Facco Giulia, Greco Luciano, Mandolini Marco, Mari Alberto, Brunzini Agnese, Manzotti Sandra, Setaro Nicola, Pieralisi Massimiliano, Simoncini Michela, Gigante Antonio Pompilio
Giulia Facco, MD, works in the Department of Clinical and Molecular Science for Università Politecnica delle Marche in Ancona, Italy.
Luciano Greco, Dr, Marco Mandolini, PhD, Agnese Brunzini, PhD, and Massimiliano Pieralisi, Dr, work in the Department of Industrial Engineering and Mathematical Sciences for Università Politecnica delle Marche in Ancona.
Radiol Technol. 2022 Jan;93(3):246-254.
To evaluate the accuracy of 3-D printed models of the femoral head based on preoperative computed tomography (CT) images. Other goals were to compare the cartilage thickness of bony specimen to the printed models and calculate the standard deviation between 3-D printed models based on CT images and laser scan models.
This retrospective study analyzed 10 patients who underwent preoperative CT imaging and hip replacement. Preoperative femoral head 3-D printed models were produced from CT images. Bony specimens were collected from surgical operations and scanned using CT and 3-D laser scanning, and cartilage thickness subsequently was measured by histological analysis. Comparisons of printed models based on CT images and printed models based on 3-D laser scanning were performed by overlapping their external surfaces using dedicated software and the standard deviation was calculated.
The average standard deviation between the bony specimen 3-D models and preoperative 3-D printed CT femoral head models was 0.651 mm. The cartilage was approximately 1.487 mm thick.
The comparison between preoperative CT image-based 3-D models and the postoperative bony specimen-based models permitted evaluation of the accuracy of preoperative CT image-based 3-D printed models. Cartilage thickness was estimated indirectly by comparing models obtained by CT and laser scanning, and it was related to the calculated standard deviation to overcome the cartilage detection limit of CT. This study shows how each step can generate accuracy errors on the final 3-D printed model. A repeatable and sustainable workflow for creating accurate and reproducible 3-D printed models could overcome this issue. Moreover, orthopedic surgeons should be aware of 3-D printed model precision in clinical practice.
This study provides encouraging results on the accuracy of 3-D printed models for surgical planning.
基于术前计算机断层扫描（CT）图像评估股骨头三维打印模型的准确性。其他目标是比较骨标本与打印模型的软骨厚度，并计算基于CT图像的三维打印模型与激光扫描模型之间的标准差。
这项回顾性研究分析了10例行术前CT成像和髋关节置换术的患者。从CT图像生成术前股骨头三维打印模型。从手术中收集骨标本，使用CT和三维激光扫描进行扫描，随后通过组织学分析测量软骨厚度。通过使用专用软件重叠基于CT图像的打印模型和基于三维激光扫描的打印模型的外表面进行比较，并计算标准差。
骨标本三维模型与术前三维打印CT股骨头模型之间的平均标准差为0.651毫米。软骨厚度约为1.487毫米。
术前基于CT图像的三维模型与术后基于骨标本的模型之间的比较允许评估术前基于CT图像的三维打印模型的准确性。通过比较CT和激光扫描获得的模型间接估计软骨厚度，并将其与计算出的标准差相关联以克服CT的软骨检测极限。本研究展示了每个步骤如何在最终的三维打印模型上产生精度误差。创建准确且可重复的三维打印模型的可重复且可持续的工作流程可以克服这个问题。此外，骨科医生在临床实践中应意识到三维打印模型的精度。
本研究为手术规划的三维打印模型的准确性提供了令人鼓舞的结果。
