Purpose: This study evaluated the accuracy of an automated 2D-3D registration software for matching preoperative 3D models of the pelvis and acetabular component to intraoperative 2D fluoroscopy images in total hip arthroplasty (THA).

Methods: We developed a 2D-3D registration software that registers a 3D model of the pelvis from preoperative CT and a 3D model of the acetabular implant to intraoperative fluoroscopic imaging, thereby calculating the implant position relative to the 3D pelvic reference frame. A total of 145 datasets were used including 65 digitally reconstructed radiographs, 20 dry bone phantoms datasets and 60 clinical datasets with preoperative CT and intraoperative fluoroscopy imaging. Achieved acetabular positions from the clinical images were determined from post-operative CT using a 3D/3D registration method. Accuracy was assessed by comparing the calculated acetabular position from the 2D-3D software to the ground truth data.

Results: Mean absolute difference between ground truth and the 2D-3D software was 1.9° [signed error range: -4.4, 4.8] for inclination, 1.5° [-7.3, 4.1] for anteversion, 1.6 mm [-5, 3.8] for cup height and 1.8 mm [-7.3, 4.1] for depth across all datasets. In total, 100% of inclination results and 98% of anteversion results were within 5° while 90% of height and 81% of depth results were within 3 mm.

Conclusion: We validated the accuracy of an automated 2D-3D registration software for use in THA. While our method requires preoperative data from CT, the results are comparable to robotics and image-based navigation, and present a promising, simple technology that can be easily integrated into an operating room for THA.

Keywords: 2D–3D registration; Acetabular positioning accuracy; CT; Computer-assisted total hip arthroplasty; Intraoperative fluoroscopy; Pelvis.

© 2025. CARS.

目的： 本研究评估了一种自动化二维至三维（2D-3D）配准软件在全髋关节置换术（THA）中，将术前骨盆和髋臼假体的三维模型与术中二维荧光透视图像进行匹配时的准确性。

方法： 我们开发了一种2D-3D配准软件，该软件可以将来自术前CT的骨盆三维模型和髋臼植入物的三维模型注册到术中的荧光透视影像中，从而计算出相对于三维骨盆参考框架的假体位置。总共使用了145个数据集，包括65个数字重建X射线图像、20个干骨仿体数据集以及60个包含术前CT和术中荧光透视图像的临床数据集。从术后CT通过3D/3D配准方法确定来自临床图像的髋臼位置。通过将计算出的髋臼位置与真实值进行比较来评估准确性。

结果： 在所有数据集中，相对于真实值的角度倾斜误差平均绝对差异为1.9° [有符号错误范围：-4.4, 4.8]，前倾角误差平均绝对差异为1.5° [-7.3, 4.1]，髋臼杯高度误差的平均绝对差异为1.6毫米 [-5, 3.8]，深度误差的平均绝对差异为1.8毫米 [-7.3, 4.1]。总体而言，所有倾斜结果中有100%在5°以内，前倾角结果中98%在5°以内；高度和深度的结果分别有90%和81%小于3毫米。

结论： 我们验证了一种用于THA的自动化2D-3D配准软件的准确性。尽管我们的方法需要从CT获取术前数据，但其结果与机器人技术和基于图像导航的方法相当，并且提供了一项有前景、简单的技术，可以轻松地在手术室中集成使用。

关键词： 2D–3D配准；髋臼定位精度；CT；计算机辅助全髋关节置换术；术中荧光透视；骨盆。