Screw length measurement in distal fracture fragment
Once you have confirmed that the proximal end of the plate is appropriately
aligned on the femur and the distal end of the plate is appropriately placed,
insert the distal screws. Use the measuring device indirectly to determine the
appropriate screw length from the previously inserted guide wires.
Although screws may be inserted in any order, it is usual to start with the
central 7.3 mm screw. Advance the guide wire until it reaches the medial cortex
of the femoral condyle. Determine the appropriate screw length using the
measuring device. For proper screw length measurement, the measuring device
must contact the end of the threaded wire guide. This will place the tip of the
screw at the tip of the guide wire.
Pearl: self-drilling/self-tapping screws
The self-drilling, self-tapping flutes of the 7.3 mm and 5.0 mm screws make
predrilling and pretapping unnecessary in most cases. In dense bone, the
lateral cortex can be predrilled, if necessary:
- use the 5.0 mm drill bit for 7.3 mm screws
- use the 4.3 mm drill bit for 5.0 mm screws.