High-resolution ultrasound in the diagnosis of trigger finger and evaluation of response to steroid injection

No studies have reported the use of ultrasound for the evaluation of trigger finger after steroid injection. We evaluated the clinical features and ultrasound appearance of trigger finger before and after steroid injection under ultrasound guidance. Thirty-eight digits with triggering were included. A single steroid injection into the tendon sheath was administered. Ultrasound findings and clinical symptoms, including pain, triggering, and the Quinnell score, were analyzed before injection and at 1 and 3 weeks after injection. Ultrasound indicated that the thickness of the flexor tendons and the thickness of A1 pulleys were significantly greater in the trigger fingers than in controls before steroid injection. Three weeks after injection, these two parameters decreased, and there was no significant difference in the two parameters between the trigger finger and the controls. The visual analogue scales at 1 and 3 weeks after the injection were significantly lower than those before the injection. The Quinnell grading system scores significantly improved at 1 and 3 weeks after injection compared with the scores before injection. Moreover, a tendency was seen for the more clinically severe cases to show more swelling of the tendon and pulley. In conclusion, ultrasound assessments could reveal that the thickened A1 pulley and flexor tendon significantly improved after steroid injection, which enables us to confirm the therapeutic effects of the steroid injection. Therefore, ultrasound assessments can be a useful adjunct to understand the response to treatment with the steroid injection.