Sonoarthrographic evalution of the ankle anterolateral capsuloligamentous complex and recess and MR arthrographic correlation

Objective: Our study aims to evaluate the diagnostic contribution of ultrasonography (USG) and sonoarthrography in detecting and characterizing pathologies of the anterolateral recess and capsuloligamentous complex of the ankle joint, using magnetic resonance arthrography (MRA) as a reference approach. Materials and Methods: Between November 2023 and January 2024, USG, sonoarthrography, and MRA examinations were performed on 40 patients who presented to the Orthopedics and Traumatology or Physical Medicine and Rehabilitation Department of our hospital with chronic ankle pain with the exhibition of suspicious pathologies in the anterolateral structures of the ankle joint upon physical examination and met the indications for arthrography. In all three imaging modalities, the integrity of the anterior talofibular ligament (ATFL) was assessed, and if a lesion was present, it was classified as either partial or complete. Additionally, thickening of the anterolateral joint capsule, if detected, was categorized as nodular or diffuse, and the presence of obliteration in the anterolateral joint recess was evaluated. Two independent radiologists interpreted the images separately. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were calculated, by considering MRA as the gold standard. Interobserver agreement was also statistically analyzed. Findings: Examinations of three methods which are ultrasonography (USG), sonoarthrography and MRA of 40 cases (23 males and 17 females) were included in the study. MRA was designated as the gold standard. The sensitivity, specificity, and diagnostic accuracy rates of sonoarthrography for the joint capsule were 58-47%, 90-86%, and 75-68%, respectively; for the anterolateral recess, these values were 45-46%, 93-93%, and 80-80%, respectively; and for the ATFL, they were 67-67%, 94-94%, and 90-90%, respectively. In USG data, substantial interobserver consistency was observed for the joint capsule, anterolateral recess, and ATFL. In sonoarthrographic examination, there was almost perfect interobserver consistency for the joint capsule and anterolateral recess, while perfect consistency for the ATFL was observed. Conclusion: Our findings indicate that sonoarthrography is a cost-effective and accessible alternative imaging modality with high sensitivity, specificity, and interobserver consistency in the assessment of anterolateral recess and capsuloligamentous complex pathologies of the ankle joint. Keywords: Sonoarthrography, Magnetic Resonance Arthrography, Anterior Talofibular Ligament, Ankle Instability, Anterolateral Impingement