To analyse the anatomical conditions of transverse sacroiliac screw (TSS) about the S1 and S2 segments in order to develop and validate a locked navigational template for TSS placement. A total of 22 patients with sacral fractures were involved in this study from May 2018 to February 2019. Patients were divided into two groups according to the surgery procedure: locked template group and conventional group. The CT data of 90 normal sacra were analysed. The long axis, short axis and lengths of TSS, cancellous corridors were measured through 3D modelling. A patient-specific locked navigation template based on simulated screws was designed and 3D printed and then used to assist in TSS placement. The operative time and radiation times were recorded. The Matta criteria and grading score were evaluated. The entry point deviation of the actual screw placement relative to the simulated screw placement was measured, and whether the whole screw was in the cancellous corridor was ob`served. S1 screws with a diameter of 7.3 mm could be inserted into 69 pelvises, and S2 screws could be inserted in all pelvises. The S1 cancellous corridor had a long axis of 25.44 ± 3.32 mm in males and 22.91 ± 2.46 mm in females, a short axis of 14.21 ± 2.19 mm in males and 12.15 ± 3.22 mm in females, a corridor length of 153.07 ± 11.99 mm in males and 151.11 ± 8.73 mm in females, and a proportional position of the optimal entry point in the long axis of the cancellous corridor of 35.96 ± 10.31% in males and 33.28 ± 7.2% in females. There were significant differences in the corridor long axis and corridor short axis between sexes (p < 0.05), and there were no significant differences in corridor length and proportional position of the optimal entry point in the long axis of the cancellous corridor between sexes (p > 0.05). The S2 cancellous corridor had a long axis of 17.58 ± 2.36 mm in males and 16 ± 2.64 mm in females, a short axis of 14.21 ± 2.19 mm in males and 13.14 ± 2.2 mm in females, a corridor length of 129.95 ± 0.89 mm in males and 136.5 ± 7.96 mm in females, and a proportional position of the optimal entry point in the long axis of the cancellous corridor of 46.77 ± 9.02% in males and 42.25 ± 11.95% in females. There were significant differences in the long axis, short axis and corridor length (p < 0.05). There was no significant difference in the proportional position of the optimal entry point in the long axis of the cancellous corridor (p > 0.05). A total of 20 transversal sacroiliac screws were successfully implanted into 10 patients with the assistance of locked navigation templates, and a total of 24 transversal sacroiliac screws were successfully implanted into 12 patients under C-arm fluoroscopy. There was a significant difference in surgical time (88 ± 14.76 min vs 102.5 ± 17.12 min, p = 0.048), radiation times (11.5 ± 1.78 vs 54.83 ± 6.59, p < 0.05) and screw grading between two groups (nineteen screws in grade 0, one screw in grade 1 and 0 screws in grade 2 vs fourteen screws in grade 0, 8 screws in grade 1 and 2 screws in grade 2, p = 0.005). All screw entry point deviations were shorter than the short axis of the cancellous corridor, and all screws were located completely within the cancellous corridor. Approximately 76% of males and females can accommodate screws with diameters of 7.3 mm in S1, and all persons can accommodate the same screw in S2. From the standard lateral perspective of the sacrum, the optimal entry point of the transverse screw is in the first 1/3 of the cancellous corridor for S1 and the centre of the cancellous corridor for S2. The patient-specific locked navigation template assisted in TSS placement with less operative time, less intraoperative fluoroscopy and higher safety of screw placement compared with traditional surgery.

中文翻译：

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解剖学条件和患者特定的锁定导航模板用于transverse横螺钉的放置：一项回顾性研究。

分析关于S1和S2节段的横sa螺钉（TSS）的解剖情况，以开发和验证用于TSS放置的锁定导航模板。从2018年5月至2019年2月，共有22例骨骨折患者参与了这项研究。根据手术步骤将患者分为两组：锁定模板组和常规组。分析了90例正常sa骨的CT数据。通过3D建模测量了长轴，短轴和TSS，松散走廊的长度。设计了基于模拟螺丝的特定于患者的锁定导航模板，并进行3D打印，然后用于协助TSS放置。记录手术时间和放射时间。评估了Matta标准和评分。测量实际螺钉位置相对于模拟螺钉位置的入口点偏差，并观察整个螺钉是否在松质通道中。直径7.3 mm的S1螺钉可以插入69个骨盆中，而S2螺钉可以插入所有骨盆中。S1松质走廊的长轴为雄性25.44±3.32 mm，雌性为22.91±2.46 mm，雄性的短轴为14.21±2.19 mm，雌性为12.15±3.22 mm，走廊长为153.07±11.99 mm男性为151.11±8.73毫米，女性为最佳入口点在松质走廊长轴上的比例位置，男性为35.96±10.31％，女性为33.28±7.2％。走廊长轴和走廊短轴之间的性别差异显着（p <0.05），男女之间，走廊长度和最佳入口在松质走廊长轴上的比例位置没有显着差异（p> 0.05）。S2松质走廊的长轴男性为17.58±2.36 mm，女性为16±2.64 mm，男性的短轴为14.21±2.19 mm，女性为13.14±2.2 mm，走廊长度为129.95±0.89 mm。男性为136.5±7.96毫米，女性为最佳入口点在松质走廊长轴上的比例位置为男性为46.77±9.02％，女性为42.25±11.95％。长轴，短轴和走廊长度存在显着差异（p <0.05）。最佳入口点在松散走廊长轴上的比例位置没有显着差异（p> 0.05）。在锁定导航模板的辅助下，共成功将20例横sa螺钉植入10例患者中，在C型臂透视下成功将24例横sa螺钉植入12例患者中。两组之间的手术时间（88±14.76分钟vs 102.5±17.12 min，p = 0.048），放疗时间（11.5±1.78 vs 54.83±6.59，p <0.05）和两组之间的螺钉分级存在显着差异（等级为19个螺钉） 0，等级1的一颗螺钉和等级2的0螺钉，等级0的十四个螺钉，等级1的8螺钉，等级2的2螺钉，p = 0.005）。所有螺钉入口点的偏差都小于松质通道的短轴，并且所有螺钉都完全位于松质通道内。在S1中，大约76％的男性和女性可以容纳直径7.3 mm的螺钉，而在S2中所有人都可以容纳相同的螺钉。从standard骨的标准侧面角度来看，横向螺钉的最佳进入点在S1的松质通道的前1/3和S2的松质通道的中心。与传统手术相比，患者特定的锁定导航模板可帮助TSS放置，缩短了手术时间，减少了术中透视检查，并提高了螺钉放置的安全性。