Casting Without Reduction Versus Reduction With or Without Fixation for Mildly Displaced Pediatric Distal Radius Metaphyseal Fractures: A Randomized Noninferiority Trial

OBJECTIVE: To determine whether immobilization without reduction is noninferior to closed reduction under general anesthesia, with or without fixation, with respect to upper-extremity function at 6 months in children with mildly displaced distal radius metaphyseal fractures. METHODS: We conducted a randomized, open-label, noninferiority trial at a tertiary pediatric orthopaedic hospital. Children aged 5 to 10 years with unilateral mildly displaced distal radius metaphyseal fractures were assigned to immobilization without reduction or closed reduction under general anesthesia, with or without fixation. The primary outcome was the PROMIS Pediatric Upper Extremity T-score at 6 months. The prespecified noninferiority margin was -5 points for the between-group difference. RESULTS: Sixty children were randomized: 29 to immobilization without reduction and 31 to reduction under general anesthesia. Primary outcome data were available for 59 children. The mean PROMIS scores were 45.59 (SD=9.62) in the immobilization-without-reduction group and 45.62 (SD=8.24) in the reduction-under-anesthesia group. The mean between-group difference was -0.03 points (95% CI: -4.71 to 4.65), meeting the prespecified criterion for noninferiority. No serious adverse events occurred in the immobilization-without-reduction group; 2 anesthetic-related complications occurred in the reduction-under-anesthesia group. CONCLUSIONS: In children with mildly displaced distal radius metaphyseal fractures, immobilization without reduction was noninferior to reduction under general anesthesia with respect to upper-extremity function at 6 months. These findings suggest that routine reduction under anesthesia may not be necessary in children aged 5 to 10 years with isolated distal radius metaphyseal fractures with shortening ≤10 mm and/or angulation of 10 to 20 degrees. LEVEL OF EVIDENCE: Level I-randomized controlled trial.