Lady Gaga has cancelled the remainder of her world tour after discovering she needs surgery for a hip injury.
The announcement was made on Wednesday, one day after the pop superstar lamented having to delay some of her forthcoming North America concerts.
A news release said Gaga, 26, has a tear in the labrum in her right hip that would require surgery followed by a recovery period.
The labrum is a layer of muscle that helps holds the ball-shaped hip joint in place.
Earlier, the Bad Romance singer had told her 34 million Twitter followers that she was suffering from a case of severe joint inflammation called synovitis.
Twenty-one dates until March 20 remained on Lady Gaga's two-year Born This Way Ball tour schedule.
Gaga told her "little monsters" she had hurt herself a while ago, but initially tried to cover up the injury.
She tweeted: "I hid it from my staff, I didn't want to disappoint my amazing fans. However after last night's performance I could not walk and still can't."
Over the last month, the injury became worse and she said she was unable to walk following a performance on Monday in Montreal.
She followed it up with another tweet declaring: "I'm on crutches and occasionally using a wheelchair, but I'm okay, I promise!"
The tour, in support of her second album Born This Way, began last April in Asia and was one of the biggest money earners of the year.
The tour made an estimated \$161m (£104m) with an average attendance of more than 31,000, making it the fifth-highest grossing tour.
Fans who have already bought tickets for the cancelled shows will receive a refund.