Sign IM Nail and Interlocking Screw System Technique Manual page 40

Changes of SIGN interlocking procedure
Vietnam has soft bone. We used a hand drill and large drill bits to make the hole in the near cortex.
The bone was soft and the drill did not walk along the bone.
Bangladesh has hard bone. The large drill bit in the hand drill walked along the bone during the
attempt to drill a hole in the near cortex. We made a pilot hole and used a step drill to enlarge it. We
improved step drills in many ways. No matter how we improve them they become dull.
SIGN surgeons began to use a commercial drill which allowed them to drill faster and more
accurately. We were not satisfied with the sterility of the drill. A drill cover placed over the drill
with a chuck extension has allowed us to use commercial drills in a sterile manner.
We can use power so we are modifying our drill bits to enable the interlock holes to be drilled
quicker.
The slot finders have also changed. The curved slot finder has become very helpful. If the
longitudinal alignment has been maintained, the slot in the nail can always be found.
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