Automated Syndesmotic Distance, Area, and Volume Measurements Using 3D Segmentations of Weightbearing Computed Tomography Scans

Abstract

Category: Ankle; Sports Introduction/Purpose: Syndesmotic injuries may be associated with subsequent instability, even following operative fixation of etiologic fractures. The development of advanced imaging techniques like weightbearing computed tomography (WBCT) has enabled clinicians to identify subtle syndesmotic instability under physiologic conditions that would otherwise go undetected using conventional CT scans. Moreover, the normal reference ranges for the syndesmotic interval distance, area at 1 cm above the plafond, and volume 5 cm above the plafond have been established. These measurements, however, may be cumbersome and time-consuming to perform. This validation study aims to develop and evaluate the reliability of an automated algorithm that automatically segments WBCTs of the ankle and performs dimensional measurements. Methods: Five bilateral WBCT scans of individuals with operatively confirmed syndesmotic instability were included (10 ankles). An independent observer manually performed the anterior tibiofibular distance (ATFD) at 1 cm above the plafond, posterior talofibular distance (PTFD) at 1 cm above the plafond, the syndesmotic area (SA) at 1 cm above the plafond using 2D ROI, and the syndesmotic volume (SV) at 5 cm above the plafond using 3D ROI. Visage software was used to perform the measurements manually. The same WBCT scans were fed into the automated algorithm to perform the same measurements. The time required to perform the manual and automated measurements was recorded for comparison. The intraclass correlation coefficient (ICC) was measured for repeated automated measurements to evaluate the automation's consistency Results: The manual measurements required 19 (+/-4) minutes on average to perform for each case compared to 9 (+/-1) minutes for the automated measurements (P< 0.05). The ICC between the repeated automated measurements for each case was 0.99. Conclusion: Our automated syndesmosis dimension measurement tool can efficiently perform the ATFD, PTFD, SA, and SV measurements as reliably as an expert clinician would with significantly less time. Incorporating such a tool into existing healthcare software infrastructure, particularly in foot and ankle clinics, may expand the accessibility of this tool and provide immediate data for clinicians to support their decision-making in real time.