Vonn lost balance on her right leg while landing a jump in the super-G, flipped over in the air and landed on her back as she smashed through a gate before coming to a halt. Although she will miss the rest of this season, the U.S. ski team said the 28-year-old Vonn is expected to return in time for the 2014 Sochi Olympics.
The four-time overall World Cup winner and 2010 Olympic downhill champion received medical treatment on the slope for 12 minutes before being taken by helicopter to a hospital in Schladming.
"Vonn suffered a torn ACL (anterior cruciate ligament) and MCL (medial collateral ligament) in her right knee and a lateral tibial plateau fracture," U.S. Ski Team medical director Kyle Wilkens said in a statement.
Christian Kaulfersch, the assistant medical director at the worlds, said Vonn left the Schladming hospital on Tuesday afternoon and will undergo surgery in another hospital.
"She first wanted to go back to the team hotel to mentally deal with all what has happened," Kaulfersch said.
Team physician William Sterett, who was with Vonn, declined to offer any more information when contacted by The Associated Press.
The crash in the opening event of the championships came almost exactly a year before the start of the 2014 Winter Olympics in Sochi, Russia.
"She will be out for the remainder of this season but is expected to return to racing for the 2013-14 ... World Cup season and the 2014 Olympic Winter Games in Sochi," the team said.
Vonn returned to the circuit last month after taking an almost month-long break from racing to fully recover from an intestinal illness that put her in a hospital for two days in November.
The start of Tuesday's race was delayed by 3 1/2 hours due to fog hanging over the course and it started in waning light at 2:30 p.m. Even before Vonn's crash, a course worker fell and also had to be airlifted. He was reported to have only broken his nose.
All the delays made for flat light when Vonn raced.
"Lindsey did a great job on top and Lindsey has won a lot of races in flat light so the flat light was definitely not a problem," U.S. Alpine director Patrick Riml told the AP.
"We are upset obviously with what happened but if you don't know the facts and why they decided to start and what the weather forecast was it's hard to say without any reasoning," Riml said. "And they probably had a reason, otherwise they wouldn't have started."
It was difficult to analyze when exactly Vonn lost control as she came off a left turn into the jump.
"She jumped a little bit in the wrong direction and started to correct that a little bit in the air and put a lot of pressure on the outside ski exactly in the landing and she couldn't hold the pressure and then (she crashed)," International Ski Federation women's race director Atle Skaardal said.
Skaardal defended the decision to race.
"I can confirm that the visibility was great, there were no problems, and the course was also in good shape," he said. "I don't see that any outside factors played a role in this accident. ... The other factors were like they were supposed to be for ski racing."
It's the sixth straight major championship in which Vonn has been hit with injury.
Two years ago, she pulled out midway through the last worlds in Garmisch-Partenkirchen, Germany, because of a mild concussion. At the 2010 Vancouver Olympics, Vonn skied despite a severely bruised shin to win the downhill and take bronze in the super-G.
At the 2009 worlds in Val d'Isere, France, she sliced her thumb open on a champagne bottle after sweeping gold in the downhill and super-G, forcing her out of the giant slalom. At the 2007 worlds in Are, Sweden, Vonn injured her knee in training and missed her final two events.
And at the 2006 Turin Olympics, she had a horrific crash in downhill training and went directly from her hospital room to the mountain to compete in four of her five events.
Having regained her form in recent weeks, Vonn trailed eventual race winner Tina Maze of Slovenia by just 0.12 seconds at an intermediate interval shortly before Tuesday's crash.
The conditions varied from racer to racer.
Former overall winner Maria Hoefl-Riesch of Germany started immediately after Vonn and skied off course.
"It's not a very difficult course but in some parts you couldn't see anything," said Fabienne Suter of Switzerland, who finished fifth.
However, Vonn teammate Julia Mancuso thrived in the difficult conditions and won the bronze medal.
"It's the same for everybody," U.S. speed coach Chip White said. "Everyone had to wait for a long time and that's always difficult. And the holds were every 15 minutes so it really doesn't give you a chance to go and do something else. You're always kind of on edge at the ready. It's a difficult situation but everybody had the same difficult situation."