System used to describe femoral head fracture with hip dislocation. Type 1, fracture of head caudad to fovea centralis with posterior dislocation; type 2, fracture of head cephalad to fovea centralis with posterior dislocation; type 3, type 1 or 2 fractures with additional femoral neck fracture; type 4, any of above fractures with addition of acetabular fracture.