Richard J Cleary

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Despite the widespread use of cement as a means of fixation of implants to bone, surprisingly little is known about the micromechanical behavior in terms of the local interfacial motion. In this work, we utilized digital image correlation techniques to quantify the micromechanics of the cement-bone interface of laboratory-prepared cemented total hip(More)
BACKGROUND Aseptic loosening continues to be a short- and long-term complication for patients with cemented TKAs. Most studies to this point have evaluated tibial component fixation via radiographic changes at the implant-bone interface and quantification of component migration; direct assessment of morphologic features of the interface from functioning(More)
The vertebral column of the Atlantic white-sided dolphin, Lagenorhynchus acutus, reflects the radical reorganization of the cetacean column for locomotion in water. Both posterior thoracic and anterior caudal vertebrae have been ‘‘lumbarized,’’ and discontinuities occur within the caudal series at the synclinal point and fluke base. Morphology changes(More)
An in vitro study of cemented femoral hip components was conducted to determine if microcracks in the cement mantle would preferentially form in thin-mantle regions as a result of cyclic fatigue loading via stair-climbing. Overall, there was not an increased amount of microcracks in thin-mantle (<2 mm) regions (number found/number expected = 0.59, P<.03).(More)
Maintaining adequate fixation between cement and bone is important for successful long term survival of cemented total joint replacements. Mixed-mode loading conditions (combination of tension/compression and shear) are present during in vivo loading, but the micromotion response of the interface to these conditions is not fully understood. Non-destructive,(More)
Biological adaptation following placement of a total knee replacements (TKRs) affects peri-implant bone mineral density (BMD) and implant fixation. We quantified the proximal tibial bone strain and implant-bone micro-motion for functioning postmortem retrieved TKRs and assessed the strain/micro-motion relationships with chronological (donor age and time in(More)
The cement-bone interface plays an important role in load transfer between cemented implant systems and adjacent bone, but little is known about the micromechanical behavior of this interface following in vivo service. Small samples of postmortem-retrieved cement-bone specimens from cemented total hip replacements were prepared and mechanically loaded to(More)
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(More)
We have compared the interface morphology at the stem-cement interface of standard Charnley stems with a satin finish (Ra = 0.75 microm) with identical stems which had been grit-blasted over their proximal third (Ra = 5.3 microm) to promote a proximal bond. The stems were cemented into cadaver femora using conventional contemporary cementing techniques.(More)
A combination of laboratory experiment and computational simulation was performed to assess the role of interface porosity on stem migration. The early motion of in vitro prepared cemented femoral components was measured during application of cyclic stair climbing loads. Following testing, transverse sections were obtained and the distribution of pores at(More)