Ultrasound Features for the Diagnosis of Adhesive Capsulitis/Frozen Shoulder: A Systematic Review

While ultrasound has become a preferred tool for musculoskeletal imaging, differing ultrasound findings that have been reported in patients with adhesive capsulitis can create confusion and misconceptions. This systematic review was aimed at summarizing all the ultrasound features currently described in the literature and providing a critical analysis of the sources to allow the readers to make a well-informed decision on the reliability of these features in the diagnosis of this condition. Databases were searched for original studies up to August 2021. Twenty-three studies were included. The QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool was used to assess the quality of each selected article. Fourteen ultrasound features were identified. A quality analysis of all ultrasound features was performed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) framework. All studies exhibited considerable heterogeneity in investigated ultrasound features and methodologies employed; therefore, meta-analysis was not considered to be appropriate. Hence, narrative synthesis was performed. The overall quality of each ultrasound outcome was found to be of "low" to "very low" level, and the generalisability of the results was also thought to be limited. Cautious interpretation and clinical correlation are recommended while applying these ultrasound features in clinical practice.