In this article, we present a 68 year-old female case admitted with complaints of a painful knee and walking difficulty with simultaneous advanced gonarthrosis and a huge osteochondroma in posterior distal femur which was adjacent to the vessel and nerve structures, who was treated with a single incision via posterior approach for tumor excision and arthroplasty. Simultaneous tumor excision and arthroplasty application were scheduled and the knee joint was reached via posterior popliteal approach. Hinged knee prosthesis was applied through the same incision following tumor excision. Two-stage surgical procedures can be an option for coexisting bone tumor and arthrosis. Arthroplasty can be performed following tumor excision. In our case, we managed two distinct different problems in a single session with a single approach. To the best of our knowledge, this is the first knee arthroplasty case performed with posterior approach.