<prompt> Pipkin fracture is defined as -Head of radius fractureHead of femur fractureFracture dislocation of ankleFracture neck of femur  <response>: Pipikins classification of femoral head fractureType I: Femoral head fracture inferior caudal to foveaType II: Femoral head fracture superior cephalad to foveaType III: Femoral head fracture with associated femoral neck fractureType IV : Type I, II or III with associated acetabular fracture 