Repeat posterior wall acetabular fracture-dislocation: High-energy trauma as a 'second hit phenomenon'.

Acetabular fractures are injuries that require significant force transmission, especially when associated with a femoral head dislocation. The mechanism of injury is typically in the setting of a high-speed motor vehicle collision. In a similar manner, this is an injury that is highly demanding for the orthopaedic trauma surgeon to treat as well. We present a patient who sustained an initial posterior wall acetabular fracture with an associated posterior dislocation. This was treated surgically with open reduction, internal fixation without complication. The patient subsequently sustained a second posterior wall acetabular fracture with dislocation fifteen years later through the plated and healed previous fracture. Both injuries were sustained in high-speed motor vehicle collisions, so it is difficult to presume the patient was predisposed for the repeat injury. At any rate, the repeat injury makes the surgical management significantly more challenging. In complicated acetabular fractures like these, a post or intra-operative CT scan can be of utility to determine quality of reduction as well as assessing for retained bony fragments. Our patient underwent a post-operative CT scan with the finding of intra-articular bony fragments that subsequently required arthroscopic removal. Given the rare nature of this complicated injury occurring twice in a patient, it is difficult to make evidence-based comments on long-term prognosis and functional outcomes. This unique case and the applied treatment will serve as a guide for future similar cases.