Hsu Wei-En, Yu Ching-Hsiao, Chang Chih-Ju, Wu Hung-Kang, Yu Tsong-Han, Tseng Ching-Shiow
Department of Mechanical Engineering, National Central University, Taoyuan 32001, Taiwan.
Department of Orthopedics, Taoyuan General Hospital, Taoyuan 33004, Taiwan.
Appl Bionics Biomech. 2018 May 23;2018:4530386. doi: 10.1155/2018/4530386. eCollection 2018.
Due to the curvature of the bone marrow cavity, the intramedullary nail used in long bone fracture fixation can be deformed, causing displacement of the locking holes. In this study, an algorithm using only one C-arm image to determine the center positions and axial directions of locking holes was developed for drilling guidance. Based on conventional method that the axial direction of locking hole would be identified when locking hole contour is presented as a circle, the proposed method can locate the circle contour centroid by using one C-arm image including two elliptical contours. Then the two distal locking holes' axial direction and centers would be determined. Three experiments were conducted to verify the performance of the proposed algorithm, which are (1) computer simulation, (2) use of real intramedullary nails, and (3) actual drilling test with the bone model. The experimental results showed that the average error of the axial direction and center position were 0.62 ± 0.6°, 0.73 ± 0.53 mm (simulation) and 3.16 ± 1.36°, 1.10 ± 0.50 mm (actual nail), respectively. The last ten drilling test sets were completed successfully (with an average duration of 48 seconds). Based on the experimental results, the proposed algorithm was feasible for clinic applications.
由于骨髓腔的曲率，用于长骨骨折固定的髓内钉可能会变形，导致锁定孔移位。在本研究中，开发了一种仅使用一张C形臂图像来确定锁定孔中心位置和轴向方向的算法，用于钻孔引导。基于传统方法，即当锁定孔轮廓呈现为圆形时确定锁定孔的轴向方向，所提出的方法可以通过使用包含两个椭圆形轮廓的一张C形臂图像来定位圆形轮廓的质心。然后确定两个远端锁定孔的轴向方向和中心。进行了三个实验来验证所提出算法的性能，分别是（1）计算机模拟，（2）使用真实的髓内钉，以及（3）使用骨模型进行实际钻孔测试。实验结果表明，轴向方向和中心位置的平均误差分别为0.62±0.6°，0.73±0.53毫米（模拟）和3.16±1.36°，1.10±0.50毫米（实际钉子）。最后十组钻孔测试成功完成（平均持续时间为48秒）。基于实验结果表明，所提出的算法在临床应用中是可行的。
