Association of osteoporotic fractures of femoral neck and femoral neck geometric parameters in native Chinese women.

BACKGROUND: Although it is generally believed that the femoral neck fracture is related to the femoral neck geometric parameters (FNGPs), the association between the risk of osteoporotic fracture of the femoral neck and FNGPs in native Chinese women is still unclear. METHODS: A total of 374 female patients (mean age 70.2 ± 9.32 years) with osteoporotic fracture of the femoral neck, and 374 non-fracture control groups were completely matched with the case group according to the age ratio of 1:1. Using DXA bone densitometer to measured eight FNGPs: the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compressive strength index (CSI) at the narrowest point of the femoral neck. RESULTS: Compared with the control group, the average values of OD (2.9%), ED (4.5%), and BR (26.1%) in the patient group significantly increased (p = 0.015 to < 0.001), while CSA (‒15.3%), CT (‒18.2%), SM (‒10.3%), CSMI (‒6.4%), and CSI (‒10.8%) significantly decreased (all p < 0.001). The prevalence of osteoporosis in the lumbar spine, femoral neck, and total hip was, respectively, 82%, 81%, and 65% in fracture patients. Cox proportional hazard model analysis showed that in the age adjusted model, the fracture hazard ratio (HR) of CSA, CT, BR, SM, and CSI significantly increased (HRs = 1.60‒8.33; 95% CI = 1.08‒16.6; all p < 0.001). In the model adjusted for age and femoral neck BMD, HRs of CT (HRs = 3.90‒8.03; 95% CI = 2.45‒15.1; all p < 0.001) and BR (HRs = 1.62‒2.60; 95% CI = 1.20‒5.44; all p < 0.001) were still significantly increased. CONCLUSION: These results suggest that the majority of osteoporotic fractures of the femoral neck of native Chinese women occur in patients with osteoporosis. CT thinning or BR increase of FNGPs may be independent predictors of fragility fracture of femoral neck in native Chinese women unrelated to BMD.

Comparison of femoral neck geometric parameters between Chinese and Japanese females. / ä¸­å›½å¥³æ€§ä¸Žæ—¥æœ¬å¥³æ€§è‚¡éª¨é¢ˆå‡ ä½•å‚æ•°çš„æ¯”è¾ƒ.

OBJECTIVES: Femoral neck fracture is the most serious osteoporotic fractures that is responsible for high medical costs and high mortality. Femoral neck geometric parameters (FNGPs) are important parameters that reflect the geometrical characteristics of femoral neck, and are closely related to the strength of femoral neck and the risk of fragility fracture.There are differences in the incidence of femoral neck fractures among races. However, whether there is difference in FNGPs among races is unknown.Therefore, this study aims to compare the differences in FNGPs between Chinese and Japanese females. METHODS: This study was a cross-sectional study, in which 3 859 healthy females aged 10-86 (45.7±17.1) years old were recruited from Changsha City of Hunan Province and surrounding areas. The weight and height were measured and recorded, and the body mass index (BMI) was calculated. A dual energy X-ray absorptiometry (DXA) bone densitometer was used to measure femoral neck projective bone area (BA) and bone mineral density (BMD). FNGPs were calculated using the BMD and BA, which included the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compression strength index (CSI). The data of FNGPs in Japanese females was collected from literature. These subjects were grouped by 10-year age. The mean and standard deviation of height, weight, BMI, femoral neck BMD, and FNGPs of each group were calculated. The model with the best goodness-of-fit was selected from various mathematical regression models to analyze the distribution trend and the best fitting curve of FNGPs with age. The differences in FNGPs between Chinese and Japanese females were analyzed by using age-corresponding mean fitting curve for paired t-test, and the relative change rates of FNGPs were compared. RESULTS: The mean values of FNGPs were significantly different among different years old healthy females (all P<0.01). The mean values of OD, CSA, CT, SM, and CSMI in femoral neck were high at 30 to 39 years old, and then they were gradually decreased with age. The CSI reached its peak at 20-29 years old, and it was decreased gradually after 30 years old. ED and BR were at a low level before 40 years old, they were gradually increased after 40 years old, and reached the maximum average value at 80-86 years old. The variations in FNGPs with age were fitted with the best goodness-of-fit by applying the cubic regression model and the determination coefficients of regression equations (R2: 0.062-0.404) were significant (all P<0.01). The distribution trend of FNGPs with age varied with the indices, among which CSA, CT, SM, CSMI and CSI were increased with age before 35 years old, and then they were decreased with age; BR was at a low level in the early stage, and then it was increased with age after about 40 years. There were significant differences in the fitting curves of FNGPs related to age between Chinese and Japanese females (all P<0.01). The fitting curves of OD, ED, BR and SM in Chinese females were significantly higher than those in Japanese females (all P<0.01), while those of CSA and CT in Chinese females were significantly lower than those in Japanese females (all P<0.01). Before the age of 50, the curves of CSMI and CSI of Chinese females were significantly higher than those of Japanese females (all P<0.01), while after the age of 60 the situation was reversed (all P<0.01). Except for SM and CSI, there were significant differences in the rate of OD, CSA, CT, ED, BR and CSMI with age (all P<0.01). By the age of 80 years old, the rates of change in OD, ED, and BR with the age in Chinese females were increased by 0.91%,3.94%, and 47.5%, respectively, while those in Japanese females were increased by 8.57%, 15.8% and 85.3%, respectively；the rates of change of CSA, CT, and CSMI with the age in Chinese females were declined 28.0%, 29.6%, and 25.2%, respectively, while those in Japanese females were declined 29.9%, 36.2%, and 10.9%, respectively. There were significant difference in the rates of change in FNGPs with the age between Chinese and Japanese females (all P<0.01). CONCLUSIONS: The study reveals the variation of FNGPs with age in Chinese, and confirms that there are racial differences in FNGPs between Chinese and Japanese females, which may be one of the important reasons for the difference in the incidence of femoral neck fracture between Chinese and Japanese females.

Comparison of femoral neck geometric parameters between Chinese and Japanese females / 中南大学学报(医学版)

OBJECTIVES@#Femoral neck fracture is the most serious osteoporotic fractures that is responsible for high medical costs and high mortality. Femoral neck geometric parameters (FNGPs) are important parameters that reflect the geometrical characteristics of femoral neck, and are closely related to the strength of femoral neck and the risk of fragility fracture.There are differences in the incidence of femoral neck fractures among races. However, whether there is difference in FNGPs among races is unknown.Therefore, this study aims to compare the differences in FNGPs between Chinese and Japanese females.@*METHODS@#This study was a cross-sectional study, in which 3 859 healthy females aged 10-86 (45.7±17.1) years old were recruited from Changsha City of Hunan Province and surrounding areas. The weight and height were measured and recorded, and the body mass index (BMI) was calculated. A dual energy X-ray absorptiometry (DXA) bone densitometer was used to measure femoral neck projective bone area (BA) and bone mineral density (BMD). FNGPs were calculated using the BMD and BA, which included the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compression strength index (CSI). The data of FNGPs in Japanese females was collected from literature. These subjects were grouped by 10-year age. The mean and standard deviation of height, weight, BMI, femoral neck BMD, and FNGPs of each group were calculated. The model with the best goodness-of-fit was selected from various mathematical regression models to analyze the distribution trend and the best fitting curve of FNGPs with age. The differences in FNGPs between Chinese and Japanese females were analyzed by using age-corresponding mean fitting curve for paired t-test, and the relative change rates of FNGPs were compared.@*RESULTS@#The mean values of FNGPs were significantly different among different years old healthy females (all P<0.01). The mean values of OD, CSA, CT, SM, and CSMI in femoral neck were high at 30 to 39 years old, and then they were gradually decreased with age. The CSI reached its peak at 20-29 years old, and it was decreased gradually after 30 years old. ED and BR were at a low level before 40 years old, they were gradually increased after 40 years old, and reached the maximum average value at 80-86 years old. The variations in FNGPs with age were fitted with the best goodness-of-fit by applying the cubic regression model and the determination coefficients of regression equations (R2: 0.062-0.404) were significant (all P<0.01). The distribution trend of FNGPs with age varied with the indices, among which CSA, CT, SM, CSMI and CSI were increased with age before 35 years old, and then they were decreased with age; BR was at a low level in the early stage, and then it was increased with age after about 40 years. There were significant differences in the fitting curves of FNGPs related to age between Chinese and Japanese females (all P<0.01). The fitting curves of OD, ED, BR and SM in Chinese females were significantly higher than those in Japanese females (all P<0.01), while those of CSA and CT in Chinese females were significantly lower than those in Japanese females (all P<0.01). Before the age of 50, the curves of CSMI and CSI of Chinese females were significantly higher than those of Japanese females (all P<0.01), while after the age of 60 the situation was reversed (all P<0.01). Except for SM and CSI, there were significant differences in the rate of OD, CSA, CT, ED, BR and CSMI with age (all P<0.01). By the age of 80 years old, the rates of change in OD, ED, and BR with the age in Chinese females were increased by 0.91%,3.94%, and 47.5%, respectively, while those in Japanese females were increased by 8.57%, 15.8% and 85.3%, respectively；the rates of change of CSA, CT, and CSMI with the age in Chinese females were declined 28.0%, 29.6%, and 25.2%, respectively, while those in Japanese females were declined 29.9%, 36.2%, and 10.9%, respectively. There were significant difference in the rates of change in FNGPs with the age between Chinese and Japanese females (all P<0.01).@*CONCLUSIONS@#The study reveals the variation of FNGPs with age in Chinese, and confirms that there are racial differences in FNGPs between Chinese and Japanese females, which may be one of the important reasons for the difference in the incidence of femoral neck fracture between Chinese and Japanese females.

Gender differences in a reference database of age-related femoral neck geometric parameters for Chinese population and their association with femoral neck fractures.

Femoral neck geometric parameters (FNGPs) are closely related to the strength of the femoral neck and the risk of fragility fractures. No reference database is available for FNGPs for Chinese population, and gender-related differences in FNGPs as well as their association with the risk of femoral neck fractures are unknown. This investigation aimed to set up reference databases for FNGPs, understand gender-related differences in FNGPs, and examine the association between FNGPs and the risk of osteoporotic fractures of the femoral neck. This study included 5268 females and 2156 males (aged 15-91years) from Chinese population. A total of 384 patients (282 females and 102 males) had sustained femoral neck fractures; 384 age- and sex-matched individuals without any fractures served as controls. Femoral neck DXA images were used to measure bone mineral density (BMD) and eight FNGPs. Our results showed that the age-related trends of FNGPs were fitted with the best goodness-of-fit by applying the cubic regression model. The trends shown by FNGPs were significantly different between male and female subjects, and the fitting curves were significantly higher in male subjects. After adjustments were made for age, height, weight, and body mass index, Cox regression analysis showed that changes in all FNGPs were related to increased hazard ratios (HRs) of femoral neck fractures. After further adjustment was made for BMD of the femoral neck, the HRs related to a cortical thickness (CT) decrease and buckling ratio (BR) increase in females went up by 3.35-folds (95% CI: 2.75-4.07) and 1.86-folds (95% CI: 1.33-2.60), respectively. In males, the HRs related to the decrease in CT and cross-sectional area (CSA) increased by 3.21-folds (95% CI: 2.32-4.45) and 1.88-folds (95% CI: 1.03-3.44), respectively. In conclusions, the reference databases of FNGPs established in this study will assist in the evaluation and prediction of femoral neck fracture risk in the clinic. The decrease in CT and increase in BR of the femoral neck were independent risk factors for osteoporotic fractures of the femoral neck in females from mainland China, while a decrease in CT and CSA were risk factors in male.