To explore the surgical method and clinical effect of the free medial arm flap to repair the finger wound with ultrasound-assisted positioning.

From January 2022 to June 2023, 7 patients (7 fingers) with skin necrosis after finger preserving treatment who met the inclusion criteria were admitted to Department of Hand Surgery, Suzhou Ruihua Orthopedic Hospital, including 6 males and 1 female, aged from 16 to 50 years, with an average of 31 years old. The finger wounds area were 3.5 cm×3.0 cm to 5.5 cm×4.0 cm, and all wounds accompanied by bone and tendon exposure. All the wounds were repaired by using the free medial arm flap in the second stage. Color Doppler ultrasound was used to locate the perforating vessels before the operation. During the operation, the source or perforating vessels of the flap were anastomosed with the digital artery and subcutaneous vein of the finger in the recipient area to establish the blood supply of the flap. The area of the medial arm flap ranged from 4.0 cm×3.5 cm to 6.0 cm×4.5 cm, and all the donor areas of the arm were sutured directly. After operation, the patients were treated with anti-infection, anticoagulation and anti-vasospasm, and the survival of the flap was observed. During follow-up, the appearance, texture, and sensation of the flaps, and the wound healing of the donor area were observed. At the last follow-up, the function of the fingers was assessed according to the trial standard of upper limb partial function assessment of the Hand Surgery Society of Chinese Medical Association.

All the flaps grafted in 7 patients survived, in which one patient developed venous reflux disturbance after operation, and survived successfully after wet compress and bloodletting of the flap incision. The wounds in the operative area of all patients healed at the first stage. The follow-up period ranged from 5 to 15 months, with an average of 7 months. All flaps were in good appearance and soft texture, the sensation recovered to S2-S3+. All the donor areas of the arm showed linear scar and the function was normal. At the last follow-up, the finger function was evaluated as excellent in 3 cases, good in 3 cases and fair in 1 case, with an excellent and good rate at 85.7%.

The application of free medial arm flap to repair the postoperative wound of the finger can maintain the integrity of the finger body. The flap is convenient for transplantation, the supply area is relatively hidden, and the repair effect is good.