I'm A Lifelong Classical Ballet Dancer, Teacher And Choreographer. Age

I'm a lifelong classical ballet dancer, teacher and choreographer. Age 57. Female. In very good health. Not over weight.
I'm having a problem with my right knee. Started with a back problem. Fell down some stairs landed on my right side, another time on my right knee then right eye orbit. Pain migrated down the leg and the hamstring got extremely tight. Balance was off. About a year ago I was kneeling and the felt a flipping of ? behind my knee. Since then it really hasn't felt right. Anything from it won't bend with ease to unstable to minor pain that shifts location. Usually under the knee middle or towards the inside or above. Muscules in the thigh and calf have been tight. Where they're tight, shifts. I've had chiropractic treatment and that has helped. Balance is back. No visible swelling. I'm still dancing, stretching and doing Pilates daily.
I perform physically integrated dance now. Floor work is necessary. https://youtu.be/FkTKXUG0M_k
I look forward to your opinion.
Tina Christina-Price