Ultrasound Assessment of Anterior Humeral Head Translation in Patients With Anterior Shoulder Instability: Correlation With Demographic, Radiographic, and Clinical Data

Abstract

Background: Ultrasonography can be used to quantitatively assess anterior humeral head translation (AHHT) at different degrees of shoulder abduction. Risk factors for recurrent shoulder instability have been identified. Hypothesis: It was hypothesized that the number of dislocations or glenoid or humeral bone loss would be associated with more AHHT as measured using ultrasound. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 39 patients who underwent surgery for anterior shoulder instability were prospectively studied. Ultrasound assessment of AHHT was performed immediately after general anesthesia was induced. The upper arm was placed at 0°, 45°, and 90° of abduction, and a 40-N anterior force was applied to the proximal third of the arm. The distance from the posterior edge of the glenoid to that of the humeral head was measured at each abduction angle using ultrasound with and without a 40-N anterior force, and the AHHT was calculated. The differences in translation at each shoulder angle were compared. Additionally, the authors investigated the association between AHHT and demographic, radiographic, and clinical data. Results: Compared with the AHHT at 0° of abduction (5.29 mm), translation was significantly larger at 45° of abduction (8.90 mm; P