Landry had an ankle injury in 2017 which caused him to miss their last 5 games. He was dominant in 2016 with 16 sacks. His draft position could well depend on whether teams feel the ankle is still an issue.
I'm guessing it's an ankle sprain. I've read nothing to indicate surgery was needed. He does not appear to be on the Senior Bowl roster, although he was invited. Guess we'll have to wait until the Combine to find out about him.