[Feasibility study of protecting ulnar nerve by ultrasound in treating children with supracondylar fracture of humerus by closed reduction and intercross needle fixation].

Objective: To explore feasibility of protecting ulnar nerve by ultrasound in treating children with supracondylar fracture of humerus by closed reduction and intercross needle fixation.

Methods: From January 2018 to December 2019, 63 children with supracondylar fractures of humerus were divided into two groups(ultrasound group and X-ray group) depend on the different ways of guidance. Therer were 32 children in ultrasound group treated with closed reduction and Kirschner wire fixation guided by ultrasound, including 20 males and 12 females, aged from 3 to 11 years old with an average of (6.06±2.02) years old. There were 31 children in X-ray group treated with closed reduction and Kirschner wire fixation guided by X-ray, including 17 males and 14 females, aged from 2 to 10 years old with an average of (5.61±1.96) years old. Operation time, X-ray times, fracture healing time, ulnar nerve injury and postoperaqtive Flynn clinical function assessment at 1 year between two groups were recorded and compared.

Results: All patients were followed up. The follow-up time of ultrasound group ranged from 9 to 12 months with an average of (11.53±0.76) months, and X-ray group ranged from 10 to 13 months with an average of (11.51±0.72) months. There was no significant difference in operation time, follow-up time and fracture healing time between two groups(>0.05). The number of intraoperative electrodialysis in ultrasound group was (3.06±1.24) times, and that in X-ray group was (21.65±5.58) times, which was significantly higher than that in ultrasound group(<0.01). No iatrogenic ulnar nerve injury occurred in ultrasound group, and 2 cases of ulnar nerve injury occurred in X-ray group, the incidence of ulnar nerve injury in ultrasound group was lower than that in X-ray group, but the difference was not statistically significant(>0.05). At 1 year after operation, Flynn clinical function assessment results in ultrasound group was excellent in 27 cases, 4 cases good and 1 case fair, in X-ray group 23 cases got excellent result, 6 cases good, 1 fair and 1 poor, there was no significant difference between two groups(>0.05 ).

Conclusion: Ultrasound guided and X-ray guided treatment of supracondylar fractures of humerus in children have similar effect of opertaion time and fracture healing, while ultrasound guidance could clearly detected the position of ulnar nerve, and avoid occurrence of iatrogenic ulnar nerve injury caused by ulnar puncture, which is a safe and effective treatment method.