ABSTRACT
Re-establishment of normal biomechanical properties in the diseased or degenerative disc continues to be a challenge in the field of spinal surgery. Restoration of the nucleus with a prosthetic implant has undergone a gradual evolution in design and surgical approach modifications. The earliest attempts in replacing the nucleus were in conjunction with a discectomy for leg pain to maintain discal height and function, rather than as a functional alternative to spinal fusion. An injectable biomaterial is ideal for restoration of the disc removed during a nuclear excision and for further prevention of disc height loss. Flowable materials may be injected percutaneously thereby interdigitating with irregular surgical defects and may, depending on the material used, physically bond to the adjacent tissue. Surgeons are continuing to develop methods that allow the minimally invasive placement of nuclear replacement devices that prevent implant migration or extrusion.
