Repair of distal finger soft-tissue defects with free fibular great toe neurovascular flaps.

[BACKGROUND] This work aimed to investigate the change in fingerprint depth and the recovery rule of fingerprint biological recognition function after repairing finger abdominal defects and rebuilding fingerprint with a free flap.

[METHOD] From April 2018 to March 2023, we collected a total of 43 cases of repairing finger pulp defects using the free flap of the fibular side of the great toe with the digital nerve. After surgery, irregular follow-up visits were conducted to observe fingerprint clarity, perform the ninhydrin test or detect visible sweating with the naked eye. We recorded fingerprint clarity, nail shape, two-point discrimination, cold perception, warm perception and fingerprint recognition using smartphones. The reconstruction process of the repaired finger was recorded to understand the changes in various observation indicators and their relationship with the depth of the fingerprint. The correlation between fingerprint depth and neural repair was determined, and the process of fingerprint biological recognition function repair was elucidated.

[RESULT] All flaps survived, and we observed various manifestations in different stages of nerve recovery. The reconstructed fingerprint had a clear fuzzy process, and the depth changes of the fingerprint were consistent with the changes in the biological recognition function curve.

[CONCLUSION] The free flap with the digital nerve is used to repair finger pulp defects. The reconstructed fingerprint has a biological recognition function, and the depth of the fingerprint is correlated with the process of nerve repair. The fingerprint morphology has a dynamic recovery process, and it can reach a stable state after 6-8 months.