O1068: Failed Closed Pediatric Forearm Reduction- think Arm Size, Not BMI

Background: Previous evidence suggests obesity is a risk factor for failing nonoperative management of pediatric forearm fractures. However, these studies have been limited to correlating BMI to outcomes rather than evaluating local soft tissue at the zone of injury. Therefore, we aimed to investigate the differential effects of both global obesity and local soft tissue mass on the closed management of distal third forearm fractures.

Methods: We conducted a retrospective review of distal third forearm fractures in children treated with closed reduction at a pediatric orthopaedic urgent care center from 2019-2021. Demographic data including gender, age, and BMI were recorded. A novel soft tissue envelope measurement – the soft tissue index – was recorded by measuring the width of the soft tissue at the fracture divided by the width of the radius at the proximal aspect of the fracture, both in the sagittal plane. Patients who lost reduction and required either re-reduction or surgical intervention at their initial follow-up visit were compared to those who maintained reduction.

Results: 181 children treated for distal forearm fractures were included for analysis; 59 were female (33%). 164 children maintained their reduction while 17 (9.3%) failed non-operative management. There was no difference in age (9.4 versus 8.3, p=0.23) nor number of obese, overweight, or normal weight patients between groups (p=0.17). Bone width at the fracture site was equal between groups (1.1 cm vs. 1.0 cm, p=0.80), but mean combined soft tissue sagittal width was 16% larger in the LOR compared to the MOR cohort (6.1 cm vs. 5.1 cm, p< 0.001). Moreover, soft tissue index was 20% greater in the LOR compared to the MOR cohort (6.5 vs. 5.2, p=0.027).

Conclusion: In pediatric distal third forearm fractures, a larger soft tissue envelope at the fracture site but not BMI is strongly correlated with an increased risk of failure of closed reduction.