中文摘要：

目的 探讨一种基于熔融沉积快速成型-三维打印技术制备个体化枕骨髁螺钉导航模板的可行性,并对该方法辅助置钉的准确性和安全性进行评估.方法 选取30具成人尸体的枕颈部标本,将其CT扫描数据导入Mimics软件,对枕颈部行选择性重建,测量枕骨髁相关解剖结构以确定置钉参数.手工选取钉道,设计与枕骨后部结构相贴合的阴模,并利用三维打印技术成型.基于枕骨髁打印模型,直视下徒手将阴模制成具有双侧枕骨髁螺钉钉道的导航模板,并在其辅助下于尸体标本置入双侧枕骨髁螺钉.术后对寰枕间隙行解剖观察并再次行CT扫描评估螺钉位置.结果 根据生成的计算机三维模型设计并制作30个枕骨髁螺钉个体化导航模板,在其辅助下置钉的操作耗时为（91.4 ±8.2）s.60枚螺钉的轴位内倾角、矢状位倾角和进钉点至寰枕关节面的垂直距离分别为（33.2±6.4）°、（8.9±3.4）°和（3.9 ±0.9）mm,性别及个体左右侧所致相关参数的差异均无统计学意义（P＞0.05）.术后解剖及CT检查提示所有螺钉均未侵犯椎动脉、舌下神经管、髁导静脉管或寰枕关节面.除1枚螺钉穿破枕骨髁外侧皮质外,余钉位准确.结论 本研究结果表明,基于CT图像,使用Mimics软件能够精确重建枕骨髁及相关解剖结构,并建立其对应阴模.利用三维打印模型所设计的个体化导航模板,辅助置钉准确性高、操作简单,为枕骨髁螺钉的精确置入提供了一种可供选择的新方法.

英文摘要：

Objectives To investigate the feasibility of establishing an individualized navigation template for occipital condyle screws insertion using a fused deposition modeling based three-dimensional printing forming technique,and to evaluate the accuracy and safety of template-assisted condyle screw insertion.Methods Thirty adult occipitocervical specimens were selected to take a CT-scan.After original Dicom data imported into the Mimics software,the craniocervical junction models were created,which were used to evaluate anatomic structures and define the screw-related parameters.Design and generate the cavity models of the occipital condyle based on a three-dimensional printing forming technique.After using a freehand procedure to create a navigation template with a well-established screw path,finish bilateral condyle screws insertion assisted by the navigation template.Anatomy study and CT-scan were taken postoperatively to access the position of the screws.Results Sixty condyle screws were implanted assisted by 30 individualized navigation templates with an average time cost of （91.4 ± 8.2） s.The axial medial angle,sagittal cranial angle and distance between the entry point to atlantooccipital joint surface were （33.2 ± 6.4） °,（8.9 ± 3.4） °,（3.9 ± 0.9） mm,respectively.The variations due to different sex and sides resulted in a statistically insignificant difference of the parameters.Anatomy study and CT-scan indicated no intrusion of the vertebral artery,hypoglossal canal,condyle emissary vein canal or atlantooccipital joint.Fifty-nine condyle screws were completely contained within the condyle,while only 1 screw perforated lateral condyle wall.Conclusions Using the Mimics software for establishing the occipital condyle and related cavity model based on CT-scan images proves to be a feasible and precise method.Occipital condyle screws insertion assisted by a three-dimensional printing model is highly accurate and simple,which could be a new alternative to conventional technique.