Acetabular labral entrapment following spontaneous nonconcentric reduction of posterior hip dislocation in a child.

Traumatic pediatric hip dislocations are uncommon and can occur following minor trauma. This injury may be overlooked, as pediatric hip dislocations can reduce spontaneously prior to medical attention. In this scenario, the presenting hip radiographs may provide evidence of a prior transient hip dislocation episode by demonstrating signs of a nonconcentric hip reduction, and prompt further evaluation with advanced imaging. We present a rare case of a traumatic posterior hip dislocation with spontaneous nonconcentric reduction in a child. CT and MRI revealed a block in concentric reduction by the avulsed and entrapped posterior acetabular labrum and contiguous epiphyseal fragment. This case highlights the imaging characteristics of this rare injury, and the importance of early diagnosis to guide surgical management.