患者。术前、术后及随访期间拍摄正位和侧位X线平片。研究椎间盘高度、终板凹角/深度、椎间融合器位置与椎间融合器下沉之间的相关性。采用功能评分指数（疼痛视觉模拟量表和罗兰·莫里斯残疾问卷）评估临床疗效。
椎间融合器在上终板下沉更为常见（42/119，35.29%），而下终板下沉较少（6/119，5.04%）（p<0.01）。更重要的是，上终板无凹角的患者椎间融合器下沉明显少于有凹角的患者（3/20，15%对比37/99，37.37%）（p<0.05）。椎间融合器下沉与术前椎间盘前高度呈负相关（r=-0.21，p<0.05），但与椎间盘撑开率呈正相关（r=0.27，p<0.01）。最后，椎间融合器至椎体前缘的距离呈正相关（r=0.26，p<0.01）。
本研究首次表明终板形态与OLIF术后椎间融合器下沉相关。由于相对平坦且凹角较小的终板可显著降低下沉发生率，因此在设计下一代椎间融合器时应考虑其表面形态。此外，建议精确测量椎间盘高度以避免过度撑开，并将椎间融合器更靠前放置以减少下沉。
