FP7.7 Cone Beam Tomosynthesis Fluoroscopy (CBTF) imaging utilization in periacetabular osteotomy (PAO) surgery

Abstract ICLB07 - The Digital Surgeon: Practical Tools and Navigation Basics for Your Everyday Practice, Session Room 12 (BMCC Level 3), October 8, 2026, 14:00 - 16:00 Introduction The periacetabular osteotomy (PAO) is a complex surgery used to treat symptomatic acetabular dysplasia. Surgical success depends upon accurate intra-operative acetabular fragment positioning. Enhanced outcomes may be achieved with imaging modalities that provide intra-operative 3-dimensional (3D) visualization, such as Cone Beam Tomosynthesis Fluoroscopy (CBTF). CBTF provides fast intra-operative 3D and 2D imaging. This study evaluated the reliability of 2D assessment with CBTF in comparison to x-rays and standard fluoroscopy imaging in PAO surgery. Methods A prospective, IRB-approved, single institution study was conducted evaluating PAO patients. Lateral Center Edge Angle (LCEA), Tönnis angle, Anterior Center Edge Angle (ACEA) were measured on x-ray, fluoroscopy, and CBTF before and after PAO correction. Power analysis demonstrated n=18 as the minimum study participants needed. Agreement across imaging modalities was assessed using Intraclass Correlation Coefficients (ICC). Differences between modalities were evaluated using a Friedman test. Bland-Altman analysis assessed agreement and quantified bias between imaging techniques by evaluating mean differences and limits of agreement, indicating how closely radiographic measurements correspond for each patient. Results Twenty-two patients were included. Preoperative agreement across x-ray, fluoroscopy, and CBTF imaging was excellent for LCEA (ICC = 0.956) and Tönnis angle (ICC = 0.904), and good for ACEA (ICC = 0.778). Postoperatively, LCEA maintained good agreement (ICC = 0.768), Tönnis angle had moderate agreement (ICC = 0.587), and ACEA demonstrated poor-to-moderate agreement (ICC = 0.404). No significant differences (Friedman test) were observed across modalities for LCEA at either timepoint (p > 0.05), whereas significant differences were identified for Tönnis angle and ACEA. These findings indicate that LCEA is the most reliable measurement across imaging modalities, while ACEA demonstrates variability. Bland-Altman analysis showed minimal bias and narrow limits of agreement for LCEA, while ACEA demonstrated more variability. Pairwise analysis demonstrated x-ray measurements aligned most closely with CBTF for LCEA, with tighter agreement than when compared to fluoroscopy. Conclusion Pre-operative and post-operative CBTF LCEA measurements had strong agreement with better correlation to x-ray than fluoroscopy. These findings indicate that CBTF provides valuable intra-operative imaging assessment. Further investigations utilizing CBTF 3D abilities to guide and navigate PAO osteotomies, correction, and implant placement are warranted.