Interspinous prosthesis

• US 6,626,944 B1
• Filed: 10/23/2000
• Issued: 09/30/2003
• Est. Priority Date: 02/20/1998
• Status: Expired due to Term

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: Jean Taylor
• Inventors: Taylor, Jean
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): BLANCO, JAVIER G
• Application Number:
  US09/622,513
• Time in Patent Office: 1,072 Days
• Field of Search: A61/B 1.756, A61/B 1.770, A61/F.244, 623/17.11, 623/17.16, 606/61
• US Class Current: 623/17.16
• CPC Class Codes: A61B 17/7053 with parts attached to bones or to each other by flexible wires, straps, sutures or cables
• CPC Class Codes: A61B 17/7062 Devices acting on, attached to, or simulating the effect of, vertebral processes, vertebral facets or ribs rib fixation devices A61B17/8076; Tools for such devices
• CPC Class Codes: A61B 17/82 for bone cerclage apparatus for manipulating wires or straps A61B17/8861; wires, bands or straps other than cerclage A61B17/842
• CPC Class Codes: A61B 17/842 Flexible wires, bands or straps A61B17/72, A61B17/82, A61B17/86 take precedence
• CPC Class Codes: A61B 2017/06052 Needle-suture combinations in which a suture is extending inside a hollow tubular needle, e.g. over the entire length of the needle hollow suture needles A61B2017/061
• CPC Class Codes: A61F 2/0811 Fixation devices for tendons or ligaments
• 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 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2002/30166 H-shaped or I-shaped
• 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 2002/30785 parallel
• CPC Class Codes: A61F 2230/0028 Shapes in the form of latin or greek characters
• CPC Class Codes: Y10S 606/91 Polymer

Abstract

This prosthesis is made of a material which is mult-directionally flexible and elastic, and comprises an interspinous portion having a thickness slightly greater than the anatomical interspinous space when the spine is in lordosis. According to the invention, the prosthesis has two pairs of lugs projecting longitudinally on either side of its interspinous portion, these lugs having substantial heights in relation to the total height of the prosthesis, namely, for each pair of lugs, of the order of 30 to 45% of this total height; each pair of lugs is integral with the said interspinous portion and delimits a deep recess which is able to receive the corresponding spinous apophysis without play, with a wide surface area of contact between these lugs and this apophysis.

Claims

1. Interspinous prosthesis, comprising:

an interspinous portion having a thickness slightly greater than the anatomical interspinous space when the spine is in lordosis, such that the interspinous portion is compressed slightly when the prosthesis is placed between the spinous apophyses of two vertebrae, and

two pairs of lugs projecting longitudinally on either side of the interspinous portion;

wherein, the interspinous prosthesis is composed of a multi-directionally flexible and elastic material, each pair of lugs is integral with the interspinous portion and delimits a deep recess for receiving the corresponding spinous apophysis with a wide surface area of contact between the lugs and the apophysis, and the two pairs of lugs have a length substantially larger than a length of the interspinous portion such that the lugs bear against the spinous apophyses when the interspinous portion is compressed.

2. Prosthesis according to claim 1, wherein the internal faces of two lugs of one and the same pair of lugs are inclined in such a way as to converge towards one another in the direction of the bottom of the recess which they delimit.

3. Prosthesis according to claim 1, wherein the lugs have an average thickness of 25 to 35% of the average width of the prosthesis.

4. Prosthesis according to claim 1, wherein an anterior face of the prosthesis includes a slanted and rounded zone.

5. Prothesis according to claim 1, further including at least one transverse conduit formed in the area of the interspinous portion, the conduit permitting engagement of a cord intended to join the prosthesis tightly to at least one of the spinous apophyses.

6. Prosthesis according claim 5, wherein a wall of the interspinous portion which delimits the said conduit is widened at the ends of the conduit in order to eliminate any sharp edge capable of creating a point of wear of the said cord.

7. Prosthesis according to claim 5, further comprising two transverse conduits, each receiving a cord for attaching it to the spinous apophysis of the corresponding vertebra.

8. Prosthesis according to claim 1, wherein said prosthesis is placed in a textile sheath which matches the shape of said prosthesis.

9. Prosthesis according to claim 8, wherein the sheath comprises a small strip sewn onto it on a posterior side of the prosthesis, and intended to serve as an anchoring point for a prosthetic ligament replacing the interspinous and supraspinous ligament.

10. Prosthesis according to claim 1, wherein said lugs are sized in the range of 30 to 40% of the total size of said prosthesis.

11. Prosthesis according to claim 1, wherein a combined length of the two pairs of lugs accounts for 60-90% of the length of the prosthesis.

12. Prosthesis according to claim 1, wherein a combined length of the two pairs of lugs accounts for 66-80% of the length of the prosthesis.