The Italian alpine star, who won the overall World Championship, crashed badly in the Italian championships last week.
She suffered multiple fractures in her left leg and also tore her cruciate ligament.
On Tuesday, she held a press conference, sitting in a wheelchair, before leaving the La Madonnina clinic in Milan after the operation.
I still don't know how long it will take to get back. We're taking it step by step. The next step is to start rehabilitation and then we'll see how the leg reacts, she says.
The fact that she was operated on the same day as the crash, after being airlifted by helicopter from Val di Fassa, may be crucial.
Everything they did to reduce the waiting time and prevent complications was crucial, she says.
According to Andrea Panzeri, medical chief for the Italian winter sports federations, it will take at least 45 days before a detailed schedule can be made for Brignone.
The Italian won ten World Cup competitions in three different disciplines last season, five victories in giant slalom, three in super-G, and two in downhill.
She also took World Championship gold in giant slalom and silver in super-G.
At 34 years old, she is the oldest World Cup winner on the women's side.
