Abstract:[Objective] To evaluate the clinical efficacy of ultrasound guided closed reduction and internal fixation with elastic intra- medullary nail for forearm fractures in children. [Methods] A retrospective study was performed on 60 children who received closed reduc- tion and percutaneous elastic intramedullary nail fixation for forearm fractures from September 2019 to July 2021. According to the preoper- ative doctor-patient communication, 30 children had operation performed under ultrasound guidance, while other 30 children were under fluoroscopy guidance. The perioperative, follow- up and imaging data of the two groups were compared. [Results] All children in both groups were operated on smoothly, with no neurovascular injury and other serious complications during the operation. The ultrasound group proved significantly superior to the fluoroscopy group in terms of operation time [(23.4±3.6) min vs (31.9±3.5) min, P<0.05], intraoperative blood loss [(4.5±2.7) ml vs (6.7±4.5) ml, P<0.05], intraoperative fluoroscopy times [(3.2±1.5) times vs (10.4±2.1) times, P<0.05], the hospi- tal stay [(3.2±1.5) days vs (4.2±1.0) days, P<0.05], external fixation removal time [(28.0±5.3) days vs (32.3±3.2) days, P<0.05], despite insig- nificant differences in incision length and incision healing grade between two groups (P>0.05). In addition, the ultrasound group got signifi- cantly higher success rate of initial closed reduction than the fluoroscopy group (96.7% vs 70.0%, P<0.05). Postoperative pain VAS scores significantly declined in both groups over time (P<0.05), which was not significant between the two groups at any corresponding time points (P>0.05). Regarding the data of follow-up, there was no significant difference in the time to resume full weight-bearing activity between the two groups (P>0.05). The DASH score, forearm rotation ROM, elbow extension ROM and wrist extension ROM significantly improved in both groups at 12 months after surgery compared with those 3 months postoperatively (P<0.05), whereas which were not statistically signifi-cant between the two groups at any time points accordingly (P>0.05). In terms of imaging, there were no significant differences in the quali- ty of fracture reduction and healing time between the two groups (P>0.05). [Conclusion] The ultrasonic guided closed reduction and percu- taneous elastic intramedullary pin fixation for forearm fracture in children does reduce radiation injury, improve the success rate of initial closed reduction and shorten the operation time.