Computed Tomography Scan vs Saline Load Test in the Detection of Traumatic Arthrotomies of the Ankle: A Cadaveric Study

Abstract

Category: Trauma Introduction/Purpose: The diagnosis of traumatic arthrotomy is typically made through a saline load test (SLT), though there has been a growing base of literature regarding the use of computed tomography (CT) scan in various joints for diagnosis. To date, there has been little data supporting the use of CT to diagnose traumatic arthrotomy of the ankle. Through simulated arthrotomies of the ankle in cadavers, we aim to assess the sensitivity and ability of CT for diagnosing traumatic arthrotomy. SLT were also performed in each specimen to determine the volume of saline needed for diagnosis. Methods: Six fresh-frozen cadavers with twelve ankles were initially included in this study. The presence of intra-articular air prior to arthrotomy was excluded with a baseline CT scan. Ankles underwent arthrotomy at the anterolateral, anteromedial, posteromedial, posterolateral portals with fluoroscopic guidance. A subsequent CT scan was obtained to identify the presence of intra-articular air. Ankles then underwent SLT and volumes resulting in extravasation were recorded. Results: Eleven ankles were included, with one exclusion due to the presence of implants. Arthrotomies were made in three ankles at the anterolateral portal, three at the anteromedial portal, two at the posteromedial portal, and three at the posterolateral portal. Following arthrotomy, intra-articular air was detected in all eleven ankles by CT scan. All eleven ankles were subjected to SLT, with each demonstrating extravasation through the arthrotomy site. The mean volume of saline needed for extravasation was 7.7 mL, with a range of 3 to 22 mL and a standard deviation of 5.4. Conclusion: CT scan was demonstrated to be sensitive and effective in diagnosing traumatic arthrotomy in a cadaveric model.