TKA Development in Japan: Bi-Surface Knee

The original design of recent knee prosthesis was developed in the 1960s and 1970s. While durability gradually improved, ROM did not improve. Postoperative ROM is required in Japan and other Asian and Middle Eastern countries because standing and sitting from the floor or ground are necessary for ADLs. Therefore, a new knee prosthesis design is required to achieve the conflicting goals of postoperative ROM and long-term durability to meet Japanese lifestyle needs.