Apparatus for use of porous implants

• US 20070129809A1
• Filed: 10/11/2006
• Published: 06/07/2007
• Est. Priority Date: 12/05/2005
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Lombardi, Adolph, Berend, Keith, Hershberger, Troy, Meridew, Jason
• Granted Patent: US 8,021,432 B2
• Time in Patent Office: Days
• US Class Current: 623/22.320
• 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 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/30728 Collars; Bone edge protectors A61F2/30734 takes precedence; sealing collars for use during cementing A61B17/8808
• CPC Class Codes: A61F 2/30734 Modular inserts, sleeves or augments, e.g. placed on proximal part of stem for fixation purposes or wedges for bridging a bone defect
• CPC Class Codes: A61F 2/30739 Devices connected to the proximal part of an endoprosthetic femoral shaft for reinforcing or replacing the trochanters, e.g. the greater trochanter proximal parts of endoprosthetic femoral shafts A61F2/367; non-prosthetic trochanteric devices A61B17/74
• 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 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30387 Dovetail connection
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30449 the adhesive being cement
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30729 Separate collars
• CPC Class Codes: A61F 2002/30736 : Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect
• CPC Class Codes: A61F 2002/30738 : Sleeves
• CPC Class Codes: A61F 2002/30759 : Mosaicplasty, i.e. using a plurality of individual cartilage plugs for filling a substantial cartilage defect
• CPC Class Codes: A61F 2002/30784 : Plurality of holes
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30878 : with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/3092 : having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30968 : Sintering
• CPC Class Codes: A61F 2002/3401 : with radial apertures, e.g. radial bores for receiving fixation screws
• CPC Class Codes: A61F 2002/343 : partial, i.e. not extending along the entire equatorial circumference
• CPC Class Codes: A61F 2002/3432 : having apertures for receiving fixation screws
• CPC Class Codes: A61F 2002/3487 : Partial acetabular cups, e.g. strips replacing only partially the natural acetabular cartilage
• CPC Class Codes: A61F 2002/4631 : the prosthesis being specially adapted for being cemented
• 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 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2250/0024 : made from both porous and non-porous parts, e.g. adjacent parts
• 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

Abstract

An acetabular cup assembly implantable at an acetabular socket can include an acetabular cup defining a partially spherical bone engaging surface and having a uniform thickness. A spacer can include a body portion formed of porous metal and define a radial support surface. The porous metal can be adapted to receive bone ingrowth through interstitial space at pores defined therein. The spacer can further comprise a piercing portion adapted to be advanced into the acetabular socket. The spacer can bridge a gap defined between the acetabular socket and the acetabular cup. Filler can be disposed between the acetabular cup and the acetabular socket in areas adjacent to the spacer such that the spacer and the filler collectively define a continuous support surface adapted to support the acetabular cup at the bone engaging surface.

Claims

1. An acetabular cup assembly implantable at an acetabular socket, the acetabular cup assembly comprising:

an acetabular cup defining a partially spherical bone engaging surface and having a uniform thickness;

at least one spacer having a body portion formed of porous metal and defining a radial support surface, said porous metal adapted to receive bone ingrowth through interstitial space at pores defined therein, said at least one spacer further comprising a piercing portion adapted to be advanced into the acetabular socket, said at least one spacer defining a height in an implanted position, wherein said at least one spacer bridges a gap defined between the acetabular socket and said acetabular cup; and

filler disposed between said acetabular cup and the acetabular socket in areas adjacent to said at least one spacer such that said at least one spacer and said filler collectively define a continuous support surface adapted to support said acetabular cup at said bone engaging surface.

2. The acetabular cup assembly of claim 1 wherein said height is defined by said body portion in said implanted position.

3. The acetabular cup assembly of claim 2 wherein said piercing portion is formed of solid metal.

4. The acetabular cup assembly of claim 3 wherein said piercing portion is separately formed from said body portion.

5. The acetabular cup assembly of claim 4 wherein said piercing portion defines a bone screw.

6. The acetabular cup assembly of claim 2 wherein said at least one spacer further includes a flange portion, the flange portion selectively secured to said acetabulum.

7. The acetabular cup assembly of claim 6 wherein said body portion is sintered to said flange portion.

8. The acetabular cup assembly of claim 7 wherein said flange portion includes a pair of distinct flange portions extending from said body portion.

9. The acetabular cup assembly of claim 1 wherein said filler includes morselized bone.

10. The acetabular cup assembly of claim 1 wherein said at least one spacer is implanted at an apex region of the acetabulum.

11. The acetabular cup assembly of claim 1 wherein said piercing portion is integrally formed with said body portion and comprises a pair of piercing portions arranged at a perimeter of said body portion.

13. The acetabular cup assembly of claim 11 wherein said at least one fastener extends through an opening formed in both the porous metal portion and the solid flange portion.

14. The acetabular cup assembly of claim 13, further comprising filler disposed at said gap in areas absent said augment.

12. An acetabular cup assembly implantable at an acetabular socket, the acetabular socket defining an apex region and a rim region, the acetabular cup assembly comprising:

an acetabular cup defining a partially spherical bone engaging surface;

an augment having a porous metal portion adapted to receive bone ingrowth through interstitial space at pores defined therein, said augment further including a solid flange portion, wherein said solid flange portion is adapted to rest around the rim region of the acetabular socket in an implanted position and wherein said porous metal portion is adapted to rest intermediate said acetabular cup and the acetabular socket to bridge a gap defined between the acetabular socket and said acetabular cup; and

at least one fastener selectively coupling said augment to the acetabular socket.

15. The acetabular cup assembly of claim 16 wherein said filler includes morselized bone.

16. The acetabular cup assembly of claim 12 wherein a concave surface is defined around an inboard portion of said flange, wherein said acetabular cup is adapted to rest against said concave surface in said implanted position.

17. An acetabular cup assembly implantable at an acetabular socket and surrounding pelvis, the acetabular cup assembly comprising:

an acetabular cup defining a partially spherical bone engaging surface operable to be received in the acetabular socket;

a flange integrally formed with the acetabular cup for fastening to the surrounding pelvis of the acetabulum, said flange defining a receptacle on a pelvis engaging surface; and

an augment formed of porous metal and adapted to receive bone ingrowth through interstitial space at pores defined therein, said augment adapted to be received at said receptacle in an installed position and be located in a position intermediate said flange and said surrounding pelvis of the acetabulum in an implanted position.

18. The acetabular cup assembly of claim 17 wherein said receptacle defines walls that at least partially overlap said augment in said installed position.

19. The acetabular cup assembly of claim 18 wherein said augment is press-fit into said installed position at said receptacle.

20. The acetabular cup assembly of claim 17 wherein said augment is secured at said receptacle by a fastener.