Role of shear wave elastography in the evaluation of the treatment and prognosis of supraspinatus tendinitis

BACKGROUND: Supraspinatus tendinitis recurs easily after treatment. One of the main reasons is the lack of objective tools for the efficacy evaluation. Shear wave elastography (SWE) can quantitatively analyze the tissue elasticity of region of interest by measuring the Young’s modulus (YM) value. AIM: To explore the role of SWE in the efficacy and prognostic evaluation of supraspinatus tendinitis. METHODS: Eighty-seven patients with supraspinatus tendinitis treated in Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences were recruited. Another 30 healthy volunteers were enrolled as the control group. The visual analogue scale (VAS) and Constant-Murley Score (CMS) were recorded before treatment. All participants were scanned by SWE scan, and the YM value of the region of interest were recorded. Spearman correlation analysis was performed on YM values with VAS and CMS. Univariate repeated measures analysis of variance was used to calculate the changing trend of VAS, CMS and SWE under different treatment courses. After treatment, the patients were further grouped based on who achieved significantly effective and curative treatment. The patients in the continued treatment group continued to receive treatment according to the YM value, and the remaining patients who stopped receiving treatment were included in the stopped treatment group. All patients were followed up for 1 year, and the difference in recurrence rates between the continued treatment group and the stopped treatment group were compared. RESULTS: The SWE images of supraspinatus muscle in healthy volunteers were mainly blue, while those of patients with supraspinatus tendinitis showed regional red and green areas. The average YM value of the supraspinatus muscle in healthy volunteers was 26.12 ± 4.03 kPa. The average YM value of patients with supraspinatus muscle was greater than that of healthy volunteers (average YM = 60.61 ± 11.53 kPa, t = 26.344, P < 0.001). The YM value was positively correlated with VAS (r = 0.564, P < 0.001) and negatively correlated with CMS (r = -0.411, P < 0.001). The changes of VAS and CMS were the most obvious in course 1 and then decreased gradually. The degree of change in YM values was similar in different courses. After a 1-year follow-up, the cumulative relapse-free rate in the continued treatment group was 91.43%, which was significantly higher than that in the stopped treatment group (64.71%, X(2) = 7.379, P = 0.007). CONCLUSION: SWE can objectively indicate the severity of supraspinatus tendinitis. Using the YM value as a criterion for curative effect may reduce the recurrence rate.