目的:本研究旨在评估以下假设:在距骨骨折的手术固定中,经皮螺钉导向器的使用可提高螺钉放置的精度。
方法:在2019年4月至2020年8月期间,从宁波的40名健康成年人和10名尸体标本中获得了踝关节的计算机断层扫描(CT)扫描。6医院将采集的CT数据导入到Materialise交互式医学图像控制系统(MIMICS)软件中进行处理。重建踝关节的三维(3D)数字模型,并测量相关解剖参数。设计并制造了经皮螺钉导向器(PSG),以促进在距骨后部过程中精确放置螺钉。选择10个合格的尸体踝关节进行进一步分析,并使用MIMICS软件重建其3D模型。然后根据这些尸体模型测量和分析螺钉轨迹参数,形成模型组进行比较分析。在这项研究中使用了十个尸体标本,平均分为两组:向导组(n=5)和徒手组(n=5)。在导游小组中,使用经皮螺钉引导插入距骨后突螺钉。在自由手组中,在没有指导的情况下,将螺钉插入距骨后突。对所有标本进行术后CT扫描。两组之间对以下参数进行了定量比较:螺钉轨迹,带有预选螺钉的试样的入口点距离,3D模型中的入口点距离轨迹,操作时间,荧光成像的频率,和钻井尝试的数量。
结果:从10具尸体生成3D模型后,将虚拟螺钉数字插入每个模型中。在模型组中,预选的螺钉轨迹朝向距骨颈基部的内侧,横向〜平面的头倾角(CIA)为3.1°±1.5°,冠状平面的内侧发散角(MDA)为12.0°±1.4°。导向器组螺旋轨迹的CIA和MDA分别为2.1°±1.7°和11.2°±1.6°,分别,而徒手组的CIA和MDA分别为6.0°±2.2°和18.8°±1.6°,分别。统计学分析显示两组间CIA和MDA均存在显著差异(p<0.05)。此外,导游小组在切入点距离方面取得了优异的成果,操作时间,荧光照射时间,以及与徒手组相比的钻孔尝试次数(p<0.05)。
结论:经皮螺钉引导可以提高距骨螺钉后突的准确性和安全性,这对于经皮内固定是可行的。需要进一步的研究来证实经皮螺钉引导的疗效和临床结果。
OBJECTIVE: This study aimed to evaluate the hypothesis that the utilization of percutaneous screw guides enhances the precision of screw placement in the surgical fixation of talar fractures.
METHODS: Computed tomography (CT) scans of ankle joints were obtained from 40 healthy adults and 10 cadaveric specimens between April 2019 and August 2020 at Ningbo No. 6 Hospital. The acquired CT data were imported into Materialise Interactive Medical Image Control System (MIMICS) software for processing. Three-dimensional (3D) digital models of the ankle joints were reconstructed, and relevant anatomical parameters were measured. A percutaneous screw guide (PSG) was designed and fabricated to facilitate accurate screw placement in the posterior talar process. Ten eligible cadaveric ankle joints were selected for further analysis and their 3D models were reconstructed using the MIMICS software. Screw trajectory parameters were then measured and analyzed based on these cadaveric models, forming the model group for comparative analyses. Ten cadaveric specimens were utilized in this study, equally divided into two groups: a guider group (n = 5) and a free-hand group (n = 5). In the guider group, talar posterior process screws were inserted using percutaneous screw guidance. In the free-hand group, screws were inserted into the talar posterior process without guidance. Post-operative CT scans were performed on all specimens. The following parameters were quantitatively compared between the two groups: screw trajectories, entry point distances in specimens with preselected screws, entry point distance trajectories in the 3D model, operation time, frequency of fluoroscopic imaging, and number of drilling attempts.
RESULTS: Following the generation of the 3D models from 10 cadavers, a virtual screw was digitally inserted into each model. In the model group, the preselected screw trajectory was oriented towards the medial aspect of the talar neck base, with a cephalad inclination angle (CIA) of 3.1° ± 1.5° in the transverse~plane and a medial diverge angle (MDA) of 12.0° ± 1.4° in the coronal plane. The CIA and MDA of the screw trajectory in the guider group were 2.1° ± 1.7° and 11.2° ± 1.6°, respectively, whereas the CIA and MDA in the free-hand group were 6.0° ± 2.2° and 18.8° ± 1.6°, respectively. Statistical analysis revealed significant differences in both CIA and MDA between the two groups (p < 0.05). Furthermore, the guider group yielded superior outcomes in terms of entry point distance, operation time, fluoroscopic exposure time, and number of drilling attempts compared to the free-hand group (p < 0.05).
CONCLUSIONS: Percutaneous screw guidance can improve the accuracy and safety of the posterior process of the talar screws, which can be feasible for percutaneous fixation. Further studies are required to confirm the efficacy and clinical outcomes of percutaneous screw guidance.