The validity of ultrasound and shear wave elastography to assess the quality of the rotator cuff.

OBJECTIVES: US with shear wave elastography (SWE) could reduce the burden and costs of the diagnostic process for patients with rotator cuff disorders. The aim of this study is to investigate the validity of US and SWE in preoperative assessment of fatty infiltration (FI) and muscle atrophy of the supraspinatus (SSP) and infraspinatus (ISP) muscles. METHODS: Patients with a rotator cuff disorder and a recent shoulder CT or MRI scan were eligible to participate. Goutallier and Warner stages of the SSP and ISP muscle were measured on the scan, for assessment of FI and muscle atrophy, respectively. These findings were compared with shear wave velocities (SWVs) assessed on US. Visual assessment of FI on US was compared with the Goutallier stage. To quantify the amount of muscle atrophy, the occupation ratio between SSP fossa and muscle was measured on MRI and US. RESULTS: Seventy-eight shoulders were included in the analysis. The correlation found between the occupation ratio on US and Warner and Goutallier stage and ratio on MRI ranged between r = - 0.550 to 0.589. The Goutallier stage of ISP and SSP muscle assessed on US showed a fair correlation with the Goutallier stage on a scan of r = 0.574 and r = 0.582, respectively. There was a poor correlation between the SWVs and scan results (r = - 0.116 to 0.07). CONCLUSION: SWE is not a valid method to measure the amount of FI or muscle atrophy in the SSP muscle. Therefore, SWE is not a suitable alternative for MRI in standard preoperative diagnostics in rotator cuff pathologies. CLINICAL RELEVANCE STATEMENT: Shear wave elastography should not be used in the diagnostics of rotator cuff pathologies. KEY POINTS: • There is a fair correlation between the Goutallier stage of the supraspinatus and infraspinatus muscle assessed on MRI and CT and visual assessment of fatty infiltration achieved on US. • Shear wave elastography is not a valid tool for the determination of the amount of fatty infiltration or muscle atrophy. • Shear wave elastography should not be used as a cheaper and less burdensome alternative for diagnostics in rotator cuff pathologies.

Handheld Ultrasound Does not Replace Magnetic Resonance Imaging for Diagnosis of Rotator Cuff Tears.

Purpose: The purpose of this study was to examine the reliability and validity of handheld ultrasound (HHUS) alone versus conventional ultrasound (US) or magnetic resonance imaging (MRI) for diagnosis of rotator cuff tears and versus MRI plus computed tomography (CT) for diagnosis of fatty infiltration. Methods: Adult patients with shoulder complaints were included in this study. HHUS of the shoulder was performed twice by an orthopedic surgeon and once by a radiologist. RCTs, tear width, retraction and FI were measured. Inter- and intrarater reliability of the HHUS was calculated using a Cohen's kappa coefficient. Criterion and concurrent validity were calculated using a Spearman's correlation coefficient. Results: Sixty-one patients (64 shoulders) were included in this study. Intra-rater agreement of HHUS for assessment of RCTs (к = 0.914, supraspinatus) and FI (к = 0.844, supraspinatus) was moderate to strong. Interrater agreement was none to minimal for the diagnosis of RCTs (к = 0.465, supraspinatus) and FI (к = 0.346, supraspinatus). Concurrent validity of HHUS compared to MRI was fair for diagnosis of RCTs (r = 0.377, supraspinatus) and fair-to-moderate FI (r = 0.608, supraspinatus). HHUS shows a sensitivity of 81.1% and specificity of 62.5% for diagnosis of supraspinatus tears, 60% and 93.1% for subscapularis tears, 55.6% and 88.9% for infraspinatus tears. Conclusions: On the basis of findings in this study, we conclude that HHUS is an aid in diagnosis of RCTs and higher degrees of FI in patients who are not obese, but it does not replace MRI as the gold standard. Further clinical studies on the application of HHUS comparing HHUS devices in larger patient populations and healthy patients are required to identify its utility in clinical practice. Level of Evidence: Level III.