数字化三维重建模拟前路枕骨髁螺钉置钉

Digital three-dimensional reconstruction simulating anterior occipital condyle screw placement

中文关键词:  前路枕骨髁螺钉  三维重建  枕骨髁  枕颈融合  内固定

英文关键词:Anterior occipital condyle screw  Three-dimensional reconstruction  Occipital condyle  Occipitocervical fusion  Internal fixation

中文摘要:

  【摘要】 目的：使用数字化三维重建技术测量前路枕骨髁螺钉的相关置钉参数，探讨前路枕骨髁螺钉置入的可行性和安全性。方法：选取宁波市第六医院共50例枕颈部形态正常者的上颈椎螺旋CT扫描图像，男30例，女20例，年龄42.2±8.6岁（23～68岁）。排除感染、肿瘤、解剖畸形、骨折脱位、退行性变及严重骨质疏松，将CT数据导入Mimics软件，对枕骨及寰椎进行三维CT重建后，模拟前路置入直径3.5mm的枕骨髁螺钉，测量进钉点至枕骨髁内侧缘及寰枕关节面的距离、螺钉与舌下神经管的最短垂直距离、进入枕骨髁骨质内的钉道长度，再用3-matic软件测量螺钉的头倾角及外倾角，将螺钉各置钉参数进行统计学分析。结果：共模拟成功置入100枚前路枕骨髁螺钉，三维模型观察均无枕骨髁内外侧壁、寰枕关节面及舌下神经管的损伤。前路枕骨髁螺钉各置钉参数左右两侧比较均无统计学差异（P＞0.05）。进钉点距枕骨髁内侧缘水平距离及寰枕关节面垂直距离分别为3.28±0.54mm、2.84±0.45mm，螺钉头倾角、外倾角、距离舌下神经管最短垂直距离及钉道长度分别为 4.07°±2.40°、33.09°±4.37°、4.76±0.74mm、21.54±2.01mm。结论：通过数字化三维重建模拟前路枕骨髁螺钉置钉，显示正常成人枕骨髁有足够的体积空间容纳直径3.5mm的前路枕骨髁螺钉置入，前路枕骨髁螺钉技术是治疗枕颈不稳时颅侧固定的一种安全可行的方法。

英文摘要:

  【Abstract】 Objectives: To measure the related placement parameters of anterior occipital condylar screw by using digital three-dimensional reconstruction technique, and to assess the feasibility and safety of anterior occipital condylar screw placement. Methods: The spiral CT images of the upper cervical vertebrae of 50 patients with normal occipital and neck morphology in Ningbo Sixth Hospital were selected, including 30 males and 20 females with an average age of 42.2±8.6 years(ranging from 23 to 68 years). Excluding infection, tumor, anatomical deformity, fracture and dislocation, degeneration and severe osteoporosis, CT data were imported into Mimics software. After three-dimensional CT reconstruction of occipital bone and atlas, anterior occipital condylar screws with diameter of 3.5mm were placed to measure the distances from the entry point to the medial wall of occipital condyle and the atlantooccipital joint interface, the shortest vertical distance between screw and hypoglossal canal, and the length of screw trajectory entering into the bone of occipital condyle. Then, the upper tilting angle and outside tilting angle of each screw were measured by 3-matic software. The parameters of each screw placement were statistically analyzed. Results: A total of 100 anterior occipital condylar screws were successfully placed. No injury of medial and lateral wall of occipital condyle, atlantooccipital joint interface and hypoglossal canal in three-dimensional model were observed. There were no statistical differences in the placement parameters of anterior occipital condylar screw between the left and right sides(P>0.05). The horizontal distance from the entry point to the medial wall of the occipital condyle and the vertical distance from the entry point to the atlantooccipital joint interface were 3.28±0.54mm and 2.84±0.45mm, respectively. The upper tilting angle, outside tilting angle, the shortest vertical distance from the screw to the hypoglossal canal and the length of the screw trajectory were 4.07°±2.40°, 33.09°±4.37°, 4.76±0.74mm and 21.54±2.01mm, respectively. Conclusions: Simulating anterior occipital condyle screw placement by digital three-dimensional reconstruction demonstrates that normal adult occipital condyle has enough volume space to accommodate a 3.5mm diameter anterior occipital condyle screw, which will be a safe and feasible method for cranial internal fixation in the treatment of occipital cervical instability.