Detection of Traumatic Ankle Arthrotomies: Computed Tomography Scan vs. Saline Load Test.

OBJECTIVE: Periarticular wounds present a common diagnostic dilemma for emergency providers and orthopedic surgeons, as traumatic arthrotomies (TA) often necessitate different management from superficial soft tissue wounds. Historically, TA have been diagnosed with the saline load test (SLT). Computed tomography (CT) scan has been studied as an alternative to SLT in diagnosing TA in several joints, but there is limited data specifically pertaining to the ankle. This study aimed to compare the ability of a CT scan to identify an ankle TA versus a traditional SLT. The hypothesis was there would be no significant difference between a CT scan and SLT in diagnosing ankle TA in a cadaveric model.

METHODS: This cadaveric study utilized ten thawed fresh-frozen cadaveric ankles. A baseline CT scan was performed to ensure no intra-articular air existed before simulated TA. After the baseline CT, a 1 cm TA was created in the anterolateral arthroscopy portal site location. The ankles then underwent a post-arthrotomy CT scan to evaluate for the presence of intra-articular air. After the CT scan, a 30 mL SLT was performed using the anteromedial portal site location.

RESULTS: Following arthrotomy, intra-articular air was visualized in seven of ten cadavers in the post-arthrotomy CT scan. All the ankles had fluid extravasation during the SLT with less than 10 mL of saline. The sensitivity of the SLT for TA was 100% versus 70% for the CT scan.

CONCLUSION: The SLT was more sensitive in diagnosing 1 cm ankle TA than a CT scan in a cadaveric model.