Investigation of Biomechanical Characteristics of Intact Supraspinatus Tendons in Subacromial Impingement Syndrome: A Cross-sectional Study with Real-time Sonoelastography.

Objective: The aim of this work was to evaluate the real-time sonoelastography (RTSE) in the assessment of the supraspinatus tendon in patients with subacromial impingement syndrome (SIS).

Methods: Twenty-five patients with unilateral shoulder pain that was diagnosed as SIS according to magnetic resonance imaging findings were included in the study. Healthy shoulders of the patients comprised the control group. Bilateral shoulder RTSE examinations were performed by a radiologist who was blinded to the involved side of the participants. The RTSE images were recorded and assessed by 2 radiologists individually 1 month later. American Shoulder and Elbow Surgery shoulder index, Quick Disabilities of Arm Shoulder and Hand Questionnaire, and Constant scores were applied to evaluate the disability and functional status. The correlation between strain ratio and functional scores were investigated.

Results: Of the 25 participants, 9 (36%) were men and 16 (64%) were women. The RTSE findings were pathologic in tendons of 23 patients (92%) with SIS. The strain ratio was significantly higher in the affected shoulders (P < 0.001). The interobserver agreement was good for image analysis. There was no significant correlation between strain ratio and functional scores.

Conclusion: Structural changes in the supraspinatus tendon can be demonstrated with RTSE in patients with SIS.