Objective To investigate the effectiveness of medial and lateral column periosteal hinge reconstruction using Kirschner wire in the closed reduction of multi-directional unstable humeral supracondylar fractures in children. Methods A clinical data of 43 children with multi-direction unstable humeral supracondylar fractures, who met the selection criteria and were admitted between August 2020 and August 2022, was retrospectively analyzed. Twenty-one cases of fractures were treated wuth closed reduction after medial and lateral column periosteal hinge reconstruction using Kirschner wire and percutaneous Kirschner wires fixation (study group), while 22 cases of fractures were treated by traditional closed reduction technique and percutaneous Kirschner wire fixation (control group). There was no significant difference in gender, age, cause of injury, fracture side, and interval from injury to operation between the two groups (P>0.05). The operation time, intraoperative fluoroscopy times, the number of children who were changed to open reduction after closed reduction failure, fracture healing time, complications within 2 months after operation, and the Flynn score of elbow joint function at last follow-up were compared between the two groups. ResultsAll the fractures in the study group were successfully closed reduction, and 4 cases in the control group were changed to open reduction and completed the operation, the difference between the two groups was significant (P=0.040). The operation time and intraoperative fluoroscopy times of the study group were significantly less than those of the control group (P<0.05). All children in both groups were followed up 6-18 months with an average of 9.0 months in the study group and 9.8 months in the control group. Imaging review showed that the fractures of both groups healed, and the difference in the healing time between the two groups was not significant (P=0.373). According to Flynn score at last follow-up, the excellent and good rate of elbow joint function was 95.2% (20/21) in the study group and 86.4% (19/22) in the control group, with no significant difference (P=0.317). There was no complication such as infection or irritation at the end of Kirchner wire within 2 months after operation. Conclusion For children with multi-directional unstable humeral supracondylar fractures, the use of Kirschner wires to reconstruct the medial and lateral column periosteal hinge to assist in closed reduction has the advantages of shortening operation time, reducing intraoperative fluoroscopy times, and effectively reducing the incidence of open reduction, and can achieve similar postoperative elbow joint function when compared with traditional closed reduction technique.