Lady Gaga received a pre-surgery pep talk from Cameron Diaz and Kate Hudson's ex-boyfriend.

A source close to the 26-year-old star told the New York Post's Page Six: "Alex was at Dr. Kelly's office for a follow-up, while Gaga was preparing for surgery. It's natural for anyone to be nervous ahead of this type of surgery, especially as a performer or athlete under tremendous pressure to make a quick recovery and be back at peak performance . . . Gaga was anxious, but Alex talked to her for a while and was able to reassure her."

Lady Gaga admitted the injury had left her in "chronic pain" after she hid it from her colleagues for a long time and continued performing.

But the singer announced last week she could no longer continue the final leg of her 'Born This Way Ball' tour because of the pain, which will reportedly result in up to $30 million in refunds.

Following the operation on Wednesday (20.02.13) at New York's Hospital for Special Surgery, she thanked her fans for giving her the strength to get through her ordeal and put her problems in perspective.

In an open letter, she wrote: "As they wheeled me into surgery today, I thought about all of your pain and perseverance, your unique family situations, school environments, health issues, homelessness, identity struggles - sometimes you are so brave that it terrifies me. I wonder how it's even possible.

"So I thought to myself, I'm alive, I'm living my dream, and this is just a bump in the road. I'm grateful because this is temporary, and for some it is not. You have changed my life. I love you and am proud to be a part of your lives. If you can do it, I can do it too, and if we stick together we can get through anything."