Medical device and method

A receptacle in the form of a cup for receiving a mating member, the receptacle comprising:

• an interior first portion having a superior, first part defining a first radial value;
• and
• an interior second portion having an inferior, second part defining a second radial value,
• wherein the first and second radial values are different;
• wherein the first radial value of the first part has a first radial center, wherein the second radial value of the second part has a second radial center, and wherein the first and second radial centers are separated from one another;
• and
• wherein the first portion is a bearing surface, and wherein the second portion is a substantially non-bearing surface;
• wherein the cup has a partial hemispherical shape and defines an interior region surrounded by a lip, the interior region defining an inner mating surface sized and shaped for receipt of the mating member, said inner mating surface including the interior first and second portions defining the first and second radial values, wherein the inner mating surface is asymmetrical relative to a centerline of the receptacle;
• and
• wherein the superior first part and the inferior second part intersect one another, and wherein each of the superior first part and the inferior second part extend to the lip of the cup, and wherein the first radial value R1 of the first part relative to the second radial value R2 of the second part is given by the ratio R1/R2, and wherein R1/R2 is in the range 0.995310 to 0.999999.

A receptacle in the form of a cup for receiving a mating member, the receptacle comprising:

• an interior first portion having a superior, first part defining a first radial value;
• and
• an interior second portion having an inferior, second part defining a second radial value, wherein the first and second radial values are different;
• wherein the first radial value of the first part has a first radial center, wherein the second radial value of the second part has a second radial center, and wherein the first and second radial centers are separated from one another;
• wherein the first portion is shaped so as to contact the mating member, in normal use;
• and
• wherein the second portion is shaped so as to not contact the mating member, in normal use;
• wherein the cup defines an interior region surrounded by a lip, the interior region defining an inner mating surface sized and shaped for receipt of the mating member, said inner mating surface including the interior first and second portions defining the first and second radial values, wherein the inner mating surface is asymmetrical relative to a centerline of the receptacle;
• and
• wherein the superior first part and the inferior second part intersect one another, and wherein each of the superior first part and the inferior second part extend to the lip of the cup, and
• wherein the interior region of the cup defines a partial hemispherical-shaped surface surrounded by the lip, the partial hemispherical-shaped surface entirely defined by the superior first part and the inferior second part, and wherein the first radial value R1 of the first part relative to the second radial value R2 of the second part is given by the ratio R1/R2, and wherein R1/R2 is in the range 0.995310 to 0.999999.