Summary

A 77-year-old man sustained an acetabular fracture after falling from a staircase and landing on his right side. He fractured the anterior column of his acetabulum and the quadrilateral plate. He underwent a single-stage open reduction and internal fixation of the fracture combined with a dual mobility total hip arthroplasty (THA). He sustained a traumatic hip dislocation 1 month postoperatively. Closed reduction was attempted at another hospital, and the femoral stem was pulled out. We believe this was caused by the polyliner being hitched either to the acetabular cup or in the soft tissues around the ilium. We present this case to caution orthopaedic surgeons that dual mobility THA dislocations are difficult to diagnose as the polyliner is not clearly seen on X-rays, and reduction attempts may lead to worsening of an already difficult situation.