According to The Texans official website:
Coach Gary Kubiak confirmed the news on Tuesday afternoon, a day after Cushing was injured against the New York Jets at MetLife Stadium. Cushing will have surgery in 2-3 weeks after the swelling in his knee subsides.
“(It’s) a big blow to our team,” Kubiak said. “You feel bad for Brian because he works so hard and is playing so well. He’s going to be missed, but we’ve got to have guys pick it up around him and got to find a way to move forward. We’re just all disappointed for him.”
via Houston Texans