Identification of the length and location of the A1 pulley combining palpation technique with palm landmarks: a cadaveric study.

Through anatomical morphology, to accumulate the relevant parameters of the A1 pulley of each adult finger. A total of 100 fingers were selected, dissected layer by layer, and the A1 pulley and neurovascular of each finger were observed. Measure the length of the A1 pulley, the distance between the needle knife insertion point and the proximal edge of A1 pulley, and the nerves and blood vessels on both sides. (1) The length of A1 pulleys of each finger is 6.18 ± 0.33 mm, 6.58 ± 0.73 mm, 5.98 ± 0.67 mm, 5.36 ± 1.08 mm, 5.63 ± 1.09 mm. (2) The distances between the needle knife entry point of each finger and the volar proper nerve of the ulnar finger are 7.00 ± 1.55 mm, 8.29 ± 1.46 mm, 5.10 ± 0.25 mm, 5.30 ± 0.24 mm, 0 mm; the distances from the volar proper nerve of the radial finger are 9.08 ± 0.87 mm, 4.70 ± 1.10 mm, 7.03 ± 0.72 mm, 6.81 ± 0.22 mm, 7.81 ± 0.57 mm. (3) The distances between the needle knife entry point of each finger and the proper volar artery of the ulnar finger are 10.40 ± 0.75 mm, 8.89 ± 0.53 mm, 6.35 ± 0.44 mm, 7.26 ± 0.16 mm, 0 mm, respectively; The distances from the volar proper artery of the radial finger are 8.75 ± 1.07 mm, 6.10 ± 0.35 mm, 11.44 ± 0.41 mm, 8.19 ± 0.60 mm, 9.78 ± 0.68 mm, respectively. The landmarks of the needle entry points are located at the position corresponding to the highest point of the metacarpal heads, except the tail finger. From the needle knife entry point to distal, cut the proximal edge of the A1 pulley longitudinally along the midline until the patient can flex autonomously, and pay attention to the distance between the two sides of 3.60-11.85 mm neurovascular bundle.

Morphometric study of percutaneous A1 pulley of thumb release.

Through anatomy, microscope, histopathology, and simulating needle knife operation on specimens, to accumulate the relevant parameters of the A1 pulley of thumb, and to provide an anatomical evidence for the needle knife therapy of stenosing flexor tenosynovitis. A total of 20 fingers were selected from 20 intact adult upper limb specimens, a small amount of emerald green waterproof dye was injected from the needle insertion point, dissected layer by layer, and the A1 pulley and neurovascular bundle were observed. Observe the loosening of the thumb A1 pulley after 5 and 10 times of simulated needle knife cutting on the specimen; observe the relationship between the needle knife entry point and the A1 pulley under the thumb extension and abduction, and the thumb extension neutral position respectively; further observe the histological characteristics, and the relationship between needle entry point and A1 pulley by microscope. ① In general observation, the A1 pulleys of each finger were transverse fibers perpendicular to the flexor tendon, tough in texture, connected with synovial fibers at the proximal end. It is difficult to distinguish, and connected with oblique fibers at the distal end. ② The release rate of the thumb A1 pulley after 5 and 10 times of simulated needle knife cutting on the specimen were (40.46 ± 2.22)% and (63.52 ± 4.49)%, respectively. ③ In the neutral position of the thumb straightening, the needle entry point is 3.06 ± 0.14 mm from the proximal side of the proximal edge of the A1 pulley, which overlaps with the needle entry point where the thumb is straight and abducted. ④ Observed under a microscope, the A1 pulley is a dense transverse fiber with a pale yellow dense connective tissue, both ends are continuous with the synovial fibers. It is thin and translucent, and loose connective tissue. The A1 pulley is a dense transverse fiber with a pale yellow dense connective tissue. The anatomical key points of the needle knife therapy lie in the extended and abducted position of the thumb. Currently, it is believed that cutting the proximal edge of the A1 pulley is sufficient, and there is no need to cut the entire A1 pulley.