The formation and function of the sclerosis rim in the femoral head: A biomechanical point of view.
Sclerosis rim surrounding the necrotic area is commonly found in necrotic femoral head, but the biomechanical function of sclerosis rim has received relatively little attention. Little is known about the formation and natural history of sclerosis rim. In the present work, we assume that the necrotic change may trigger bone remodeling process in the femoral head, which took place according to Huiskes' bone remodeling model incorporated with the FE simulations as described earlier. We then investigate the function of sclerosis rim as a mechanical supporter in delaying further collapse of the femoral head based on our sclerotic rim model. The main tasks of this study are: (1) simulation of the density distribution in the necrotic femoral head after bone remodeling; (2) calculation of maximal von Mises stress in the subchondral bone of the weight-bearing area of the femoral head over the necrotic area before and after bone remodeling. Results show that the sclerotic rim is, from the biomechanical point of view, an adaptive response to the decrease in elastic modulus of the femoral head, and that the sclerotic rim that acts as a compensatory structural reinforcement can usually significantly reduce the maximal stress in the subchondral bone when the lesion is small, but not when the lesion is large.
College of Mechanical and Electronic Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China. Electronic address: chenzhiping2008.09@163.com.
ZhiPing
Z
Chen
College of Mechanical and Electronic Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
Yong
Y
Xu
Institute of Medicine on Osteopathis, Fujian Academy of Integrative Medicine, Fuzhou 350108, PR China.
ZhenXi
Z
Qi
The Second Affiliated Hospital of Xiamen University, Fuzhou 350007, PR China.
JinShui
J
Zho
D001696:Biomechanical Phenomena; D055119:Elastic Modulus; D005270:Femur Head / Q000473:pathology*; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D055595:Mechanical Phenomena; D009336:Necrosis; D012598:Sclerosis
Bone remodeling; Finite element analysis; Osteonecrosis of the femoral head; Sclerosis rim