LADY GAGA has been forced to postpone a series of concerts on her North American tour after sustaining a crippling injury which has left her unable to walk.

The pop superstar was due to take her Born This Way Ball to Chicago, Illinois, Detroit, Michigan, and Hamilton, Ontario this week (begs11Feb13), but a case of synovitis - severe inflammation of joints - has prompted her doctor to insist she bow out of the dates to rest up and recover.

In a statement issued to fans on Tuesday (12Feb13), the Poker Face hitmaker writes, "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 (per cent) again, which is what you deserve."

The shows are expected to be rescheduled for the near future.