Pop superstar Lady GaGa has checked into hospital to undergo hip surgery.

The Poker Face hitmaker scrapped several shows on her Born This Way Ball tour in the U.S. earlier this month (Feb13) after being diagnosed with synovitis, a severe inflammation of the joints.

She subsequently cancelled the rest of the trek last Wednesday (13Feb13) after being told she needed an operation to treat the injured hip, and now Gaga is going under the knife in a bid to address the problem.

In a post on her Twitter.com page on Wednesday (20Feb13), she writes, "Going in for surgery now. Thank you so much for sending me love and support. I will be dreaming of you."