人工膝関節置換術における3次元術後設置評価技術の検証

抄録

Several surgical assistance systems for total knee arthroplasty (TKA) have been applied to enhance the surgical precision. The accuracy of these surgical assistance systems has been evaluated with regards to the implant setting posture by 2-dimensional X-ray images. It was found that these systems were effective in enhancing surgical precision as reported in several publications. On the other hand, some authors reported no significant difference between these systems and conventional operation. When using 2-dimensional X-ray images for evaluation, a wrong knee posture during image acquisition introduces an error. Therefore, we evaluated several 3-dimensional evaluation methods using CT scans. In this study, we adopted three evaluation methods for TKA : 1) CT-based preplanning software, 2) 3-dimensional matching using a CAD model, and 3) a surgical navigation system. The error of these evaluation methods was less than 2 mm and 2 degrees. In conclusion, 1) it is important to validate the evaluation tool for each implant geometry and/or each evaluation method, 2) a suitable evaluation method should be selected in accordance with the intended use.