Cannulated screws have a hollow central shaft. Both cortical and cancellous screws can be cannulated. Cannulated cancellous screws are used for metaphyseal fractures while cannulated and non-cannulated cortical screws are used as lag screws for fixation of diaphyseal. Cannulated Screws are in Diameter of 4.0mm, 6.5mm and 7.0mm with Partially Threaded, 16mm Threaded, 32mm Threaded or Fully Threaded.