Objective: Know the results of percutaneous release of trigger digits by using full handle knife 15º.
Material and Method: The author identified 510 cadaveric digits to find the anatomical landmark of A1 pulley that relates to the knuckle and measurements of A1 pulley lengths. The proximal margin of the A1 pulleys on the perpendicular line from the knuckle to the palm was in the same line in 327 (64.1% ) digits, while 464 (91.0%) digits were < 1 mm and 509 (99.8%) were <2 mm. The average lengths of A1 pulleys in each digit were as follows: thumb; 5.30, index finger; 6.32, middle finger; 6.58, ring finger; 6.32, and little finger 5.30 mm. The average lengths of all fingers were 6.13 mm. A further 338 digits of trigger digit in 248 patients were treated by percutaneous release by using full handle knife 15º with these landmarks.
Results: Three hundred and thirty-eight trigger digits were treated. There was a complete resolution of symptoms in 314 digits (92.90%) when followed up 6 weeks after operation. One digit, an index finger had residual grade 1 after 3 weeks and complete resolution in 8 weeks. Three digits (0.89%), which were one thumb and two index fingers, underwent local steroid injection because of painful scar. Nineteen digits (5.62%) were stiff at proximal interphalangeal joint because of grade 4 triggering and osteoarthritis of the proximal interphalangeal joint but they increased the range of motion after 6 months. A case (0.30%) had numbness of the radial tip of the thumb, which may have been caused by injury to the radial digital nerve of the thumb. No one had open release of A1 pulley.
Conclusion: This technique was a safe and effective out patient procedure on 248 patients and had a complete resolution of symptoms 92.90%

Keywords: Trigger finger, Percutaneous release, Landmark, A1 pulley, Result