THE ROLE OF ULTRASONOGRAPHY IN THE EVALUATION OF INJURY TO THE GLENOID LABRUM

Participants: J.E. Kuhn, M. Taljanovic, L.J. Huston, K. Carlson, R. Adler

Keywords: shoulder, ultrasound, Bankart lesion

Introduction

Ultrasonography has been a useful imaging modality for a variety of shoulder disorders. Clinical experience and some reports in the literature suggest that ultrasound may have a role in detecting labral pathology. The purpose of this study was to assess the utility of ultrasonography in the evaluation of Bankart lesions in a cadaver model.

Materials and Methods

Twenty cadaver shoulders (mean age 80.5+9.4 years; 15 male, 5 female; 10 left, 10 right) were disarticulated from the thorax at the medial border of the scapula and the sternoclavicular joint. The specimens were then examined arthroscopically through a standard posterior portal. An anterior portal was made in all specimens through the rotator interval from inside to out. The specimens were randomly assigned to two groups. In ten specimens a Bankart lesion was created by elevating the labrum away from the glenoid from the 3 o’clock to 6 o’clock position arthroscopically. Fluid was drained from all shoulders before ultrasonographic examination. Ultrasound examination was carried out by two experienced radiologists with conventional Diasonics 5 or 7.5 Mhz linear ultrasound transducers. The radiologists were blinded to the test group for each specimen. The radiologists recorded the presence or absence of a Bankart lesion. Sensitivity, specificity, positive predictive value, and negative predictive value were then calculated. Errors in identification were evaluated by a later review of the specimens and ultrasound records.

Results

The sensitivity of detecting Bankart lesions with ultrasound in this study was 70%. Specificity was 70%. The positive predictive value and negative predictive value were each 70%. Additional abnormal pathology such as osteoarthritis, degeneration of the labrum, and synovitis in these specimens created the potential for errors in detecting Bankart lesions in this cadaver model. One specimen had the Buford anatomic variant that was misinterpreted as a Bankart lesion on ultrasound.

Conclusions

Ultrasonography may be a helpful adjunct in detecting Bankart lesions. Pre-existing pathology in the glenohumeral joint may limit the usefulness of this imaging modality for this application, however, there may be a role in younger patients without concurrent pathology.