One Direction's Irish heartthrob Niall Horan spent this afternoon (January 6) reflecting as it has been one whole year since he had major surgery on his knee. 

The 'Steal My Girl' superstar took to his official Twitter page and thanked trainer Mark Jarvis along with the Chelsea Football Club for getting him back into shape and fit again now that he has fully recovered: "This day last year I had my knee operated on, would like to thank everyone @ChelseaFC and @M1Jarvis for gettin' me back fit."

Upon seeing the tweet, Jarvis replied: "You're very welcome mate x."

On January 17, 2014 Horan told his followers that the operation was far more serious than he initially anticipated: 

"Hey guys I know most of you have seen those pics today! Yes I've had major knee surgery, a much larger surgery than first anticipated. But I would like to tell u, it was a complete success! Considering the scale of it! So all I ask of you guys is that you would respect my privacy as I try to recover and get for the where we are tour!"

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