Methods for Deploying Spinal Motion Preservation Assemblies

• US 20080195156A1
• Filed: 03/07/2008
• Published: 08/14/2008
• Est. Priority Date: 10/23/2003
• Status: Abandoned Application

• Current Assignee: TranS1 Incorporated (Baxano Surgical, Inc.)
• Original Assignee: TranS1 Incorporated (Baxano Surgical, Inc.)
• Inventors: Assell, Robert L., Wessman, Bradley J., Ainsworth, Stephen D., Dickhudt, Eugene A.
• Application Number:
  US12/044,901
• Publication Number:
  US 20080195156A1
• Time in Patent Office: Days
• US Class Current: 606/279
• CPC Class Codes: A61B 17/025 Joint distractors
• CPC Class Codes: A61B 17/70 Spinal positioners or stabilisers ; Bone stabilisers comprising fluid filler in an implant
• CPC Class Codes: A61B 17/8888 at its central region
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/30742 Bellows or hose-like seals; Sealing membranes A61B17/8808 takes precedence; sealing membranes for retaining bone substitute A61F2/2846
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• 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 2/4425 made of articulated components
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4637 for connecting or disconnecting two parts of a prosthesis
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30075 swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30289 helically-coiled
• CPC Class Codes: A61F 2002/30327 differing in diameter
• 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 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30495 using a locking ring
• CPC Class Codes: A61F 2002/30507 : using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/3055 : for adjusting length
• 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 2002/30566 : Helical springs
• CPC Class Codes: A61F 2002/30571 : Leaf springs
• CPC Class Codes: A61F 2002/30579 : with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30581 : having a pocket filled with fluid, e.g. liquid
• CPC Class Codes: A61F 2002/30583 : filled with hardenable fluid, e.g. curable in-situ
• CPC Class Codes: A61F 2002/30588 : filled with solid particles
• CPC Class Codes: A61F 2002/30601 : telescopic
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30649 : Ball-and-socket joints
• CPC Class Codes: A61F 2002/30677 : Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30859 : having threaded portions of different pitches
• CPC Class Codes: A61F 2002/30863 : the entry end surface having flutes, relief grooves, starter notches or bevelled indentations
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/444 : for replacing the nucleus pulposus
• CPC Class Codes: A61F 2002/4495 : having a fabric structure, e.g. made from wires or fibres
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2210/0061 : swellable
• 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 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• 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 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0091 : helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0039 : differing in diameter
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium

Abstract

Spinal motion preservation assemblies adapted for use in a spinal motion segment are disclosed including the process for delivering and assembling the spinal motion preservation assemblies in the spinal motion segment via an axial channel created with a trans-sacral approach. The spinal motion preservation assemblies make use of a dual pivot. A number of different embodiments of spinal motion preservation assemblies are disclosed which include at least one component adapted for elastic deformation under compressive loads. The disclosed mobility preservation assemblies provide for dynamic stabilization (DS) of the spinal motion segment.

Claims

1. A method for deploying a spinal motion preservation assembly in a motion segment accessed by an axial trans-sacral approach, the implanted spinal motion preservation assembly comprising a distal component and a proximal component both with external threads, an implant subassembly extending between the distal and proximal components which comprises a pivot adapted for unconstrained engagement by means of dual pivot ends within both the distal component and the proximal component, and an expandable membrane which is expanded with a prosthetic nucleus material, the method comprising:

rotating a driver which simultaneously deploys the distal component and the proximal component to engage the distal component with a distal vertebral body and to engage the proximal component with a proximal vertebral body while maintaining a predetermined separation distance between the distal component and the proximal component and without cross threading the thread path cut into the proximal vertebral body;

inserting a distal end of the pivot into the proximal end of the distal implant device assembly; and

selectively advancing a portion of the proximal implant device assembly to push the pivot against the distal implant device assembly to change the distribution of loading between A) the prosthetic nucleus and B) the external threads on the proximal component and the external threads on the distal component.

2. The method of claim 1 further comprising the step of engaging the distal component with at least one component adapted to elastically deform under compressive load.

3. The method of claim 1 further comprising the step of engaging the proximal component with at least one component adapted to elastically deform under compressive load.

4. The method of claim 3 further comprising the step of engaging the distal component with at least one component adapted to elastically deform under compressive load.

5. A method of providing dynamic stabilization to a motion segment in a spine, the method comprising;

deploying into the motion segment by an axial channel created with a trans-sacral approach a spinal motion stabilization assembly with a pair of unconstrained pivot points and at least one component capable of elastic deformation such that motion segment after receipt of the spinal motion stabilization assembly can undergo motion that enables the normal range of motion in all six degrees of freedom.

6. The method of claim 5 further comprising the steps of:

expanding a membrane connected to the spinal motion stabilization assembly with prosthetic nucleus material to form a prosthetic nucleus; and

selectively varying the loading between the prosthetic nucleus and sets of threads on the spinal motion stabilization assembly engaged with vertebral bodies on the superior and inferior ends of the motion segment.

7. The method of claim 6 wherein prosthetic nucleus material is provided to the membrane through a distractor/injector tool after distraction of the motion segment and before removal of the distractor/injector tool.