"The operation has gone well," doctor Miguel Del Cerro told reporters after inserting two screws in the keeper's hand.
"The recovery period is eight to 12 weeks. It is best to wait and not talk about time periods."
Spain's number one suffered the injury during Real's Copa del Rey quarter-final second leg against Valencia on Wednesday when defender Alvaro Arbeloa accidentally kicked his hand while trying to clear the ball.
Casillas is set to miss both legs of the Cup semi-final against arch-rivals Barcelona and their Champions League last 16 tie against Manchester United.
- Sports & Recreation
- Alvaro Arbeloa