Proximal femur geometry assessed by hip structural analysis in hip fracture in women

Hip Axis Length and Femoral Neck-Shaft Angle as Risk Factors for Proximal Femur Fractures in Octogenarians to Centenarians

(1) Background: The prevention of proximal femoral fractures among people of very advanced age is relevant as they are common and increasing in number. The aim of this study was to determine if the hip axis length (HAL) and the neck-shaft angle (caput-collum-diaphyseal CCD) are risk factors for those fractures among people aged 80 years and over. Consequently, it was additionally analysed if these parameters are associated with a certain fracture type. (2) Methods: Anteroposterior radiographs of the pelvis were collected to form three groups (femoral neck fractures (FNFx), trochanteric fractures (TFx) and non-fractured femora (NFx)). Two independent blinded observers separately conducted each measurement of the HAL and CCD. Statistical analysis was performed to determine the association between the measured parameters and type of fracture. (3) Results: One hundred and fifty patients (50 per group) were examined, of which the mean age was 92.7 ± 3.5 (range 81-104) years. Both the HAL and CCD of the FNFx group were significantly larger than in the TFx group (p = 0.013, 0.003). The CCD was higher in the FNFx than that of the NFx group (p = 0.001). No further significant differences of HAL and CCD were observed between the groups. (4) Conclusions: For people aged 80 years and over, an increased HAL represented no risk factor for proximal femur fractures, and a large HAL was associated with an increased occurrence of FNFx instead of TFx. A large CCD was associated with an increased risk of suffering a femoral neck fracture, showing evidence of the CCD being a risk factor for the extremely old population.

Is there a femoral morphology at risk of a cervical or pertrochanteric fracture? Description and validation of the "Neck shaft ratio" and the "Intertrochanteric distal ratio" after analyzing a continuous cohort of 126 bilateral fractures of the proximal femur

BACKGROUND

Proximal femur fractures constitute a public health concern given their high frequency and the aging population. The frequency of a contralateral fracture occurring can reach up to 15% of cases. Certain historical or demographic factors constitute risk factors for refracture, but the type of fracture, either of the femoral neck (FN) or pertrochanteric (PT), cannot be predicted. The objectives of this retrospective study were: firstly, to analyze several anatomical markers in order to determine whether they predispose to a certain type of fracture in the event of contralateral refracture, and secondly, to determine the predictive power of these possible radiological markers for the type of contralateral fracture.

HYPOTHESIS

The hypothesis was that the "Neck shaft ratio" (NSR) and the "Intertrochanteric distal ratio" (ITDR) made it possible to determine a proximal femoral morphology at risk of FN and/or PT fracture in the event of a second fracture.

MATERIAL AND METHODS

This continuous retrospective single-center series from January 2011 to December 2019 of patients who presented with bilateral fractures of the proximal femurs was analyzed. Radiographs, taken after the first fracture, of the contralateral femur were studied. Morphological measurements previously described in the literature were carried out as well as the NSR (ratio of the medial cortical thicknesses of the femoral neck at its narrowest and basicervical level) and the ITDR (ratio of the medial diaphyseal cortical thicknesses at 5mm and 20mm from the distal portion of the lesser trochanter). One hundred and twenty-six patients were included: 46/126 (36.5%) had bilateral FN, 50/126 (39.7%) bilateral PT and 30/126 (23.8%) one of each.

RESULTS

Only NSR and ITDR were significant predictive measures for FN or PT fracture type [0.54±0.11 vs. 0.81±0.16 (p<0.0001) and 0. 85±0.1 vs. 0.68±0.1 (p<0.0001), respectively]. These two ratios had an excellent predictive value for the type of fracture occurring on the contralateral side [NSR: AUC ROC = 0.91 (95% CI; 0.86-0.96); ITDR: AUC ROC = 0.81 (95% CI; %, 0.74-0.89)]. The NSR had excellent intra- and inter-observer reproducibility with an interclass correlation coefficient of 0.93 [95% CI: 0.86-0.97] and 0.91 [95% CI: 0.82-0.96] respectively, the same also applied for the ITDR with interclass correlation coefficient values of 0.93 [95% CI: 0.87-0.97] and 0.86 [95% CI: 0.73-0.93] respectively.

DISCUSSION

The NSR and ITDR ratios offer a simple and reproducible means to predict a morphological predisposition to a certain fracture type, respectively an FN and PT on the side contralateral to an initial osteoporotic proximal femur fracture. A prospective cohort study would be useful in defining a possible prognostic nature on the occurrence and/or time until refracture.

LEVEL OF EVIDENCE

III; retrospective control case.

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.

A machine learning approach to identify important variables for distinguishing between fallers and non-fallers in older women

Falls are a significant ongoing public health concern for older adults. At present, few studies have concurrently explored the influence of multiple measures when seeking to determine which variables are most predictive of fall risks. As such, this cross-sectional study aimed to identify those functional variables (i.e. balance, gait and clinical measures) and physical characteristics (i.e. strength and body composition) that could best distinguish between older female fallers and non-fallers, using a machine learning approach. Overall, 60 community-dwelling older women (≥65 years), retrospectively classified as fallers (n = 21) or non-fallers (n = 39), attended three data collection sessions. Data (281 variables) collected from tests in five separate domains (balance, gait, clinical measures, strength and body composition) were analysed using random forest (RF) and leave-one-variable-out partial least squares correlation analysis (LOVO PLSCA) to assess variable importance. The strongest discriminators from each domain were then aggregated into a multi-domain dataset, and RF, LOVO PLSCA, and logistic regression models were constructed to identify the important variables in distinguishing between fallers and non-fallers. These models were used to classify participants as either fallers or non-fallers, with their performance evaluated using receiver operating characteristic (ROC) analysis. The study found that it is possible to classify fallers and non-fallers with a high degree of accuracy (e.g. logistic regression: sensitivity = 90%; specificity = 87%; AUC = 0.92; leave-one-out cross-validation accuracy = 63%) using a combination of 18 variables from four domains, with the gait and strength domains being particularly informative for screening programmes aimed at assessing falls risk.

Higher BMI and lower femoral neck strength in males with type 2 diabetes mellitus and normal bone mineral density

BACKGROUND

Type 2 diabetes mellitus (T2DM) and osteoporosis are two age-associated diseases. Body mass index (BMI) is positively associated with osteoporosis or osteopenia in T2DM population. Bone mineral density does not necessarily reflect the alterations in bone microarchitecture. Our aims were to investigate the relationship between BMI and femoral neck strength in males with T2DM and normal range of bone mineral density (BMD).

METHODS

This study enrolled 115 males (median age 53.3 years) with T2DM and normal BMD. Femoral neck strength indexes, including compression strength index (CSI), bending strength index (BSI), impact strength index (ISI), were calculated by parameters generated from Dual-energy X-ray absorptiometry software. Pearson correlation analysis was performed to evaluate the relationships between BMI and femoral neck strength variables.

RESULTS

Compared with T2DM-normal weight group, T2DM-overweight group and T2DM-obesity group had a higher femur neck and total femur BMDs. Cross sectional moment of inertia (CSMI), cross sectional area (CSA), section modulus (SM) were significantly higher (all p<0.05), and buckling ratio (BR) (6.35±2.08 vs 7.18±1.71) was lower in T2DM-obesity group than in T2DM-normal weight group. Compared with T2DM-normal weight group, CSI (all p<0.001), BSI (all p<0.001), ISI (all p<0.001) were significantly reduced in T2DM-obesity and T2DM-overweight groups. Pearson correlation analysis indicated that BMI was negatively correlated with CSI (r= - 0.457, p<0.001), BSI(r = -0.397, p<0.001), ISI (r = - 0.414, p<0.001).

CONCLUSIONS

Higher BMI is associated with lower femoral neck strength in males with T2DM and normal BMD. It implies that femoral neck fracture risk increases in obese and diabetic males, despite their high bone density.

Bone fragility: conceptual framework, therapeutic implications, and COVID-19-related issues

Bone fragility is the susceptibility to fracture even for common loads because of structural, architectural, or material alterations of bone tissue that result in poor bone strength. In osteoporosis, quantitative and qualitative changes in density, geometry, and micro-architecture modify the internal stress state predisposing to fragility fractures. Bone fragility substantially depends on the structural behavior related to the size and shape of the bone characterized by different responses in the load-deformation curve and on the material behavior that reflects the intrinsic material properties of the bone itself, such as yield and fatigue. From a clinical perspective, the measurement of bone density by DXA remains the gold standard for defining the risk of fragility fracture in all population groups. However, non-quantitative parameters, such as macro-architecture, geometry, tissue material properties, and microcracks accumulation can modify the bone's mechanical strength. This review provides an overview of the role of different contributors to bone fragility and how these factors might be influenced by the use of anti-osteoporotic drugs and by the COVID-19 pandemic.

Retrospective Analysis of Factors Associated with Fracture in 714 Patients with Polymyalgia Rheumatica

Introduction

Polymyalgia rheumatica (PMR) is a disease of the elderly, associated with increased fracture risk due to glucocorticosteroid (GC) treatment with the additional possible influence of chronic inflammation. Risk factors for fracture in PMR have not been extensively studied. Hip structure analysis (HSA) is a way to measure bone morphology in the hip using dual X-ray absorptiometry (DEXA). It has been used as a predictor of fracture in epidemiological settings. HSA has not been studied in PMR before.

Objectives

The object of this retrospective study was to determine if fracture risk in PMR was associated with densitometry data and to determine the influence, if any, of HSA on that association.

Methods

714 patients with PMR referred for a bone density estimate at a district general hospital from June 2004 to October 2010 were studied. Demographic data, GC use, alcohol consumption, smoking status, secondary osteoporosis, and fracture history were recorded. Bone mineral density (BMD), Z score, T score, body composition data, and HSA measurements were collected. These were geometric measurements taken from 2-dimensional DEXA images of the hip. Fracture was modelled as an outcome variable using logistic regression models, adjusted for age and sex. And the fit of the model was assessed by comparing the area under the curve (AUC).

Results

714 patients were studied, 532 (75%) were female, and mean age was 70.5 with SD of 8.8. 703 (98%) had been treated with GCs. Lumbar and femoral BMD models were significantly associated with fracture. Right femur OR 0.062 (0.014-0.285), left femur OR 0.098 (0.023-0.412), right femoral neck 0.078 (0.014-0.43), left femoral neck 0.104 (0.022-0.492), L1 0.192 (0.066-0.56), L2 OR 0.138 (0.053-0.358), L3 0.192 (0.079-0.463), and L4 0.243 (0.108-0.544). Cross-sectional area was the only HSA parameter that was associated with fracture OR 0.988 (0.980–0.997).

Conclusion

L2 association models were strongest. Prospective studies are needed to elucidate whether these factors predict future fracture. GC data were binary, not reflecting dose and duration.

Comparison of hip structure analysis and grip strength between femoral neck and basicervical fractures

Background

The purpose of this study was to analyze differences in geometrical properties of the proximal femur and predict the occurrence of basicervical fractures through a comparative study of femoral neck and basicervical fractures in patients undergoing hip structural analysis (HSA).

Methods

All patients with hip fractures who were at least 65 years old and admitted to our hospital between March 2017 and December 2019 were eligible for this study. During the study period, 149 femur neck fractures (FNF) and basicervical fractures (intertrochanteric fractures of A31.2) were included in this study. Fifty-nine patients were included in the final analysis. Factors considered to be important confounders affecting the occurrence of basicervical hip fractures were chosen for propensity-score analysis. A logistic model with basicervical hip fracture as the outcome and age, sex, weight, spinal T-score, hip T-score, and vitamin D levels as confounders was used to estimate the propensity score.

Results

The cross-sectional moment of inertia (CSMI) of the intertrochanter was significantly lower in patients with basicervical hip fracture (HF) than in patients with FNF (p = 0.045). However, there was no significant differences in any other HSA variable between the two groups. Receiver operating characteristic (ROC) analysis showed that cutoff point for HSA was 100 for hip axis length (HAL) (AUC = 0.659, p < 0.001) and 5.712 for CSMI of the intertrochanter (AUC = 0.676, p < 0.001). ROC analysis showed that cutoff points of HAL, CSMI of intertrochanter, and handgrip strength were 104.8, 8.75, and 16.9, respectively (AUC = 0.726, p < 0.001).

Conclusions

Proximal femoral geometric analysis using HSA is a useful method for predicting the type of hip fracture. Additionally, a lower CSMI, a shorter HAL, and a lower grip strength are major predictors of basicervical fractures.

Elevated 1-Year Mortality Rate in Males Sustaining Low-Energy Proximal Femur Fractures and Subgroup Analysis Utilizing Age-Adjusted Charlson Comorbidity Index

INTRODUCTION

Low-energy proximal femur fractures are common in the aging population and the ability to identify patients at increased mortality risk provides surgeons information to improve informed decision-making with patients and families. We evaluated for gender differences in 1-year mortality after sustaining low-energy proximal femur fractures with subgroup analysis to identify the impact of fracture location, age, and comorbidities on mortality.

MATERIALS AND METHODS

Patients ≥40 years of age sustaining a low-energy proximal femur fracture identified at our institution between January 1, 2014, and December 31, 2017. International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes were used to identify comorbidities for calculation of the age-adjusted Charlson comorbidity index (ACCI). The county clerk database was searched to identify mortality within 1 year of injury. One-year mortality rates were calculated and multiple comparisons were made between genders controlling for age, fracture location, and/or ACCI.

RESULTS

Women presented with low-energy proximal femur fractures at a rate of almost 3:1 to men at our institution (P = .001). Men demonstrated a significantly increased ACCI at presentation (5.35 ± 2.55 vs 4.86 ± 1.77, P = .03). Men had an increased 1-year mortality rate for all (31.3% vs 21.5%, P = .004) and intertrochanteric (IT) fractures (36.2% vs 22.9%, P = .008). Controlling for ACCI, gender, and fracture location, men demonstrated increased mortality rate with IT fractures (P = .002) and trended toward but did not reach significance with femoral neck fractures (P = .07).

DISCUSSION

Men presenting with low-energy femur fractures are at an increased mortality risk compared to women. On average, men present with an overall worse health status as identified by ACCI, which could predispose these patients not only to fractures themselves but also impair their ability to recover from injury.

CONCLUSION

Men are at an increased 1-year mortality risk after sustaining proximal femur fractures.

Differences in Bone Mineral Density and Hip Geometry in Trochanteric and Cervical Hip Fractures in Elderly Chinese Patients

OBJECTIVE

To assess the differences in bone mineral density (BMD) and hip geometry in trochanteric and cervical hip fractures in elderly Chinese patients.

METHODS

A consecutive series of 196 hip fracture patients aged over 50 years was recruited from November 2013 to October 2015, including 109 cases of cervical fractures (36 males and 73 females) and 87 cases of trochanteric fractures (34 males and 53 females). All patients were evaluated through dual-energy X-ray absorptiometry, and baseline characteristics, BMD and structural parameters were collected and reviewed.

RESULTS

There were statistically significant differences in age, height, and body mass index between patients with each type of fracture, and patients with trochanteric fractures were older than those with cervical fractures, especially in women. The BMD in trochanteric fractures was markedly lower than in cervical fractures in all five sites of the hip by an approximate reduction of 10%, in both men and women. The cross-sectional area, cross-sectional moment of inertia, and the cortical thickness in the cervical fracture group were significantly higher than in the trochanteric fracture group. However, the buckling ratio of both the femoral neck and trochanteric region were significantly lower in the cervical fracture group. Age (/10 years), cross-sectional moment of inertia in femoral neck and buckling ratio in trochanteric region were significant risk factors for trochanteric fractures compared with cervical fractures.

CONCLUSIONS

Compared with cervical hip fractures, patients with trochanteric fractures were older, had a lower BMD, and had less bone mechanical strength, especially in female patients. Age, femoral neck cross-sectional moment of inertia (FNCSMI), and trochanteric region buckling ratio (ITBR) were stronger risk factors for trochanteric hip fractures than for cervical fractures.

Comparative Study of Femur Bone Having Different Boundary Conditions and Bone Structure Using Finite Element Method

Background:

Femur bone is an important part in human which basically gives stability and support to carry out all day to day activities. It carries loads from upper body to lower abdomen.

Objective:

In this work, the femur having composite structure with cortical, cancellous and bone marrow cavity is bisected from condyle region with respect to 25%, 50% and 75% of its height. There is considerable difference in the region chosen for fixing all degrees of freedom in the analysis of femur.

Methods:

The CT scans are taken, and 3D model is developed using MIMICS. The developed model is used for static structural analysis by varying the load from 500N to 3000N.

Results:

The findings for 25% bisected femur model report difference in directional deformation less than 5% for loads 2000N and less. In the study comparing fully solid bone and the composite bone, the total deformation obtained for a complete solid bone was 3.5 mm which was 18.7% less than that determined for the composite bone.

Conclusion:

The standardization for fixing the bone is developed. And it is required to fix the distal end always with considering full femur bone.

Proximal Femoral Geometry as Fracture Risk Factor in Female Patients with Osteoporotic Hip Fracture

Background

Proximal femoral geometry may be a risk factor of osteoporotic hip fractures. However, there existed great differences among studies depending on race, sex and age of subjects. The purpose of the present study is to analyze proximal femoral geometry and bone mineral density (BMD) in the osteoporotic hip fracture patients. Furthermore, we investigated proximal femoral geometric parameters affecting fractures, and whether the geometric parameters could be an independent risk factor of fractures regardless of BMD.

Methods

This study was conducted on 197 women aged 65 years or more who were hospitalized with osteoporotic hip fracture (femur neck fractures ; 84, intertrochanteric fractures; 113). Control group included 551 women who visited to check osteoporosis. Femur BMD and proximal femoral geometry for all subjects were measured using dual energy X-ray absorptiometry (DXA), and compared between the control and fracture groups. Besides, proximal femoral geometric parameters associated with fractures were statistically analyzed.

Results

There were statistically significant differences in the age and weight, cross-sectional area (CSA)/length/width of the femoral neck and BMD of the proximal femur between fracture group and control group. BMD of the proximal femur in the control group was higher than in the fracture group. For the femoral neck fractures group, the odds ratio (OR) for fractures decrease in the CSA and neck length (NL) of the femur increased by 1.97 times and 1.73 times respectively, regardless of BMD. The OR for fractures increase in the femoral neck width increased by 1.53 times. In the intertrochanteric fracture group, the OR for fractures increase in the femoral neck width increased by 1.45 times regardless of BMD.

Conclusions

We found that an increase of the femoral neck width could be a proximal femoral geometric parameter which plays important roles as a risk factor for fracture independently of BMD.