Cartilage repair unit and method of assembling same

• US 5,749,874 A
• Filed: 12/30/1996
• Issued: 05/12/1998
• Est. Priority Date: 02/07/1995
• Status: Expired due to Term

• Current Assignee: DePuy Orthopaedics Incorporated (Johnson & Johnson)
• Original Assignee: Matrix Technology (China) Co. Ltd.
• Inventors: Schwartz, Robert E.
• Primary Examiner(s): Tucker, Guy V.
• Application Number:
  US08/774,390
• Time in Patent Office: 498 Days
• Field of Search: 606/75, 606/72, 606/60, 606/77, 606/76, 606/80, 606/88, 606/96, 606/99, 606/100, 606/104, 606/213, 606/215, 606/219, 623/16, 623/20
• US Class Current: 606/75
• CPC Class Codes: A61F 2/30749 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/4618 of cartilage
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/3028 polyhedral different from parallelepipedal and pyramidal
• 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 2002/30367 with additional means for preventing said rotation
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30487 Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• 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 2002/30733 Inserts placed into an endoprosthetic cavity, e.g. for modifying a material property
• CPC Class Codes: A61F 2002/30751 for attaching cartilage scaffolds to underlying bone
• CPC Class Codes: A61F 2002/30766 Scaffolds for cartilage ingrowth and regeneration
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30808 : parallel
• 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 2002/30881 : Circumferential ribs, flanges or fins
• CPC Class Codes: A61F 2002/30891 : Plurality of protrusions
• CPC Class Codes: A61F 2002/4677 : using a guide wire
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• 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 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes

Abstract

A method of assembling an improved bio-absorbable cartilage repair system includes the step of directly inserting the insert into a cavity in the delivery unit so as to leave a top of the insert exposed. A flexible, porous fabric piece, consisting substantially of bio-absorbable material, is then applied over the exposed top of the inserted insert and through a plurality of the windows of the delivery unit sidewall. The fabric piece includes a central body portion configured and dimensioned to substantially cover the exposed top of the inserted insert, and a plurality of leg portions extending outwardly from the body portion, the leg portions being configured and dimensioned to fit through the windows. Substantially all of each leg portion is next pulled through a respective window to cause the body portion to deform the inserted insert into assuming the shape of the cavity therebelow. Finally, the leg portions projecting from the windows are trimmed. The remaining fabric piece retains the inserted insert within the delivery unit. Preferably, the pulling also causes the body portion to deform the exposed top of the inserted insert into assuming a desired shape or contour.

Claims

1. A method of assembling a bio-absorbable cartilage repair system for regenerating damaged or destroyed articular cartilage on a surface of a bone by establishing a chondrogenic growth-supporting matrix between an area of damaged or destroyed articular cartilage that has been removed and an adjacent healthy area of articular cartilage and cancellous bone, the system comprising an assembly of:

(A) a dimensionally stable, ceramic-free, bio-absorbable delivery unit configured and dimensioned to be mounted in both an area of damaged or destroyed articular cartilage that has been removed and an adjacent healthy area of articular cartilage and cancellous bone; and

(B) a deformable, ceramic-free, porous, bio-absorbable insert supported by and in the delivery unit and establishing communication between the removed area and the adjacent healthy area for a chondrogenic growth-supporting matrix;

the delivery unit having an open top, a bottom and a sidewall connecting said top and bottom, the sidewall defining a plurality of windows to which the insert extends to allow cellular migration to the sides of the insert by an adjacent healthy area of articular cartilage;

the method comprising the steps of;

(a) directly inserting the insert into a cavity in the delivery unit so as to leave a top of the insert exposed;

(b) applying a flexible, porous fabric piece consisting substantially of bio-absorbable material over the exposed top of the inserted insert and through a plurality of the windows of the delivery unit sidewall, the fabric piece including a central body portion configured and dimensioned to substantially cover the exposed top of the inserted insert and a plurality of leg portions extending outwardly from the body portion, the leg portions being configured and dimensioned to fit through the windows;

(c) pulling substantially all of each leg portion through a respective window to cause the body portion to deform the inserted insert into assuming the shape of the cavity therebelow; and

(d) trimming the leg portions projecting from the windows;

whereby the remaining fabric piece retains the inserted insert within the delivery unit.

2. The method of claim 1 wherein in step (c) the pulling also causes the body portion to deform the exposed top of the inserted insert into assuming a desired shape.

3. In a bio-absorbable cartilage repair system for regenerating damaged or destroyed articular cartilage on a surface of a bone by establishing a chondrogenic growth-supporting matrix between an area of damaged or destroyed articular cartilage that has been removed and an adjacent healthy area of articular cartilage and cancellous bone, said system comprising an assembly of:

(A) a dimensionally stable, ceramic-free, bio-absorbable delivery unit defining an open top cavity and configured and dimensioned to be mounted in both an area of damaged or destroyed articular cartilage that has been removed and an adjacent healthy area of articular cartilage and cancellous bone; and

(B) a deformable, ceramic-free, porous, bio-absorbable insert supported by and in said cavity of said delivery unit so as to leave a top of said insert exposed and establishing communication between the removed area and the adjacent healthy area for a chondrogenic growth-supporting matrix;

said delivery unit cavity having an open top, a bottom and a sidewall connecting said top and bottom, said sidewall defining a plurality of windows to which said insert extends to allow cellular migration to the sides of said insert by an adjacent healthy area of articular cartilage;

the improvement comprising;

a flexible, porous fabric piece consisting substantially of bio-absorbable material disposed over the exposed top of said insert and through a plurality of said windows of said delivery unit sidewall, said fabric piece including a central body portion configured and dimensioned to substantially cover said exposed top of said insert and a plurality of leg portions extending outwardly from said body portion, said leg portions having free ends extending through respective windows, said body portion assuming the shape of the cavity therebelow;

whereby said fabric piece retains said insert within said delivery unit.

4. The repair system of claim 3 wherein said leg portions extend beyond said respective windows by 1-2 mm.

5. The repair system of claim 3 wherein said fabric piece is formed of fibers of a substantially bio-absorbable material which is the same as the bio-absorbable insert.

6. The repair system of claim 3 wherein said plurality of leg portions is equal in number to said plurality of windows.

7. The repair system of claim 3 wherein said fabric piece is spider-shaped.

8. The repair system of claim 3 wherein said body portion completely covers said exposed top of said insert.

9. A method of assembling a bio-absorbable cartilage repair system for regenerating damaged or destroyed articular cartilage on a surface of a bone by establishing a chondrogenic growth-supporting matrix between an area of damaged or destroyed articular cartilage that has been removed and an adjacent healthy area of articular cartilage and cancellous bone, the system comprising an assembly of:

(A) a bio-absorbable delivery unit configured and dimensioned to be mounted in both an area of damaged or destroyed articular cartilage that has been removed and an adjacent healthy area of articular cartilage and cancellous bone; and

(B) a deformable, porous, bio-absorbable insert supported by the delivery unit and establishing communication between the removed area and the adjacent healthy area for a chondrogenic growth-supporting matrix;

the delivery unit having a support portion which supports the insert to allow cellular migration to the sides of the insert by an adjacent healthy area of articular cartilage;

the method comprising the steps of;

(a) directly placing the insert on the support portion of the delivery unit so as to leave a top of the insert exposed;

(b) applying a flexible, porous fabric piece consisting substantially of bio-absorbable material over the exposed top of the insert, the fabric piece including a central body portion configured and dimensioned to substantially cover the exposed top of the insert and a plurality of leg portions extending outwardly from the body portion; and

(c) using the leg portions to secure the insert on the delivery unit.

10. The method of claim 9 wherein in step (c) the leg supporting portions are used to cause the body portion to deform the exposed top of the insert into assuming a desired shape.

11. The method of claim 9 wherein said fabric piece is formed of fibers of a substantially bio-absorbable material which is the same as the bio-absorbable insert.

12. The method of claim 9 wherein said body portion completely covers said exposed top of said insert.

13. The method of claim 9 wherein said fabric piece is about 95% voids by volume.