Age / Sex : 50 / M

Chief complaint : right knee pain
Past hx; S/P Arthroscopic synovectomy, right knee

What is your diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer)

Courtesy : 이민희 (Min Hee Lee), 울산의대 서울아산병원 (University of Ulsan College of Medicine, Asan Medical Center)