PROBLEM TO BE SOLVED: To provide an artificial knee joint for controlling the rotation of a knee joint according to a bending angle, and at the same time, securing high stability in forward/backward directions.SOLUTION: The artificial knee joint includes: a femoral component fixed to the distal end of a femur and a tibial plate fixed to the proximal end of a tibia and slidably receiving the femoral component. The femoral component has an internal condyle and an external condyle. An opening and an ovally spherical sliding part, which connects the rear ends of the internal and external condyles and is slid with respect to the tibial plate when the knee joint is bent, are formed between the internal condyle and the external condyle. The tibial plate has an internal fovea for receiving the internal condyle and an external fovea for receiving the external condyle. A spine, which is moved in the forward/backward directions inside the opening according to the bending and extending actions of the knee joint and makes contact with the ovally spherical sliding part when the knee joint is bent, and a recessed sliding surface, which constitutes the rear surface of the spine and slidably receives the ovally spherical sliding part, are formed between the internal fovea and the external fovea. The width of the ovally spherical sliding part is continuously widened toward the rear end from the opening.COPYRIGHT: (C)2010,JPO&INPIT【課題】膝関節の回旋を屈曲角度に応じて制御し、同時に前後方向への高い安定性を確保できる人工膝関節を提供する。【解決手段】大腿骨遠位端に固定される大腿骨コンポーネントと、脛骨近位端に固定され大腿骨コンポーネントを摺動可能に受容する脛骨プレートとを備えた人工膝関節であり、大腿骨コンポーネントが内側顆と外側顆とを有し、内側顆と外側顆の間には、開口と内側顆と外側顆との後端を接続し膝関節屈曲時に脛骨プレートに対して摺動する楕円球状摺動部とが形成され、脛骨プレートが、内側顆を受容する内側窩と外側顆を受容する外側窩とを備え、内側窩と外側窩との間には、膝関節の屈曲・伸展動作に対応して開口内を前後方向に移動し膝関節屈曲時に楕円球状摺動部に接触するスパインと、スパインの後面を構成し楕円球状摺動部を摺動可能に受容する凹状摺動面とが形成され、楕円球状摺動部の幅が開口から連続して後端に向かって広くなっている。【選択図】図1
