@article {Simula.sc.972,
	title = {The Modified Cam Clay Model for Constrained Compression of Human Morsellised Bone: Effects of Porosity on the Mechanical Behaviour},
	journal = {Journal of the Mechanical Behavior of Biomedical Materials},
	volume = {2},
	number = {1},
	year = {2009},
	month = {January},
	pages = {43-50},
	abstract = {Morsellised cortico-cancellous bone (MCB) is often used in revision surgery for filling skeletal defects. The MCB porosity is found to influence the degree of bone ingrowth. Thus expressing a material model in terms of porosity may be attractive from a clinical point of view. We analysed the moisture content and performed constrained compression testing of human impacted and unimpacted MCB, in order to determine material parameters for the common constitutive soil model: modified cam clay. The model seemed to be suitable for the unimpacted pellets with a logarithmic bulk modulus {\k a}ppa=0.059\pm0.0019 and a logarithmic hardening constant {\l}ambda=0.36\pm0.014. This model, relating the specific volume (and porosity) to the logarithm of stress, may be suited to find the best compromise of stiffness and porosity for MCB.},
	doi = {10.1016/j.jmbbm.2008.02.004},
	author = {Knut B. {Lunde} and Bj{\o}rn H. {Skallerud}}
}
@article {Simula.sc.940,
	title = {On the Applicability of Bovine Morsellized Cortico-Cancellous Bone As a Substitute for Human Morsellized Cortico-Cancellous Bone for in Vitro Mechanical Testing},
	journal = {Journal of Biomechanics},
	volume = {41},
	number = {16},
	year = {2008},
	month = {December},
	pages = {3469-3474},
	abstract = {Morsellized cortico-cancellous bone (MCB) is frequently used in orthopaedic revision surgery to restore lost bone stock. In this study, we examine the validity of using bovine MCB as a substitute for human MCB in in vitro mechanical testing of bone grafts. The paper describes the fat and water content of impacted and unimpacted human and bovine MCB. During this work we applied constrained compression testing to describe the elastic, plastic and time dependent response. Nearly all parameters were found to be significantly different and were influenced differently by impaction for the two types of MCB. The denser trabecular structure, higher fat content of bovine MCB and higher stiffness and compressive strength of cortical bovine bone may explain the differences observed. Consequently we are not confident about the applicability of bovine MCB as a substitute for human MCB for in vitro mechanical testing.},
	doi = {10.1016/j.jbiomech.2008.08.030},
	author = {Knut B. {Lunde} and Olav A. {Foss} and Bj{\o}rn H. {Skallerud}}
}
@article {Simula.sc.938,
	title = {Constitutive Models for Constrained Compression of Unimpacted and Impacted Human Morselized Bone Grafts},
	journal = {Journal of Biomechanical Engineering},
	volume = {130},
	number = {6},
	year = {2008},
	month = {December},
	pages = {61014},
	abstract = {Morselized corticocancellous bone (MCB) is widely used in revision surgery with and without impaction. In the current study material parameters for the nonlinear viscoelastic and plastic responses of impacted and unimpacted human MCBs were determined during constrained compression. These models may be useful in finite element analyses of surgical constructs involving impacted and unimpacted MCBs. MCB is impacted layer by layer in the femoral canal during revision surgery. The influence of different layers on the mechanical properties was therefore also examined by comparing the relaxation strength and elastic and plastic strains for bone pellets impacted in one and two layers during constrained compression of human MCB. The relaxation strength was found to increase significantly by 14\% for two layer pellets compared to one layer pellets, and the plastic strains decreased significantly by 15\%, while the elastic strains were similar.},
	doi = {10.1115/1.2979878},
	author = {Knut B. {Lunde} and Olav A. {Foss} and Fosse, Lars and Bj{\o}rn H. {Skallerud}}
}
@article {Simula.sc.942,
	title = {The Fluid Phase of Morsellized Bone: Characterization of Viscosity and Chemical Composition},
	journal = {Journal of the Mechanical Behavior of Biomedical Materials},
	volume = {1},
	number = {2},
	year = {2008},
	pages = {199-205},
	abstract = {Morsellized bone is widely used in orthopaedics to fill skeletal defects. The material behaviour is highly time-dependent, due to the liquid consisting of fat and water present in the impacted graft layer. In this study this fluid was characterized with respect to viscosity and chemical composition. Bovine bone was ground in a bone mill, transferred to tubes and centrifuged. This procedure allowed to successfully extract the fluid present inside the ground bone. The fluid was found to have similar composition to yellow bone marrow and a temperature dependent viscosity that could be described by Andrade{\textquoteright}s equation with coefficients A = 1.3 * 10^-4 Pa s and B = 3950 C. The viscosity data can be used in quantitative modelling based on a mixture theory approach to simulate the mechanical behaviour of the graft during packing and cement filling in the femur.},
	doi = {10.1016/j.jmbbm.2007.10.001},
	author = {Knut B. {Lunde} and Sletmoen, Marit and Bj{\o}rn Torger {Stokke} and Bj{\o}rn H. {Skallerud}}
}
