Spiral fractures are one of the most common fractures seen in non-accidental injury. In such cases, with radiographic evidence for the mechanism of injury, the physician is more capable of identifying any inconsistencies in the offered explanatory history.

The objectives of the study were to detail and differentiate the fracture patterns created by rotation forces in different directions and to determine the reliability of that recognition method applied to standard radiographs.

Twenty rabbit femurs were fractured using a torque transducer and imaged using standard anterior-posterior and lateral radiographs. The radiographic interpretation skills of paediatric, radiology, orthopaedic and emergency room doctors were assessed before and after being given the findings of this study.

The radiographic propagation of the spiral fractures was consistent and followed six simple principles. There was a statistically significant difference in the numbers of correctly diagnosed radiographs, before and after the explanation of our findings, by these doctors (chi-squared=14.06, df=1, p=0.002).

The direction of the torsional force producing spiral fractures can be determined from characteristic features on routine radiographs but does not seem to be intuitive. These derived six principles will be a useful aid to physicians who manage paediatric spiral fractures where non-accidental injury is being considered.