The impact of bone microstructure on the field distribution of electrostimulative implants

Since the 1980s several methods of electrostimulative techniques have been developed to accelerate bone regeneration during orthopedic treatment. These techniques have proven to provide increased bone formation while curing fractures and bone diseases. The electric parameters, however, are mostly results of empiric research regarding the bone tissue as homogeneous material. Especially cancellous bone, which is the objective of a new electrostimulative total hip revision system, has a porous, inhomogeneous microstructure. The present work investigates numerically the electric field distribution within this tissue using microscopic computer tomography scans of small bone samples. The 3-dimensional X-ray absorption values of these scans are correlated with conductivity values from literature applying different correlation approaches. Compared to electric fields within a homogeneous material strong elevations can be observed within the structures which include most of the bone forming cells.