What is a cannulated screw? or What is a cannulated hip screw? The answer is that these type of screws are inserted at the place where the neck of femur is fractured and also where there is higher possibility that the fracture will heal if held in place via some internal fixation. This aforesaid scenario comprises three large screws which are placed via the neck of femur into the head. These are popular with their central shaft which is hollow. The category of cannulated screws can include cortical as well as cancellous screws. These are ideal for metaphyseal fractures.