Traumatic hip dislocation in a child with an acetabular fleck sign indicating posterior osteochondral avulsion: a...

Pediatric traumatic hip dislocation is rare and may be accompanied by structural injuries requiring surgical treatment. We report the case of traumatic posterior hip dislocation sustained by a 9-year-old boy while playing rugby. Closed reduction was initially performed at a local hospital, but redislocation occurred 3 days later. Computed tomography demonstrated a small bony fragment adjacent to the posterior acetabular rim consistent with the acetabular fleck sign. Magnetic resonance imaging revealed an osteochondral fragment continuous with the labrum. Open reduction using the Kocher-Langenbeck approach confirmed posterior osteochondral avulsion, which was repaired with soft anchors. At the 3-year follow-up, the patient was pain-free, had a normal gait, and showed no evidence of femoral head osteonecrosis. This case suggests that the acetabular fleck sign may indicate posterior labral osteochondral avulsion in pediatric traumatic hip dislocation, and that early recognition may promote timely surgical intervention and prevent recurrent instability.