title: The effects of low-intensity pulsed ultrasound on bioabsorbable self-reinforced poly L-lactide screws.
abstract: The effects of low-intensity pulsed ultrasound on the mechanical and molecular properties of self-reinforced poly L-lactide (SR-PLLA) screws were studied in vitro. SR-PLLA screws of 4.5 mm diameter were exposed on low-intensity ultrasound for 1, 3. 6, 9, and 12 weeks. After exposure, the bending strength, shear strength, and molecular weight were investigated. There were no differences in the investigated properties between the ultrasound exposure and control groups. We found no evidence that low-intensity ultrasound has any effect on the mechanical or molecular properties of SR-PLLA screws in vitro. The present results suggest that biodegradable SR-PLLA fixation devices are compatible with low-intensity ultrasound in vitro.
authors.affiliation: Department of Orthopaedics and Traumatology, Helsinki University Central Hospital, Finland. lauri.handolin@hus.fi
authors.forename: Lauri
authors.initials: L
authors.lastname: Handolin
authors.forename: Timo
authors.initials: T
authors.lastname: Pohjonen
authors.forename: Esa K
authors.initials: EK
authors.lastname: Partio
authors.forename: Ilkka
authors.initials: I
authors.lastname: Arnala
authors.forename: Pertti
authors.initials: P
authors.lastname: Törmälä
authors.forename: Pentti
authors.initials: P
authors.lastname: Rokkanen
mesh_terms: D020341:Absorbable Implants; D000042:Absorption; D001672:Biocompatible Materials / Q000737:chemistry*; D001863:Bone Screws; D019344:Lactic Acid / Q000031:analogs & derivatives* / Q000737:chemistry*; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013314:Stress, Mechanical; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; C445939:polylevolactic acid; D019344:Lactic Acid; C033616:poly(lactide)