Pediatric supracondylar humeral fractures: Does pin and splint removal 3 weeks after surgery increase the risk of secondary displacement?

Abstract Purpose Supracondylar fractures of the distal humerus are among the most common pediatric fractures. For unstable fractures, reduction with pin fixation and postoperative immobilization is standard, but the optimal duration of pin fixation and splinting remains uncertain. This study evaluated whether pin and splint removal approximately 3 weeks after surgery was associated with secondary fracture displacement in children treated for displaced supracondylar humeral fractures. Methods We retrospectively reviewed pediatric patients surgically treated for displaced supracondylar humeral fractures at our institution between January 2015 and December 2024. Both closed and open reduction cases were eligible. Collected data included demographics, Rigault-Lagrange fracture stage, fixation construct, duration of pin and splint immobilization, radiographic displacement before and after removal, and postoperative complications. Results A total of 211 patients were included (mean age 6.5 ± 2.3 years). According to the Rigault-Lagrange classification, 87 fractures were stage 2, 54 were stage 3, and 70 were stage 4. Pins and splints were removed after a mean of 23.6 ± 4.0 days. Secondary radiological displacement was observed in 11 patients, corresponding to 13 displacement events: 10 occurred before pin removal and 3 after removal. Three patients showed a change in Baumann’s angle greater than 12° after removal, and no patient lost intersection of the anterior humeral line with the capitellar ossification center after removal. One patient required early revision before pin removal, and no patient required delayed corrective osteotomy. Conclusion In this retrospective cohort, pin and splint removal approximately 3 weeks after surgical fixation of pediatric supracondylar humeral fractures was associated with a low rate of subsequent secondary displacement, irrespective of fracture stage. Most displacement events occurred before pin removal, and no patient required delayed corrective osteotomy. Early removal may limit exposure to complications associated with prolonged pin fixation and immobilization, although this potential benefit requires confirmation in comparative studies. Level of evidence III (retrospective cohort study).