A Parametric Study: Influence of Geometry and Material Properties on the Response of the Femoral Head Through Biofluid

Abstract

Friction-induced stick-slip phenomenon has been reported in 1–20% of patients with ceramic-on-ceramic total hip replacement. The friction behavior of the bearing surfaces is ruled by the lubrication conditions, which may be from hydrodynamic lubrication to mixed or boundary lubrication. In the latter two situations, surface-to-surface mechanical contact may give rise to the friction-induced stick-slip phenomenon. Essentially, stick-slip occurs when the film lubrication is broken. Stick-slip is an undesired phenomenon and is understood to give rise to the squeaking phenomenon in the hip bearing surfaces. In this study, the influence of the relative densities of biofluid, size, mass, and femoral head material is investigated to study the system’s response and the approach of the femoral head towards the acetabulum shell (initial contact to pre-swing phase). Two configurations were developed, which included ball-on-plane and ballon socket configurations. Utilizing parametric studies, the role of these variables was studied. Higher velocity-derived energy may contribute to the vibration of the system via stick-slip. High approach velocity combined with high-density material may influence and lead to surface-surface articulation.