Vonn, however, got up and skied down the hill after being tended to by medical personnel.
Last week, the all-time leader in women’s World Cup wins announced that she will retire after racing the super-G and downhill at the worlds.
Vonn has been slowed by persistent pain in both of her knees.
Losing control in mid-air and skiing through a gate, the panel fitted between the two poles detached and got stuck on Vonn’s boots.
When she hit the ground she slid downhill face first, using her hands to keep her head from hitting the snow, then came to a stop when she hit the safety netting.
Vonn was slated to conclude her career with Sunday’s downhill.