[Three-dimensional finite element analysis responsible to bone cement with customized prosthesis of proximal segmental femur].
OBJECTIVE
To create three-dimensional finite element models for the large defect of proximal femur and the customized prosthesis of proximal segmental defect femur, and to analyze the influence on the stress distribution of femur-cement after the intramedullary implantation of different stem length prostheses.


METHODS
Three-dimensional finite element models were established for the large defect of proximal femur and proximal femoral segmental prostheses with different stem-lengths (140 mm, 120 mm, 100 mm, 80 mm and 60 mm). The influence on stress distribution of femur-cement was analyzed for the different stem-length prostheses implanted.


RESULTS
The stress on bone cement gradually increased from proximal end to distal end, and reached its highest value near the tip of prostheses. The prostheses with stem lengths of 120 mm, 100 mm, 80 mm and 60 mm could bring the cement mantle stress to the value beyond the fatigue strength of cement. Only when the intramedullary stem-length of prosthesis was 140 mm, the stress on the cement mantle was under the fatigue strength of cement.


CONCLUSIONS
The intramedullary stem of the proximal femoral segmental prosthesis must have enough length to decrease the stress on the cement mantle in order to avoid the prosthesis loosening.
Liu
Yang
Y
Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China.
Tu
Chong-Qi
CQ
Li
Xiao-Biao
XB
Duan
Hong
H
Pei
Fu-Xing
FX
D000328:Adult; D001843:Bone Cements; D005221:Fatigue / Q000503:physiopathology; D005269:Femur / Q000033:anatomy & histology* / Q000502:physiology; D020342:Finite Element Analysis; D006801:Humans; D016268:Internal Fixators; D008297:Male; D008953:Models, Anatomic; D019736:Prostheses and Implants; D013314:Stress, Mechanical; D016474:Weight-Bearing
D001843:Bone Cements