I've had a few knee injuries as of late.
Broken meniscus and broken cartilages (operated) and broken cruciatus ligament (not operated) in my left knee. Broken meniscus and broken cartilages (operated) and broken again meniscus (waiting for the operation) in my right knee.
Inner knee is often meniscus related, at least in my experience. Best thing is to have an MR scan; tests are fine but not 100% affordable: all ligament tests were negative for my left knee, and when the surgeon went in they found out that my cruciatus was completely disappeared. Like, not broken: shredded to thin filaments.
Now my left knee is kind of ok, let's hope my right one will heal properly also.
I have to say that also having both external ankle ligaments broken does not help knee health. A few weeks ago a simple farmer's walk with a heavier load fucked my knee properly for a good two weeks.
Despite this, yesterday I flashed 2xBW deadlift again after a lot of time without going heavy. Miracles.