MTV News reports Britney Spears injured her knee while filming her video for ‘Outrageous’ on Tuesday night, delaying the shoot and complicating her forthcoming tour. While doing some choreography, her knee gave out and she crashed to the ground. Spears was rushed to a hospital, where she received an MRI scan. Doctors determined that the singer had floating cartilage in her knee, and she underwent arthroscopic surgery, according to her spokesperson. Read more.