Consideration of physical parameters to predict thermal necrosis in acrylic cement implants at the site of giant cell tumors of bone.

In the previous paper we had developed a general thermodynamic equation describing a polymethylmethacrylate implant at the site of giant cell tumors. In this paper we consider various characteristics of bone and methylmethacrylate crucial to the analysis such as thermal conductivity, specific heat, density, and heat generation. Also, an estimation of the temperature at which adjacent cells die is analyzed from literature. Finally, using the physical constants measured in laboratory situations a temperature profile is developed at various depths of bone that could facilitate predicting the zone of necrosis. These analyses show the maximum temperature attained in the acrylic cement-bone system depends primarily on the volume of the implant, the relative proportion of polymerization of the monomer, the temperature at which the monomer and polymer are mixed together, and the time lapse between the beginning of polymerization and implantation into the bone cavity. The temperature profile is shown to be relatively insensitive to the geometry of the system, greatly simplifying the analysis.