Granted Patent B2

US 12,636,159 · App. 17/561,862 · Granted May 26, 2026

Inventors: Simon Collins (Tetbury, GB); Andrew Clive Taylor (Chichester, GB); Michael Antony Tuke (Guildford, GB); Carolina Avila Carrasco (Leatherhead, GB)

Assignee: MatOrtho Limited

A61F2/3603A61F2/30771A61F2/3609A61F2/4609A61F2002/30327A61F2002/30593A61F2002/30616A61F2002/30822A61F2002/30881A61F2002/3605A61F2002/3615

Abstract

Claims (31)

1 . A ceramic femoral resurfacing head prosthesis comprising:

a ceramic convex part-spherical articulation surface adapted to engage with an acetabulum of a patient or an acetabular cup prosthesis;

a concave inner fixation surface;

a ceramic stem projecting from the inner fixation surface, the stem adapted to be received by a stem bore, the stem being the only projection of the inner fixation surface; and

a rim which comprises an outer edge adjoining the ceramic part-spherical articulation surface, the outer edge being defined by an outer arc having a first radius of curvature, and an inner edge adjoining the inner fixation surface, the inner edge being defined by an inner arc having a second radius of curvature, wherein an axial extent of the inner edge is less than an axial extent of the outer edge;

the inner fixation surface extending axially further than the ceramic part-spherical articulation surface to improve femoral engagement whilst preventing or limiting in use fracture, chipping or breakage.

2 . The ceramic femoral resurfacing head as claimed in claim 1 , wherein the inner arc has an angular range of any one of 90° and substantially of 90°.

3 . The ceramic femoral resurfacing head as claimed in claim 1 , wherein the outer arc has an angular range of less than 90°.

4 . The ceramic femoral resurfacing head as claimed in claim 1 , wherein the inner arc has a greater angular range than that of the outer arc.

5 . The ceramic femoral resurfacing head prosthesis as claimed in claim 1 , wherein the first radius of curvature is greater than the second radius of curvature.

6 . The ceramic femoral resurfacing head prosthesis as claimed in claim 5 , wherein the first radius of curvature is in a range of 0.5 mm and 2.0 mm.

7 . The ceramic femoral resurfacing head prosthesis as claimed in claim 6 , wherein the first radius of curvature is any one of 1.0 mm and substantially 1.0 mm.

8 . The ceramic femoral resurfacing head prosthesis as claimed in claim 5 , wherein the second radius of curvature is in a range of 0.2 mm and 1.5 mm.

9 . The ceramic femoral resurfacing head prosthesis as claimed in claim 8 , wherein the second radius of curvature is any one of 0.5 mm and substantially 0.5 mm.

10 . The ceramic femoral resurfacing head prosthesis as claimed in claim 1 , wherein the centre of radius of the first radius of curvature is radially offset with respect to the centre of radius of the second radius of curvature.

11 . The ceramic femoral resurfacing head prosthesis as claimed in claim 1 , wherein the centre of radius of the first radius of curvature is any one of positioned and substantially positioned at a radial centre between an axial end of the inner fixation surface and an axial end of the ceramic part-spherical articulation surface.

12 . The ceramic femoral resurfacing head prosthesis as claimed in claim 1 , further comprising a rim which comprises an outer edge adjoining the ceramic part-spherical articulation surface, and an inner edge adjoining the inner fixation surface, a plane defined by the rim being non-perpendicular to a longitudinal axis of the ceramic stem.

13 . The ceramic femoral resurfacing head prosthesis as claimed in claim 1 , further comprising a rim which comprises an outer edge adjoining the ceramic part-spherical articulation surface and an inner edge adjoining the inner fixation surface, the rim comprising a planar portion.

14 . The ceramic femoral resurfacing head prosthesis as claimed in claim 1 , further comprising a rim which comprises an outer edge adjoining the ceramic part-spherical articulation surface, and an inner edge adjoining the inner fixation surface, the rim being non-planar.

15 . A ceramic femoral resurfacing head prosthesis comprising:

a ceramic convex part-spherical articulation surface adapted to engage with an acetabulum of a patient or an acetabular cup prosthesis;

a concave inner fixation surface;

a ceramic stem projecting from the inner fixation surface, the stem adapted to be received by a stem bore, the stem being the only projection of the inner fixation surface; and

a rim which comprises an outer edge adjoining the ceramic part-spherical articulation surface, the outer edge being defined by an outer are having a first radius of curvature, and an inner edge adjoining the inner fixation surface, the inner edge being defined by an inner are having a second radius of curvature, wherein the centre of radius of the first radius of curvature is axially offset with respect to the centre of radius of the second radius of curvature;

the inner fixation surface extending axially further than the ceramic part-spherical articulation surface to improve femoral engagement whilst preventing or limiting in use fracture, chipping or breakage.

16 . A ceramic femoral resurfacing head prosthesis comprising:

a ceramic convex part-spherical articulation surface adapted to engage with an acetabulum of a patient or an acetabular cup prosthesis;

a concave inner fixation surface;

a ceramic stem projecting from the inner fixation surface, the stem adapted to be received by a stem bore, the stem being the only projection of the inner fixation surface; and

a rim which comprises an outer edge adjoining the ceramic part-spherical articulation surface, and an inner edge adjoining the inner fixation surface, the concave inner fixation surface comprising a skirt which widens in diameter towards the rim;

the inner fixation surface extending axially further than the ceramic part-spherical articulation surface to improve femoral engagement whilst preventing or limiting in use fracture, chipping or breakage.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (80)