to 25 cm and the length of the short shaft l 2 can be between 2 5 to 15 cm the dimensions for the rod and screw can vary in length or diameter so that a range of devices having different sizes can be available for patients of different sizes this will allow a surgeon to select and use two specific components that will work best in that specific patient after the surgeon has analyzed the nature and severity of the damage disease or defect that requires surgical intervention in one preferred approach an assortment of vertical rods having lengths of between 15 to 30 cm can be provided with diameters of between 9 to 14 mm oblique screws with lengths of between 5 5 to 7 cm and diameters of between 4 to 7 mm can be provided these will allow surgeons to choose rod and screw combinations that will accommodate the majority of patients if different sizes or angles are needed they can be stocked by a manufacturer or fabricated on a custom basis preferably using computer controlled machining methods such as laser cutting to minimize the additional expenses of custom fabrication the rod and screw preferably should have beveled but not sharply pointed tips screw tips can be provided with external threads in at least a region which extends back about 1 5 cm or more from the tip these threads should having a spacing and height which allow the threaded tip to securely engage and pull against the lower end of the tibial bone as screw is tightened during surgical placement preferred dimensions including the pitch depth and shape of the peaks have been established for threaded screws that will be inserted into bones those dimensional are well known to.