Sign IM Nail and Interlocking Screw System Technique Manual page 17

Incise the fascia but use the periosteal elevator
to spread the muscle down to the bone. Insert the
cannula on the bone, figure 14. Use a curved
clamp to remove soft tissue between the cannula
Fig. 14
and the bone. Be sure no fascial bands are
pushing the cannula. Tap cannula lightly with a
mallet to secure to the bone.
Insert the small drill guide into the cannula and
use a small drill bit to drill a hole through the near
cortex. Avoid hitting the nail with the drill bit or it
will become dull.
Insert the large drill guide and use the step drill or
Fig. 15
large drill bit to enlarge the pilot hole. Be sure the
step drill tip engages the pilot hole, figure 15.
Stop rotating the step drill or drill bit when it stops
suddenly after engaging in the slot of the nail.
Further twisting will break the step drill. If the step
drill does not progress, use the large drill bit.
Insert the solid slot finder through the hole
in the near cortex, figure 16. In hard bone
the screw hole broach inserted through the
cannula must be used to enlarge the hole
to allow the slot finders to enter the canal.
Fig. 16
See figure 17 for comparison of screw
hole broach and step drill.
Push the solid slot finder with the flats in
the plane of the target arm. Rotation is not
used to place the slot finder. Push the slot
finder in. If the slot finder engages the slot
in the nail, 10-15º of rotation with a sharp
stop to the rotation will occur. This is the
"SIGN feel." If the slot finder rotates 360º,
it is not in the slot or stuck in the hole in the cortex. Rotate the nail to orient the slot in the nail
parallel to the hole in the near cortex. If the solid slot finder enters the slot and the "SIGN feel" is felt,
place the cannulated slot finder. Test again for "SIGN feel."
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