Screw placement depends on the type of fracture. The positions of the locking head screws should be chosen in accordance with the established biomechanical principles for internal fixation. The locking head screws should be inserted remote from the fracture gap in the main diaphyseal fragment. Three to four plate holes in the region of the fracture zone should remain free of screws to ensure sufficient elasticity of the construct.
It should be noted that once the initial locking head screws have been inserted into each main fragment, length and rotation are fixed. Antecurvatum and recurvatum deformities can still be adjusted within narrow limits. For this reason, it is recommended to start by inserting the first locking head screw in the proximal fragment.
If a screw has to be removed and reinserted, the hand torque limiting screwdriver should be used and not the power tool.
Measuring of screw length for proximal fragment
Use the measuring device with a 2.0 mm K-wire of 280 mm length, placed through the centering sleeve in the drill sleeve. This will allow you to determine the appropriate screw length. Using image intensification, the K-wire is pushed to the desired depth, leaving at least 5 mm between the tip of the K-wire and the medial cortex. The screw length is measured over the K-wire using the measuring device for K-wires while the guide sleeve in place. The length is rounded down to the nearest screw length. This will
ensure that the tip of the screw will not protrude through the medial cortex.