title: Holding power of bioabsorbable self-reinforced poly-L/DL-lactide 70/30 tacks and miniscrews in human cadaver bone.
abstract: Several bioabsorbable internal fixation systems are currently in use in the field of bone surgery. To test the mechanical properties of recently developed amorphous self-reinforced poly-L/DL-lactide [SR-P(L/DL)LA] 70/30 tacks in comparison with commercially available SR-P(L/DL)LA 70/30 (BioSorbFX; Bionx Implants Ltd) miniscrews, SR-P(L/DL)LA miniscrews (length = 6.0 mm, core diameter = 1.5 mm, thread diameter = 2.0 mm) and tacks (length = 5.4 mm, core diameter = 1.5 mm, thread diameter = 2.0 mm) were applied to human cadaveric metatarsal (MT) bones (6 pairs of fourth MT bones and 6 pairs of fifth MT bones from donors who were from 29 to 56 years of age at the time of death). Pullout force was measured using a mechanical testing machine. Forty-eight pullout tests were carried out for each implant type. The Student test, Mann-Whitney test, and Spearman coefficient were used for statistical evaluation. The pullout force of tacks was 135.0 +/- 26.1 N, and that of the miniscrews was 119.3 +/- 26.1 N ( = 0.04, statistically significant difference). Accordingly novel SR-P(L/DL)LA 70/30 tacks have a statistically better pullout strength than the SR-P(L/DL)LA 70/30 miniscrews when tested in cadaver MT bones.
authors.affiliation: Department of Surgery, Oulu University Hospital, Finland.
authors.forename: Sanna
authors.initials: S
authors.lastname: Leinonen
authors.forename: Johanna
authors.initials: J
authors.lastname: Tiainen
authors.forename: Minna
authors.initials: M
authors.lastname: Kellomäki
authors.forename: Pertti
authors.initials: P
authors.lastname: Törmälä
authors.forename: Timo
authors.initials: T
authors.lastname: Waris
authors.forename: Milomir
authors.initials: M
authors.lastname: Ninkovic
authors.forename: Nureddin
authors.initials: N
authors.lastname: Ashammakhi
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D001672:Biocompatible Materials / Q000737:chemistry*; D001858:Bone Nails; D001863:Bone Screws; D002102:Cadaver; D003799:Dental Stress Analysis / Q000295:instrumentation; D004867:Equipment Design; D006801:Humans; D019344:Lactic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D008682:Metatarsal Bones / Q000601:surgery; D008875:Middle Aged; D011091:Polyesters / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; C445939:polylevolactic acid; D019344:Lactic Acid; C033616:poly(lactide)