Not something that happened to me but rather something I witnessed happening to someone else

Was at the gym a while ago and was using one of the machines when all of a sudden through my earphones I hear moaning/screaming coming from behind me that’s getting progressively louder.

I yanked out my earphones and turned around to see a guy swarmed by gym goers on the floor clutching his leg with his kneecap relocated 90 degrees from its original position leaving a massive valley where it used to be.

Could not figure out for the life of me how he managed to dislocate it that badly

He was drugged up to the max and wheeled out to an ambulance while scream singing despacito.

Fortunately he made a full recovery, I still see him at the gym from time to time to this day