The mechanical effects of different levels of cement penetration at the cement–bone interface

Abstract

The mechanical effects of varying the depth of cement penetration in the cement-bone interface was investigated using finite element analysis (FEA) and validated using companion experimental data. Two FEA models of the cement-bone interface were created from microcomputed tomography data and the penetration of cement into the bone was varied over six levels each. The FEA models, consisting of the interdigitated cement-bone constructs with friction between cement and bone, were loaded to failure in tension and in shear. The cement and bone elements had provision for crack formation due to excessive stress. The interfacial strength showed a strong relationship with the average interdigitation (r 2 =0.97 and r 2 =0.93 in tension and shear, respectively). Also, the interface strength was strongly related with the contact area (r 2 =0.98 and r 2 =0.95 in tension and shear, respectively). The FEA results compared favorably to the stiffness-strength relationships determined experimentally. Overall, the cement-bone interface was 2.5 times stronger in shear than in tension and 1.15 times stiffer in tension than in shear, independent of the average interdigitation. More cracks occurred in the cement than in the bone, independent of the average interdigitation, consistent with the experimental results. In addition, more cracks were generated in shear than in tension. In conclusion, achieving and maintaining maximal infiltration of cement into the bone to obtain large interdigitation and contact area is key to optimizing the interfacial strength.

Hydroxyapatite-lignin composite as a metallic implant-bone tissue osseointegration improver: experimental study in dogs

“…Thus, results from XRD and histological analyses, indicate that the composite may have a low rate degradability associated with increased activation and proliferation of osteoblasts, contributing to osseointegration, but not enough to promote satisfactory metal implant anchoring. According to WAANDERS et al (2010), viscosity of the bone cement is directly proportional to its penetration into the bone and this is an important feature affecting mechanical cement-bone stability for immediate and long-term implant feasibility. In this study, lignin was used in order to favor intramedullary pin fixation while bone formation promoted by hydroxyapatite occurs.…”

3D real-time micromechanical compressive behaviour of bone–cement interface: Experimental and finite element studies

“…This technique has so far been applied only to single phase cellular materials. Recently, micro FE models of bone-cement composite (Janssen et al, , 2009Waanders et al, 2010) have been developed to investigate the effects of friction, morphology and cement penetration on the micro-mechanical behaviour of bone-cement interface under tensile and shear loading conditions. In these studies, the resolution of the CT images was reduced to facilitate meshing.…”

Effect of cementing technique and cement type on thermal necrosis in hip resurfacing arthroplasty—a numerical study

“…But more cement penetration does not necessarily increase the strength of the fixation. 23 Our FEA study highlights a different potential risk of excessive cement penetration, as all models with a thick mantle produced thermal bone necrosis, while no necrosis was found in the thin mantle models. We did not simulate thermal necrosis in the bone that was penetrated with cement, though some thermal damage also likely occurred in this region.…”