My OS calls anything that is not done through keyhole surgery 'extensive'. Each OS probably differs as with everything else
All surgery is traumatic and not to be taken into lightly, however, open procedures and knee issues which take a long time on the OR table to repair would be extensive. (I really could have worded this better!)
According to my surgeons, the two quad tendon repairs and my TTT for patella baja, both were considered 'extensive'.
My scopes, LR's, and VMO advancement were not.
If in question, by all means, ask your OS for clarification. Going into surgery without having a full understanding of your OS's intentions can be trouble. I'm proof of that.
Hope that helps some,