gms | German Medical Science

Objectives/Interrogation: Literature examining the effectiveness of corticosteroid injection as a treatment method for trigger finger has typically grouped all of the digits together, with no distinction made between the thumb and lesser fingers. In this study, we use the novel ICD-10 coding to determine if the effectiveness of corticosteroid injections in the thumb and lesser fingers differs according to affected digit.

Methods: We queried a national insurance database from 2007 to 2017 to identify all patients who were treated for a trigger digit with 6-month follow-up. We categorized trigger digits by laterality and by digit (thumb, index, long, ring and small fingers). We reviewed all tendon-sheath injections and trigger digit releases (TDR) during the observation period. The time in days from trigger digit diagnosis to TDR was recorded and compared between thumb and all other fingers. Kaplan-Meier survival curves were calculated to analyze the effectiveness of tendon sheath injection and conversion to TDR.

Results and Conclusions: The study population included 38,268 patients with the diagnosis of a trigger digit (TD) and 6-month follow-up. Long and ring fingers were treated most commonly, accounting for 32.2% and 27.2% of all digits, respectively. Trigger thumbs accounted for 22.3% of the study population. While the lesser fingers converted to release in an average of 170 days (SD 114.5 days) after injection, thumbs converted to release on an average of 130 days (SD 94.2 days) (Figure 1 [Fig. 1]).

Among digits that went on to surgical release, trigger thumbs on average progressed to surgical release 40 days more quickly than lesser fingers. Notably, our analysis revealed that the overall survival wasn't affected in the same way, as the number of days from trigger digit diagnosis to release in the thumb and fingers were very similar. Taken together, these data suggest that corticosteroid injection is less effective in alleviating symptoms in thumbs than in fingers and that trigger thumb may be more recalcitrant to non-operative treatment than trigger finger.