title: In vitro properties of PLLA screws and novel bioabsorbable implant with elastic nucleus to replace intervertebral disc.
abstract: The suitability of two different implant types for the replacement of the intervertebral disc was studied in vitro. Self-reinforced poly-L-lactide (SR-PLLA) screws Ø 4.5 mm were studied 24 weeks in vitro and cylindrical implants with elastic nucleus made of poly(L/D)lactide 96/4, poly(L/DL)lactide 70/30, Bioactive Glass n:o 13-93 and Polyactive 1000PEOT70PBT30 were studied 15 weeks in vitro. The cylindrical implant mimics the size and shape of the intervertebral disc. During the in vitro, there were no changes in compression properties with either implant types. The screws had sufficient modulus for intervertebral ossification in the canine model and the cylindrical implant showed also sufficient mechanical properties. These results suggest that both implant types could be used in clinical testing.
authors.affiliation: Institute of Biomaterials, Tampere University of Technology, P.O. Box 589, FIN-33101, Tampere, Finland, ville.ella@tut.fi.
authors.forename: V
authors.initials: V
authors.lastname: Ellä
authors.forename: M
authors.initials: M
authors.lastname: Kellomäki
authors.forename: P
authors.initials: P
authors.lastname: Törmälä
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D001863:Bone Screws; D019245:Compressive Strength; D004548:Elasticity; D019544:Equipment Failure Analysis; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008422:Materials Testing; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013499:Surface Properties; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; C033616:poly(lactide)