Length and landmark of A1 pulley in hand: an anatomical study.

OBJECTIVE: The purpose of the present study was to identify length and landmark of proximal of A1 pulley in hand. MATERIAL AND METHOD: An anatomical study of the length and landmark of A1 pulley in hand was performed in 510 fingers and thumbs from 51 preserved cadavers. There were 25 females and 26 males whose ages at the time of death ranged from 48 to 89 years. RESULTS: The lengths of A1 pulley were 5.30 +/- 0.53 mm in average of thumbs and 6.32 +/- 0.17, 6.58 +/- 0.19, 6.32 +/- 0.20, and 5.30 +/- 0.49 for the index, middle, ring, and small finger respectively. The average of all fingers were 6.13 +/- 0.17 mm. The margin from the proximal edge of A1 pulley related to the perpendicular line from posterior superior prominent of metacarpal head to the volar aspect of its fingers, which was in the same line for 327 (64.1%) fingers and thumbs, and for 464 (91.0%) fingers and thumbs were differences < or = 1 mm, and for 509 (99.8%) were differences < or = 2mm to proximal edge of A1 pulley of its finger and thumb. CONCLUSION: The posterior superior prominent of metacarpal head line in perpendicular to the volar aspect of its finger and thumb may be used as an anatomical landmark to predict of the proximal edge of A1 pulley with reasonable accuracy. The length of A1 pulley can serve as an important guide for the distal termination ofA1 pulley release.

The results of percutaneous release of trigger digits by using full handle knife 15 degrees: an anatomical hand surface landmark and clinical study.

OBJECTIVE: Know the results of percutaneous release of trigger digits by using full handle knife 15 degrees. MATERIAL AND METHOD: The author identified 510 cadaveric digits to find the anatomical landmark of Al pulley that relates to the knuckle and measurements of A1 pulley lengths. The proximal margin of the Al 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 < or =1 mm and 509 (99.8%) were < or =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 15 degrees 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 ofthe 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%.