Wang Wei, Hu Wei, Yang Pei, Dang Xiao Qian, Li Xiao Hui, Wang Kun Zheng
The First Department of Orthopaedics, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, P. R. China.
The Department of Orthopaedics, Xian Yang Central Hospital, Xian Yang, Shaanxi Province, P. R. China.
PLoS One. 2017 May 2;12(5):e0175366. doi: 10.1371/journal.pone.0175366. eCollection 2017.
Core decompression is an efficient treatment for early stage ischemic necrosis of the femoral head. In conventional procedures, the pre-operative X-ray only shows one plane of the ischemic area, which often results in inaccurate drilling. This paper introduces a new method that uses computer-assisted technology and rapid prototyping to enhance drilling accuracy during core decompression surgeries and presents a validation study of cadaveric tests.
Twelve cadaveric human femurs were used to simulate early-stage ischemic necrosis. The core decompression target at the anterolateral femoral head was simulated using an embedded glass ball (target). Three positioning Kirschner wires were drilled into the top and bottom of the large rotor. The specimen was then subjected to computed tomography (CT). A CT image of the specimen was imported into the Mimics software to construct a three-dimensional model including the target. The best core decompression channel was then designed using the 3D model. A navigational template for the specimen was designed using the Pro/E software and manufactured by rapid prototyping technology to guide the drilling channel. The specimen-specific navigation template was installed on the specimen using positioning Kirschner wires. Drilling was performed using a guide needle through the guiding hole on the templates. The distance between the end point of the guide needle and the target was measured to validate the patient-specific surgical accuracy.
The average distance between the tip of the guide needle drilled through the guiding template and the target was 1.92±0.071 mm.
Core decompression using a computer-rapid prototyping template is a reliable and accurate technique that could provide a new method of precision decompression for early-stage ischemic necrosis.
髓芯减压术是治疗早期股骨头缺血性坏死的一种有效方法。在传统手术中，术前X线仅显示缺血区域的一个平面，这常常导致钻孔不准确。本文介绍一种利用计算机辅助技术和快速成型技术提高髓芯减压手术钻孔准确性的新方法，并进行尸体试验验证研究。
使用12具人尸体股骨模拟早期缺血性坏死。通过嵌入玻璃球（靶点）模拟股骨头前外侧的髓芯减压靶点。在大转子顶部和底部钻入三根定位克氏针。然后对标本进行计算机断层扫描（CT）。将标本的CT图像导入Mimics软件构建包括靶点的三维模型。然后使用三维模型设计最佳髓芯减压通道。使用Pro/E软件为标本设计导航模板，并通过快速成型技术制造以引导钻孔通道。使用定位克氏针将标本特异性导航模板安装在标本上。使用导针通过模板上的引导孔进行钻孔。测量导针端点与靶点之间的距离以验证针对患者的手术准确性。
通过引导模板钻出的导针尖端与靶点之间的平均距离为1.92±0.071毫米。
使用计算机快速成型模板进行髓芯减压是一种可靠且准确的技术，可为早期缺血性坏死提供一种新的精准减压方法。
