Out-of-sheath corticosteroid injections through the dorsal webspace for trigger finger and trigger thumb. A prospective cohort study.

Objective: Steroid injections are effective in the treatment of trigger digits but the pain during the injection is an always-present accompanying effect. The aim of this study was to assess the effectiveness and perceived pain during an out-of-sheath corticosteroid injection through the dorsal webspace in the treatment of trigger digits.

Methods: A total of 126 consecutive patients were included. A subcutaneous (out-of-sheath) corticosteroid injection was performed through the dorsal webspace in all digits. In cases where signs or symptoms persisted, a second injection was offered. Visual analog scale for pain during the injection, DASH questionnaire, success rate and complications were collected.

Results: There were 86 women and 40 men with a mean age of 61 years. The mean visual analog scale for pain during the injection was 3.8. Twelve patients were lost to follow-up. The overall success was 68% and success after a single injection was 54%. The best result was achieved on the ring finger. Patients who were not previously operated on carpal tunnel syndrome responded better. No complications were noted.

Conclusions: The extra-sheath corticosteroid injection through the dorsal webspace is effective and safe. It seems to be less painful than the reported scores for the palmar midline technique although it should be assessed in a comparative study.