title: Biomechanical testing of bioabsorbable cannulated screws for slipped capital femoral epiphysis fixation.
abstract: This study compared cannulated 4.5-mm bioabsorbable screws made of self-reinforced poly-levolactic acid to cannulated 4.5-mm steel and titanium screws for resistance to shear stress and ability to generate compression in a polyurethane foam model of slipped capital femoral epiphysis fixation. The maximum shear stress resisted by the three screw types was similar (self-reinforced poly-levolactic acid 371 +/- 146 MPa, steel 442 +/- 43 MPa, and titanium 470 +/- 91 MPa). The maximum compression generated by both the self-reinforced poly-levolactic acid screw (68.5 +/- 3.3 N) and the steel screw (63.3 +/- 5.9 N) was greater than that for the titanium screw (3 +/- 1.4 N, P <.05). These data suggest cannulated self-reinforced poly-levolactic acid screws can be used in the treatment of slipped capital femoral epiphysis because of their sufficient biomechanical strength.
authors.affiliation: Department of Orthopedic Surgery, University of Heidelberg, Germany.
authors.forename: Markus W
authors.initials: MW
authors.lastname: Kroeber
authors.forename: David
authors.initials: D
authors.lastname: Rovinsky
authors.forename: Andrew
authors.initials: A
authors.lastname: Haskell
authors.forename: Moira
authors.initials: M
authors.lastname: Heilmann
authors.forename: Jeff
authors.initials: J
authors.lastname: Llotz
authors.forename: Norman
authors.initials: N
authors.lastname: Otsuka
mesh_terms: D020341:Absorbable Implants; D001863:Bone Screws; D002404:Catheterization; D019245:Compressive Strength / Q000502:physiology*; D004838:Epiphyses / Q000601:surgery*; D005264:Femoral Fractures / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D019344:Lactic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011108:Polymers / Q000627:therapeutic use; D033081:Shear Strength; D013232:Steel; D013314:Stress, Mechanical; D014025:Titanium / Q000627:therapeutic use
chemical_list: D011108:Polymers; C445939:polylevolactic acid; D013232:Steel; D019344:Lactic Acid; D014025:Titanium