Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, China.
Orthop Surg. 2024 Nov;16(11):2699-2707. doi: 10.1111/os.14182. Epub 2024 Aug 6.
When implanting the Zero-P device, the screws of Zero-P form a bone wedge with a 40 ± 5° cranial and caudal angle (CCA). However, no study has been performed in the optimal CCA of the Zero-P implant. To investigate whether the cranial/caudal angles (CCA) of the screws affect the clinical and radiological outcomes in patients undergoing ACDF with the Zero-P implant.
From January 2016 to December 2023, we retrospectively analyzed 186 patients who underwent 1-level ACDF with the Zero-P device. The patients were divided into four groups: group A (cranial angle ≤40°, caudal angle ≤40°); group B (cranial angle ≤40°, caudal angle >40°); group C (cranial angle >40°, caudal angle ≤40°); and group D (cranial angle >40°, caudal angle >40°). The clinical outcomes, including Japanese Orthopaedic Association (JOA), neck disability index (NDI), and visual analogue scale (VAS) scores, the radiological parameters, including cervical lordosis (CL), cervical lordosis of operated segments (OPCL), intervertebral space height (ISH) and fusion rate (FR), and the complications, were evaluated and compared. Parametric tests, non-parametric tests, and chi-square tests were conducted to analyze the data.
The OPCL of group A was significantly less than that of the other groups at the final follow-up (p < 0.05). The ISH of group D was significantly less than that of group A at the final follow-up (p < 0.05). The subsidence rate of group A was significantly less than that of group D at the final follow-up (p < 0.05). At the final follow-up, the upper adjacent-level degeneration (ASD) of group D was significantly less severe than that of groups A and B (p < 0.05). The clinical outcomes do not differ among groups (p > 0.05).
A larger CCA of the screws (cranial angle >40°, caudal angle >40°) was better for maintaining OPCL and reducing the incidence of ASD. A smaller CCA of the screws (cranial angle ≤40°, caudal angle ≤40°) was better for maintaining ISH and reducing the rate of subsidence.
在植入 Zero-P 装置时，Zero-P 的螺钉形成一个具有 40±5°颅尾角（CCA）的骨楔形。然而，尚未对 Zero-P 植入物的最佳 CCA 进行研究。研究螺钉的颅尾角（CCA）是否会影响使用 Zero-P 植入物行颈椎前路椎体间融合术（ACDF）的患者的临床和影像学结果。
从 2016 年 1 月至 2023 年 12 月，我们回顾性分析了 186 例接受 Zero-P 装置行 1 节段 ACDF 的患者。将患者分为四组：A 组（颅角≤40°，尾角≤40°）；B 组（颅角≤40°，尾角>40°）；C 组（颅角>40°，尾角≤40°）；D 组（颅角>40°，尾角>40°）。评估和比较临床结果，包括日本矫形协会（JOA）评分、颈部残疾指数（NDI）评分和视觉模拟评分（VAS）、影像学参数，包括颈椎前凸（CL）、手术节段颈椎前凸（OPCL）、椎间间隙高度（ISH）和融合率（FR），以及并发症。进行参数检验、非参数检验和卡方检验来分析数据。
在最终随访时，A 组的 OPCL 明显小于其他组（p<0.05）。D 组的 ISH 在最终随访时明显小于 A 组（p<0.05）。A 组的下沉率在最终随访时明显小于 D 组（p<0.05）。在最终随访时，D 组的上邻近节段退变（ASD）明显轻于 A 组和 B 组（p<0.05）。各组之间的临床结果无差异（p>0.05）。
螺钉的较大 CCA（颅角>40°，尾角>40°）有利于维持 OPCL 并降低 ASD 的发生率。螺钉的较小 CCA（颅角≤40°，尾角≤40°）有利于维持 ISH 并降低下沉率。
