TY - JOUR
T1 - Biomechanical robustness of a new proximal epiphyseal hip replacement to patient variability and surgical uncertainties : A FE study
AU - Martelli, Saulo
AU - Taddei, Fulvia
AU - Schileo, Enrico
AU - Cristofolini, Luca
AU - Rushton, Neil
AU - Viceconti, Marco
PY - 2012/3
Y1 - 2012/3
N2 - The biomechanical behaviour of current hip epiphyseal replacements is notably sensitive to the typical variability of conditions following a standard surgery. The aim of the present study was to assess the biomechanical robustness to the variability of post-operative conditions of an innovative proximal epiphyseal replacement (PER) hip device featuring a short, curved and cemented stem. The risk of femoral neck fractures, prosthesis fractures and aseptic loosening were assessed through a validated finite element procedure following a systematic approach. Risk changes due to anatomical variations were assessed mimicking extreme conditions in terms of femoral size and level of osteoporosis. Failure risks associated with surgical uncertainties were assessed mimicking extreme conditions in terms of uncertainties on the prosthesis position/alignment, cement-bone interdigitation depth, and friction between the prosthesis and the hosting cavity. The femoral neck strength increased after implantation from 9% to 49% and was most sensitive to changes of the anatomo-physiological variables. The risk of stem fractures was low in all studied configurations. The risk of stem loosening was low and most sensitive to surgical uncertainties. In conclusion, the new device can be considered an effective alternative to current epiphyseal replacements. Care is recommended in a proper seating of the prosthesis in the femur.
AB - The biomechanical behaviour of current hip epiphyseal replacements is notably sensitive to the typical variability of conditions following a standard surgery. The aim of the present study was to assess the biomechanical robustness to the variability of post-operative conditions of an innovative proximal epiphyseal replacement (PER) hip device featuring a short, curved and cemented stem. The risk of femoral neck fractures, prosthesis fractures and aseptic loosening were assessed through a validated finite element procedure following a systematic approach. Risk changes due to anatomical variations were assessed mimicking extreme conditions in terms of femoral size and level of osteoporosis. Failure risks associated with surgical uncertainties were assessed mimicking extreme conditions in terms of uncertainties on the prosthesis position/alignment, cement-bone interdigitation depth, and friction between the prosthesis and the hosting cavity. The femoral neck strength increased after implantation from 9% to 49% and was most sensitive to changes of the anatomo-physiological variables. The risk of stem fractures was low in all studied configurations. The risk of stem loosening was low and most sensitive to surgical uncertainties. In conclusion, the new device can be considered an effective alternative to current epiphyseal replacements. Care is recommended in a proper seating of the prosthesis in the femur.
KW - Biomechanics
KW - Epiphyseal hip replacement robustness
KW - Failure risk sensitivity
KW - Femoral head resurfacing
KW - Finite element model
KW - Hip prosthesis
KW - Numerical pre-clinical validation
UR - http://www.scopus.com/inward/record.url?scp=84856977369&partnerID=8YFLogxK
U2 - 10.1016/j.medengphy.2011.07.006
DO - 10.1016/j.medengphy.2011.07.006
M3 - Article
VL - 34
SP - 161
EP - 171
JO - Medical Engineering and Physics
JF - Medical Engineering and Physics
SN - 1350-4533
IS - 2
ER -