Sonographic evaluation of anterosuperior hip labral tears with magnetic resonance arthrographic and surgical correlation

Objectives-The purpose of this study was to retrospectively evaluate the sonographic findings compared with magnetic resonance (MR) arthrographic and arthroscopic findings in diagnosis of anterosuperior labral tears of the hip. Methods-The Ethics Committees of our institution did not require patient approval or informed consent for this retrospective study. Sixteen symptomatic patients (4 male and 12 female; mean age, 43 years) with sonography, MR arthrography, and arthroscopy were enrolled. At arthroscopy, 11 patients were shown to have anterosuperior labral tears. We evaluated the findings of the anterosuperior acetabular labrum on sonography, with an emphasis on the presence or absence and types of labral tears, and correlated the findings with MR arthrography and arthroscopy. The types of tears were classified into radial flap, radial fibrillated, and longitudinal peripheral (base) tears. We calculated the sensitivity, specificity, and accuracy of sonography and MR arthrography. Results-On sonography, 12 of 16 patients (75%) had a correct diagnosis of the presence or absence of an anterosuperior labral tear. On MR arthrography, 14 of 16 patients (88%) had a correct diagnosis of the presence or absence of a tear. The sensitivity, specificity, and accuracy for the diagnosis of tears by sonography and MR arthrography were 82%, 60%, and 75% and 91%, 80%, and 88%, respectively. Conclusions-When the arthroscopic results were used as the reference standard, our preliminary study revealed that sonography managed to show anterosuperior labral abnormalities, although it had a lesser diagnostic ability than MR arthrography in diagnosing anterosuperior labral tears. Additional investigations including larger numbers of patients are required to determine whether sonography can be an alternative or adjunctive imaging technique for diagnosis of hip labral tears, especially in patients who decline or are unable to undergo MR arthrography.