[Effects of free gracilis muscle flap combined with sural nerve transfer for reconstruction of digital flexion and sensory function of hand in patient with wrist electric burn].

Objective: To explore the effects of free gracilis muscle flap combined with sural nerve transfer for reconstruction of digital flexion and sensory function of hand in patient with severe wrist electric burn. Methods: A retrospective observational study was conducted. From January 2017 to December 2020, 4 patients with wrist high-voltage electric burn admitted to the Department of Burns of the First People's Hospital of Zhengzhou and 4 patients with wrist high-voltage electric burn admitted to the Department of Hand Surgery of Beijing Jishuitan Hospital met the inclusion criteria, including 6 males and 2 females, aged 12 to 52 years. They were all classified as type Ⅱ wrist high-voltage electric burns with median nerve defect. In the first stage, the wounds were repaired with free anterolateral thigh femoral myocutaneous flap. In the second stage, the free gracilis muscle flap combined with sural nerve transplantation was used to reconstruct the digital flexion and sensory function of the affected hand in 3 to 6 months after wound healing. The cut lengths of muscle flap and nerve were 32 to 38 and 28 to 36 cm, respectively. The muscle flap donor area and nerve donor area were both closed and sutured. The survival condition of gracilis muscle flap and sural nerve, the wound healing time of recipient area on forearm, the healing time of suture in muscle flap donor area and nerve donor area were observed and recorded after operation, and the recovery of donor and recipient areas was followed up. In 2 years after operation, the muscle strength of thumb and digital flexion and finger sensory function after the hand function reconstruction were evaluated with the evaluation criteria of the hand tendon and nerve repair in the trial standard for the evaluation of functions of upper limbs of Hand Surgery Society of Chinese Medical Association. Results: All the gracilis muscle flap and sural nerve survived successfully after operation. The wound healing time of recipient area on forearm was 10 to 14 days after operation, and the healing time of suture in muscle flap donor area and nerve donor area was 12 to 15 days after operation. The donor and recipient areas recovered well. In the follow-up of 2 years after operation, the muscle strength of thumb and digital flexion was evaluated as follows: 4 cases of grade 5, 3 cases of grade 4, and 1 case of grade 2; the finger sensory function was evaluated as follows: 4 cases of grade S3+, 2 cases of grade S3, and 2 cases of grade S2. Conclusions: For patients with hand dysfunction caused by severe wrist electric burn, free gracilis muscle flap combined with sural nerve transplantation can be used to reconstruct the digital flexion and sensory function of the affected hand. It is a good repair method, which does not cause great damage to thigh muscle flap donor area or calf nerve donor area.