Evaluation of overgrowth in pediatric radius fractures

Purpose: Forearm fractures are the most frequent long bone fractures in children. There have been many reports of differences in leg length due to overgrowth in lower extremity fractures. However, reports of such overgrowth in fractures of the upper extremity are rare. The purpose of this study was to investigate the relationship between angulation and overgrowth in pediatric radius fractures. We hypothesized that more angular deformation of the fracture would result in a periosteal transection and more overgrowth.Methods: Retrospectively, between 2013 and 2022, 14 patients under 16 years of age (mean age 9.43 years; 10 boys, four girls) with unilateral radius shaft or metaphyseal fracture without physeal injury, and a minimum follow-up of 12 months, were included. Demographic factors were analyzed; age, sex, body mass index (BMI), right or left. We evaluated the radiologic parameters; ulnar variances, degree of angularity before intervention, fracture gap and treatment options. The patients underwent conservative or surgical treatment.Results: The mean follow-up period was 27.9 months (range, 13-53 months). Eight patients underwent cast treatment, and six patients underwent surgical treatment. The difference in ulnar variances between the unaffected side and fracture side were statistically significant (P < 0.001). Sex, age, left or right, height, weight, and BMI were not statistically significant. The surgical treatment group (P = 0.013) and the sum of the maximum angularity (P = 0.017) were statistically significant. When the sum of the max-imum angularity(SMA) was 30 degrees or more, the ulnar variances were statistically significant, compared with the case where the SMA was less than 30 degrees. The clinical results evaluated at the last outpatient follow-up were good in all patients.Conclusions: First, this study implies that the degree of angulation of the fracture may affect the over-growth of the radius in case of radius shaft or metaphyseal fracture, without physeal injury. Second, it implies that the degree of overgrowth may increase with surgical treatment, as opposed to that with conservative treatment.Level of evidence: Level IV, Retrospective study (c) 2023 Elsevier Ltd. All rights reserved.