García-Fantini Manuel, De Casas Ricardo
Neurosurgery Department of Hospital HM Modelo, Rúa Virrey Osorio 30, 15011 La Coruña, Spain.
Orthopaedic Surgery Department of Clínica Traumacor, Ronda de Nelle 72, 15005 La Coruña, Spain.
J Spine Surg. 2018 Dec;4(4):736-743. doi: 10.21037/jss.2018.10.03.
Three-dimensional (3D) navigation techniques can theoretically provide higher accuracy rates and increased safety for pedicle screw (PS) placement than traditional fluoroscopy (FL) guided methods. In this study, we compare the pedicular accuracy of 3D isocentric fluoroscopic navigation (3DFL) versus FL guidance in PS L4-L5-S1 fixation and evaluate the differential cortical purchase and safety of fixation of the S1 PS.
This is a single-centre retrospective study of 810 PSs placed in open L4-L5-S1 fixation between 2012 and 2017 in 39 patients using standard FL and in 96 patients under 3DFL. Pedicular screw accuracy was determined by postoperative computed tomography (CT) and graded on a 4-tiered classification system according to Gertzbein and Robbins. In addition, sacral screws were evaluated depending on the degree of cortical fixation: monocortical, bicortical or tricortical, and the degree of safety with respect to retroperitoneal structures.
Grade 0 perfect pedicular screw placement was 95% for 3DFL screws compared to 85% for screws placed under fluoroscopy (P<0.05). The number of grade 0 versus grade 1 and higher (breached screws) was statistically significant (P<0.05). Higher S1 cortical screw accuracy [77% versus 51% (P<0.05)] for bi- and tricortical fixation and a lower percentage of "at risk" PSs (P<0.05) were achieved with placement under 3DFL versus FL.
3DFL enhances the accuracy and safety of PS placement in L4-L5-S1 fixation, reducing the rate of misplaced screws and improving S1 cortical fixation.
理论上，三维（3D）导航技术在椎弓根螺钉（PS）置入方面比传统的荧光透视（FL）引导方法能提供更高的准确率和更高的安全性。在本研究中，我们比较了3D等中心荧光透视导航（3DFL）与FL引导在L4-L5-S1节段PS固定中的椎弓根置入准确性，并评估S1节段PS固定的不同皮质骨把持情况和安全性。
这是一项单中心回顾性研究，对2012年至2017年间39例采用标准FL及96例采用3DFL在开放手术中进行L4-L5-S1固定置入的810枚PS进行研究。术后通过计算机断层扫描（CT）确定椎弓根螺钉的准确性，并根据Gertzbein和Robbins的4级分类系统进行分级。此外，根据皮质骨固定程度（单皮质、双皮质或三皮质）以及相对于腹膜后结构的安全程度对骶骨螺钉进行评估。
3DFL置入的螺钉0级完美椎弓根螺钉置入率为95%，而荧光透视下置入的螺钉为85%（P<0.05）。0级与1级及以上（螺钉穿破）的数量具有统计学意义（P<0.05）。与FL相比，3DFL置入时双皮质和三皮质固定的S1皮质螺钉准确性更高[分别为77%和51%（P<0.05）]，“有风险”的PS比例更低（P<0.05）。
3DFL提高了L4-L5-S1固定中PS置入的准确性和安全性，降低了螺钉误置率并改善了S1皮质固定。
