股骨近端解剖参数的自动化三维测量

Automated three-dimensional measurement on anatomic parameters of proximal femur

目的基于解剖标志建立股骨三维坐标系,实现股骨近端解剖参数的自动化测量,辅助术前规划及个性化股骨柄设计。方法自主研发专用于股骨解剖测量的Femeter软件,可读取显示股骨STL模型,手工选取目标解剖标志点。运用半球形搜索迭代方法实现髓腔快速三维建模,运用经典最小二乘拟合等算法实现股骨头半径、颈干角、前倾角等相关16个测量参数的自动计算。结果通过30例股骨STL模型进行测量实验,平均单次测量的算法执行时间为（0.95±0.16）s,9个解剖测量项的评定者内和评定者间可靠性较高（组内相关性系数为0.907~0.999）。结论 Femeter软件的自动建模和测量算法执行速度较快,测量可重复性较好,操作简易,适用于临床。自动化三维股骨近端解剖测量可为人工全髋关节置换术前规划、股骨柄选择和个性化股骨柄设计提供可靠数据。

Objective To automatically measure anatomic parameters of proximal femur by establishing three-dimensional（ 3D） coordinate system of the femur based on bony landmarks,so as to assist pre-operative planning and design of customized femoral stem. Methods The software named ＂ Femeter＂ was independently developed for anatomic measurement of the femur,which allowed importing the femur models with STL format and manually locating the targeted anatomic landmarks. The 3D modeling of femoral medullary canal was rapidly created by semi-spherical iterative searching algorithm,and 16 key anatomic parameters of proximal femur,including femoral head radius,neck-shaft angle,anterversion were automatically calculated by least-squares fitting algorithm.Results By experimenting on 30 femur STL models,the average execution time of single measurement was（ 0. 95 ± 0. 16） seconds,and the intra-class correlation coefficient of 9 anatomic parameters was between 0. 907 and 0. 999,which showed high intra-rater and inter-rater reliability. Conclusions The automatic modeling and execution time of measuring algorithm by Femeter are fast,with satisfactory measurement repeatability and easy interaction,which is easily applicable to clinical practice. The 3D anatomic measurement of proximal femur can provide solid data for pre-operative planning of total hip arthroplasty,selection of commercialized femoral stem and design of customized femoral stem.