Steroid versus placebo injection for trigger finger. Controlled study of the use of local steroid injection in the treatment of trigger finger and thumb.
The ability of a single injection of steroid and lidocaine to bring about cure of primary trigger finger was determined and compared with a control placebo injection of only lidocaine. Twenty-four patients were randomized to the therapeutic or control group and were followed prospectively. One physician administered the injection, another the clinical examination after injection, and a third evaluated the results blindly. Patients were not told to which group they were assigned. Nine of the 14 patients in the steroid group versus two of the ten patients in the placebo group were cured of trigger finger at final follow-up examination. After injection, seven patients had immediate but temporary relief of triggering because of flexor sheath distention. One injection cured 64% [corrected] of patients with primary trigger finger with no side effect and is the recommended nonsurgical treatment. A controlled double-blind prospective study of injection of methylprednisolone acetate plus local anaesthetic against a control injection of a local anaesthetic in the treatment of trigger finger and thumb has shown a 60% success rate for the steroid injection against 16% for the control group (p less than 0.05). This is the first controlled trial of local steroid therapy in this condition.
The effectiveness of local corticosteroid injections was studied in only two small randomized controlled trials of poor methodological quality. Both studies showed better short-term effects of corticosteroid injection combined with lidocaine compared to lidocaine alone on the treatment success outcome. In one study the effects of corticosteroid injections lasted up to four months. No adverse effects were observed. The available evidence for the effectiveness of intra-tendon sheath corticosteroid injection for trigger finger can be graded as a silver level evidence for superiority of corticosteroid injections combined with lidocaine over injections with lidocaine alone.