PROSTHESIS AND METHOD FOR REPLACING THE NUCLEUS PULPOSUS OF AN INTERVERTEBRAL DISC OR FOR REPLACING AN ENTIRE INTERVERTEBRAL DISC

摘要

A prosthetic nucleus pulposus (5) for replacing the natural nucleus pulposus of an intervertebral disc. The prosthetic nucleus pulposus comprises a partially collapsed sealed envelope formed from a material which is permeabl e to extracellular body fluid. The envelope contains a solute (20) which provides an osmotic potential across the walls of the envelope. In use, the partially collapsed envelope is surgically implanted in the hallowed-out interior of an intervertebral disc and is allowed to absorb fluid, whereby expansion of the envelope and subsequent disc expansion is accomplished.