Drill a 3.5 mm gliding hole for the lag screw into the anterior cortex of the proximal fragment. The hole should be drilled as perpendicular to the fracture plane as possible.
Insert the 2.5 mm drill sleeve into the gliding hole, then drill the far cortex with the 2.5 mm drill bit.
In order to prevent cortical stress and micro fractures, the cortex can be countersunk to increase the area of contact between the bone and the screw head.
Measure the depth of the hole with the hook of the depth gauge pointing distally.
Tapping the far cortex
Tap the posterior cortex with the 3.5 mm cortical tap and protection sleeve.
Insertion of the screw
Closely observe the compression effect on the fracture line while tightening the lag screw.
The reduction forceps should be removed just before the final tightening of the screw.