I have pvns in left knee, i'm having a complete synovectomy aswell as he's having a look at pcl as its a bit lax. how long will i be under roughly?

30-60 minutes: Most arthroscopic synovectomies probably take anywhere from 20 minutes to an hour and a half depending on how extensive and the amount of bleeding and visibility.

PVNS: Depending on whether you have a localized (focal) pvns versus a more "diffuse" pvns presentation surgery may take 1/2 hour to an hour and a half. Your surgeon will want to ensure that all the affected tissue is removed to lower the incidence of recurrence.