Prosthetic implant

• US 7,497,876 B2
• Filed: 11/02/2004
• Issued: 03/03/2009
• Est. Priority Date: 11/03/2003
• Status: Active Grant

• Current Assignee: Finsbury (Development) Limited (WPP PLC)
• Original Assignee: Finsbury (Development) Limited (WPP PLC)
• Inventors: Taylor, Andrew C., Taylor, Mark, Thomsen, Peter, Tuke, Michael A.
• Primary Examiner(s): Stewart; Alvin J
• Application Number:
  US10/979,513
• Publication Number:
  US 20050119759A1
• Time in Patent Office: 1,582 Days
• Field of Search: 623 2329- 2331, 623/16.11, 623 235- 2355, 623 2372- 2376, 623/22.31, 623/22.33, 264/21, 264400-402
• US Class Current: 623/23.5
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/367 Proximal or metaphyseal parts of shafts trochanteric devices connected to said proximal parts A61F2/30739
• CPC Class Codes: A61F 2/3676 Distal or diaphyseal parts of shafts
• CPC Class Codes: A61F 2/468 Testing instruments for artificial joints for testing non-implantable prostheses A61F2/76
• CPC Class Codes: A61F 2002/30176 V-shaped
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30273 pyramidal
• CPC Class Codes: A61F 2002/30275 tetrahedral, i.e. having a triangular basis
• CPC Class Codes: A61F 2002/30276 frustopyramidal
• CPC Class Codes: A61F 2002/30303 polypod-shaped
• CPC Class Codes: A61F 2002/30322 differing in surface structures
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30449 the adhesive being cement
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30795 Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30805 : Recesses of comparatively large area with respect to their low depth
• CPC Class Codes: A61F 2002/3097 : using laser
• CPC Class Codes: A61F 2002/3414 : Polar protrusion, e.g. for centering two concentric shells
• CPC Class Codes: A61F 2002/3432 : having apertures for receiving fixation screws
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2002/4619 : for extraction
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2230/0054 : V-shaped
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0086 : Pyramidal, tetrahedral, or wedge-shaped
• CPC Class Codes: A61F 2230/0089 : tetrahedral, i.e. having a triangular basis
• CPC Class Codes: A61F 2250/0026 : differing in surface structures
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: B33Y 10/00 : Processes of additive manufacturing
• CPC Class Codes: B33Y 70/00 : Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 : Products made by additive manufacturing

Abstract

The invention relates to an element for incorporation into a prosthetic implant so as to form a bone-contacting portion thereof, the element comprising a rear face, a front face, and a body extending between the rear face and the front face, wherein the front face comprises a basal surface and at least one upstanding portion projecting above the basal surface and having a transverse hole extending therethrough from one side of the upstanding portion to another. It further relates to a prosthetic implant for implantation into a patient so as to contact a bone of the patient, the prosthetic implant comprising a body including a bone-contacting portion for contacting the patient'"'"'s bone after implantation of the prosthetic implant, wherein the bone-contacting portion is provided with at least one upstanding portion that projects above a surrounding basal surface portion and that is provided with a transverse hole that extends through the upstanding portion from one side to another.

Claims

1. A process for forming an element for a prosthetic implant having a bone-contacting portion provided with a plurality of upstanding portions each surrounded by a corresponding rim, wherein the upper surfaces of the upstanding portions and the rims together define an outer envelope for at least a part of the bone-contacting portion of the prosthetic implant, and wherein a basal surface comprises valleys each within a corresponding rim, said element forming a bone-contacting portion of said prosthetic implant, the element comprising a rear face, a front face, and a body extending between the rear face and the front face, wherein the front face comprises the basal surface and at least one upstanding portion projecting above the basal surface and having at least one transverse hole extending therethrough from a first side of the upstanding portion to a second side of the upstanding portion, said process comprising the steps of:

(i) spreading a layer of metal powder on said basal surface of the front face of the element;

(ii) selectively directing a laser to fuse the metal powder in a desired pattern to form a metallic layer overlying the basal surface of the front face; and

(iii) repeating steps (i) and (ii) as required to build up metallic layers to form the upstanding portion of the front face projecting above the basal surface having at least one transverse hole extending therethrough.

2. A prosthetic implant having a body and at least one element made according to the process of claim 1 connected at the rear face to the body.

3. A prosthetic implant according to claim 2, wherein the at least one element is integrally formed on the surface of the prosthetic implant.

4. A prosthetic implant according to claim 3 wherein the element is integrally formed on the implant by selective laser melting.

5. A prosthetic implant according to claim 2, wherein the element is made from stainless steel, cobalt-chrome, or titanium.

6. A prosthetic implant according to claim 2, wherein the bone-contacting portion is provided with a plurality of upstanding portions each surrounded by a corresponding rim, wherein the upper surfaces of the upstanding portions and the rims together define an outer envelope for at least a part of the bone-contacting portion of the prosthetic implant, and wherein the basal surfaces comprises valleys each within a corresponding rim.

7. A prosthetic implant according to claim 2, wherein the prosthetic implant is a femoral implant, and wherein the bone-contacting portion of the prosthetic implant comprises a stem of the implant for insertion in a surgically prepared channel in a resected upper end of a femur of the patient.

8. A prosthetic implant according to claims 2, wherein the prosthetic implant is a femoral implant having a stem for insertion in a surgically prepared channel in a resected upper end of a femur of the patient, and a wedge-shaped portion having a front face and a rear face extending laterally from an upper end of the stem and a spigot for receipt of ball head, the ball head being adapted for insertion in a natural or artificial acetabular socket, and wherein the bone-contacting portion of the prosthetic implant comprises at least a portion of at least one out of the front and rear faces of the wedge-shaped portion.

9. A prosthetic implant according to claim 2, wherein the prosthetic implant is a femoral implant having a stem for insertion in a surgically prepared channel in a resected upper end of a femur of the patient, a wedge-shaped portion having a front face and a rear face extending laterally from an upper end of the stem, and a ball head on the wedge-shaped portion, the ball head being adapted for insertion in a natural or artificial acetabular socket, and wherein the bone-contacting portion of the prosthetic implant comprises at least a portion of at least one out of the front and rear faces of the wedge-shaped portion.

10. A process according to claim 9, wherein the upstanding portion above the basal surface has a height of less than about 2 mm.

11. A process according to claim 10, wherein the height of the upstanding portion above the basal surface is from about 0.75 to about 1.75 mm.

12. A process according to claim 9, wherein at least one transverse hole has an axis extending substantially parallel to the basal.

13. A process according to claim 9, wherein at least one upstanding portion has of an arched configuration.

14. A process according to claim 9, wherein at least one upstanding portion substantially comprises a truncated pyramid.

15. A process according to claim 14, wherein the truncated pyramid is a truncated rectangular pyramid, a truncated square pyramid, a truncated triangular pyramid or a truncated hexagonal pyramid.

16. A process according to claim 15, wherein the upstanding portion is a truncated rectangular or square pyramid provided having first and second holes each of which extends from a first face to a second face opposite the corresponding first face.

17. A process according to claim 16, wherein the two holes intersect substantially at right angles.

18. A process according to claim 15, wherein the upstanding portion comprises a truncated triangular pyramid and has a first hole extending from a first face, being in the interior of the upstanding portion, and extending to a second face of the upstanding portion, and wherein the upstanding portion is provided with a second hole extending from a third face and intersecting the first hole.

19. A process according to claim 14, wherein the upstanding portion comprises a truncated hexagonal pyramid and has first, second and third holes, each hole extending from a first face to a second face opposite the corresponding first face.

20. A process according to claim 19, wherein the first, second and third holes all intersect each other.

21. A process according to claim 1, wherein the basal surface is surrounded by a raised rim.

22. A process according to claim 1, wherein the element is substantially rectangular in plan.

23. A process according to claim 1, wherein the basal surface is substantially rectangular.

24. A process according to claim 23, wherein the basal surface has a dimension of about 2 mm by about 4 mm.

25. A process according to claim 1, wherein the element has the form of a sleeve and wherein the rear face comprises the inner face of the sleeve and the front face comprises the outer face of the sleeve.

26. A process according to claim 1, wherein the element is formed from stainless steel, cobalt-chrome or titanium.

27. A process according to claim 1, wherein the metal powder has a particle size of about 20 μ

m.

28. A process according to claim 27, including directing the laser as required to produce bridges.