Joint prosthesis

• US 6,007,580 A
• Filed: 03/11/1998
• Issued: 12/28/1999
• Est. Priority Date: 06/13/1995
• Status: Expired due to Fees

• Current Assignee: Bionx Implants, Oy (Jefferies Financial Group, Inc.)
• Original Assignee: Bionx Implants, Oy (Jefferies Financial Group, Inc.)
• Inventors: Tormala, Pertti, Lehtimaki, Mauri, Lehto, Matti, Paasimaa, Senja
• Primary Examiner(s): Willse, David H.
• Assistant Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US08/973,361
• Time in Patent Office: 657 Days
• Field of Search: 623/21, 623/18, 623/16
• US Class Current: 623/21.11
• CPC Class Codes: A61B 17/06166 Sutures suture materials A61L17/00; manufacture of artificial threads D01D; treatment of threads D06M
• CPC Class Codes: A61B 17/68 Internal fixation devices , including fasteners and spinal fixators, even if a part thereof projects from the skin bone staples A61B17/0642
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• 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 2/30767 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 2/4225 for feet, e.g. toes
• CPC Class Codes: A61F 2/4241 for hands, e.g. fingers
• 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 2002/30064 Coating or prosthesis-covering structure made of biodegradable material
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30461 sutured, ligatured or stitched
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• 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 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/4233 for metatarso-phalangeal joints, i.e. MTP joints
• CPC Class Codes: A61F 2002/4251 for metacarpo-phalangeal joints, i.e. MCP or MP joints, e.g. knuckle joints
• CPC Class Codes: A61F 2002/4256 for carpo-metacarpal joints, i.e. CMC joints
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• 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 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2250/003 : differing in adsorbability or resorbability, i.e. in adsorption or resorption time

Abstract

The invention relates to a joint prosthesis intended to be mounted between two bones to be joined together. The joint prosthesis comprises a spacer part, intended to be placed between the joint surfaces of the bones to be joined. The spacer part is manufactured of biodegradable polymer, co-polymer, polymer mixture and/or composite. The spacer part is, at least under tissue conditions, porous and elastic. The joint prosthesis further comprises fixation parts which are arranged to fix the spacer part to the bones to be joined, and which are manufactured of biodegradable material.

Claims

1. A joint prosthesis intended to be mounted between two bones to be joined together, wherein the joint prosthesis comprises:

a spacer part intended to be placed between the joint surfaces of the bones to be joined, and which is manufactured of biodegradable polymer, co-polymer, polymer mixture and/or composite, and at least one fixation part arranged to fix the spacer part to the bones to be joined, at least a portion of the fixation part being inside the spacer part, wherein the spacer part and the fixation part are manufactured in separate pieces of one or several biodegradable polymers, co-polymers, polymer mixtures and/or composites and fixed together in order to form a joint prosthesis, and wherein the spacer part is a three-dimensional, uniform form piece which is formed, at least under tissue conditions, to be porous in a manner that the construction comprises continuous and/or broken fibers.

2. A joint prosthesis as set forth in claim 1, wherein the spacer part is a form piece having the form of a pillow, cylinder, ellipsoid, (flattened) ball, cubic or rectangular prism.

3. A joint prosthesis as set forth in claim 1, wherein the spacer part is a string, braiding, cloth, pillow, or non-woven felt.

4. A joint prosthesis as set forth in claim 1, wherein at least one fixation part is composed, at least partially, of at least one thread, braiding or cloth constructed of fiber.

5. A joint prosthesis as set forth in claim 1, wherein at least one fixation part is formed at least partially of one rigid pin, screw, bolt or rod, wherein the stem of the fixation part is situated inside or on the outer surface of the spacer part.

6. A joint prosthesis as set forth in claim 1, wherein fixation parts are joined together inside the spacer part.

7. A joint prosthesis as set forth in claim 1, wherein the fixation part forms at least one uniform, at least partially elastic bar or string which is preferably directed through the spacer part to extend to the bones to be joined.

8. A joint prosthesis as set forth in claim 4, wherein at least one fixation part is constructed of the patient'"'"'s own fibrous tissue.

9. A joint prosthesis as set forth in claim 1, wherein the porosity of the spacer part is between 50 μ

m and 1000 μ

m.

10. A joint prosthesis as set forth in claim 1, wherein the spacer part is a composite structure comprising at least two compounds, the structure comprising materials with different degrading times under tissue conditions, wherein the construction of the spacer part is formed by coating a polymer which degrades slower under tissue conditions with a polymer which degrades faster under tissue conditions, and/or by forming the spacer part of polymers having the above mentioned properties in mixture, in fiber form.

11. A joint prosthesis as set forth in claim 1, wherein the spacer part is formed of biodegradable fibers having a typical fiber thickness of 1 to 300 μ

m.

12. A joint prosthesis as set forth in claim 2, wherein at least one fixation part is composed, at least partially, of at least one thread, braiding or cloth constructed of fiber.

13. A joint prosthesis as set forth in claim 3, wherein at least one fixation part is composed, at least partially, of at least one thread, braiding or cloth constructed of fiber.

14. A joint prosthesis as set forth in claim 2, wherein at least one fixation part is formed at least partially of one rigid pin, screw, bolt or rod, wherein the stem of the fixation part is situated inside or on the outer surface of the spacer part.

15. A joint prosthesis as set forth in claim 2, wherein fixation parts are joined together inside the spacer part.

16. A joint prosthesis as set forth in claim 6, wherein the fixation part forms at least one uniform, at least partially elastic bar or string which is directed through the spacer part to extend to the bones to be joined.

17. A joint prosthesis as set forth in claim 1, wherein at least one fixation part is constructed of the patient'"'"'s own fibrous tissue.