Meniscus-type implant with hydrogel surface reinforced by three-dimensional mesh

• US 20020022884A1
• Filed: 03/27/2001
• Published: 02/21/2002
• Est. Priority Date: 03/27/2000
• Status: Active Grant

• Current Assignee: Kevin A. Mansmann
• Original Assignee: Kevin A. Mansmann
• Inventors: Mansmann, Kevin A.
• Granted Patent: US 6,629,997 B2
• Time in Patent Office: Days
• US Class Current: 623/14.12
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/3804 for elbows
• CPC Class Codes: A61F 2/3872 Meniscus for implantation between the natural bone surfaces
• CPC Class Codes: A61F 2/40 for shoulders
• CPC Class Codes: A61F 2/4202 for ankles
• CPC Class Codes: A61F 2/4225 for feet, e.g. toes
• CPC Class Codes: A61F 2/4241 for hands, e.g. fingers
• CPC Class Codes: A61F 2/4261 for wrists
• CPC Class Codes: A61F 2002/30009 differing in fibre orientations
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30016 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/30131 horseshoe- or crescent- or C-shaped or U-shaped
• CPC Class Codes: A61F 2002/30563 having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0019 : differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2250/0028 : differing in fibre orientations
• CPC Class Codes: A61F 2250/0031 : made from both resorbable and non-resorbable prosthetic parts, e.g. adjacent parts
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

A device designed for surgical implantation to replace damaged tissue (such as a meniscus in a knee) is disclosed, having a hydrogel component reinforced by a three-dimensional mesh. The mesh component provides strength and structural support for the implant, which has at least one articulating surface, and at least one anchoring surface. In one embodiment, the mesh emerges from one or more selected locations around the peripheral rim of a meniscal implant, to provide anchoring attachments that can be sutured, pinned, clipped, or otherwise securely affixed to the fibrous capsule that surrounds the knee. Preferably, the rim surface should be porous, to promote scar tissue (or, in some cases, bone tissue) ingrowth into the implant, to create a strong permanent anchoring support for the implant. In addition, at least some portion of the mesh component preferably should extend through most of the thickness of the hydrogel portion, to create a reinforcing “interpenetrating network” (IPN) of fibers, modelled after certain types of natural body tissues. The “articulating” surfaces of a meniscal wedge, which will rub and slide against femoral and tibial cartilage, should be coated with a hydrogel layer which is smooth and nonabrasive, and made of a material that remains constantly wet. This composite structure, with hydrogel layers surrounding an embedded mesh component, provides a joint-repair implant with improved anchoring, strength, and performance compared to implants of the prior art. Because of certain design advantages, this type of implant may also be useful in surgical repair of other joints, such as damaged shoulders, wrists, ankles or elbows, or in surgical repair of feet or hands.

Claims

1. A device designed for surgical emplacement in a mammalian joint, comprising a hydrogel component and a mesh component, wherein:

a. the hydrogel component provides a smooth and lubricious surface, on at least one surface area which will contact and rub against a natural cartilage surface in the joint;

b. the mesh component reinforces the smooth and lubricious surface, and provides reinforced means for anchoring the device to tissue which surrounds the joint.

2. The device of claim 1, having a size and shape which render the device suitable for implantation in a human knee joint to replace a damaged meniscus.

3. The device of claim 1, having a size and shape which render the device suitable for implantation in a joint selected from the group consisting of shoulders, wrists, ankles, and elbows.

4. The device of claim 1, having a size and shape which render the device suitable for implantation in an appendage selected from the group consisting of feet and hands.

5. The device of claim 1, having a first relatively soft hydrogel portion which provides a lubricious surface on at least one surface area of the device, and having a second hydrogel portion which has greater hardness and stiffness in at least one portion of the device.

6. The device of claim 1, having a hydrogel portion which provides a lubricious surface on at least one surface area of the device, and having at least one interior portion comprising an elastomeric material which is not a hydrogel.

7. A device for surgical implantation, comprising:

a. a body made of elastomeric material, and a mesh component embedded within the body of the device, wherein at least a portion of said elastomeric material comprises a hydrogel material which retains water molecules that are able to permeate into and out of the hydrogel material;

b. at least one articulating surface made of a smooth and lubricious hydrogel material, wherein the articulating surface is designed to press against at least one bone or cartilage surface following implantation of the device, and,

c. at least one anchoring surface having an exposed porous surface, made of material that will promote tissue ingrowth into the porous surface following implantation of the device;

and wherein the mesh component embedded within the body of said device is sized and positioned in a manner which;

(i) provides a flexible supporting structure beneath at least one articulating surface, which reinforces and strengthens said articulating surface, and (ii) provides a plurality of anchoring accommodations which will reinforce anchoring of the device to surrounding tissue after surgical implantation of the device.

8. The device of claim 7, having a size and shape which render the device suitable for implantation in a human knee joint to replace a damaged meniscus.

9. The device of claim 7, having a size and shape which render the device suitable for implantation in a joint selected from the group consisting of shoulders, wrists, ankles, and elbows.

10. The device of claim 7, having a size and shape which render the device suitable for implantation in an appendage selected from the group consisting of feet and hands.

11. The device of claim 7, having a first relatively soft hydrogel portion which provides a lubricious surface on at least one articulating surface of the device, and having a second hydrogel portion which has greater hardness and stiffness in an interior portion of the device.

12. The device of claim 7, having a hydrogel portion which provides a lubricious surface on at least one articulating surface of the device, and having at least one interior portion comprising an elastomeric material which is not a hydrogel.

14. The device of claim 13, which also contains an embedded mesh component which is sized and positioned in a manner which provides a flexible supporting and reinforcing structure beneath at least one articulating surface, and which provides a plurality of anchoring accommodations which will reinforce anchoring of the device to surrounding tissue after surgical implantation of the device.

16. The method of claim 15, wherein the device is implanted in a human knee joint to replace damaged meniscal tissue.

17. The method of claim 15, wherein the device has a first relatively soft hydrogel portion which provides a lubricious surface on at least one articulating surface of the device, and a second hydrogel portion which has greater hardness and stiffness in an interior portion of the device.

18. The device of claim 15, wherein the device has a first hydrogel portion which provides a lubricious surface on at least one articulating surface of the device, and at least one interior portion comprising an elastomeric material which is not a hydrogel.

20. The method of claim 19, wherein the device is implanted in a human knee joint to replace damaged meniscal tissue.

21. The method of claim 19, wherein the device has a first relatively soft hydrogel portion which provides a lubricious surface on at least one articulating surface of the device, and a second hydrogel portion which has greater hardness and stiffness in an interior portion of the device.

22. The device of claim 19, wherein the device has a first hydrogel portion which provides a lubricious surface on at least one articulating surface of the device, and at least one interior portion comprising an elastomeric material which is not a hydrogel.

13. A device for surgical implantation to replace meniscal tissue in a joint, comprising a body made of elastomeric material and having:

a. at least one articulating surface made of a smooth and lubricious material which is suitable for pressing and rubbing against a cartilage surface following implantation of the device; and

,

b. at least one anchoring surface having exposed pores that will promote tissue ingrowth into the porous surface following implantation of the device.

15. A method of surgically replacing damaged meniscal tissue in a mammalian joint, comprising the step of surgically implanting, into the joint, a device comprising a hydrogel component and a mesh component, wherein:

a. the mesh component provides the implant device with means for securely anchoring the device to tissue which surrounds the joint; and

,

b. the hydrogel component provides a smooth and lubricious surface, in at least one surface area which will contact and rub against a cartilage surface in the joint.

19. A method of surgically replacing damaged meniscal tissuemin a mammalian joint, comprising the step of surgically implanting, into the joint, a device comprising an elastomeric body component and a mesh component embedded within the elastomeric body component, wherein the elastomeric body component is provided with:

a. at least one articulating surface made of a hydrogel material, and,

b. at least one anchoring surface made of a porous material that will promote tissue ingrowth into the porous surface following implantation of the device;

and wherein the mesh component embedded within the elastomeric body component is sized and positioned in a manner which;

(i) provides a flexible supporting structure beneath at least one articulating surface, which reinforces and strengthens said articulating surface, and (ii) provides a plurality of fibrous anchoring accommodations, which will reinforce anchoring of the device to surrounding tissue after surgical implantation of the device.