The modelling and mechanical consequences of fibrous-tissue formation around femoral hip prostheses

On the longer term, bone resorption around the prosthesis may occur, at least when acrylic cement is used for fixation, resulting in a soft fibrous tissue layer between cement and bone. The mechanical behavior of a fibrous-tissue interface connection will therefore be governed by the following effects: 1) reduced compliance; 2) material nonlinearity of the tissue itself; 3) loosening on tension; 4) slip in shear; 5) time dependency. In the present analysis, a (nonlinear) 2-D finite element method model (using quasi 3-D structural characteristics) of femoral hip replacement was used to study the consequences of the effects 1 through 4 on the load-transfer mechanism, the stress patterns and the relative motions occurring between implant and bone. [9 Refs; In English