Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR
<p>Abstract</p> <p>Background</p> <p>Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This...
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doaj-0c693ef0ed71463b8dc2212be0e03ce92020-11-24T21:19:53ZengBMCJournal of Orthopaedic Surgery and Research1749-799X2011-05-01612010.1186/1749-799X-6-20Influence of prosthesis design and implantation technique on implant stresses after cementless revision THRDuda Georg NSpeirs AndrewKim Dong-YeongTaylor William RMehta ManavHeller Markus OPerka Carsten<p>Abstract</p> <p>Background</p> <p>Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This study investigates the influences of femoral anteversion and offset on stresses in the Wagner SL revision stem implant under varying extents of bone defect conditions.</p> <p>Methods</p> <p>Wagner SL revision stems with standard (34 mm) and increased offset (44 mm) were virtually implanted in a model femur with bone defects of variable extent (Paprosky I to IIIb). Variations in surgical technique were simulated by implanting the stems each at 4° or 14° of anteversion. Muscle and joint contact forces were applied to the reconstruction and implant stresses were determined using finite element analyses.</p> <p><b>Results</b></p> <p>Whilst increasing the implant's offset by 10 mm led to increased implant stresses (16.7% in peak tensile stresses), altering anteversion played a lesser role (5%). Generally, larger stresses were observed with reduced bone support: implant stresses increased by as much as 59% for a type IIIb defect. With increased offset, the maximum tensile stress was 225 MPa.</p> <p><b>Conclusion</b></p> <p>Although increased stresses were observed within the stem with larger offset and increased anteversion, these findings indicate that restoration of offset, key to restoring joint function, is unlikely to result in excessive implant stresses under routine activities if appropriate fixation can be achieved.</p> http://www.josr-online.com/content/6/1/20revision hip arthroplastyimplant stressesimplant designsurgical techniquephysiological loadingcomputational modelling |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Duda Georg N Speirs Andrew Kim Dong-Yeong Taylor William R Mehta Manav Heller Markus O Perka Carsten |
spellingShingle |
Duda Georg N Speirs Andrew Kim Dong-Yeong Taylor William R Mehta Manav Heller Markus O Perka Carsten Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR Journal of Orthopaedic Surgery and Research revision hip arthroplasty implant stresses implant design surgical technique physiological loading computational modelling |
author_facet |
Duda Georg N Speirs Andrew Kim Dong-Yeong Taylor William R Mehta Manav Heller Markus O Perka Carsten |
author_sort |
Duda Georg N |
title |
Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR |
title_short |
Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR |
title_full |
Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR |
title_fullStr |
Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR |
title_full_unstemmed |
Influence of prosthesis design and implantation technique on implant stresses after cementless revision THR |
title_sort |
influence of prosthesis design and implantation technique on implant stresses after cementless revision thr |
publisher |
BMC |
series |
Journal of Orthopaedic Surgery and Research |
issn |
1749-799X |
publishDate |
2011-05-01 |
description |
<p>Abstract</p> <p>Background</p> <p>Femoral offset influences the forces at the hip and the implant stresses after revision THR. For extended bone defects, these forces may cause considerable bending moments within the implant, possibly leading to implant failure. This study investigates the influences of femoral anteversion and offset on stresses in the Wagner SL revision stem implant under varying extents of bone defect conditions.</p> <p>Methods</p> <p>Wagner SL revision stems with standard (34 mm) and increased offset (44 mm) were virtually implanted in a model femur with bone defects of variable extent (Paprosky I to IIIb). Variations in surgical technique were simulated by implanting the stems each at 4° or 14° of anteversion. Muscle and joint contact forces were applied to the reconstruction and implant stresses were determined using finite element analyses.</p> <p><b>Results</b></p> <p>Whilst increasing the implant's offset by 10 mm led to increased implant stresses (16.7% in peak tensile stresses), altering anteversion played a lesser role (5%). Generally, larger stresses were observed with reduced bone support: implant stresses increased by as much as 59% for a type IIIb defect. With increased offset, the maximum tensile stress was 225 MPa.</p> <p><b>Conclusion</b></p> <p>Although increased stresses were observed within the stem with larger offset and increased anteversion, these findings indicate that restoration of offset, key to restoring joint function, is unlikely to result in excessive implant stresses under routine activities if appropriate fixation can be achieved.</p> |
topic |
revision hip arthroplasty implant stresses implant design surgical technique physiological loading computational modelling |
url |
http://www.josr-online.com/content/6/1/20 |
work_keys_str_mv |
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