Sensitivity, specificity, and predictive values of ultrasound imaging in primary adhesive capsulitis diagnosis

Compare the ultrasound findings in primary adhesive capsulitis and a control group to determine the sonographic diagnostic performance.

This retrospective single-center study compared US findings in patients with a clinical and MRI diagnosis of adhesive capsulitis and a control group of consecutive patients. The US findings were as follows: coracohumeral ligament thickening, increased tissue and vascularity of the rotator interval, axillary recess thickening and hypervascularity, and subacromial gliding. Ultrasound findings were evaluated by Student's t-test and Fisher's exact test (p < 0.05).

The mean (± SD) thickness of the coracohumeral ligament (2.3 ± 0.6 vs 1.6 ± 0.3; p < 0.001) was significantly greater in the adhesive capsulitis group (n = 61) than in the control group (n = 69). A cut-off value of 1.6 mm (AUC 0.963, 95% CI 0.934-0.992), yielded 90.2% sensitivity and 90.9% specificity. In the rotator interval, the presence of tissue (72.1% vs 11.6%; p < 0.001) and hypervascularity (8.2% vs 0%, p < 0.02) were significantly higher in the adhesive capsulitis group. In the axillary recess, the mean thickness in the axial (4.7 ± 1.3 vs 1.4 ± 0.4; p < 0.001) and longitudinal plane (4.4 ± 1.2 vs 1.4 ± 0.5; p < 0.001) was significantly higher in the adhesive capsulitis group. A cut-off value of 3 mm (AUC 1) obtained 100% sensitivity and specificity. Increased Doppler flow in the axillary recess (9.8% vs 0%, p < 0.009) and limited subacromial gliding (93.4% vs 2.9%; p < 0.001) were also associated with adhesive capsulitis.

Several ultrasound findings are typical in primary adhesive capsulitis. Therefore, ultrasound can be considered the first diagnostic tool.