Abstract: Objective To study the injury manners of Bennett fracture and Rolando fracture and explore its identification principle of the first metacarpal base fractures. Methods Totally 31 cases of Bennett fracture and Rolando fracture were collected. The injury manners of cases of 19 Bennett fractures and 12 Rolando fracture were classified, and various injury manners were analysed statistically. Results The injury manners of the cases of 19 Bennett fracture and 12 Rolando fracture were divided into three types, including the first metacarpus hit hard objects during a punching, the first metacarpus hit hard objects when making fists and fell, or the first metacarpus was punched by hard objects when making fists. Conclusion The injury mechanism of Bennett fracture and Rolando fracture is formed by a force on the first metacarpus when making fists, which transmits to the basilar part along the vertical axis of metacarpus. The inference of injury manners should be focused on the confirmation of entrusted matters.

Key words: forensic medicine, fractures, bone, hand injuries, finger injuries, injury manners