Proximal Femoral Geometry And Hip Fracture Risk Assessment In An Elderly Chinese Population And Analysis Of Influential Factors

BackgroundHip fractures are the most serious complication of osteoporosis and the most debilitating fractures in the elderly population.Despite substantial advances in orthopedic treatment, these fractures are associated with a high morbidity and mortality. Hip fractures are categorized as intracapsular femur neck (FN) fractures and extracapsular intertrochanteric (IT)fractures. These two fractures are distinct entities and subject to different surgical treatment. Furthermore, the two fracture types differ in etiology, risk factors, and patient characteristics. Many studies on the predictors of proximal femoral fractures types have been reported. Various parameters specific to these fracture types have been suggested, such as mechanism of fall,functional mobility, bone mineral density (BMD), morphological features of femur, and others. In general, factors associated with an increased risk of femoral intertrochanteric fractures include short stature,low body weight, and lower BMD in the trochanter and whole neck. In contrast, factors associated with an increased risk of femoral neck fractures include longer femoral neck, greater neck-shaft angle, and lower BMD in the superior femoral neck than the inferior. The mechanical strength of an object is related to physical properties of the materials, geometry, and loading conditions. This rule is also applies to the proximal femoral bone.While low bone mineral density (BMD) has been used toestimate the risk of hip fractures, parameters of proximalfemoral geometry (PFG) are also associated with increased fracture risk Among these predictors, proximal femur geometry (PFG) parameters have also been proposed, as bone shape adjusts the transmission of the impact forces through the bone to determine the effective stress within the bone.Those correlations are used for diagnosis, treatment and prediction of fracture risk in osteoporosis cases. Hip axis length (HAL) and neck-shaft angle (NSA) have been shown to be increased in the osteoporotic hip fractures, in spite of some disagreement. Some authors have reported that longer The NL andgreater NSA could be associated with a higher risk of femoral neck fracture.While a number of studies have focused on hip morphometry in Caucasians, corresponding studies from the Asian population are limited. Thus, the purpose of this study was to describe the association between PFG and the risk of hip fractures based on measurements obtained from a Chinese Population.. Materials and methodsPatients the study included1332patients (176 patients with IT fractures,168 patients with FN fractures, and 991 control patients). The fracture groups were recruited from a consecutive series of patients with hip fractures treated between 2009.1.lto 2015.1.1 inthe authors’ institution(the Nanfang Hospital of Southern Medical University and the No2. Affiliated Hospital of Inner Mongoliar Medical University). Only fractures due to minor trauma were included, such as falls from a standing position or walking; fractures due to high-energy injuries were excluded from the study. Patients with malignancies, paralysis, major rheumatic diseases, chronic diseases (renal, hepatic, or pulmo-nary), or long-term treatment with drugs known to affect bone (>6 months for estrogen, anabolic steroids, calcitonin, or bisphosphonates, or>3 months for glucocorticoids or antiepileptic drugs) were also excluded from the design of the study. The control group was comprised of outpatients who had undergone a dual energy X-ray absorptiometry (DXA) scan and pelvic radiograph during a routine health evaluation and were matched in age and gender to the patients in the fracture groups. MeasurementsData on, PFG parameters, and demographics (diagnose,district,age,gender,left or right side, height, and body weight telephone number,address,et al.) were collected. Five experienced observers independently using the image acquisitionand transmission system (PACS), to selet femur DR standard anteroposterior pelvic or femur X-ray images. The data were obtained from radiographs from patients who have received X-ray scan during 2009.1.1to 2015.1.1.And Measure 7 morphological parameters of the proximal femur(including The femoral hip axis length[HAL],The femoral neck-shaft angle [NSA],The femoral neck length (NL), the femoral head the OFFSET (the OFFSET) The femoral neck diameter (ND), The femoral shaft diameter (SD). Statistical analysis of data was processed by SPSS 13.0 statistical software. Summarize the regulations, analyses the relationship between classification of fracture gender、age、laterality、district and femoral morphological parameters to analyseis the possible correlation between race, climate,latitude and the proximal femoral morphological parameters.The AP radiographic views of the pelvis were standardized for the position of the beam and the radiographic penetration. The patients were placed in the supine position with their hips extended and internally rotated 15°. The distance between the X-ray tube and the cassette was 100 cm. The central radiographic ray was aligned to be perpendicular to the cassette, and it was centered 5 cm superior to the symphysis pubis. The films with incorrect patient positioning (misalignment of the sacrum-pubic symphysis vertical axis≥1.5 cm) were excluded from the study. All of the radiographs were digitized by the picture archiving communication system (PACS) software, Southern Medical University) in the authors’ institution,and all the distances and angles were measured using the calipers and goniometer provided by the software. The software enables straight-line measurements with an accuracy of 0.01 mm and 0.01°. HAL was measured from the inner pelvic brim to the lateral side of the femur. Femoral head the OFFSET was the distance of the head center from the mid-shaft axis. The NSA was the angle formed by the mid-cervical axis and the mid-shaft axis. Femoral neck length (NL) was the distance from the shaft axis to the head center measured along the central axis of the femoral neck. Femoral neck diameter (ND) was measured in its narrowest section perpendicular to the hip axis. Femoral SD was taken 2 cm below the calcar after identifying the inferior margin Statistical analysisStatistical analysis was performed using SPSS 13.0 software.To compare the value of each parameter between the twofracture groups and the controls, descriptive statistics wereused to determine group means and sds for numerical data,and analysis was performed using analysis of variance,followed by Bonferroni’s correction for multiple comparisons. Statistical significance was defined as a p value<0.05.We first estimated the odds ratio (OR; the relative increase of the fracture risk for a variation of 1 sd) of each variable (HAL, NSA, NL, the OFFSET, ND, SD,HD) using logistic regression analysis in which the OR of each variable was corrected for demographical variables (age, gender, height, and body weight). ResultsThe details of measured variables are listed in Tables as follows. The demographic parameters were comparable among all three groups.Part One:China Normal Adults Proximal femoral morphological parameters measurement and analysis of influencing factorsThe results this study included 1002 cases, after the exclusion, The study included 991 patients (747 cases were male, female 254 cases, with an average age of 62.64± 18.53 years. Data in the study, the mean the OFFSET was 36.46±5.75mm, The ND was 30.87±3.96 mm, The mean NL was 45.45±5.66mm, the mean femoral the HD was 45.75±4.25mm, the mean NSA was 132.62±4.88, the mean SD wass 27.31± 3.81mm, the mean HAL of 104.99±13.97mm.Except the northern area NSA was significantly higher than the southern area (133.01 vs.127.55, P=0.000), others 6 proximal morphological parameters (HAL,NSA,HD,NL, the OFFSET,ND, SD), the northern district population parameters were significantly higher than the South zone parameters, and there was no significant difference (P=0.000). Adult male in neck diameter, neck diameter, the SD and HAL and other parameters were significantly higher than women, the difference was significant statistical significance (P<0.05), and in the OFFSET, NL and NSA there was no significant difference between the men and women (P>0.05). In addition to the left of the OFFSET is significantly larger than the right side, the remaining proximal femoral morphological parameters werer no significant difference (P>0.05) in the left and right side.Part Two The morphological parameters difference between proximal femoral neck fracture and intertrochanteric fracturesThe results The study included 400 cases (200 cases IT fracture patients, FN fractures 200 cases). After elimination finally included 176 cases of femoral neck fracture patients, mean age was 62.30±16.96 years; 89 cases were male, female 87 cases,86 cases in the south, the northern region 90 cases,80 cases of left side, right side of the 96 cases.165 cases of intertrochanteric fracture patients, mean age 67.45± 16.10 years, male 74 cases, female 91 cases,124 cases of the south, the northern region in 41 cases,32 cases of left side, right side of the 133 cases.The patients with FN fractures had a NL, HD, NSA and HAL significantly greater than the IT patients (P<0.05)Northern District patients had a femoral the OFFSET, NL and diameter significantly greater than patients in the South region, (P<0.05), and ND, HD, neck-shaft angle and HA1 of patient data in two areas there was no significant statistical difference (P>0.05).Male patients with ND, length of neck, the HD, the SD and HAL were significantly larger than females (P<0.05), while the OFFSET and NSA was not significantly different between the sex of the patient differences between different (P >0.05).Femoral neck fracture patients from around the eccentric side, there was no significant difference between the ND, ND, HD, neck-shaft angle, SD and HAL (P> 0.05)Presence in different regions of intertrochanteric proximal femoral morphological parameters of fracture patients are some differences, in particular, the southern region of the patient the OFFSET, the NL, and NSA was significantly smaller than the diameter of the Northern District of patients, a significant difference statistically significant (P<0.05), and ND, HD and HAL no significant difference in the patient two regions (P>0.05).Male patients with ND, HD, hip and SD shaft length were significantly larger than females (P<0.05), and the OFFSET, NSA and length were not significantly different between the sex of the patient differences between different (P>0.05).Intertrochanteric fracture patients from around the eccentric side, there was no significant difference between the ND, ND, HD, neck-shaft angle, SD and HAL (P> 0.05)Part Three The correlation between the proximal femur morphological parameters and femoral neck fracture riskThere was closely correlation between the femoral neck fractures risk and femoral parameters. The parameters include:the OFFSET (protective factors), HD (risk factors), ND (risk factors) and the NL (risk factors), while the NSA, SD and HAL had no significant correlation.with the risk of femoral neck fractures. Except the NSA in normal group was significantly higher than patients with femoral neck fracture (132.62° vs.130.72°, P= 0.000), others six parameters in femoral neck fracture patients were significantly higher than normal group (P= 0.000).There was closely correlation between the southern region femoral neck fractures risk and femoral parameters. The parameters include:the OFFSET (protective factors), HD (risk factors) and the NL (risk factors), and may be there was no significant correlation between the ND, the NSA, the SD and the HAL with femoral neck fracture risk.There was closely correlation between the northern region femoral neck fractures risk and femoral parameters. The parameters include:the ND (risk factors), the NL (risk factors), NSA (risk factors), the SD (protective factors) and the HAL (protective factors), while the OFFSET, the HD and the NL may not had significantly neck fractures risk correlation.the NL, HD and neck-shaft angle in Northern District femoral neck fracture group were significantly higher than the normal group (P<0.05), and the OFFSET, the NL, the HAL and the SD between the two groups was no significant difference (P >0.05).In men, the risk of femoral neck fracture were significantly associated with proximal femoral morphological parameters.The parameters include:the OFFSET (protective factors), HD (risk factors), ND (risk factors), NL (hazard factor), and SD (protective factors), while the NSA and HAL may be not associated with hip fracture risk.In men, except the NSA in femoral neck fracture group was significantly lower than the normal group, the remaining parameters such as the OFFSET, the ND, the NL, the HD, the SD and HAL were significantly higher than the control group (P= 0.000)In women,the proximal femoral morphological parameters were significantly associated with the risk of femoral neck fracture include:ND (risk factors), and may be there was no significant correlation between the other parameters and femoral FN fracture risk.In women,in addition to NSA in the normal group was significantly higher than the femoral neck fracture patients, the remainder of the femoral neck fracture group parameters include the OFFSET, ND, the NL, the HD, the SD and the HAL were significantly higher than the normal group (P<0.05).Part Four The correlation between the proximal femur morphological parameters and femoral intertrochanteric fracture riskThe risk of femoral IT fracture were significantly associated with proximal femoral morphological parameters.The parameters included:the OFFSET (protective factors), the HD (risk factors), the ND (risk factors), the NL (risk factors), the NSA (protective factors) and the SD (risk factors), and between the HAL and intertrochanteric fracture risk may be no significant correlation.In addition to the NSA, normal group was significantly higher than that in patients with intertrochanteric fractures, the remaining six parameters the OFFSET, ND, NL, the HD, the SD and HAL, intertrochanteric fracture group were significantly higher than the normal group, the difference was significant statistical significance (P = 0.000).In Southern region, the risk of femoral IT fracture were significantly associated with proximal femoral morphological parameters.The parameters included:the OFFSET (protective factors), HD (risk factors), NL (risk factors), NSA (protective factors) and SD (risk factors), and more than the ND and HAL may intertrochanteric fracture risk no significant correlation.In addition to the normal neck-shaft angle was significantly higher than intertrochanteric fracture patients (133.01 °vs.129.44°, P= 0.007), others six parameters, intertrochanteric fracture patients were significantly higher than normal group (P<0.05).In northern region, the risk of femoral IT fracture were significantly associated with proximal femoral morphological parameters.The parameters included:the HD (risk factors) and HAL (protective factors), and the OFFSET, ND, NL, NSA and SD may intertrochanteric fracture risk no significant correlation.proximal femoral morphological parameters between Northern District normal and intertrochanteric fractures were not significantly different.In men, the risk of femoral IT fracture were significantly associated with proximal femoral morphological parameters.The parameters include:the OFFSET (protective factors), HD (risk factors), NL (risk factors) and the NSA (protective factors), there was no significant correlation between the ND, the SD, the HA1 and intertrochanteric fracture risk.In men, except the NSA in normal group was significantly higher than patients with intertrochanteric fractures (P= 0.005), the remaining six parameters in inter-trochanteric fracture patients were significantly higher than normal group (P <0.05).In women, the risk of femoral IT fracture were significantly associated with proximal femoral morphological parameters.The parameters include the OFFSET (protective factors), the ND (risk factors), the NL (risk factors) and the NSA (protective factors), there was no significant correlation between the HD, the SD, the HA1 and intertrochanteric fracture risk.In women, except the NSA in normal group was significantly higher than patients with intertrochanteric fractures (P= 0.000), the remaining six parameters in intertrochanteric fracture patients were significantly higher than normal group (P <0.05).Conclusion1, The preliminary test to measure Chinese adults proximal femoral morphological parameter has certain characteristics;2, Region, gender and the left and right side influence the proximal femoral morphological parameters of Chinese adults3, China adult proximal femoral morphological parameters influenced by Region factors, followed by gender impact, while the left and right side have less Influence...