It is not known how long Mustafina will be out.

Mustafina would later state a high temperature was the cause of her poor performance.

Mustafina touched the floor at the end of one tumbling pass and finished second.

In the individual all-around final, Mustafina again placed first with a score of 58.566.

Mustafina's injury could be a big blow for Russia, which had its best showing in almost 20 years at last fall's world championships.

Prior to the competition, Mustafina had been sick for weeks and started experiencing heavy pain in her knees.

Mustafina led the effort with two bronzes and Balandin added silver.

In the floor final, she tied for third place with Aliya Mustafina.

Alexandrov said Mustafina would likely have surgery next week in Germany.

"It is how it is now, but everything can change tomorrow" said Mustafina.

This led to Mustafina taking the bronze medal.

Mustafina has won 11 medals at the World Championships.

In July, Mustafina was only doing upper body conditioning and rehabilitation on her leg.

However, the highest score was by her teammate Mustafina and only one gymnast per country could advance to the final at these games.

After the operation, Mustafina said, "I ache a little, but not too much, yesterday was worse."

Russia had four, but only gold from Aliya Mustafina on the balance beam.

Mustafina wins her first individual world title.

Mustafina is a question mark, according to Bela Karolyi, who keeps close watch on international competition.

Mustafina's trademarks are her elegance, strong all-around abilities and focused demeanor.

When Mustafina followed with a first vault of 15.733, it seemed Sacramone was reduced to silver at best.

Mustafina will have surgery Tuesday to repair the damage in her left knee, according to her official website.

In May, Mustafina returned to Germany for a check-up on her knee.

Mustafina competed as a junior at the European championships this year and helped Russia win that team title.

She began gymnastics at age three, and her favorite gymnast is Aliya Mustafina.

In the team final, Mustafina contributed an all around score of 60.266 towards the Russian team's second-place finish.