title: Application of circular statistics in the study of crack distribution around cemented femoral components.
abstract: Cemented stem constructs were loaded in cyclic fatigue using stair climbing loading and the resulting fatigue damage to the cement mantle was determined in terms of angular position of crack and crack length. Techniques from circular statistics were used to determine if the distribution of micro-cracks was uniform. With a designated orientation of 0 degrees -90 degrees -180 degrees -270 degrees indicating lateral-anterior-medial-posterior anatomic directions, the overall distribution of cracks was not uniform (p<0.05) with a mean crack direction in the postero-medial (249 degrees) quadrant of the mantle. The crack angular distribution for proximal (postero-medial; 251 degrees) and distal (antero-medial; 112 degrees) regions of the cement mantle was also different (p<0.025). These findings suggest that the location of cement damage depends on anatomic position and appears to correspond with the tensile stress field in the cement mantle.
authors.affiliation: Department of Orthopedic Surgery, Institute for Human Performance, Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA. mannk@mail.upstate.edu
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Mann
authors.forename: Sameer
authors.initials: S
authors.lastname: Gupta
authors.forename: Amos
authors.initials: A
authors.lastname: Race
authors.forename: Mark A
authors.initials: MA
authors.lastname: Miller
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cleary
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000379:methods; D001843:Bone Cements; D002102:Cadaver; D002484:Cementation / Q000009:adverse effects*; D019544:Equipment Failure Analysis / Q000379:methods*; D006622:Hip Prosthesis; D006801:Humans; D007593:Joint Instability / Q000209:etiology* / Q000503:physiopathology*; D008422:Materials Testing / Q000379:methods; D015233:Models, Statistical; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D001843:Bone Cements