Vividly simulated prosthetic intervertebral disc

• US 6,893,465 B2
• Filed: 03/31/2003
• Issued: 05/17/2005
• Est. Priority Date: 03/31/2003
• Status: Expired due to Fees

• Current Assignee: Tain-Yew Shi
• Original Assignee: Tain-Yew Shi
• Inventors: Huang, Shih-Shing
• Primary Examiner(s): Robert, Eduardo C.
• Assistant Examiner(s): Ramana, Anuradha
• Application Number:
  US10/407,075
• Publication Number:
  US 20040193273A1
• Time in Patent Office: 778 Days
• Field of Search: 623/11.11, 623/16.11, 623 1711- 1716, 623/20.16, 623/20.17, 623/23.34, 623/23.56, 623/23.57, 623/23.75, 623/23.76, 623/23.51, 623/23.6, 623/23.61, 623/23.63, 606/60, 606/61, 606/76, 606/77, 606/69, 606/70, 606/71
• US Class Current: 623/17.12
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/441 made of inflatable pockets or chambers filled with fluid, e.g. with hydrogel
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• 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 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• 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 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30583 filled with hardenable fluid, e.g. curable in-situ
• CPC Class Codes: A61F 2002/30586 having two or more inflatable pockets or chambers
• CPC Class Codes: A61F 2002/30622 Implant for fusing a joint or bone material
• CPC Class Codes: A61F 2002/30675 Means for regulating synovial fluid pressure
• CPC Class Codes: A61F 2002/30784 Plurality of holes
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/443 having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/4495 having a fabric structure, e.g. made from wires or fibres
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2210/0085 : hardenable in situ, e.g. epoxy resins
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• 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
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00293 : containing a phosphorus-containing compound, e.g. apatite

Abstract

A prosthetic intervertebral disc includes an upper fusion member adapted to be gradually fused and secured to an upper vertebra, a lower fusion member adapted to be gradually fused and secured to a lower vertebra, and a restorable cushioning coupler retained in between the upper and lower fusion members, whereby upon bending or twisting of a patient'"'"'s spine, the upper and the lower fusion members may be flexibly moved with each other for enhancing free movement of the patient'"'"'s spine and body, safely resiliently cushioned and easily restored by the cushioning coupler in between the upper and lower fusion members.

Claims

1. A prosthetic intervertebral disc comprising:

an upper fusion member having a biodegradable composition filled or formed therein, and adapted to be secured to and gradually fused to an upper vertebra;

a lower fusion member having a biodegradable composition filled or formed therein and adapted to be secured to and gradually fused to a lower vertebra adjacent to the upper vertebra; and

a restorable cushioning coupler resiliently formed between said upper and lower fusion members;

said restorable cushioning coupler secured to one of said fusion members and flexibly engaging with the other of said fusion members to thereby flexibly couple the upper and lower vertebrae;

wherein said upper fusion member includes;

an upper fusion cage having a biodegradable fusion composition filled or preformed in the upper fusion cage, an upper implanting plate formed on an upper portion of the upper fusion cage adapted to be secured to an upper vertebra, a base plate formed on a bottom portion of the upper fusion cage having a pivoting ball axially protruding downwardly from the base plate about a longitudinal axis defined at a longitudinal center of the prosthetic disc and having an outer skirt generally spherically shaped and protruding downwardly from the base plate for protectively surrounding the restorable universal cushioning coupler in cooperation with the lower fusion member; and

wherein said lower fusion member includes;

a lower fusion cage having a biodegradable fusion composition filled or preformed in the lower fusion cage, a lower implanting plate formed on a bottom portion of the lower fusion cage adapted to be secured to the lower vertebra, a supporting base plate formed on an upper portion of the lower fusion cage having an inner skirt generally spherically shaped and protruding upwardly from the supporting base plate to be concentric with the outer skirt of the upper fusion case for engaging the restorable universal cushioning coupler on the inner skirt and on the supporting base plate of the lower fusion member.

2. A prosthetic intervertebral disc according to claim 1, wherein said pivoting ball axially protruding downwardly from the upper fusion member about the longitudinal axis of the intervertebral disc has a center of the ball aligned with the center of curvature of the outer skirt.

3. A prosthetic intervertebral disc according to claim 1, wherein said inner skirt and said outer skirt cooperatively define an annular chamber between the inner and outer skirts allowing a relative tangential movement whenever performing a bending, twisting or rotational movement of the patient'"'"'s spinal vertebrae;

and providing a space for retracting or expanding the inner and outer skirts for minimally invasive surgery.

4. A prosthetic intervertebral disc according to claim 3, wherein said annular chamber as defined between the outer and inner skirts is filled with a buffer liquid which is bio-compatible.

5. A prosthetic intervertebral disc according to claim 1, wherein said restorable cushioning coupler includes:

a lower cushioning portion secured to a supporting base plate of the lower fusion member, an upper cushioning portion protruding upwardly from the lower cushioning portion in slideable contact with a base plate of the upper fusion member, a sealing flap circumferentially formed on a lower perimeter of the cushioning coupler to be slidably engageable with an outer skirt of the upper fusion member for shielding a free-end edge portion of the outer skirt and for sealing a port between the sealing flap and the outer skirt, and a spherical recess formed in a central portion of the upper cushioning portion to be universally engageable with a pivoting ball formed on the upper fusion member for universally coupling the upper fusion member with the lower fusion member, said lower fusion member being formed with the cushioning coupler;

said coupler having a wear-resistance layer formed on an upper surface of the upper cushioning portion and on a surface of the recess.

6. A prosthetic intervertebral disc according to claim 5, wherein said cushioning coupler is formed as a bellows.

7. A prosthetic intervertebral disc according to claim 5, wherein said pivoting ball has a neck portion having a diameter less than a diameter of the ball;

and the spherical recess has a narrowing port engageable with the neck portion of the ball wherein a port diameter of the narrowing port is smaller than a diameter of the spherical recess for ensuring a stable coupling of the ball with the recess;

the diameter of the ball being equal to that of the spherical recess.

8. A prosthetic intervertebral disc according to claim 5, wherein said cushioning coupler includes a cushioning sac filled with a viscous liquid therein, said coupler having an inflating valve protruding outwardly through the lower fusion member.