Finite element analysis of cementless femoral stems based on mid- and long-term radiological evaluation

BMC Musculoskeletal Disorders

Research Article

Yong-Ming Guo¹  Shingo Maeda²  Kanehiro Matsuyama²  Yasuhiro Ishidou²  Ichiro Kawamura²  Setsuro Komiya³  Hironori Kakoi⁴  Satoshi Nagano⁴  Takao Setoguchi⁵ 

[1] Department of Mechanical Engineering, Graduate School of Science and Engineering, Kagoshima University, Kagoshima, Japan;Department of Medical Joint Materials, Graduate School of Medical and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, 890-8520, Kagoshima, Japan;Department of Medical Joint Materials, Graduate School of Medical and Dental Science, Kagoshima University, 8-35-1 Sakuragaoka, 890-8520, Kagoshima, Japan;Department of Orthopaedic Surgery, Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan;The Near-Future Locomotor Organ Medicine Creation Course (Kusunoki Kai), Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan;Department of Orthopaedic Surgery, Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan;The Near-Future Locomotor Organ Medicine Creation Course (Kusunoki Kai), Graduate School of Medical and Dental Science, Kagoshima University, Kagoshima, Japan;

关键词: Finite element analysis (FEA);    Stress shielding;    Cementless stem;    Total hip arthroplasty (THA);   

DOI  :  10.1186/s12891-016-1260-z

 received in 2016-04-19, accepted in 2016-09-15,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundFemoral bone remodeling in response to stress shielding induces periprosthetic bone loss. Computerized finite element analysis (FEA) is employed to demonstrate differences in initial stress distribution. However, FEA is often performed without considering the precise sites at which the stem was fixed. We determined whether FEA reflects mid-term radiological examination exactly as predicted following long-term stress shielding.MethodsFemur–stem fixation sites were evaluated radiologically according to the location of spot welds in two anatomical cementless stem designs. Based on mid-term radiological results, four femur–stem bonding site conditions were defined as: (Condition A) no bonding; (Condition B) bonding within the 10 mm area proximal to the distal border of the porous area; (Condition C) bonding of the entire porous area; and (Condition D) bonding of the entire femoral stem, prior to conducting FEA analysis. Furthermore, we radiographically evaluated mid- and long-term stress shielding, and measured bone mineral density of the femur 10 years after total hip arthroplasty.ResultsSpot welds appeared frequently around the border between the porous and smooth areas. FEA showed that, based on mid-term radiological evaluation, von Mises stress was reduced in condition B in the area proximal to the femur–stem bonding sites for both stem designs compared with condition A (no bonding). Conversely, von Mises stress at all areas of the femur–stem bonding sites in conditions C and D was higher than that in condition A. With respect to stress shielding progression, there was no significant difference between the two types of stem designs. However, stress shielding progressed and was significantly higher in the presence of spot welds (p = 0.001). In both stem designs, bone mineral density in zone VII was significantly lower than that in the contralateral hips.ConclusionsThese results indicate that FEA based on mid-term radiological evaluation may be helpful to predict the influence of long-term stress shielding more precisely.

【 授权许可】

CC BY   
© The Author(s). 2016