Finite Element Analyses Of Impacted Allografts ForTotal Hip Arthoplasty

Over 800,000 total hip replacement (THR) operations are performed each year in the UK. A third of these operations fail due to aseptic loosening of the prosthesis. The revision surgeries are carried out using the 'Impaction grafting technique' introduced in Exeter in 1987. This technique largely depends on the mechanical strength of the impacted bone graft into which the prosthesis is fixed. As the patient mobilises the bone graft must withstand forces of 2.5 to 3.5 times the body weight during normal walking. In this paper we consider the effects of these forces on the bone graft-prosthesis system. The stresses and deformations in different regions of the Femur and bone graft under these forces will be analysed. A parameteric study on the effects of the properties of the Femur, bone graft and the PMMA cement used in the revision THR surgeries is presented.