Objective:To explore the clinical effect on reconstruction of the soft tissue defects after resection of mucous cysts of distal interphalangeal joint (DIP) with transfer of the flap of dorsal branch of proper palmar digital artery.Methods:From September 2021 to September 2023, 8 patients (8 digits) with mucous cysts on DIP were treated in the Department of Hand and Microsurgery, the Affiliated Hospital of Binzhou Medical University. All 8 cases were females, aged 55-65 years old, with an average age of 60 years old. The cyst was located in the thumb in 1 case, in the index finger in 3 cases, in the middle finger in 3 cases, and in the ring finger in 1 case. After extensive resection of the mucous cysts, the size of soft tissue defects was at 0.8 cm×0.6 cm-1.7 cm×0.9 cm. Pedicled with the dorsal branch of proper palmar digital artery, the flaps adjacent to the defects were designed to cover the wounds. The size of the flaps was 1.2 cm×1.0 cm-2.0 cm×1.2 cm. Donor sites of the flap were covered by the full thickness skin grafts of medial upper arm. The postoperative follow-up was conducted by the combination of outpatient revisits and telephone reviews to observe the survival of the flap, and the functional recovery was evaluated according to the Evaluation Standard of Upper Limb Functional of Hand Surgery of Chinese Medical Association.Results:All flaps survived well after surgery. Postoperative follow-up ranged from 4 to 12 months, with a mean of 10 months. At the final follow-up, there was no recurrence of mucous cyst and all symptoms disappeared. All flaps healed well, with good appearance, soft texture and without obvious difference in colour from the surrounding skin. All skin grafts healed in one stage. The range of motion of the affected DIP was 0°-70°, and the TPD was at 7-8 mm, both caused no impact on daily life. The outcomes were excellent according to the evaluation criteria set by the Evaluation Standard of Upper Limb Functional of Hand Surgery of Chinese Medical Association.Conclusion:The flap pedicled with dorsal branch of proper palmar digital artery has obvious advantages with less damage and simple operation in the treatment of a mucous cyst of DIP. It is an ideal surgical procedure.