Department of Orthopaedic Surgery and Orthopaedic Research Institute, West China Hospital, Sichuan University, Chengdu, China.
Department of Spine Surgery, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
Orthop Surg. 2023 Dec;15(12):3263-3271. doi: 10.1111/os.13882. Epub 2023 Sep 28.
Cage subsidence (CS) has been reported to be one of the most common complications following oblique lumbar interbody fusion (OLIF). To reduce the incidence of CS and improve intervertebral fusion rates, anterolateral fixation (AF) has been gradually proposed. However, the incidence of CS in patients with oblique lumbar interbody fusion combined with anterolateral fixation (OLIF-AF) is still controversial. Additionally, there is a lack of consensus regarding the optimal placement of screws for OLIF-AF, and the impact of screw placement on the incidence of CS has yet to be thoroughly investigated and validated. The objective of this investigation was to examine the correlation between screw placements and CS and to establish an optimized approach for implantation in OLIF-AF.
A retrospective cohort study was undertaken. From October 2017 to December 2020, a total of 103 patients who received L4/5 OLIF-AF for lumbar spinal stenosis or spondylolisthesis or degenerative instability in our department were followed up for more than 12 months. Demographic and radiographic data of these patients were collected. Additionally, screw placement related parameters, including trajectory and position, were measured by anterior-posterior X-ray and axial CT. Analysis was done by chi-square, independent t-test, univariable and multivariable binary logistic regression to explore the correlation between screw placements and CS. Finally, the receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of screw placement-related parameters.
A total of 103 patients were included, and CS was found in 28 (27.18%) patients. Univariable analysis was firstly performed for each parameter. Next, variables with p-value of <0.05, including bone mineral density (BMD), concave morphology, and screw placement-related parameters were included in the multivariate logistic regression analysis. Significant predictor factors for subsidence were coronal plane angle (CPA) (OR 0.580 ± 0.208, 95% CI 1.187-2.684), implantation point (IP) (L4) (OR 5.732 ± 2.737, 95% CI 1.445-12.166), and IP (L5) (OR 7.160 ± 3.480, 95% CI 1.405-28.683). Furthermore, ROC curves showed that the predictive accuracy of CS was 88.1% for CPA, 77.6% for IP (L4) and 80.9% for IP (L5).
We demonstrate that the trajectory of vertebral screws, including angle and position, was closely related to CS. Inserting screws parallel to each other and as close to the endplate as possible while keeping the cage inside the range of the superior and inferior screws are an optimal implantation strategy for OLIF-AF.
cage 沉降（CS）是腰椎斜外侧融合术（OLIF）后最常见的并发症之一。为了降低 CS 的发生率和提高椎间融合率，已经逐渐提出了前外侧固定（AF）。然而，OLIF-AF 患者 CS 的发生率仍存在争议。此外，对于 OLIF-AF 的最佳螺钉放置位置尚无共识，并且螺钉放置对 CS 发生率的影响尚未得到充分研究和验证。本研究的目的是探讨螺钉放置与 CS 的相关性，并确定 OLIF-AF 中植入的优化方法。
本研究为回顾性队列研究。2017 年 10 月至 2020 年 12 月，我科共对 103 例腰椎管狭窄症、腰椎滑脱症或退行性不稳定患者行 L4/5 OLIF-AF 治疗，随访时间超过 12 个月。收集这些患者的人口统计学和影像学数据。此外，通过前后位 X 线和轴向 CT 测量螺钉放置相关参数，包括轨迹和位置。采用卡方检验、独立 t 检验、单变量和多变量二项逻辑回归分析探讨螺钉放置与 CS 的相关性。最后，采用受试者工作特征（ROC）曲线分析评估螺钉放置相关参数的预测能力。
共纳入 103 例患者，其中 28 例（27.18%）发生 CS。首先对每个参数进行单变量分析。接下来，将 p 值<0.05 的变量，包括骨密度（BMD）、凹面形态和螺钉放置相关参数纳入多变量逻辑回归分析。CS 的显著预测因素为冠状面角度（CPA）（OR 0.580±0.208，95%CI 1.187-2.684）、植入点（IP）（L4）（OR 5.732±2.737，95%CI 1.445-12.166）和 IP（L5）（OR 7.160±3.480，95%CI 1.405-28.683）。此外，ROC 曲线显示 CPA 对 CS 的预测准确率为 88.1%，IP（L4）为 77.6%，IP（L5）为 80.9%。
我们证明了椎体螺钉的轨迹，包括角度和位置，与 CS 密切相关。在保持 cage 在上下螺钉范围内的同时，使螺钉彼此平行并尽可能靠近终板插入，这是 OLIF-AF 的最佳植入策略。
