One Direction star undergoes surgery, resting for April tour

One Direction Star Niall Horan said he has undergone knee surgery and asked his fans to respect his privacy as he recovers. Horan, 20, had been spotted in a London airport earlier in the week wearing a cast and using crutches, the Mirror reported. "Hey guys I know most of you have seen those pics today! Yes I've had major surgery, a much larger surgery than first anticipated, but I would like to tell you, it was a complete success!" he wrote on Twitter Friday. "So all I ask of you guys is that you would respect my privacy as I try to recover." Horan's surgery was the result of a dislocation problem he has had since childhood. He is resting up for the group's tour in April, the Mirror said.