Accuracy of MRI to Detect Lateral Ulnar Collateral Ligament Tears.

The objective of this study was to determine accuracy of magnetic resonance imaging (MRI) in detecting lateral ulnar collateral ligament (LUCL) tears. In this retrospective cohort study, two shoulder and elbow surgeons performed blinded review of preoperative MRIs to determine the presence of complete LUCL tears. Consensus interpretations were compared with operative reports. Fifty-nine patients were identified, 11 with LUCL tears confirmed intra-operatively. Sensitivity of the two observers and original radiologists was 90.9%, 90.9%, and 72.7, and specificity was 81.3%, 91.6%, and 97.9%, respectively. Combined consensus sensitivity and specificity of MRI in detecting LUCL tears was 100% and 95.8%, respectively. Inter-observer reliability was moderate (k = 0.54). Positive predictive value and negative predictive value were 84.6% and 100%, respectively. Overall accuracy was 96.6%. Clinical interpretation by shoulder and elbow surgeons results in moderate inter-observer agreement for diagnosis of complete LUCL disruption. Despite modest positive predictive value, data indicate high accuracy, sensitivity, specificity, and negative predictive value using MRI to detect LUCL tears. Level of Evidence: Level III Diagnostic. (Journal of Surgical Orthopaedic Advances 34(4):185-187, 2025).