PDF(Pubmed)
Abstract：
The introduction of three-dimensional (3D) printed anatomical models has garnered interest in pre-operative planning, especially in orthopedic and trauma surgery. Identifying potential error sources and quantifying their effect on the model dimensional accuracy are crucial for the applicability and reliability of such models. In this study, twenty radii were extracted from anatomic forearm specimens and subjected to osteotomy to simulate a defined fracture of the distal radius (Colles\' fracture). Various factors, including two different computed tomography (CT) technologies (energy-integrating detector (EID) and photon-counting detector (PCD)), four different CT scanners, two scan protocols (i.e., routine and high dosage), two different scan orientations, as well as two segmentation algorithms were considered to determine their effect on 3D model accuracy. Ground truth was established using 3D reconstructions of surface scans of the physical specimens. Results indicated that all investigated variables significantly impacted the 3D model accuracy (p < 0.001). However, the mean absolute deviation fell within the range of 0.03 ± 0.20 to 0.32 ± 0.23 mm, well below the 0.5 mm threshold necessary for pre-operative planning. Intra- and inter-operator variability demonstrated fair to excellent agreement for 3D model accuracy, with an intra-class correlation (ICC) of 0.43 to 0.92. This systematic investigation displayed dimensional deviations in the magnitude of sub-voxel imaging resolution for all variables. Major pitfalls included missed or overestimated bone regions during the segmentation process, necessitating additional manual editing of 3D models. In conclusion, this study demonstrates that 3D bone fracture models can be obtained with clinical routine scanners and scan protocols, utilizing a simple global segmentation threshold, thereby providing an accurate and reliable tool for pre-operative planning.
摘要：
三维（3D）打印解剖模型的引入引起了术前计划的兴趣，尤其是骨科和创伤外科.识别潜在的误差源并量化它们对模型尺寸精度的影响对于此类模型的适用性和可靠性至关重要。在这项研究中,从解剖前臂标本中提取20个半径，并进行截骨术，以模拟桡骨远端确定的骨折（Colles骨折）。各种因素,包括两种不同的计算机断层扫描（CT）技术（能量积分探测器（EID）和光子计数探测器（PCD）），四种不同的CT扫描仪,两种扫描协议(即，常规和高剂量)，两种不同的扫描方向，以及两种分割算法被认为是确定他们对三维模型精度的影响。使用物理标本的表面扫描的3D重建来建立地面实况。结果表明，所有研究的变量都显着影响3D模型的准确性（p<0.001）。然而,平均绝对偏差落在0.03±0.20至0.32±0.23mm的范围内，远低于术前计划所需的0.5毫米阈值。操作员内和操作员间的可变性证明了3D模型准确性的良好一致性，类内相关性（ICC）为0.43至0.92。此系统调查显示了所有变量的亚体素成像分辨率大小的尺寸偏差。主要陷阱包括在分割过程中丢失或高估的骨骼区域，需要对3D模型进行额外的手动编辑。总之,这项研究表明，3D骨折模型可以通过临床常规扫描仪和扫描协议获得，利用简单的全局分割阈值，从而为术前计划提供了准确可靠的工具。
