Gessmann Jan, Frieler Sven, Königshausen Matthias, Schildhauer Thomas A, Hanusrichter Yannik, Seybold Dominik, Baecker Hinnerk
Department of Trauma Surgery, BG University Hospital Bergmannsheil, Ruhr University Bochum, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany.
BMC Musculoskelet Disord. 2021 Mar 18;22(1):284. doi: 10.1186/s12891-021-04084-0.
The correction accuracy of the Taylor Spatial Frame (TSF) fixator depends considerably on the precise determination of the mounting parameters (MP). Incorrect parameters result in secondary deformities that require subsequent corrections. Different techniques have been described to improve the precision of MP measurement, although exact calculation is reportedly impossible radiologically. The aim of this study was to investigate the accuracy of intraoperative and postoperative radiographic measurement methods compared to direct MP measurement from TSF bone mounting.
A tibial Sawbone® model was established with different origins and reference ring positions. First, reference MPs for each origin were measured directly on the frame and bone using a calibrated, digital vernier calliper. In total 150 MPs measured with three different radiographic measurement techniques were compared to the reference MPs: digital radiographic measurements were performed using soft-copy PACS images without (method A) and with (method B) calibration and calibrated image intensifier images (method C).
MPs measured from a non-calibrated X-ray image (method A) showed the highest variance compared to the reference MPs. A greater distance between the origin and the reference ring corresponded to less accurate MP measurements with method A. However, the MPs measured from calibrated X-ray images (method B) and calibrated image intensifier images (method C) were intercomparable (p = 0.226) and showed only minor differences compared to the reference values but significant differences to method A (p < 0,001).
The results demonstrate that MPs can be accurately measured with radiographic techniques when using calibration markers and a software calibration tool, thus minimizing the source of error and improving the quality of correction.
泰勒空间框架（TSF）固定器的矫正精度在很大程度上取决于安装参数（MP）的精确测定。参数不正确会导致继发畸形，需要后续矫正。尽管据报道通过放射学方法无法进行精确计算，但已有不同技术用于提高MP测量的精度。本研究的目的是比较术中及术后影像学测量方法与通过TSF骨安装直接测量MP的准确性。
建立具有不同原点和参考环位置的胫骨Sawbone®模型。首先，使用校准的数字游标卡尺直接在框架和骨上测量每个原点的参考MP。将用三种不同影像学测量技术测得的总共150个MP与参考MP进行比较：使用未校准（方法A）和校准（方法B）的软拷贝PACS图像以及校准图像增强器图像（方法C）进行数字放射学测量。
与参考MP相比，从未校准的X射线图像（方法A）测得的MP显示出最大的差异。原点与参考环之间的距离越大，方法A测得的MP越不准确。然而，从校准的X射线图像（方法B）和校准图像增强器图像（方法C）测得的MP相互可比（p = 0.226），与参考值相比仅显示出微小差异，但与方法A有显著差异（p < 0.001）。
结果表明，使用校准标记和软件校准工具时，通过放射学技术可以准确测量MP，从而将误差源降至最低并提高矫正质量。
