To explore the evaluation effect of computer grayscale analysis value on patients with supraspinatus tendinopathy.

Forty-six patients with unilateral supraspinatus tendinopathy in the rehabilitation department of the Fifth Affiliated Hospital of Guangzhou Medical University were selected. The patients with shoulder pain caused by bilateral shoulder pain and other non-tendon factors were excluded. According to gender, age, disease course, the patients were divided into the male group (16 cases) and the female group (30 cases), or the young adults group (10 cases), the middle-age group (19 cases), the elderly group (17 cases), and the acute phase group (13 cases), the chronic phase group (19 cases), the chronic prolongation group (14 cases). The supraspinatus tendon was palpated for visual analogue scale (VAS) scoring and locating the primary and secondary trigger points. Ultrasound short axis radiographs of the supraspinatus tendon were acquired in the Crass posture. The screenshot of the main and secondary trigger points was taken on the affected side and healthy side with equal-area and their grayscale values were measured by computer gray analysis. The paired t test was used to compare the grayscale values of the affected side and the healthy side, as well as the main and secondary trigger points. Single factor analysis of variance was used to compare the grayscale values on the main and secondary trigger points between different genders, ages, and disease courses. The computer grayscale analysis method was used to quantitatively evaluate the echo difference of supraspinatus trigger points.

There were multiple trigger points on the supraspinatus tendon, which could be divided into primary and secondary trigger points according to the VAS score. The VAS score of main trigger points in the female group was higher than that in the male group (P=0.035). The VAS score of main trigger point in the elderly group was higher than that in middle-age group and the young adults group (P<0.05). The grayscale value of the main and secondary trigger points of the supraspinatus tendon was less than that of the healthy side (t=8.109, 4.816, both P<0.001). Grouping by gender, disease course or ages, the grayscale values on the affected side were significantly lower than those on the healthy side (all P<0.05). The grayscale value of the healthy side in females was lower than that in males (t=3.881, P<0.001), which was lower in the elderly group than that in the middle-age group and the young adults group (F=14.000, P<0.001).

The supraspinatus tendon is a disease that often has multiple trigger points, and ultrasound examination of all trigger points is required. For visual evaluation of supraspinatus tenderness points with no characteristic signs, a decrease in the grayscale average compared to the healthy side may indicate supraspinatus tendinopathy. This method can quantify the degree of rotator cuff tendinopathy and is expected to provide a reference for the diagnosis of the disease.