To measure the position of body surface projection, depth and axial length of the A1 pulley in patients with tenosynovitis of flexor pollicis longus tendon.

A total of 35 patients with tenosynovitis of flexor pollicis longus tendon (37 fingers) were enrolled in the patients group in the Pain Department of Dongguan Songshan Lake Central Hospital from January to July 2021. Another 60 normal thumbs in 30 volunteers were enrolled as the control group. The position of body surface projection, depth and axial length of the A1 pulley were measured by high frequency ultrasonography.

The body surface projection of thumb A1 pulley in the patients group and the control group is located at the distal end of the metacarpal finger stripes (3.0±0.3) mm and (2.9±0.3) mm, respectively. The depth of thumb A1 pulley in the patients group and the control group was (4.0±0.3) mm and (3.9±0.4) mm, and the axial length was (5.1±0.4) mm and (5.0±0.5) mm respectively, no significant difference between the two groups (all P>0.05). Body surface projection of thumb A1 pulley located at the distal end of the metacarpal finger stripes 3.0 mm (2.9-3.1 mm), with a depth of 4.0 mm (3.9-4.1 mm) and the axial distance of 5.1 mm (5.0-5.2 mm) in patients group.

In patients with tenosynovitis of flexor pollicis longus tendon, the body surface projection of thumb A1 pulley located at the distal end of the metacarpal finger stripes 3.0 mm (2.9-3.1 mm), with a depth of 4.0 mm (3.9-4.1 mm) and the axial distance of 5.1 mm (5.0-5.2 mm).

Trigger finger disorder; Ultrasonography; Anatomy