Intra-tendon sheath injection for trigger finger: the randomized controlled trial.

The most common technique used for non-surgical treatment of trigger fingers is the direct injection of steroids into the flexor tendon sheath over the metacarpal head. However, this method causes more pian to the patient and can result in tendon rupture due to insertion of needle into the tendon. Carlson and Curtis described the mid-axial injection technique which is simple and relatively painless. We aim to compare the pain result from the injection between these two methods. The prospective randomised control trial study was designed. There were 103 trigger fingers included in the study which were divided into two groups: the conventional technique of injection (CI technique) and the mid-axial injection technique (MAI technique). The visual analogue scale for pain score had been recorded at the time of injection: one, three and six weeks. The complication after injection and the recurrent symptoms within one year were also recorded. The Student's t-test, Chi-squared and Fisher-exact analysis were used for statistical testing. The results showed that the mean VAS pain scores immediately after needle insertion were 40.19 ± 23.3 and 48.39 ± 26.5 in the MAI and CI technique groups, respectively. The MAI technique was less painful than the CI technique (p < 0.05). There were no complications from the injections in both methods. However, the recurrent rate seems to be higher in the conventional technique (p = 0.23). We concluded that the MAI injection technique provided less pain result than the CI technique and there were no complications from this injection technique.