The 23-year-old was ruled out for the rest of the Premier League season and also the World Cup finals in Brazil this summer after suffering the injury in training last Thursday.
And he has now returned to his native Belgium to have surgery.
Manager Paul Lambert said: "Our doctor (Roddy Macdonald) is over in Belgium and he has spoken with the surgeon, and it's pretty imminent he will get it done - today, tonight or tomorrow.
"Then after that it's all about the rehabilitation with him. When it's a long-term injury you have good days, bad days, like everyone else when they are out injured for a long time, but he'll be fine."
Lambert agreed that missing the World Cup would be a big blow to the forward but backed him to get over that disappointment and come back stronger.
"It's probably just sinking in now he is going to miss the World Cup, which is a major blow for him," added Lambert.
"But he is in a generation of Belgian players who will qualify for a few more tournaments down the line.
"He is still a young guy in that group, and he will come back totally strong, given the way he is as a guy and his physical aspect.
"Of course, everybody is different as to how they want to progress, and how quick their body heals.
"But looking at Christian and the way he is as a pro he will knuckle down and work really hard to get back.
"I've been told the surgeon is really highly regarded, so as long as the job is done right and everything goes swimmingly then he will be okay."
In better news for Villa, striker Gabby Agbonlahor and midfielders Fabian Delph and Karim El Ahmadi should all be fit to face Crystal Palace on Saturday having missed the 2-1 loss at home to Fulham last weekend.
"They all trained this week and they're all fine," revealed Lambert.