Purpose: In skeletally immature children with acceptably angulated (< = 15 degrees angular deformity at presentation) distal radius and/or ulnar fractures, to determine if a pre-fabricated wrist splint is at least as effective as a cast. The primary outcome was recovery of physical function six weeks after the injury as measured by the validated Activities Scale for Kids. Secondary objectives included determining differences in angulation of fracture, wrist range of motion, wrist strength, pain with movement, return to baseline activities, and patient preferences at six weeks.

Method: A randomized controlled, non-inferiority, single (evaluator) blinded, single-centre trial in a tertiary care pediatric emergency department. Minimal required sample size of 76 patients with was based on testing the null hypothesis (H0) that the brace is 7% less effective at the 2.5% level. Physical function was tested by a t-test for a non-zero difference. For the other outcomes, proportions and means were compared with the Fisher Exact and Student s t-test, respectively.

Results: Of the 100 randomized patients, 3 were excluded due to non-eligibility on radiographic review. 93 of the 97 completed full clinical, radiographic, and patient determined followup. ASK scores at six weeks were 92.8 in the splint group and 91.4 in the cast group, neither clinically nor statistically significantly different. Among patients treated in a cast, the average angular deformity at followup was 11.0 degrees and compared with an average of 6.6 degrees angulation among patients treated in a splint (p=.02, t-test). These groups were equal at baseline, with an average of 7.5 degrees of angulation in the cast group and 6.7 degrees in the splint group. Complications did not differ between groups, nor did range of motion with the exception that pronation was slightly better (84 versus 74 degrees) in the splint group at the end of treatment. No patient required any operative procedure. Parents preferred splinting over casting (p< 0.001) and children preferred splinting over casting (p=0.028).

Conclusion: Splinting was non-inferior to casting, and in fact may be superior to casting, for maintaining the position of a minimally displaced distal radial metaphyseal fracture. Significance: The benefits of splinting over casting have been previously established for undisplaced distal radius and ulnar fractures (Plint), this is the first study which extends these benefits to the large group of children with minimally displaced distal radius fractures. Splint treatment simplifies care for children, reduces cost, and improves short term outcomes.