Corticosteroid injections for trigger finger

Trigger finger is a disease of the tendons of the hand leading to triggering (locking) of affected fingers, dysfunction, and pain. Available treatments include local injection with corticosteroids, surgery, or splinting.

To summarize the evidence on the effectiveness and safety of corticosteroid injections for trigger finger in adults using the following endpoints: treatment success, frequency of triggering or locking, functional status of the affected fingers, and severity of pain of the fingers.

The databases CENTRAL, DARE, Medline (1966 to November 2007), EMBASE (1956 to November 2007), CINAHL (1982 to November 2007), AMED (1985 to November 2007), and PEDro (a physiotherapy evidence database) were searched.

The authors selected randomized and controlled clinical trials evaluating effectiveness and safety of corticosteroid injections for trigger finger in adults.

The databases were searched for titles of eligible studies. After screening abstracts of these studies, full text articles of studies that fulfilled the selection criteria were obtained. Data were extracted using a predefined electronic form. The methodologic quality of included trials was assessed by using items from the checklist developed by Jadad and the Delphi list. The authors planned to extract data regarding information on the primary outcome measures: treatment success, frequency of triggering or locking, functional impairment of fingers, and severity of the trigger finger; and the secondary outcome measures: proportion of patients with side effects, types of side effects, and patient satisfaction with injection.

Two randomized controlled studies were found that involved 63 participants: 34 were allocated to corticosteroids and lidocaine (Xylocaine), and 29 were allocated to lidocaine alone. Corticosteroid injection with lidocaine was more effective than lidocaine alone on treatment success at four weeks (relative risk = 3.15; 95% confidence interval, 1.34 to 7.40). The number needed to treat to benefit was 3. No adverse events or side effects were reported.

The effectiveness of local corticosteroid injections was studied in only two small randomized controlled trials of poor methodologic quality. Both studies showed better short-term effects of corticosteroid injection combined with lidocaine compared with 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 intratendon 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.