Mobile bearing hip assembly having decoupled motion along multiple axes

摘要

An acetabular hip implant includes an acetabular shell component, a first insert secured to the acetabular shell component, a second insert secured to the first insert, and a femoral head configured to be secured to the second insert. The first insert is permitted to rotate relative to the acetabular shell about a first axis, the second insert is permitted to rotate relative to the first insert about a second axis, and the femoral head is permitted to rotate relative to the second insert about a third axis.

主权项

1. An acetabular hip implant, comprising:
an acetabular shell component configured to be implanted within an acetabulum of a patient, a first insert secured to the acetabular shell component such that the first insert is (i) permitted to rotate relative to the acetabular shell component about a first axis, and (ii) prevented from rotating relative to the acetabular shell component about a second axis and a third axis, the first insert having a first set of separate and discrete opposing flats defined in its inner surface on opposing sides of the first insert, a second insert secured to the first insert such that the outer surface of the second insert contacts the inner surface of the first insert, the second insert having a second set of separate and discrete opposing flats defined in its outer surface on opposing sides of the second insert, and wherein the second set of opposing flats contact the first set of opposing flats defined in the inner surface of the first insert such that the second insert is (i) permitted to rotate relative to the first insert about the second axis, and (ii) prevented from rotating relative to the first insert about the first axis and the third axis, the second insert having a third set of separate and discrete opposing flats defined in its inner surface on opposing sides of the second insert, and a femoral head configured to be secured to a femoral stem, the femoral head being secured to the second insert such that the outer surface of the femoral head contacts the inner surface of the second insert, the femoral head having a fourth set of separate and discrete opposing flats defined in its outer surface on opposing sides of the femoral head, and wherein the fourth set of opposing flats contact the third set of opposing flats defined in the inner surface of the second insert such that the femoral head is (i) permitted to rotate relative to the second insert about the third axis, and (ii) prevented from rotating relative to the second insert about the first axis and the second axis.