In the morning, she alerted fans on Twitter about the impending trip under the knife, writing, "Going in for surgery now. Thank you so much for sending me love and support. I will be dreaming of you."
Later in the day she gave her Little Monsters an update on the procedure on the Little Monsters site, praising them for helping her through the procedure. "Monsters, You really gave me a lot of strength today," she wrote.
"Everything happened so fast, but when it came time to face it I reflected on the many stories and experiences you've shared with me about your lives. Meeting you backstage, reading your letters, watching you communicate with fans from around the globe to form a community that supports one another -- You have completely blown my mind."
Gaga, 26, said that as she was wheeled into surgery she thought about all the "pain and perseverance" her Monsters have gone through, as well as their unique family situations, school environments, health issues, homelessness, identity struggles, she marveled, "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."
Before the surgery, Dr. Alexis Colvin, an orthopedic surgeon who specializes in sports medicine at the Icahn School of Medicine at Mt. Sinai in New York City (but who is not treating Gaga) told MTV News that the injury is not uncommon in very active people the singer's age.
"It could be from repeated twisting and turning from dancing. She's like an athlete, but she sings," said Colvin. Depending on the extent of the damage, Colvin said a patient is typically on crutches for two to four weeks, and then can be back performing within three-to-six months depending on how the physical therapy goes. The good news is that given her age and athleticism, Colvin suspected a successful surgery means that Gaga should be able to bounce back with no problem.