Suddenly Developed Creaking Knee

I was doing my usual routine of pistol squats (which I’ve been at for 4 years now, so no sudden change in routine), but then my left knee started suddenly creaking with every rep. The creak isn’t accompanied by any pain (at the moment). The creak happens when the knee is at about a quarter squat position.

It sounds pretty bad. I’m 24, so maybe this is the start of some serious arthritis?

Anyway, should I be worried? Is this going to be the start of some serious problems? What can I do to make the creak go away?

Thanks.

Is it possible that I’ve torn my meniscus and/or ACL doing unweighted pistol squats?

I didn’t particularly screw up a rep or anything, and I didn’t hear or feel a sudden pop. On one rep, I noticed that my knee had just started creaking, and now it creaks every time it goes into the quarter squat position. Lower and high it doesn’t creak. It also doesn’t creak if doing like a leg extension movement - only when doing a squat like movement when the body is pressing down on it. And I can’t ‘feel’ the creaking - I can only hear it. So if I bend my knee when there is a bit of ambient noise about it feels, and sounds fine.

My knee is still, basically painless, but now (in addition to the new creaking sound) it feels slightly wobbly. When my knee is fully flexed my patella sort of feels a bit strange like it wants to pop out - but it’s still painless.

I know I should probably see a doctor, and I might if I can get time off, but, reading this, does your gut feeling tell you that this is a meniscus/ACL tear, and that I’ll probably need surgery?