The 50-year-old "Dirty Dancing" star had the operation last week to repair a ruptured disc in her back.
Dr. Robert S. Bray Jr. told People.com he removed "a huge fragment" from Grey's back during the procedure, which he categorized as a success.
"I'm still recovering at home. I have to rest a bit more, but I feel great -- completely pain-free," Grey told the magazine's Web site exclusively.
Grey suffered the ruptured disc on the first night of last month's "Dancing with the Stars" two-part finale, but continued competing and ultimately won the coveted mirror-ball trophy, alongside her professional dance partner Derek Hough.