# US 8,771,356 B2 · Intervertebral prosthetic disc

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- Number: US 8,771,356 B2
- Document ID: US8771356B2
- Status: Granted
- Kind: B2
- Application number: 13/619,281
- Filed: 2012-09-14
- Published: 2013-01-10
- Granted: 2014-07-08
- Earliest claimed: 2003-05-27
- Assignees: SpinalMotion, Inc.
- Applicants: Malan de Villiers; Ulrich Hähnle
- Inventors: Malan de Villiers; Ulrich Hähnle
- Web page: https://patentgrep.com/patent/US8771356B2

## CPC

- A61F 2/4425: {made of articulated components}
- A61F 2/4611: {of spinal prostheses}
- A61F 2/30771: {applied in original prostheses, e.g. holes or grooves}
- A61F 2/44: for the spine, e.g. vertebrae or spinal discs
- A61F 2002/30052: {differing in electric or magnetic properties}
- A61F 2002/3008: {radio-opaque, e.g. radio-opaque markers}
- A61F 2002/30331: {made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit}
- A61F 2002/30405: {made by screwing complementary threads machined on the parts themselves}
- A61F 2002/30462: {retained or tied with a rope, string, thread, wire or cable}
- A61F 2002/30574: {with an integral complete or partial collar or flange}
- A61F 2002/30649: {Ball-and-socket joints}
- A61F 2002/30662: {with rotation-limiting means}
- A61F 2002/30663: {multiaxial, e.g. biaxial; multipolar, e.g. bipolar or having an intermediate shell articulating between the ball and the socket}
- A61F 2002/30884: {Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity}
- A61F 2002/30899: {Protrusions pierced with apertures}
- A61F 2002/30904: {serrated profile, i.e. saw-toothed}
- A61F 2002/443: {having two transversal endplates and at least one intermediate component}
- A61F 2220/0025: Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
- A61F 2220/0033: made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
- A61F 2220/0075: sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
- A61F 2230/0071: spherical
- A61F 2250/0045: differing in electromagnetical properties
- A61F 2250/0098: radio-opaque, e.g. radio-opaque markers
- A61F 2310/00023: Titanium or titanium-based alloys, e.g. Ti-Ni alloys
- A61F 2310/00029: Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
- A61F 2310/00179: Ceramics or ceramic-like structures
- A61F 2310/00604: Coating made of aluminium oxide or hydroxides
- A61F 2310/0088: Coating made of titanium nitride
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)

## Abstract

A prosthetic disc for insertion between adjacent vertebrae includes upper and lower plates, a core disposed between the plates, and at least one projection extending from at least one of the upper and lower curved surfaces of the core into at least one recess of one of the inner surfaces of the plates. The recess is oversize with respect to the projection to allow sliding movement of the plate over the core while retaining the core between the plates during such sliding movement. The projection(s) may include a rod extending through an axial hole in the core, multiple surface features of the core, or the like.

## Claims

### Claim 1

An intervertebral prosthetic disc for insertion between adjacent vertebrae, the disc comprising:
upper and lower plates having outer surfaces locatable against the respective vertebrae and inner bearing surfaces;
a core between the plates, the core having upper and lower curved surfaces complementary in shape to the inner bearing surfaces of the plates to allow the plates to slide over the core, wherein a lateral portion of the upper plate and a lateral portion of the lower plate contact one another during sliding movement of the plates over the core;
an elongated rib formed on the core, wherein a central axis of the core does not pass through the rib;
a channel formed on at least one of the inner bearing surfaces, the channel arranged to receive and cooperate with the rib, wherein the rib and channel are located between a central axis of the plates and an outer periphery thereof, and wherein the channel has a substantially rectangular cross section bottom wall and two opposite side walls extending substantially perpendicular to the bottom wall to retain the core between the plates when the plates slide over the core.

### Claim 2 (depends on 1)

The prosthetic disc of claim 1, wherein the rib is located with clearance in the channel.

### Claim 3 (depends on 1)

The prosthetic disc of claim 1, wherein at a limit of sliding movement of the plates over the core, the rib abuts against edges one of the side walls of the channel.

### Claim 4 (depends on 1)

The prosthetic disc of claim 1, wherein the rib extends from the core in a direction substantially perpendicular to the adjacent surface of the core.

### Claim 5 (depends on 1)

The prosthetic disc of claim 1, wherein the core comprises polyethylene.

### Claim 6 (depends on 1)

The prosthetic disc of claim 1, further comprising at least one fin extending from the outer surfaces of the upper and lower plates.

### Claim 7

A method of retaining a core in a prosthetic disc, the method comprising:
providing upper and lower plates and a core;
providing a channel in at least one of the plates and a rib on the core, wherein a central axis of the core does not pass through the rib and wherein with the channel is located between a central axis of the plates and an outer periphery thereof;
positioning the core between the upper and lower plates, wherein the upper and lower plates slide over the core in the anterior/posterior and lateral directions;
holding the core captive between the plates while the plates slide over the core by locating the rib within the channel, wherein the channel is substantially rectangular in cross section has a bottom wall and two opposite side walls extending substantially perpendicular to the bottom wall; and
restricting movement of the plates by allowing for contact between a lateral portion of the upper plate with a lateral portion of the lower plate.

### Claim 8 (depends on 7)

The method of claim 7, wherein the core comprises at least one spherical surface.

### Claim 9 (depends on 7)

The method of claim 7, wherein the rib is located with clearance in the channel.

### Claim 10 (depends on 7)

The method of claim 7, wherein at a limit of sliding movement of the plates over the core, the rib abuts against edges of the channel.

### Claim 11 (depends on 7)

The method of claim 7, wherein the rib is an elongated rib which extends from the core in a direction substantially perpendicular to the adjacent surface of the core.

### Claim 12 (depends on 1)

The prosthetic disc of claim 1, wherein the upper and lower plates slide over the core in the anterior/posterior and lateral directions.

### Claim 13 (depends on 1)

The prosthetic disc of claim 1, wherein the plates are configured to slide over the core when the prosthetic disc is implanted in a patient.