| 摘要 |
An acetabular cup (200; 230) has an outer surface (202; 232) and an inner surface (204; 234). The inner surface has a spherical cap portion (206; 236) having a centre of curvature (210; 240), and a toroidal portion (212; 242) defined by the outer surface of a torus defined by the rotation of two circles (214, 216; 244, 246), having respective centres (218, 220; 248, 250). The centre of curvature of the spherical cap portion is located between the inner surface of the cup and the plane which is defined by the centres of the circles which define the torus when the circles are rotated. |
