Precision acetabular machining system and resurfacing acetabular implant

• US 20080009952A1
• Filed: 07/02/2007
• Published: 01/10/2008
• Est. Priority Date: 06/30/2006
• Status: Abandoned Application

• Current Assignee: W Hodge
• Original Assignee: W Hodge
• Inventors: Hodge, W.
• Application Number:
  US11/772,698
• Publication Number:
  US 20080009952A1
• Time in Patent Office: Days
• US Class Current: 623/022.21
• CPC Class Codes: A61B 17/1666 for the acetabulum
• CPC Class Codes: A61B 17/1746 for the acetabulum
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61F 2/30721 Accessories
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30306 harpoon-shaped
• CPC Class Codes: A61F 2002/3414 Polar protrusion, e.g. for centering two concentric shells
• CPC Class Codes: A61F 2002/3611 Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2230/0097 Harpoon-shaped
• 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 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00796 Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

This application is directed toward a quantitative high precision acetabular machining system designed to enable accurate and precise positioning of acetabular resurfacing implants, or the like bone socket resurfacing devices, in a manner which eliminates malpositioning, loss of center, drift and inappropriate depth calculations. Subsequent to site preparation, a precision implant is disclosed which provides for resurfacing of damaged articular cartilage with bone preserving and non-drift instrumentation utilizing synthetic materials in an anatomically correct fashion to maintain excellent hip stability while maintaining an accurate hip joint center mated with anatomic femoral head sizes.

Claims

1. A method of securing an acetabular cup to an anatomical center of an acetabulum comprising:

providing a drilling guide assembly including a drilling guide, drilling guide adapter, and drill chuck, effective for positioning and forming a guide hole in bone at said anatomical center of the acetabulum;

providing a hemispherical reamer assembly including a reamer basket and a centering guide peg, effective for reaming a concentric hemispherically-shaped hole within the acetabulum;

drilling a guide hole in the anatomical center of the acetabulum;

reaming a hemispherical cavity into the acetabulum with said reamer assembly about said guide hole;

providing a hemispherical acetabular cup assembly including an acetabular cup and a centering peg adapted for insertion within said guide hole; and

fixing said hemispherical acetabular cup within said acetabulum;

whereby a firm overall fixation along the entire surface of the acetabular cup is achieved.

2. The method of claim 1, further comprising:

inserting a liner into the acetabular cup.

3. The method of claim 2, wherein inserting a liner into the acetabular cup includes inserting a liner made of a polymeric material into the acetabular cup.

4. The method of claim 1, wherein said acetabular cup comprises a biocompatible material selected from the group consisting of titanium or an alloy thereof, cobalt chrome or an alloy thereof, stainless steel or an alloy thereof, ceramics and combinations thereof.

5. The method of claim 1, wherein an outside surface of said acetabular cup is porous.

6. The method of claim 5, wherein said porous outside surface is configured to enhance bone ingrowth.

7. The method of claim 1, wherein said acetabular cup includes a centering guide pin adapted for insertion within said guide hole.

8. The method of claim 7 wherein said centering guide pin is provided with fixation means for positive attachment to said guide hole.

16. The method of claim 1 further including providing a depth gauge for determining a depth drilled into said bone.

9. A hemispherical acetabular cup for securement in an acetabulum comprising a hemispherical body and a central guide pin adapted for insertion within a guide hole formed in said acetabulum.

12. The hemispherical cup of claim 9 wherein said cup comprises a biocompatible material selected from the group consisting of titanium or an alloy thereof, cobalt chrome or an alloy thereof, stainless steel or an alloy thereof, ceramics and combinations thereof.

13. The hemispherical cup of claim 9, wherein an outside surface of said cup is porous.

14. The hemispherical cup of claim 9, wherein said porous outside surface is configured to enhance bone ingrowth.

10. The hemispherical cup of claim 10, wherein said acetabular cup further includes fixation means for positive attachment to said acetabulum.

11. The hemispherical cup of claim 10, wherein said fixation means for positive attachment to said acetabulum are positioned within said guide hole.

15. A reamer assembly adapted for precise forming of a hemispherical concentric hole within an acetabulum comprising in combination a reamer basket and a guide peg;

wherein said reamer assembly including said reamer basket and guide peg are adapted to provide precise hemispherical reaming of an acetabulum.