ObjectiveTo investigate the feasibility and effectiveness of the latissimus dorsi myocutaneous flap in repair of large complex tissue defects of limb and the relaying posterior intercostal artery perforator flap in repair of donor defect after latissimus dorsi myocutaneous flap transfer.MethodsBetween January 2016 and May 2017, 9 patients with large complex tissue defects were treated. There were 8 males and 1 female with a median age of 33 years (range, 21-56 years). The injury caused by traffic accident in 8 cases, and the time from post-traumatic admission to flap repair was 1-3 weeks (mean, 13 days). The defect in 1 case was caused by the resection of medial vastus muscle fibrosarcoma. There were 5 cases of upper arm defects and 4 cases of thigh defects. The size of wounds ranged from 20 cm×12 cm to 36 cm×27 cm. There were biceps brachii defect in 2 cases, triceps brachii defect in 3 cases, biceps femoris defect in 2 cases, quadriceps femoris defect in 2 cases, humerus fracture in 2 cases, brachial artery injury in 2 cases, and arteria femoralis split defect combined with nervus peroneus communis and tibia nerve split defect in 1 case. The latissimus dorsi myocutaneous flaps were used to repair the wounds and reconstruct the muscle function. The size of the skin flaps ranged from 22 cm×13 cm to 39 cm×28 cm; the size of the muscle flaps ranged from 12 cm×3 cm to 18 cm×5 cm. The wounds were repaired with pedicle flaps and free flaps in upper limbs and lower limbs, respectively. The donor sites were repaired with posterior intercostal artery perforator flaps. The size of flaps ranged from 10 cm×5 cm to 17 cm×8 cm. The second donor sites were sutured directly.ResultsAll the flaps survived smoothly and the wounds and donor sites healed by first intention. All patients were followed up 10-19 months (mean, 13 months). At last follow-up, the flaps had good appearances and textures. The muscle strength recovered to grade 4 in 5 cases and to grade 3 in 4 cases. After latissimus dorsi myocutaneous flap transfer, the range of motion of shoulder joint was 40-90°, with an average of 70°. The two-point discrimination of latissimus dorsi myocutaneous flap was 9-15 mm (mean, 12.5 mm), and that of posterior intercostal artery perforator flap was 8-10 mm (mean, 9.2 mm). There were only residual linear scars at the second donor sites.ConclusionThe latissimus dorsi myocutaneous flap combined with posterior intercostal artery perforator flap for the large complex tissue defects and donor site can not only improve the appearance of donor and recipient sites, but also reconstruct muscle function, and reduce the incidence of donor complications.