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8Preliminary plate fixation

Usage of the indirectly measuring device

Screw length measurement in distal femoral articular block

Use the measuring device indirectly to measure the lengths of the screws using 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. Measure for 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.