Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
World Neurosurg. 2021 Jun;150:e155-e161. doi: 10.1016/j.wneu.2021.02.117. Epub 2021 Mar 5.
Although pedicle screw sizes may affect the rate of bone union after lumbar fusion surgery, there is currently no supportive clinical evidence.
Eighty-five patients older than 50 years who underwent single-level L4/5 transforaminal lumbar interbody fusion with posterior pedicle screw (PS) fixation were analyzed. Patients with factors that potentially inhibit bone fusion, such as Parkinson disease, were excluded. Bone union was assessed using computed tomography and dynamic radiographs 1 year after surgery. Explanatory factors considered included sex, age, smoking, bone density, material of the cage, PS diameter (PSD), relative PS length, theoretical maximum PSD (PSD), which was defined as the maximum diameter of the screw that may be inserted without breaking cortical bone around the pedicle, and the filling index, which was defined as the difference between the cross-sectional area of maximum PS and actual PS (PSD 2 - PSD 2). Japanese Orthopaedic Association scores before and 1 year after surgery were evaluated as a clinical outcome.
Nineteen levels were diagnosed as pseudoarthrosis. A multivariate logistic regression analysis identified a larger filling index (P = 0.016) and older age (P = 0.047) as risk factors for pseudoarthrosis. The Japanese Orthopaedic Association score 1 year after surgery and its recovery rate were significantly worse in patients with pseudoarthrosis than in those with fusion.
The selection of an appropriately sized screw is important for achieving rigid fusion after transforaminal lumbar interbody fusion. Preoperative planning using multiplanar reconstruction computed tomography is an important approach for ensuring good clinical results.
虽然椎弓根螺钉的大小可能会影响腰椎融合手术后骨融合的速度，但目前尚无临床证据支持这一观点。
分析了 85 例年龄大于 50 岁的患者，他们接受了单节段 L4/5 经椎间孔腰椎体间融合后路椎弓根螺钉（PS）固定术。排除了可能抑制骨融合的因素，如帕金森病。术后 1 年采用 CT 和动态 X 线片评估骨融合情况。考虑的解释因素包括性别、年龄、吸烟、骨密度、 cage 材料、PS 直径（PSD）、相对 PS 长度、理论最大 PSD（PSD），定义为不破坏椎弓根周围皮质骨而可能插入的最大螺钉直径，以及填充指数，定义为最大 PS 横截面积与实际 PS（PSD2-PSD2）之间的差值。手术前后的日本矫形协会评分作为临床结果进行评估。
19 个节段被诊断为假关节。多变量逻辑回归分析发现，较大的填充指数（P=0.016）和较大的年龄（P=0.047）是假关节的危险因素。与融合患者相比，假关节患者术后 1 年的日本矫形协会评分及其恢复率明显较差。
在经椎间孔腰椎体间融合术中，选择合适大小的螺钉对于获得牢固融合非常重要。使用多平面重建 CT 进行术前规划是确保良好临床效果的重要方法。
