After any fall or significant impact, inspect the stem for cracks, deformations, deep scratches, or corrosion before riding again. Check that the six clamping bolts are tightened to 9 Nm and that the pivot-stem and handlebar-stem interfaces have no play. At the slightest damage, replace the stem immediately — do not ride with a compromised cockpit.
Detailed inspection instructions can be found in the official installation guide: