Influence of Charnley hip neck-angle inclination on the stresses at stem/cement and bone/cement interfaces

The present work aims to elucidate the influence of neck-stem angle inclination on the principal normal and shear stress distributions and values along the interfaces of the stem/cement and bone/cement in a cemented Charnley curved back femoral component. The same stresses were also examined for the intact bone that was considered as a reference for the obtained results. The interface is considered the weakest link in the structure and its endurance limit to failure is much less than the limit of the adjacent materials. Interface loading is by far the influential aspect governing the induced interface stresses in femoral total hip replacement. Therefore, higher values and nonuniform distribution of stresses at the interface may lead to loosening and crack initiation and propagation that usually precede the stem fracture.