Shear fatigue micromechanics of the cement-bone interface: An in vitro study using digital image correlation techniques.
Loss of fixation at the cement-bone interface is known to contribute to aseptic loosening, but little is known about the mechanical damage response of this interface. An in vitro study using cement-bone specimens subjected to shear fatigue loading was performed, and the progression of stiffness changes and creep damage at the interface was measured using digital image correlation techniques. Stiffness changes and creep damage were localized to the contact interface between cement and bone. Interface creep damage followed a three-phase response with an initial rapid increase in creep, followed by a steady-state increase, concluding in a final rapid increase in creep. The initial creep phase was accompanied by an increase in interface stiffness, suggesting an initial locking-in effect at the interface. Interface stiffness decreased as creep damage progressed. Power law models were reasonably successful in describing the creep and stiffness damage response and were a function of loading magnitude, number of loading cycles, and contact area at the interface. More microcrack damage occurred to the cement when compared to the bone, and the damage was localized along the interface. These findings indicate that damage to the cement-bone interface could be minimized by improving cement-bone contact and by strengthening the fatigue resistance of the cement.
Department of Orthopedic Surgery, SUNY Upstate Medical University, 3216 Institute for Human Performance, 750 East Adams Street, Syracuse, New York 13210, USA. mannk@upstate.edu
Kenneth A
KA
Mann
Mark A
MA
Miller
Amos
A
Race
Nico
N
Verdonschot
D000368:Aged; D000369:Aged, 80 and over; D001843:Bone Cements / Q000009:adverse effects*; D002102:Cadaver; D005260:Female; D005269:Femur / Q000187:drug effects*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007595:Joint Prosthesis / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D033081:Shear Strength; D013314:Stress, Mechanical
D001843:Bone Cements