Modelling PMMA porosity on the cement-stem interface of hip implants

Porosity at the cement-stem interface plays a major role in failure of total hip implants. Since porosity is directly proportional to loosening and lack of stability, reducing the number of pores will result in stronger fixations of total joint arthroplasties. Knowing the porosity at the cement-stem interface will be valuable as pores interlink and form cracks. Using Monte Carlo simulation to the data compiled from the literature, a model was developed to assess and predict porosity. The contributing factors of: type of bone cement used, stem temperature upon insertion, and the type of PMMA mixing method used during surgery were incorporated in the model. The model developed was able to predict porosity levels in the cemented hip replacements.