gagaLady Gaga is battling synovitis, or severe inflammation of joints – so much so that she could barely walk after her last concert.As a result, her doctor has ordered her to postpone performances in Chicago, Detroit and Hamilton, Ontario.

“I am completely devastated and heartsick. I’ve been hiding this injury and pain from my staff for a month, praying it would heal,” said Gaga.

It did not heal, and now four nights of concerts in beginning February 13th have been axed and later rescheduled.

Said Gaga in a statement: “I am completely devastated and heartsick. I’ve been hiding this injury and pain from my staff for a month, praying it would heal, but after last night’s performance I could not walk… To the fans in Chicago, Detroit and Hamilton, I hope you can forgive me as it is nearly impossible for me to forgive myself right now. I would do anything for you. I will hopefully heal as soon as possible and be at 500% again, which is what you deserve.”

While commonly associated with arthritis, dance injuries can also contribute to the condition, causing swelling and pain in the joints. It can be treated with anti-inflammatory drugs and steroids.