Insertion of first screw
Mark the plane of the first carpo-metacarpal joint with a thin K-wire or a
hypodermic needle. Put the plate on the dorsal aspect of the proximal fragment,
with a threaded drill guide in one of the outer holes. Drilling must be
parallel to the marker wire (or needle) to ensure that the screw will not
penetrate the joint. Confirm using image intensification.
Drill through the threaded drill guide. Remove the drill guide and measure the
appropriate screw length with a depth gauge.
Insert the locking screw without completely tightening it.