Objective:To investigate the clinical efficacy of transfer of a free segment of the proximal second toe interphalangeal joint composite tissue flap in reconstruction of defects of interphalangeal joint of fingers, and simultaneously reconstruct the donor site defect left with the second toe by a transfer of a pedicled bone flap of the fibular proximal great toe.Methods:From December 2020 to April 2023, a total of 9 patients with interphalangeal joint defects of fingers were treated in the Department of Hand Microsurgery of Shunde Heping Surgery Hospital. The patients were 7 males and 2 females, aged 18-55 years old, with an average age of 31 years old. Firstly, transfers of a free segment of the proximal second toe interphalangeal joint composite tissue flap were performed to reconstruct the defects of finger joints. Simultaneously in the surgery, transfers of the fibular pedicled bone flap of the proximal great toe were conducted to reconstruct the donor site defects left in the second toe. Patients were instructed with appropriate postoperative functional exercises. K-wires were removed at 8-12 weeks after surgery. Outpatient visits, telephone and WeChat follow-ups were conducted to evaluate the appearance and functional recovery of the reconstructed interphalangeal joints and donor feet. Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, Vancouver Scar Scale (VSS) and American Orthopedic Foot and Ankle Society (AOFAS) foot function scoring standards were employed in the evaluation.Results:Postoperative follow-up lasted for 6 to 30 months. All of the 9 interphalangeal joint composite tissue flaps in the fingers survived with complete and good appearance. Function of the reconstructed interphalangeal joints of the fingers recovered well. According to the Evaluation Trial Standards of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, the average score achieved 12 points, with 6 patients of excellent, 2 of good and 1 of fair. After surgery, the appearance and function of the donor great toes and second toes all recovered well. The average score of the scars in donor second toe evaluated by VSS was 4 points. All the donor feet were kept with 5 toes, with full, intact and good in appearance. According to the AOFAS foot function scoring standard, the average score achieved 95 points, and were excellent.Conclusion:Application of transfer of free proximal segment of interphalangeal joint composite tissue flap of the second toe in reconstruction of the interphalangeal joint defect of a finger, and simultaneously reconstruct the defect left with the donor second toe with a fibular proximal great toe flap pedicled with bone tissue can achieve good clinical efficacy in reconstruction of the defects of interphalangeal joint of fingers, restore the function of the interphalangeal joint of fingers and the appearance and function of the donor foot.