A new method of calculating the rotation angle in pediatric forearm fractures using direct radiographs

BACKGROUND: The aim of this study was to measure the rotational angle defect between fracture ends in paediatric forearm diaphyseal fractures on radiographs. METHODS: Evaluations were performed on 78 paediatric patients who presented at the emergency department with a diaphyseal forearm fracture during 2013-2014. Thirty-two patients who underwent conservative treatment and had < 10 degrees of angulation and translation of not more than half the bone diameter after application of a plaster cast were included in the study. A rotational formula was used with diameter values to determine changes. The degree of rotation of both ends of the fracture line and the forearm rotational defect of the fracture line were calculated. FINDINGS: Fractures included an isolated radius in 16 cases, an isolated ulna in four cases, and both bones in 12 cases. The mean lateral angular (LAT-theta) value was 26.13 +/- 5.93 degrees on the proximal fracture end, and the distal mean LAT-theta was 30.29 +/- 6.24 degrees (p = 0.037). The mean proximal anteroposterior angular (AP-theta) value was 26.83 +/- 5.75 degrees, and the distal mean AP-theta was 30.58 +/- 7.27 degrees (p = 0.008). A significant correlation was detected between the AP-Delta and LAT-Delta measurements (p = 0.883). INTERPRETATION: The rotational defect was mathematically calculated directly from radiographs using a rotational measurement formula.