计算机辅助下三维可视化测量髋臼方位的研究

Computer-aided 3D visualization of acetabular orientation

目的在计算机辅助下对髋臼方位进行三维可视化测量，以期为人工全髋关肖置换术提供精确的个体化术前规划。方法选取10具无明显骨质缺损的成年尸体标本，将标本CT扫描后的．dicom格式原始数据导人Mimicsl0．Ol软件，重建出骨盆三维模型，然后根据三维模型在冠状面、水平面上的投影测量髋臼的外展角和前倾角。通过Imagewarel3．0软件计算髋臼旋转中心，根据髋臼外展角和前倾角的测量值计算出髋臼旋转轴线，再沿该轴线植入虚拟的髋臼杯假体，分别测量虚拟髋臼杯假体的外展角、前倾角，对比分析植入假体前、后的外展角和前倾角。结果根据测量所得的髋臼旋转中心位于髋臼中央，所确定的虚拟髋臼旋转轴线通过髋臼开口面的中心，且与髋臼开口所在的平面垂直。10具标本髋臼三维模型的冠状面投影面上髋臼外展角平均为49．5°±4．7°，虚拟髋臼杯投影面上外腱角平均为49．9°±4．1°，二者比较差异无统计学意义（t=0．326，P=0．753）；10具标本髋臼三维模型的水平面投影面E髋臼前倾角平均为17．7°±3．1°，虚拟髋臼杯投影面上前倾角平均为18，3°±3．5°，二背比较差异无统计学意义（t=0．547，P=0．600）。结论计算机辅助下三维可视化测量髋臼方位比较准确、可靠，为人工全髋关节置换术的个体化术前规划提供了新的测量方法和研究手段。

Objective To study acetabular orientation through computer-aided 3D visualization which can facilitate individualized preoperative planning in total hip arthroplasty. Methods Original data at . dicom format were obtained from CT scans of 10 adult cadaveric specimens without bone defects before they were transferred into Mimicsl0. 01 software to reconstruct 3D models of the pelvis. First, we calculated the hip joint center by the acetabular point cloud using lmagewarel3.0 software. Then, we measured the ac- etabular abduction and anteversion in the coronal and sagittal plans using 3-matic 6. 1 software. Consequently, the virtual acetabulum rotation axis was obtained based on the 2 angles. Finally, a virtual acetabular cup pros- thesis was implanted into the acetabular model along the virtual axis. Statistical analysis was performed after measurement of the abduction and anteversion of the virtual cup. Results The hip joint center was located in the center of the aeetabulum, and the virtual acetabulum rotation axis was perpendicular to the acetabular opening plane. There was no significant difference between the abduction of the virtual cup （49.9° ±4. 1°） and the actual abduction measured in the 10 cadaveric specimens （49.5°±4.7°） （ t = 0. 326, P = 0. 753）. There was no significant difference either between the anteversion of the virtual cup （ 18.3°± 3.5°） and the actual anteversion measured in the 10 cadaveric specimens （17.7° ±3. 1°） （t = 0. 547, P = 0. 600）. Conclusion Since the acetabular m＇ientatiou through computer-aided 3D visualization is accurate and reliable, it may serve as a new means of measurement and research for individualized preoperative planning in total hip arthroplasty.