Comparative Finite Element Analysis of the Debonding Process in Different Concepts of Cemented Hip Implants

Damage accumulation in the cement mantle and debonding of the bone–cement interface are basic events that contribute to the long-term failure of cemented hip reconstructions. In this work, a numerical study with these two process coupled is presented. Previously uniform bone–cement interface mechanical properties were only considered. In this work, a new approach assuming nonuniform and random bone–cement interface mechanical properties was applied to investigate its effect on cement degradation. This methodology was also applied to simulate and compare the degradation process of the cement and bone–cement interface in three different concepts of design: Exeter, Charnley, and ABG II stems. Nonuniform and random mechanical properties of the bone–cement interface implied a simulation closer to reality. The predicted results showed that the cement deterioration and bone–cement interface debonding is different for each implant depending on the stem geometry. Lower cement deterioration was obtained for the Charnley stem and lower bone–cement interface debonding was predicted for the Exeter stem, while the highest deterioration (cement and bone–cement interface) was produced for the ABG II stem.