Biaxial artificial disc replacement

• US 20040127991A1
• Filed: 10/22/2003
• Published: 07/01/2004
• Est. Priority Date: 10/22/2002
• Status: Active Grant

• Current Assignee: Bret A. Ferree
• Original Assignee: Bret A. Ferree
• Inventors: Ferree, Bret A.
• Granted Patent: US 7,267,688 B2
• Time in Patent Office: Days
• US Class Current: 623/17.11
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30069 elastomeric
• 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 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30471 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2002/30481 using a locking clip
• CPC Class Codes: A61F 2002/30517 using a locking plate
• CPC Class Codes: A61F 2002/30528 Means for limiting said movement
• 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 2002/30777 Oblong apertures
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30934 Special articulating surfaces
• CPC Class Codes: A61F 2002/443 having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/4622 having the shape of a forceps or a clamp
• 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 2220/0041 using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/0091 : connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2310/00395 : Coating or prosthesis-covering structure made of metals or of alloys

Abstract

An artificial disc replacement (ADR) is designed to protect a cushioning component from excessive force. Physical features on the front and back of the ADR enable the device to replicate the normal movements of the spine through predetermined, limited, movements of the endplate components relative to one another. For example, though not limited to these characteristics, the components of the ADR could be dimensioned to allow 15 degrees of flexion, 5 degrees of extension, 5 degrees of lateral bending, and 1-2 mm of translocation. In the preferred embodiment the physical features are axles that extend through overlapping lateral portions associated with the endplate components. A desirable configuration includes a pair of axles, one in the anterior portion and another in the posterior portion, wherein some or all of the axles extend through an oversized aperture that allows the limited relative movement of the endplate components. Alternatively, the anterior and posterior physical features may include mating projections and depressions to permit a desired degree of relative movement.

Claims

1. An artificial disc replacement (ADR) configured for placement between two vertebral bodies having a medial-lateral orientation and anterior and posterior portions, the ADR comprising:

opposing endplate components, each fixed to a respective one of the vertebral bodies;

a cushioning component disposed between the opposing endplate components; and

anterior and posterior features that permit a predetermined, limited, movement of the endplate components relative to one another.

2. The ADR of claim 1, wherein the anterior and posterior features permit a predetermined, limited degree of flexion.

3. The ADR of claim 1, wherein the anterior and posterior features permit a predetermined, limited degree of extension.

4. The ADR of claim 1, wherein the anterior and posterior features permit a predetermined, limited degree of lateral bending.

5. The ADR of claim 1, wherein the anterior and posterior features permit a predetermined, limited degree of translocation.

6. The ADR of claim 1, wherein:

the opposing endplate components have overlapping medial and lateral portions; and

the features are axles that extend through the overlapping lateral portions.

7. The ADR of claim 6, including a pair of axles, one in the anterior portion and another in the posterior portion.

8. The ADR of claim 6, wherein one of the axles extends through an oversized aperture formed in an overlapping portion that allows the limited relative movement of the endplate components.

9. The ADR of claim 1, wherein:

the opposing endplate components have overlapping lateral portions; and

the anterior and posterior physical features include mating projections and depressions associated with the overlapping lateral portions.