PROBLEM TO BE SOLVED: To provide an artificial hip joint, capable of securing the fitting length without any increase in total height of a bone head ball, and avoiding concentration of stress to relax the stress generated in the bone head ball.SOLUTION: An artificial hip joint includes: a stem 6 including a neck part 5 having a truncated cone-like outer peripheral surface 4 reduced in diameter as it goes toward the tip 3 a bone head ball 8 provided with a recessed part 7 for inserting the neck part 5, and including a truncated cone-like inner peripheral surface 10 such that the inner surface for defining the recessed part 7 is reduced in diameter as it goes toward the insertion direction of the neck part 5 and a sleeve 2A interposed between the outer peripheral surface 4 of the neck part 5 inserted in the recessed part 7 and the inner peripheral surface 10 of the bone head ball 8. The sleeve 2A has an inner peripheral part 13 coming into contact with the outer peripheral surface 4 of the neck part 5 and an outer peripheral part 16 coming into contact with the inner peripheral surface 10 of the bone head ball 8 taking the position of retreating from an opening part 14 of the recessed part 7 in the insertion direction A as a starting end.COPYRIGHT: (C)2014,JPO&INPIT【課題】 骨頭球の全高を大きくせずに嵌合長を確保し、かつ応力の集中を回避して、骨頭球に発生する応力の緩和を図ることができる人工股関節を提供する。【解決手段】 先端3に向かって小径となる円錐台状の外周面4を有するネック部5を有するステム6と、ネック部5を挿入可能な凹所7が形成され、凹所7を規定する内面が、ネック部5の挿入方向に向かって小径となる円錐台状の内周面10を含む骨頭球8と、凹所7に挿入されたネック部5の外周面4と骨頭球8の内周面10との間に介装されるスリーブ2Aとを含む。スリーブ2Aは、ネック部5の外周面4に接触する内周部13と、骨頭球8の内周面10に、凹所7の開口部14から挿入方向Aに退避した位置を始端として接触する外周部16とを有する。【選択図】 図1
