“…In the late sixties at the Imperial College in London a study was conducted on the model of an implant without any direct mechanical link between the components that resurfaced the distal femur and proximal tibia. The original model, known as Freeman-Swanson [3] prosthesis, was none other than the metal "roller" component placed on the distal femur which articulated with a polyethylene tibial tray; nevertheless, it was necessary to perform the resection of both cruciate ligaments. In 1970 Peter Walker, John Insall, Chitranjan Ranawat and Alan Inglis at the Hospital for Special Surgery (HHS) of New York, developed the Duocondylar knee ( Figure 1).…”