[Efficacy of free lateral arm tissue flap in repairing complex finger wounds]

Objective: To explore the efficacy of free lateral arm tissue flap in repairing complex finger wounds. Methods: This study was a retrospective case series study. From January 2020 to December 2023, 8 patients with complex finger wounds who met the inclusion criteria were admitted to the 920^th Hospital of Joint Logistic Support Force of PLA, including 5 males and three females, aged 24 to 56 years. There were 4 cases with multi-finger skin defects; there were 4 cases with single-finger skin combined with bone defects, three of whom were complicated with extensor tendon defects. The size of skin defects was 2.5 cm×2.0 cm to 8.0 cm×3.5 cm, and the size of bone defects was 1.5 cm×1.0 cm×1.0 cm to 2.0 cm×1.5 cm×1.0 cm. Five cases underwent emergency extended debridement and simultaneous transplantation of free lateral arm tissue flap for repair; the remaining three patients underwent extended debridement in stage Ⅰ and free lateral arm tissue flap transplantation for repair in stage Ⅱ. Four patients each underwent resection of lobulated flaps and chimeric osteocutaneous flaps, including 4 cases carrying the posterior arm cutaneous nerve and three cases having their extensor tendons being reconstructed with the triceps brachii aponeurosis. The size of skin flaps was 3.0 cm×2.5 cm to 9.0 cm×4.0 cm, and the size of bone flaps was consistent with the size of bone defects. The donor site wounds of skin flaps and bone flaps were closed with interrupted sutures. Postoperatively, the survival status of the tissue flaps was observed, and the pedicle division status of the lobulated flaps was recorded. At the final follow-up, the following parameters were assessed and documented: the appearance and texture of skin flaps, the sensory recovery of the affected finger transplanted with the posterior arm cutaneous nerve evaluated using the British Medical Research Council sensory function assessment criteria, the dorsiflexion of the affected finger transplanted with the triceps brachii aponeurosis, the survival of the bone flaps confirmed via X-ray examination, the scar formation at the donor sites of skin flaps, and the function of the affected fingers evaluated based on the trial standard for functional evaluation of the upper limb of the Hand Surgery Society of the Chinese Medical Association. Results: Postoperatively, the tissue flaps survived well. The pedicles of the lobulated flaps were successfully divided under local anesthesia 4 weeks after surgery. The follow-up duration ranged from 10 to 24 months, with an average of 13.5 months. At the final follow-up, the color and texture of the skin flaps were good, the sensation of the affected fingers transplanted with posterior arm cutaneous nerve recovered to level S2 or S3, the affected fingers transplanted with triceps brachii aponeurosis all achieved limited improvement in dorsiflexion, X-ray examination showed that the bone flaps survived, linear scars formed at the donor sites of skin flaps after wound healing, and the function of the affected fingers was evaluated as excellent in 5 cases and good in three cases. Conclusions: The lateral arm tissue is rich in perforators and has few anatomical variations, which can be prepared into lobulated flaps and chimeric osteocutaneous flaps for repairing complex finger wounds. The surgical operation is relatively simple, and the appearance and function of the donor and recipient sites are fairly good after surgery.