Fig. 2

The Garden classification of non-displaced (Garden type I and II) and displaced (Garden type III and IV) femoral neck fractures. Incomplete or impacted fractures, including a valgus dislocation, are classified as type I. If neither impaction nor dislocation occurs, the fracture is classified as type II. Type III refers to a dislocated fracture with existing bony contact in the calcar femoris region, including the retinacula of Weitbrecht being still intact [77]. Type IV indicates a complete disassociation of the femoral head from capsule and vessels. A higher dislocation grade is associated with a higher probability of disruption of the femoral neck’s blood supply