Increase in gap index over time after reduction of unstable paediatric both-bone forearm fracture does not cause displacement


Conservative treatment, gap index, loss of reduction, unstable paediatric both-bone forearm fractures

Published online: Jan 08 2024


Basaksehir Çam and Sakura City Training and Research Hospital, Department of Orthopaedics and Traumatology, ?stanbul, Turkey


This study investigated the effects of changes in the gap index on fracture displacement during follow-up. Patients who underwent closed reduction and casting with a diagnosis of unstable paediatric both-bone forearm fractures and a cast index < 0.8 were retrospectively evaluated. Patients were divided into Groups 1 and 2 based on their gap index (<0.15 and >0.15, respectively). Anteroposterior and lateral displacements of the radius and ulna and the gap index of the cast were measured on the X-ray after the first reduction and on the last X-ray before plaster removal. The mean patient age (n = 94, 74 boys and 20 girls; 51 in Group 1 and 43 in Group 2) was 7.09 ± 2.66 years. Fracture union times (plaster removal) were 38.8 ± 7.1 days. The mean cast index was 0.76 ± 0.05 (0.59–0.8). Both groups had similar distributions in terms of age, sex, fracture side, anatomic location and plaster removal time (p > 0.05). No significant differences were observed in either group in any radial or ulnar angulation values at any time point or the difference between the first and last values (all p > 0.05). Moreover, the gap index difference between the first and last measurements was significantly different in both groups (p = 0.002). If the cast index remains <0.8, despite the increase in the gap index in both groups, the amount of fracture displacement was small and acceptable.