A treatment strategy to avoid iatrogenic Pipkin type III femoral head fracture–dislocations

Introduction: Reduction is urgently required in cases of traumatic hip dislocation to decrease the risk of avascular necrosis of the femoral head. However, successful reduction may not always be feasible for hip dislocations associated with femoral head fractures. This irreducibility may provoke further incidental fractures of the femoral neck with resultant Pipkin type III injuries. The purpose of this study was to describe an appropriate treatment strategy for irreducible femoral head fracture–dislocations. Materials and methods: We treated nine patients with irreducible hip dislocations with femoral head fractures (eight Pipkin type II and one type IV) for which reduction failed in the emergency room or operating theater. All of these cases required operative management. Results: Five of the nine patients experienced femoral neck fractures after closed reduction were attempted. These five cases underwent joint replacement at the time of injury or after developing avascular necrosis of the femoral head. Analysis of radiographs and computed tomography (CT) scans revealed that the fractured femoral head was perched on the sharp angle of the posterior wall of the acetabulum in the irreducible hips. After recognizing the irreducibility, the other four cases underwent immediate open reduction without further attempts at closed reduction, which saved the natural hip joint without neck fracture or avascular necrosis. Conclusions: Repeated or forceful closed reduction of irreducible femoral head fracture–dislocation injuries may result in iatrogenic femoral neck fractures with Pipkin type III injuries. Before attempting reduction, careful examination of plain radiographs and CT images may be helpful for determining the safest treatment strategy.