title: The effect of hole diameter on the torsional mechanical properties of the equine third metacarpal bone.
abstract: The torsional monotonic structural material properties of equine metacarpi with or without, either a 5/16 inch or 3/8 inch diameter bicortical lateromedial middiaphyseal hole were assessed to determine the effect of a hole on metacarpal strength. Torsional stiffness was not significantly effected by the presence of a bicortical hole, whereas yield and failure angles, torques and energies of metacarpi with a hole were 51% to 97% of those of intact bones. Significant differences were not apparent for yield and failure mechanical properties between metacarpi with a 5/16 inch diameter hole and metacarpi with a 3/8 inch diameter hole; however, postyield mechanical properties were lower for metacarpi with a 3/8 inch hole. Whereas some metacarpi with a 5/16 inch hole were capable of plastic deformation before failure, metacarpi with a 3/8 inch diameter hole appeared to have sufficient stress concentration to propagate complete fracture on structural yield.
authors.affiliation: Veterinary Medical Teaching Hospital, Davis, CA., USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Seltzer
authors.forename: S M
authors.initials: SM
authors.lastname: Stover
authors.forename: K T
authors.initials: KT
authors.lastname: Taylor
authors.forename: N H
authors.initials: NH
authors.lastname: Willits
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005260:Female; D050723:Fractures, Bone / Q000209:etiology / Q000601:surgery / Q000662:veterinary; D006734:Horse Diseases / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D006736:Horses / Q000033:anatomy & histology* / Q000502:physiology / Q000601:surgery; D016268:Internal Fixators / Q000662:veterinary*; D016014:Linear Models; D008297:Male; D008663:Metacarpus / Q000033:anatomy & histology* / Q000502:physiology / Q000601:surgery