A Comparison of Blinded versus Ultrasound-Guided Limited-Open Trigger Finger Release Using the Yasunaga Knife

Background: An open approach is the gold standard for trigger finger (TF) release. However, this may be associated with infection and scar tenderness. Percutaneous trigger release is an alternative, but this can sometimes result in incomplete release and digital nerve injury, even with ultrasound (US) guidance. Limited-open TF release is an intermediate technique that uses a specially designed knife via a 2-3 mm incision. The aim of this study is to compare the outcomes of blinded versus US-guided limited-open TF release using the Yasunaga knife (Medical U&A, Inc., Japan). Methods: About 138 fingers in 111 patients underwent limited-open TF release using the Yasunaga knife. Green classification was used to grade the severity of TF. Thirty-one patients had grade 3 TF and 80 patients had grade 4 TF. The TF was released in a blinded fashion in 60 patients and using US guidance in 51 patients. Outcome measures included residual triggering, contracture of the proximal interphalangeal joint, visual analog scale (VAS) for assessment of pain, Quick Disability of the Arm, Shoulder, and Hand (DASH) score, and the Patel and Moradia grading of patient satisfaction. Complications were also recorded. Results: Six patients had residual triggering in the blinded group, whereas it resolved in all patients in the US-guided group. This difference was statistically significant (p = 0.03). Patients in both groups showed significant improvement in VAS and Quick DASH score postoperatively. There were no significant differences between the two groups for these two outcomes. Patient satisfaction was graded as excellent by 20 patients and good by 30 patients in the US-guided group compared to eight excellent and 45 good in the blinded group. Conclusion: The incidence of residual triggering was lower and overall satisfaction higher in patients who underwent US-guided limited-open TF release using the Yasunaga knife. Level of Evidence: Level III (Therapeutic).