Contrast-Enhanced Ultrasound (CEUS) Determines Supraspinatus Muscle Atrophy after Cuff Repair

Muscle degeneration following rotator cuff tears is mainly assessed by MRI. Contrast-enhanced ultrasound (CEUS) as functional imaging can assess microvascular perfusion which represents muscle tissue vitality. In this cross-sectional study we evaluated the supraspinatus muscle perfusion after cuff repair and analyzed its association to the grade of echogenicity in B-mode ultrasound indicating fatty infiltration and the functional shoulder outcome. Patients that received unilateral refixation of the supraspinatus were invited for a single follow-up, functional scores such as Constant-Score (CS) were assessed. CEUS examination was performed bilaterally in an oblique sagittal plane of the supraspinatus fossa. Perfusion was quantified with parameters like Wash-in-Perfusion-Index (WiPI) and Peak Enhancement (PE) using VueBox quantification software. Function and perfusion were referenced to the contralateral shoulder and correlated. Echogenicity was classified in a three-point scale compared to the trapezius muscle. 67 patients were available with a mean follow-up of 38.0±18.5 months. The function of the operated shoulder was worse than contralaterally (relative CS: 80±19%). CEUS revealed diminished perfusion on the operated shoulder (WiPI, 55.1±40.2%, p