Shah Rukh Khan injured his knee over a year back. The injury has come back to haunt the actor and he has to undergo a knee surgery in July.Following the rigorous shoot and action sequences the actor had to undertake in his film RA.One the injury, which was earlier treated by Kolkata Knight Riders physiotherapist Andrew Lepius has aggravated.In fact Mumbai based Dr Ali Irani has recently paid the actor a visit in Hyderabad where he is currently shooting to check his knee. "He has been going through a lot of discomfort for sometime. And hence the doctor was called in. He has a tear in the meniscus of his left knee," informed a source.When contacted Dr Ali Irani admitted, "Yes he does have a knee problem and he will need to undergo surgery in July."