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By Entertainment Tonight

Brad Pitt was spotted walking with a cane earlier this week in Los Angeles and at tonight's Palm Springs International Film Festival's Annual Awards Gala -- where he walked the red carpet with Angelina Jolie and the support of a cane -- he revealed the source of the injury.

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The actor, who is being honored at the festival for his work in "Moneyball" and "Tree of Life," tells ET that he wiped out on a ski slope while carrying one of his twins. He twisted his knee and suffered some ACL damage in the process.

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Brad's bruised arrival led to additional injuries as the mere sight of him and partner Angelina Jolie sent one fan into such a state, an ambulance had to be called and the unidentified reveler was taken away in a stretcher.

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