Gan Yudong, Xu Dachuan, Lu Sheng, Ding Jing
Department of Mechanics Lab, Southern Medical University, Guangzhou, China.
Comput Aided Surg. 2011;16(6):288-97. doi: 10.3109/10929088.2011.621214.
Current techniques for total knee arthroplasty have certain drawbacks, including violation of the intramedullary canals and limited accuracy. The aim of this research was to develop and validate the accuracy of a new computer-assisted preoperative planning concept for the creation of patient-specific navigational templates to replace conventional instruments. Volumetric computerized tomography (CT) scanning was performed on 30 cadaveric knees, and a three-dimensional reconstruction model of each knee was generated from the scan data. Using a reverse-engineering technique, optimal lower-limb alignment and rotational alignment were determined. A navigational template was also designed with a surface that matched the distal femur and proximal tibia. This template, with its corresponding femur and tibia, was manufactured using a rapid-prototyping technique and tested for violations. The navigational template was then used intraoperatively to assist with an arthroplasty in each of the 30 cadaveric knees. Following surgery, the positions of the prostheses were evaluated with X-rays and CT scans. The method showed a high degree of accuracy and reproducibility. In all cases, placing the template manually on the lamina of the femur and tibia was relatively easy. Twenty-eight prostheses were considered to be positioned entirely accurately, whereas two prostheses were considered to have a 1-2° malpositioning. This study thus introduces a novel navigational template for total knee arthroplasty. Preliminary cadaveric trials have demonstrated that this design can improve the accuracy of osteotomy in the surgical procedure.
目前的全膝关节置换技术存在一定缺陷，包括侵犯髓腔以及精度有限。本研究的目的是开发并验证一种新的计算机辅助术前规划概念的准确性，该概念用于创建患者特异性导航模板以取代传统器械。对30个尸体膝关节进行容积计算机断层扫描（CT），并从扫描数据生成每个膝关节的三维重建模型。采用逆向工程技术，确定最佳下肢对线和旋转对线。还设计了一种导航模板，其表面与股骨远端和胫骨近端相匹配。该模板及其相应的股骨和胫骨采用快速成型技术制造，并进行了违规测试。然后在手术中使用该导航模板辅助30个尸体膝关节中的每一个进行关节置换术。手术后，通过X射线和CT扫描评估假体的位置。该方法显示出高度的准确性和可重复性。在所有情况下，将模板手动放置在股骨和胫骨的骨板上相对容易。28个假体被认为完全准确放置，而两个假体被认为有1-2°的位置不当。因此，本研究引入了一种用于全膝关节置换术的新型导航模板。初步尸体试验表明，这种设计可以提高手术过程中截骨的准确性。
