三维桡骨成角楔形截骨术前自动规划算法

Automatic preoperative planning algorithm for three-dimensional wedge osteotomy of radius

针对桡骨成角畸形,仅凭经验很难找到准确的截骨位置,为此提出一种三维(3D)桡骨成角楔形截骨术前自动规划算法,以精确定位具体截骨位置并计算出最佳复位角度。首先,以补偿差异的对侧桡骨镜像模型为参考模板,计算骨畸形区域;其次,基于关节解剖区域的权重配准桡骨远端关节,创建旋转轴方向向量,通过三次样条插值法求解XOZ平面的畸形轮廓曲线,确定复位旋转轴方位;最后,利用单目标优化算法优化迭代,计算最优的截骨位置和复位角度,自动生成楔形截骨矫形术前计划。选择6例桡骨成角实例,以外科医生在三维空间手动截骨矫形规划方法作为实验对照组,对比关节解剖区域的配准精度。仿真结果表明,与Miyake等提出的外科医生手动截骨复位方法相比,所提算法获得的关节解剖区域的配准均方根误差(RMSE)减小0.09~0.42 mm;与Fürnstahl等提出的自动规划方法相比,所提算法可明确楔形类型,临床可行性更高。

For radial angulation deformity,it is difficult to accurately locate the osteotomy position only by experience,thus a three-Dimensional(3D)automatic planning algorithm for radial angulation wedge osteotomy was proposed to accurately determine the specific osteotomy position and calculate the best reset angle.Firstly,the contralateral radius mirror model with compensation difference was used as the reference template to calculate the bone deformity area.Secondly,the distal radius joint was registered based on the weight of the joint anatomical area to create the rotation axis direction vector,and the deformity contour curve of the XOZ plane was solved by the cubic spline interpolation method to determine the orientation of the rotation axis.Finally,the single-objective optimization algorithm was used to optimize the iteration,calculate the optimal osteotomy position and reset angle,and automatically generate the preoperative plan of wedge osteotomy.Six cases of radial angulation were selected to compare the registration accuracy of the joint anatomical area with the surgeon’s manual osteotomy planning method in 3D space as the experimental control group.Experimental results show that compared with manual osteotomy and reset by surgeons proposed by Miyake et al.,the Root Mean Square Error(RMSE)of the registration of the joint anatomical area obtained by the proposed algorithm is decreased by 0.09 to 0.42 mm;compared with the automatic planning method proposed by Fürnstahl et al.,the proposed algorithm can clarify the type of wedge and has higher clinical feasibility.