When you say inside your knee, do you mean actually inside you knee (2 cruciates) or on the inside of your knee (medial). If its the latter, these can really, really hurt even with just a minor injury as they have apparently a lot of flex in them. The cruciates inside are quite tight and add stability.
For what’s it worth i’ve had 4 right knee ops, the first 20 years ago. Not sure exactly what the original injury was, and as a indestructable 19yr old was not that worried, but was told i could forget sport. Only found out finally at my last op 6 years ago i appear to not have much cruciate left ie they did not reconstruct them during the original operation, although scar tissue is doing a job. At the time also did something to the medial, which if i recall made my eye’s water i could not even move my leg. Have had a fair amount of cartilage removed and can’t run, apparently walk with a limp, and the arthritus hurts like buggery when its cold. But i can still bike. 😀