Lag Screw Placement - Zimmer Biomet Zimmer Natural Nail Manual

Lag Screw Placement

For the targeting guide Asia, instruments marked
pink-pink are utilized to place the lag screw.
The targeting guide Asia has a built in locking
mechanism for the lag screw cannula. To lock, the
knob at the end of the guide has to be turned
until the cannula is fixed. Marks on the targeting
guides near the holes indicate the color of cannula
that should be passed through that specific hole.
The chart shown above details the color coded
instruments that are used to target and place the
lag screw.
Caution: Retighten the connecting bolt to the
nail to maintain targeting accuracy.
Instrument Type
Double Cannula
Drill Sleeve (Optional) 4.3 mm
Lag Screw Cannula
3.2 mm Lag Screw Pin Sleeve
Lag Screw Reamer
Lag Screw Tap
Lag Screw Inserter
Lag Screw Retaining Shaft
Zimmer Natural Nail – Cephalomedullary Asia Nail Surgical Technique
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Asia
Pink-Pink
Pink-Pink-Red
Pink-Pink
Pink-Pink
Pink-Pink
Pink-Pink
Pink-Pink
Pink-Pink
The Tip-Apex Distance (TAD), the sum of the
distances of the tip of the lag screw to the apex of the
femoral head in the A/P and Lateral x-ray views, has
been shown to be a key indicator in reducing cut-out
of lag screws in the femoral head. The TAD should
be less than 25 mm.
Position the targeting guide so that the trajectory
of the lag screw cannula will place the lag screw in
the appropriate position in the femoral head and
neck. Pins can be held over the skin in line with the
lag screw cannula to help estimate this position
and correct CCD angle.
Note: If planning to use an antirotation pin to
further stabilize the femoral head, insert the
double cannula instead of the lag screw cannula.
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