Hefny Mohamed S, Rudan John F, Ellis Randy E
School of Computing, Queen's University, Kingston, ON, K7L 2N8, Canada,
Int J Comput Assist Radiol Surg. 2015 Jun;10(6):707-15. doi: 10.1007/s11548-015-1209-y. Epub 2015 May 1.
Hip resurfacing is a surgical option for osteoarthritis young and active patients. Early failures has been reported due to improper implant placement. Computer-assisted surgery is a promising avenue for more successful procedures.
This paper presents a novel automatic surgical planning for computer-assisted hip resurfacing procedures. The plan defined the femoral head axis that was used to place the implant. The automatic planning was based on a Lie group statistical shape model.
A statistical shape model was constructed using 50 femurs from osteoarthritis patients who underwent computer-assisted hip resurfacing. The model was constructed using product Lie groups representation of shapes and nonlinear analysis on the manifold of shapes. A surgical plan was drawn for the derived base shape. The base shape was transformed to 14 femurs with known manual plans. The transformed base plan was used as the computed plan for each femur. Both actual and computed plans were compared.
The method showed a success by computing plans that differ from the actual plans within the surgical admissible ranges. The minimum crossing distance between the two plans had a mean of 0.75 mm with a standard deviation of 0.54 mm. The angular difference between the two plans had the mean of 5.94° with a standard deviation of 2.145.94°.
Product Lie groups shape models were proved to be successful in automatic planning for hip resurfacing computer-assisted surgeries. The method can be extended to other orthopedic and general surgeries.
髋关节表面置换术是年轻活跃的骨关节炎患者的一种手术选择。据报道，由于植入物放置不当会导致早期失败。计算机辅助手术是实现更成功手术的一条有前景的途径。
本文提出一种用于计算机辅助髋关节表面置换手术的新型自动手术规划方法。该规划确定了用于放置植入物的股骨头轴线。自动规划基于李群统计形状模型。
使用50例接受计算机辅助髋关节表面置换术的骨关节炎患者的股骨构建统计形状模型。该模型采用形状的乘积李群表示以及形状流形上的非线性分析来构建。为导出的基础形状绘制手术规划。将基础形状变换到14例具有已知手动规划的股骨上。变换后的基础规划用作每例股骨的计算规划。对实际规划和计算规划进行比较。
该方法通过计算在手术允许范围内与实际规划不同的规划而取得成功。两个规划之间的最小交叉距离平均为0.75毫米，标准差为0.54毫米。两个规划之间的角度差平均为5.94°，标准差为2.145.94°。
乘积李群形状模型被证明在髋关节表面置换计算机辅助手术的自动规划中是成功的。该方法可扩展到其他骨科手术及普通外科手术。
