# US 2014/0207246 A1 · Femoral head prosthesis > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0207246 A1 - Document ID: US20140207246A1 - Status: Published application - Kind: A1 - Application number: 14/127,020 - Filed: 2012-07-13 - Published: 2014-07-24 - Earliest claimed: 2011-07-15 - Inventors: Derek James Wallace McMinn - Web page: https://patentgrep.com/patent/US20140207246A1 ## CPC - A61F 2/3609: {Femoral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic femoral shafts (A61F2/3601 takes precedence)} - A61F 2/3607: {including proximal or total replacement of the femur} - A61F 2002/30112: {Rounded shapes, e.g. with rounded corners} - A61F 2002/30332: {Conically- or frustoconically-shaped protrusion and recess} - A61F 2002/30367: {with additional means for preventing said rotation} - A61F 2002/30474: {using an intermediate sleeve interposed between both prosthetic parts to be coupled} - A61F 2002/30604: {modular} - A61F 2002/30688: {Means for allowing passage or sliding of tendons or ligaments} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract A femoral head prosthesis (110) comprises an articulating surface (112) which is more than hemi-spherical; an internal recess (114) having a longitudinal axis defining a pole P of the articulating surface (112), the longitudinal axis passing through the centre of curvature of the articulating surface (112); a first edge (116) which constitutes a posterior edge in use, and a second edge (118) which constitutes an anterior edge and/or an antero-inferior edge in use. The first edge (116) is further from the pole P than the second edge (118). Also provided is a femoral prosthesis comprising a femoral head, and a femoral implant comprising a femoral stem and a femoral head. The prostheses and implants of the invention find use in total hip replacements. ## Claims ### Claim 1 A femoral head prosthesis comprising: an articulating surface which is more than hemi-spherical; an internal recess having a longitudinal axis defining a pole of the articulating surface, the longitudinal axis passing through the centre of curvature of the articulating surface; a first edge which constitutes a posterior edge in use, and a second edge which constitutes at least one of an anterior edge or an antero-inferior edge in use; and wherein the first edge is further from the pole than the second edge. ### Claim 2 (depends on 1) The femoral head according to claim 1 wherein an anterior-posterior plane is defined which is perpendicular to the axis of the pole and passes through the centre of curvature of the articulating surface and wherein the second edge has an outer end at an intersection between the anterior-posterior plane and the articulating surface. ### Claim 3 (depends on 1) The femoral head according to claim 1 wherein the first edge has an outer end at a position which is more than 90 degrees from the pole. ### Claim 4 (depends on 1) The femoral head according to claim 1 wherein the second edge comprises an arcuate portion having a radius of curvature which is less than that of the articulating surface. ### Claim 5 (depends on 2) The femoral head according to claim 2, wherein the second edge comprises an arcuate portion having a radius of curvature which is less than that of the articulating surface and wherein a tangent to the arcuate portion is perpendicular to the anterior-posterior plane at the outer end of the second edge and/or wherein the second edge comprises an inner end wherein a tangent to the arcuate portion is parallel to the anterior-posterior plane. ### Claim 6 (depends on 1) The femoral head according to claim 1 wherein the first edge is parallel to the anterior-posterior plane. ### Claim 7 (depends on 1) The femoral head according to claim 1 wherein the first and second edges are joined by at least one intermediate edge. ### Claim 8 (depends on 7) The femoral head according to claim 7 wherein the first and second edges are joined by two diametrically opposed intermediate edges. ### Claim 9 (depends on 8) The femoral head according to claim 8 wherein the intermediate edges provide a smoothly curved step from the first edge to the second edge. ### Claim at position 10 10-12. (canceled) ### Claim 13 (depends on 1) The femoral head according to claim 1 wherein the recess terminates at an inner end of the second edge and an inner end of the first edge. ### Claim 14 (depends on 1) The femoral head according to claim 1 which is symmetrical about a plane which is collinear with the pole and which extends along an anterior-posterior direction. ### Claim 15 (depends on 1) The femoral head according to claim 1 having an outer diameter in the range of 38 mm to 58 mm. ### Claim 16 (canceled) ### Claim 17 A femoral prosthesis comprising: a femoral head comprising (i) an articulating surface which is more than hemi-spherical, (ii) an internal recess having a longitudinal axis defining a pole of the articulating surface, the longitudinal axis passing through the centre of curvature of the articulating surface, (iii) and a first edge which constitutes a posterior edge in use, and a second edge which constitutes at least one of an anterior edge or an antero-inferior edge in use, and wherein the first edge is further from the pole than the second edge; and one or more of a femoral stem prosthesis or a sleeve for a femoral neck. ### Claim 18 (depends on 17) The femoral prosthesis according to claim 17 comprising a sleeve configured such that, when inserted into the internal recess of the femoral head, a base of the sleeve is level with an inner end of the second edge. ### Claim 19 (depends on 17) The femoral prosthesis according to claim 17 wherein the sleeve comprises a generally frusto-conical annulus having an inner surface configured for mating with a co-operating end of a femoral neck of a femoral stem prosthesis. ### Claim 20 (depends on 19) The femoral prosthesis according to claim 19 wherein the inner surface of the sleeve is offset with respect to the centre of the sleeve so that the central axis of the sleeve is not coincident with the central axis of the co-operating end of the femoral neck. ### Claim 21 (depends on 17) The femoral prosthesis according to claim 17 wherein a plurality of different sleeves are provided, each sleeve being configured such that, when inserted into the internal recess of the femoral head, a base of the sleeve is level with an inner end of the second edge and wherein the inner surface of each sleeve is different so that each sleeve engages with the end of a femoral neck at varying positions therewithin. ### Claim 22 A femoral implant comprising: a femoral stem and a femoral head; the femoral head comprising an articulating surface which is more than hemi-spherical; the femoral stem comprising a neck having a longitudinal axis defining a pole of the articulating surface of the femoral head, the longitudinal axis passing through the centre of curvature of the articulating surface; the femoral head having a first edge which constitutes a posterior edge in use, and a second edge which constitutes an anterior edge and/or an antero-inferior edge in use; and wherein the first edge is further from the pole than the second edge. ### Claim 23 (depends on 22) The femoral implant according to claim 22 configured as a one-piece component having an integral femoral head and femoral stem. ### Claim at position 22 24-28. (canceled)