Department of Spine Surgery, Shanghai East Hospital, Tongji University School of Medicine, 150 Jimo Rd., Shanghai, 200120, China.
J Orthop Surg Res. 2022 Nov 16;17(1):486. doi: 10.1186/s13018-022-03383-z.
Numerous complications of lumbar fusion surgery have been reported, with adjacent segment disease (ASD) being one of the most important. Few studies describe the effect of sagittal, horizontal screw angles and distance of pedicle screw apex to superior endplate on the incidence of ASD in lumbar spine. The purpose of this retrospective study is to evaluate the hypothesis that unsatisfactory pedicle screw insertion positions would increase the likelihood of ASD.
Outpatients with lumbar spinal stenosis underwent posterolateral lumbar fusion at L4-S1 with a least 2-year follow-up were studied. ASD at L3-L4 was defined as a condition in which intervertebral disk narrowing, posterior vertebral opening, and vertebral slippage progress at the last follow-up in comparison with the postoperative. Independent t test was performed to compare data between two groups; Spearman analysis was performed to analyze the relationship between two continuous variables. Multivariate binary logistic models were performed to identify the independent risk factors of ASD. The receiver operating characteristic (ROC) curve was performed to measure model discrimination and Hosmer-Lemeshow (H-L) test was used to measure calibration. ROC curve evaluated the discrimination ability of sagittal screw angle and distance in predicting incidence of ASD.
Patients in ASD group exhibit higher incidence of osteoporosis, higher Visual analogue scale (VAS), Oswestry disability index (ODI), bigger sagittal screw angle, shorter distance of pedicle screw apex to superior endplate than those in non-ASD group (p < 0.05). VAS, ODI at the last follow-up were positively correlated with Pfirrmann grade of L3-4 disk and sagittal screw angle, while negatively correlated with distance of screw apex to superior endplate (p < 0.05). Multivariate binary logistic model indicated that follow-up time (odds ratio [OR] 1.637, 95% confidence interval [CI] 1.186-2.260), distance of screw apex to superior endplate (OR 0.150, 95% CI 0.067-0.336), sagittal screw angle (OR 2.404, 95% CI 1.608-3.594) were statistically significant. The models showed great discrimination and calibration. The area under the curve of ASD identified by sagittal angle and distance was 0.895 and the cut-off values were 5.500° and 6.250 mm, respectively.
Sagittal screw angle and distance of screw apex to superior endplate were significantly associated with the risk of ASD.
腰椎融合手术后有许多并发症，其中之一是邻近节段疾病（ASD）。很少有研究描述矢状面、水平螺钉角度和椎弓根螺钉顶点到上终板的距离对腰椎 ASD 发生率的影响。本回顾性研究的目的是评估不满意的椎弓根螺钉插入位置会增加 ASD 发生可能性的假设。
研究了接受 L4-S1 后路腰椎侧融合术的腰椎管狭窄症门诊患者，随访时间至少 2 年。ASD 在 L3-L4 的定义为在最后一次随访时与术后相比，椎间盘狭窄、后椎体开口和椎体滑脱进展的情况。采用独立 t 检验比较两组数据；采用 Spearman 分析分析两个连续变量之间的关系。采用多变量二项逻辑模型确定 ASD 的独立危险因素。采用受试者工作特征（ROC）曲线评价矢状面螺钉角度和距离预测 ASD 发生率的鉴别能力，采用 Hosmer-Lemeshow（H-L）检验评价校准。
ASD 组患者的骨质疏松症发生率、视觉模拟量表（VAS）评分、Oswestry 功能障碍指数（ODI）、矢状面螺钉角度较大、椎弓根螺钉顶点到上终板的距离较短（p<0.05）。最后随访时的 VAS、ODI 与 L3-4 椎间盘的 Pfirrmann 分级和矢状面螺钉角度呈正相关，与螺钉顶点到上终板的距离呈负相关（p<0.05）。多变量二项逻辑模型表明，随访时间（比值比[OR]1.637，95%置信区间[CI]1.186-2.260）、螺钉顶点到上终板的距离（OR 0.150，95%CI 0.067-0.336）、矢状面螺钉角度（OR 2.404，95%CI 1.608-3.594）有统计学意义。模型显示出很好的鉴别力和校准度。由矢状角和距离确定的 ASD 的曲线下面积为 0.895，截距值分别为 5.500°和 6.250mm。
矢状面螺钉角度和螺钉顶点到上终板的距离与 ASD 的风险显著相关。
