Stable cartilage defect repair plug

• US 7,758,643 B2
• Filed: 02/26/2007
• Issued: 07/20/2010
• Est. Priority Date: 02/26/2007
• Status: Active Grant

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Sports Medicine LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Troxel, Karen, Stone, Kevin T
• Primary Examiner(s): Isabella; David
• Assistant Examiner(s): Sharma; Yashita
• Application Number:
  US11/711,178
• Publication Number:
  US 20080249632A1
• Time in Patent Office: 1,240 Days
• Field of Search: 623/14.12, 623/23.61, 623/23.75, 623/23.76, 623/908
• US Class Current: 623/14.12
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/4644 Preparation of bone graft, bone plugs or bone dowels, e.g. grinding or milling bone material bone material A61F2/28; disintegrating or milling devices B02C
• 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 2002/2839 Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/30004 the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30036 differing in release or diffusion time
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30113 circular
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30156 triangular
• CPC Class Codes: A61F 2002/30179 X-shaped
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30233 Stepped cylinders, i.e. having discrete diameter changes
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/3028 polyhedral different from parallelepipedal and pyramidal
• CPC Class Codes: A61F 2002/30327 : differing in diameter
• CPC Class Codes: A61F 2002/30332 : Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30448 : using adhesives
• CPC Class Codes: A61F 2002/30459 : stapled
• CPC Class Codes: A61F 2002/30461 : sutured, ligatured or stitched
• CPC Class Codes: A61F 2002/30677 : Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30733 : Inserts placed into an endoprosthetic cavity, e.g. for modifying a material property
• CPC Class Codes: A61F 2002/30795 : Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• 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 2220/0066 : stapled
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0023 : triangular
• CPC Class Codes: A61F 2230/0058 : X-shaped
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2250/0014 : having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: A61F 2250/0023 : differing in porosity
• CPC Class Codes: A61F 2250/0035 : differing in release or diffusion time
• CPC Class Codes: A61F 2250/0039 : differing in diameter
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00341 : Coral, e.g. aragonite, porite
• CPC Class Codes: A61F 2310/00365 : Proteins; Polypeptides; Degradation products thereof

Abstract

A method of distributing a load to a cartilage defect repair plug is provided. A load is applied to a first articulation layer. The load is distributed to a second layer and the load is transferred in the normal direction to the first density of subchondral bone. The load is distributed to a third layer and the load is transferred in the normal direction to a second density of subchondral bone. The load is then distributed to a fourth layer and the load is transferred in the normal direction to a third density of subchondral bone.

Claims

1. A method of preparing a cartilage defect repair plug that extends along a longitudinal axis for distributing a load at a cartilage defect site, comprising:

a. shaping a first layer to define a first shoulder having a first bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a first wall parallel to the longitudinal axis of the cartilage plug;

b. shaping a second layer to define a second shoulder having a second bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a second wall parallel to the longitudinal axis of the cartilage plug, said second shoulder spaced apart from said first shoulder in a direction towards said longitudinal axis; and

c. shaping a third layer to define a third shoulder having a third bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a third wall parallel to the longitudinal axis of the cartilage plug, said third shoulder spaced apart from said second shoulder in a direction towards said longitudinal axis;

wherein when a load is applied on the cartilage plug, the load is distributed in a direction normal to the cartilage defect site;

wherein each of said first, second and third bearing surfaces and walls directly engage said cartilage defect site; and

wherein the first layer includes an upper and lower layer, the upper layer being formed from a first material and configured to engage cartilage and the lower layer being formed from a second, different material and configured to engage bone, the upper and lower layers having the same width in a direction perpendicular to the longitudinal axis such that the periphery of each layer forms part of the first wall, the lower layer being disposed below the upper layer such that an upper side of the lower layer abuts the upper layer and an opposite lower side of the lower layer in a direction along the longitudinal axis abuts the second layer, the first layer being sized to extend from a region of cartilage at the cartilage defect site to a region of underlying bone at the defect site.

2. The method of claim 1, further comprising adsorbing a bioactive agent into at least one of the first layer, the second layer, and the third layer.

3. The method of claim 1, further comprising securing the first layer, the second layer, and the third layer together, wherein the securing is selected from the group consisting of:

mechanical attachment, adhesive attachment, chemical attachment, and combinations thereof, and wherein the first, second and third layers include first, second and third synthetic resorbable layers.

4. The method of claim 1, further comprising contouring the cartilage defect repair plug to match an opening in an implant site to provide a press-fit of the cartilage defect repair plug into the implant site.

5. The method of claim 1, further comprising removing a region of at least one of the first layer, the second layer, and the third layer to form a bore in the cartilage defect repair plug.

6. The method of claim 5, further comprising depositing a bioactive material in the bore for delivery to the implant site, the deposited bioactive material having a top surface formed planar with a top surface of the repair plug;

wherein the bioactivst e material is selected from the group consisting of;

chondrocytes, undifferentiated cells, differentiation media, growth factors, platelet concentrate, nutrients, bone morphogenic proteins, osteogenic factors, and combinations thereof.

19. The method of claim 1, further comprising shaping the first layer, the second layer, and the third layer into a shape selected from the group consisting of:

a cylinder, a cruciform, and a triangle.

20. The method of claim 1, further comprising shaping the first layer, the second layer, and the third layer from a monolithic substrate.

21. The method of claim 1, wherein the first layer, the second layer, and the third layer are made of at least two different materials and further comprising securing the at least two different materials together.

22. The method of claim 1, further comprising distributing a load on the cartilage plug in a direction normal to the first bearing surface, the second bearing surface, and the third bearing surface.

23. The method of claim 1, further comprising shaping the first layer to have a thickness greater than a thickness of at least one of the second layer and the third layer.

24. The method of claim 1, further comprising shaping the cartilage plug to provide a stepped cone geometry.

7. A method of preparing a cartilage defect repair plug that extends along a longitudinal axis for distributing a load at a cartilage defect site, comprising:

a. shaping a first resorbable layer to define a first shoulder having a first bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a first wall parallel to the longitudinal axis of the cartilage plug, wherein the first wall has a smooth and cylindrical periphery;

b. shaping a second resorbable layer to define a second shoulder having a second bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a second wall parallel to the longitudinal axis of the cartilage plug, wherein the second wall has a smooth, cylindrical periphery and a diameter less than a diameter of the first wall; and

c. shaping a third resorbable layer to define a third shoulder having a third bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a third wall parallel to the longitudinal axis of the cartilage plug, wherein the third wall has a smooth, cylindrical periphery and a diameter less than a diameter of the second wall;

wherein when a load is applied on the cartilage plug, the load is distributed in a direction normal to the cartilage defect site, and wherein each of said first, second and third bearing surfaces and walls directly engage said cartilage defect site;

wherein the first resorbable layer includes an upper and a lower layer, the upper layer being formed from a first material and configured to engage cartilage and the lower layer being formed from a second, different material and configured to engage bone, the upper and lower layers having the same width in a direction perpendicular to the longitudinal axis such that the periphery of each layer forms part of the first wall, the lower layer being disposed below the upper layer such that an upper side of the lower layer abuts the upper layer and an opposite lower side of the lower layer in a direction along the longitudinal axis abuts the second layer, the first resorbable layer being sized to extend from a region of cartilage at the cartilage defect site to a region of underlying bone at the defect site.

8. The method of claim 7, further comprising adsorbing a bioactive agent into at least one of the first resorbable layer, the second resorbable layer, and the third resorbable layer.

9. The method of claim 7, further comprising securing the first resorbable layer, the second resorbable layer, and the third resorbable layer together, wherein the securing is selected from the group consisting of:

mechanical attachment, adhesive attachment, chemical attachment, and combinations thereof.

10. The method of claim 7, further comprising contouring the cartilage defect repair plug to match an opening in an implant site to provide a press-fit of the cartilage defect repair plug into the implant site.

11. The method of claim 7, further comprising removing a region of at least one of the first resorbable layer, the second resorbable layer, and the third resorbable layer to form a bore in the cartilage defect repair plug, wherein the first, second and third resorbable layers include first, second and third synthetic resorbable layers.

12. The method of claim 11, further comprising depositing a bioactive material in the bore for delivery to the implant site;

wherein the bioactive material is selected from the group consisting of;

chondrocytes, undifferentiated cells, differentiation media, growth factors, platelet concentrate, nutrients, bone morphogenic proteins, osteogenic factors, and combinations thereof.

13. A method of preparing a cartilage defect repair plug that extends along a longitudinal axis for distributing a load at a cartilage defect site, comprising:

a. shaping a first synthetic resorbable layer comprising at least two different materials to define a first shoulder having a first bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a first wall parallel to the longitudinal axis of the cartilage plug, wherein the first wall has a smooth and cylindrical periphery;

b. shaping a second synthetic resorbable layer to define a second shoulder having a second bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a second wall parallel to the longitudinal axis of the cartilage plug, wherein the second wall has a smooth, cylindrical periphery and a diameter less than a diameter of the first wall;

c. shaping a third synthetic resorbable layer to define a third shoulder having a third bearing surface perpendicular to the longitudinal axis of the cartilage plug and being bound by a third wall parallel to the longitudinal axis of the cartilage plug, wherein the third wall has a smooth, cylindrical periphery and a diameter less than a diameter of the second wall;

d. forming a bore extending from at least a region of the first synthetic resorbable layer into a region of the second synthetic resorbable layer; and

e. disposing a bioactive agent within the bore;

wherein the first layer is sized to extend from a region of cartilage at the cartilage defect site to a region of an underlying bone at the cartilage defect site such that when a load is applied on the cartilage plug, the load is distributed in a direction normal to the cartilage defect site and in a direction normal to each of the first bearing surface, the second bearing surface, and the third bearing surface, and each of said first, second and third bearing surfaces and walls directly engage said cartilage defect site;

wherein the first synthetic resorbable layer includes an upper and a lower layer, the upper layer being formed from a first material and configured to engage cartilage and the lower layer being formed from a second, different material and configured to engage bone, the upper and lower layers having the same width in a direction perpendicular to the longitudinal axis such that the periphery of each layer forms part of the first wall, the lower layer being disposed below the upper layer such that an upper side of the lower layer abuts the upper layer and an opposite lower side of the lower layer in a direction along the longitudinal axis abuts the second layer.

14. The method of claim 13, further comprising adding additional layers to said cartilage plug, wherein each layer defines a shoulder having a bearing surface perpendicular to a longitudinal axis of the cartilage plug and being bound by a wall parallel to the longitudinal axis of the cartilage plug.

15. The method of claim 13, wherein the first synthetic resorbable layer, the second synthetic resorbable layer, and the third synthetic resorbable layer are each formed of different materials.

16. The method of claim 13, wherein the bore is centered about the longitudinal axis of the cartilage defect repair plug.

17. The method of claim 13, further comprising extending the bore into a region of the third synthetic resorbable layer.

18. The method of claim 13, further comprising shaping the first synthetic resorbable layer, the second synthetic resorbable layer, and the third synthetic resorbable layer from a monolithic substrate.

25. The method of claim 13, wherein the first, second and third synthetic resorbable layers are concentrically stacked to form a stepped cone geometry.