Ultra-minimally Invasive Sonographically-guided Trigger Digit Release: An External Pilot Study

OBJECTIVES: The most common surgical option for releasing the first annular pulley in trigger digit (TD) is classic open surgery followed by blind percutaneous release. However, they have been related to major complications and incomplete releases, respectively. Intrasheath sonographically-guided first annular pulley release has recently been shown to be safe and effective in every digit. The objectives of this pilot study were to preliminary compare clinically an intrasheath sonographically-guided first annular pulley release versus a classic open technique and to evaluate the feasibility of a future clinical trial in patients with TDs. METHODS: Thirty patients were randomized 1:1 in an external pilot study comparing the two surgical techniques: a percutaneous sonographically-guided release performed through a 1 mm incision using a hook knife versus a classic open surgery with a 1 cm incision. Inclusion criteria were primary TD grade III (Froimson). We defined success if primary (safety and efficacy) and secondary (recruitment rates, compliance, completion, treatment blinding, personnel resources, and sample size calculation for the clinical trial) objectives could be matched. We registered the grip strength, the QuickDASH score and a set of postoperative clinical variables at one, three, and six weeks and at three months. We calculated the sample size for the clinical trial using the QuickDASH at the end of the follow-up. Outcomes assessors were blinded. RESULTS: All patients in both groups showed resolution of their symptoms with no associated complications or relapses. Secondary feasibility objectives were matched: 76.9% of eligible patients were included in the study, 3.3% refused randomization, 20 patients per month were recruited, 100% received blinded treatment, 98.5% showed compliance, and 100% completed the study. The sample size for a future clinical trial was 84 patients. There were no differences in grip strength. The intrasheath sonographically-guided first annular pulley release showed significantly better QuickDASH scores, until the sixth postoperative week. CONCLUSIONS: The intrasheath sonographically-guided first annular pulley release is safe and efficacious, and shows a trend toward clinical superiority versus the classic open procedure, which should be confirmed with a clinical trial. Our study shows that a randomized clinical trial is feasible.