Abstract: Objective　To investigate the relationship between body surface marking line of distal finger and Kirschner's needle insertion point, and to provide anatomical basis for treating bony mallet finger by absorbable suture tying avulsion fracture fragment, including the entry point and angle of the needle for fixing distal interphalangeal joint, the position of the absorbable suture’s guiding hole.　Methods　16 fresh adult upper limb specimens were randomly selected, including 16 thumbs, 16 index fingers, 16 middle fingers, 16 ring fingers and 16 little fingers. The entry point and angle of Kirschner wire for fixing distal interphalangeal joint were measured. Bone mallet finger model group was built according to the angle between bone avulsion fracture line and the axis of the distal phalanx.　Results　When the distal interphalangeal joint extended at 0°, the fixation needle should be inserted from the side of the finger body. The optimal insertion point for the fixation of the distal interphalangeal joint was located at the junction of the base of the distal phalanx and the finger backbone. The included angle between insertion angle and the axis of the distal phalanx was 30°, and the distance from the insertion point to the plane of the distal phalanx of the finger was 13mm of the thumb, 12mm of the index finger, 13mm of the middle finger, 12mm of the ring finger, and 11mm of the little finger, respectively. The best insertion point of the absorbable guide hole was on the surface projection line of the midline lateral phalanx of the tendon insertion.　Conclusions　When the insertion point of the fixation needle and the guide hole are located in the positions of the above-mentioned fingers, the insertion point and the guide hole are fixed firmly, which will not damage the methyl matrix and will not affect the restoration of the avulsed bone slice.

Key words: Absorbable suture, 　Bony mallet finger, 　 Finger, 　Anatomical study