The effect of impact direction on the fracture load of osteoporotic proximal femurs.
Hip fractures among the elderly are a worldwide problem. The objective of this study was (1) to confirm whether or not differences in bone strength are reflected in the proximal femur finite element (FE) model constructed from CT images of healthy subjects and osteoporosis patients, and (2) to investigate the effect of loading angle direction on bone fractures. The results from comparison of bone strength between the fracture group, fragile group (osteoporosis patients with no fracture after falling), and healthy group showed that differences in bone strength were definitely reflected in this FE model. Furthermore, the relationship between the loading direction and fracture load value was significant in all groups in the age-adjusted general linear model, and the model made from the trochanteric fracture patients was more sensitive to loading direction than those from cervical neck fracture. No significant differences were observed in the age-corrected comparison of DXA Neck BMD, Wards BMD, and total BMD in these two groups. The difference in the trochanteric BMD showed a trend of low bone density in the trochanteric fracture group. There is thus a possibility that the bone density at this location is implicated in the fragility under certain loading directions.
Wakao
Norimitsu
N
Department of Orthopedic Surgery, Nagoya University, 65 Tsurumai, Showa-ku, Nagoya City, Aichi 466-8550, Japan. nwakao@med.nagoya-u.ac.jp
Harada
Atsushi
A
Matsui
Yasumoto
Y
Takemura
Marie
M
Shimokata
Hiroshi
H
Mizuno
Masashi
M
Ito
Masako
M
Matsuyama
Yukihiro
Y
Ishiguro
Naoki
N
D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001696:Biomechanical Phenomena; D015519:Bone Density; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020342:Finite Element Analysis; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011859:Radiography; D013314:Stress, Mechanical; D016474:Weight-Bearing