HYDROGEL INTERVERTEBRAL DISC NUCLEUS

• Main Authors: BAO, QI-BIN, HIGHAM, PAUL A
• Format: Patent
• Language: English
• Published: 22.06.1992
• Subjects: BANDAGES, DRESSINGS OR ABSORBENT PADS; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, ORSURGICAL ARTICLES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF,TUBULAR STRUCTURES OF THE BODY, E.G. STENTS; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; FILTERS IMPLANTABLE INTO BLOOD VESSELS; FIRST-AID KITS; FOMENTATION; HUMAN NECESSITIES; HYGIENE; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICALARTICLES; MEDICAL OR VETERINARY SCIENCE; METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS INGENERAL; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; PROSTHESES; TREATMENT OR PROTECTION OF EYES OR EARS

A prosthetic nucleus for a vertebral disc is made of a hydrogel material. The hydrogel prosthetic nucleus has a shape generally conforming to the natural nucleus pulposus. The hydrogel has a water content of at least 30% and has a compressive strength of 4MNm<-> or greater. When the hydrogel material is dehydrated, it has a dimension of less than half of that of the hydrated hydrogel nucleus. The prosthetic nucleus may be formed of two or more pieces of hydrogel material which pieces, when combined, have a shape generally conforming to the natural nucleus. The prosthetic nucleus for implantation in the disc space after removal of a damaged or degenerated nucleus may also be formed from a multiplicity of hydrogel beads having a water content of at least 30%. The beads are covered by a semi-permeable membrane. The membrane has porosity less than the size of the beads to thereby retain the beads therein but permit fluids to flow in and out of the prosthetic nucleus.