Is Arthroscopy The Only Solution For My Knee Pain, Cyst, And Cartilage Tear?

Hi Doctor, First of all thankyou for your hard work, self-less service. I am Hitesh, I am a National Level Tennis player and also working as Software Engineer. 2 years ago I had injured my Knee while tennis practice and since then it has kept me out of Sports. I did consult to multiple specialists and MRI scans. Problems which I have been facing : Pain in my right knee. I cannot bend my knee and sit on floor or use Indian Toilet. It pains when I bend my knee more than certain degree. Scans says there is a big cyst at the back on my knee and a tear around cartilage. (Not sure, just mentioning what I have been told by doctors) . Can you please suggest the best solution and is the arthroscopy the only solution ? As Physio, rest, icepacks all these I have tried in 2 years.