Corticosteroid injection for trigger finger: blinded or ultrasound-guided injection?

Trigger digit is one of the most common causes of pain and disability in the hand. The mainstay of conservative treatment of this disease has been local steroid injection into the tendon sheath. The aim of this study was to investigate the clinical benefit of an ultrasound-guided corticosteroid injection compared to a blinded application.

74 patients, who suffered from persistent or increasing symptoms of a single trigger digit, were enroled in this prospective, randomised case-control study. All patients were treated with an injection of 40 mg/1 ml methylprednisolone acetate into the flexor tendon sheath at the level of the A1 pulley. Half of the patients had their injections under ultrasound control (USG) and half without (blinded injection group, BIG). Associated metabolic diseases were recorded. At the 6-week and 6-month follow-up examinations, the complication rate and the need for a second injection were assessed. The outcome was rated using the Quinnell grading. The pain level was assessed using the visual analogue scale.

Four patients were excluded due to lack of follow-up. Both study groups were comparable in respect of age, hand dominance and associated diseases. There were significantly more female patients in the USG group (32 versus 23 %). After the corticosteroid injections, all patients improved significantly in terms of pain level and the Quinnell grading at 6 weeks and 6 months after the intervention in comparison to the pre-injection status. There were no significant differences between the groups. 9 patients (13 %) needed a second injection (6 of BIG, 3 of USG), all of whom had diabetes mellitus. No local complications were seen after the injections.

The use of ultrasound-guided injection of corticosteroid may be associated with extra time and effort, with no superior clinical benefits compared to the blinded technique.

Level 1(prospective randomised study).