Nuclear implant apparatus and method following partial nuclectomy

Inventors

Hibri, Nadi S. • FRANCIS, W. Loren • Novotny, Mark A.

Assignees

Spinal Stabilization Technologies LLC

Abstract

An expandable implant for augmenting a damaged or otherwise torn posterior annulus fibrosus. The implant is deployable into an evacuated posterior disc space following a subtotal nuclectomy. The implant includes an inflatable balloon which is fixed to the annulus fibrosus to protect against migration. When inflated with a curable polymer, the posterior wall of the implant is intimately disposed along the inner surface of the annulus fibrosus to provide a substantially fluid-tight seal of the annular tear or defect and reinforce the weakened posterior annulus. The anterior wall of the implant sequesters the nuclear remnant to guard against disc remnant herniation. The implant can restore intradiscal pressure and disc height. An integrated posterior reinforcement band creates a strong, yet flexible and resilient structure, resistant to penetration of the implant through the annular tear or defect.

Core Innovation

The invention relates to an expandable nuclear implant and apparatus for reinforcing a damaged annulus fibrosus following subtotal nuclectomy or partial nuclectomy. The implant includes an elastomeric inflatable balloon having a posterior portion configured to seal against a posterior annulus defect and an anterior portion that is more compliant than the posterior portion. When the balloon is expanded with a curable medium, the posterior wall seals and reinforces the posterior annulus tear while the anterior wall sequesters the nucleus remnant to prevent herniation.

The disclosed apparatus anchors the expandable balloon ends to the annulus fibrosus using a first anchor and a second anchor coupled to the first end and the second end of the inflatable balloon, respectively. The anchors are anchored to first and second locations at first and second lateral sides of the annulus fibrosus, including through spaced posterolateral annulotomies. The arrangement restores intradiscal pressure and disc height and is described as helping prevent migration or expulsion.

The balloon construction is described as configurable in materials and layers to achieve sealing and compliance differences, including silicone, PTFE and ePTFE, porous PTFE, and electrospun polymeric reinforcement, as well as multilayer balloon constructions with directional or differential compliance. Additional features include reinforcement layers and bonding structures, and openings that plug defects by receiving protrusions of an inner layer. Inflation is described as including an inflation port and valve behavior, and embodiments also include multi-chamber inflation with a curable elastomeric first chamber and a compressible gaseous second chamber for shock absorption. The disclosed approach includes delivery into the cavity via cannulas and removal of cannulas to allow annular fiber contraction that fixes the balloon ends to the annulotomies.

Claims Coverage

The independent claim covers an apparatus for reinforcing a damaged annulus fibrosus using a compliance-differentiated inflatable balloon anchored to the annulus fibrosus by first and second anchors. The main inventive coverage includes the posterior sealing portion, the more compliant anterior portion, and anchoring on opposite lateral sides of the annulus fibrosus.

Overall, the independent claim structure reinforces a damaged annulus fibrosus by combining a posterior sealing balloon portion with a more compliant anterior balloon portion and anchoring the balloon ends to opposite lateral sides of the annulus fibrosus using first and second anchors.

Stated Advantages

Documented Applications