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The increased limb bone density documented previously for aquatic tetrapods has been proposed to be an adaptation to overcome buoyancy during swimming and diving. It can be achieved by increasing the amount of bone deposition or by reducing the amount of bone resorption, leading to cortical thickening, loss of medullary cavity, and compaction of trabecular bone. The present study examined the effects of locomotor habit, body size, and phylogeny on the densitometric, cross-sectional, and biomechanical traits of femoral diaphysis and neck in terrestrial, semiaquatic, and aquatic carnivores, and in terrestrial and semiaquatic rodents (12 species) by using peripheral quantitative computed tomography, three-point bending, and femoral neck loading tests. Groupwise differences were analyzed with the univariate generalized linear model and the multivariate linear discriminant analysis supplemented with hierarchical clustering. While none of the individual features could separate the lifestyles or species adequately, the combinations of multiple features produced very good or excellent classifications and clusterings. In the phocid seals, the aquatic niche allowed for lower femoral bone mineral densities than expected based on the body mass alone. The semiaquatic mammals mostly had high bone mineral densities compared to the terrestrial species, which could be considered an adaptation to overcome buoyancy during swimming and shallow diving. Generally, it seems that different osteological properties at the levels of mineral density and biomechanics could be compatible with the adaptation to aquatic, semiaquatic, or terrestrial niches., (© 2024. The Author(s).)

The femoral neck is the most vulnerable site for fractures within the hip joint. Due to its complex three-dimensional structure and special blood supply mechanism, the treatment of femoral neck fractures is difficult and the healing probability is low. Using computers to accurately and automatically locate the femoral neck axis can detect the density of femoral neck, the neck-shaft angle and the anteversion angle, which effectively assists in the prevention and treatment of femoral neck fractures. Additionally, the traditional femoral neck axis positioning schemes have limitations in accuracy, automation and assistance to bone density measurement. Therefore, this paper proposes a new fully automatic femoral neck axis positioning method. First, the coronal plane's three-dimensional reconstruction highlights the details of the target bone, and then designs a coarse localization module based on multi-scale template matching to obtain the rough range of the femoral neck axis. Then, a detailed localization module based on the femoral neck virtual slices is used to obtain the contour centers and accurately locates the three-dimensional femoral neck axis. This method has been validated in comparison with the manual measurement method. Experimental results revealed that the extracted femoral neck axis in this study can achieve automation, ensure accuracy, and avoid subjective effects effectively and has the potential value to be applied in the prevention and treatment of femoral neck fractures., (© 2024. International Federation for Medical and Biological Engineering.)

Objective: To evaluate the relationship between bone mineral density (BMD) by measuring the prepatellar fat thickness with knee radiography and to gain a measurement method that has not been done before in the literature., Study Design: Cross-sectional descriptive study. Place and Duration of the Study: Department of Physical Medicine and Rehabilitation, Training and Research Hospital, Sanliurfa, Turkiye, between January and June 2020., Methodology: Patients' age, body mass index (BMI) data, prepatellar fat thickness (mm), L1-L4 total, bone mineral density femoral neck, femur trochanter major, and femur total T scores were recorded. The relationships between these three groups (normal, osteopenia, osteoporosis) and between prepatellar fat tissue measurement were evaluated. One-way analysis of variance (ANOVA) and Post Hoc Tukey tests were used in the analysis., Results:  A statistically significant difference was found in terms of trochanter major T score measurements (X2 = 20.435; p <0.001) and BMI (X2 = 66.535; p <0.001) measurements of prepatellar fat thickness measurement. A statistically significant difference was found between the three groups in terms of prepatellar fat thickness measurement, L1-4 T-score, femoral neck, and femur total values (p <0.001)., Conclusion:  Prepatellar fat thickness in postmenopausal Turkish women was positively correlated with BMD; BMD increases as the prepatellar fat thickness increases. This explains that perapatellar fat thickness creates a mechanical load on the bones and causes an increase in BMD., Key Words: Osteoporosis, Fat thickness, Bone mineral density.

Most orthopaedics implants were designed and manufactured based on data from the Western population whose skeletal dimensions are different from the Bengali Bangladeshi population. This study aims to determine the value of the femoral neck-shaft angle of the adult Bengali Bangladeshi population for adequate planning, preparation and pre-operative selection of orthopaedic implants for surgeries involving the femoral neck and stocking of orthopaedic implants. This was a cross-sectional analytical study which involved measuring the femoral neck-shaft angle (NSA) from the pelvic radiographs anterior-posterior view of adult patients reported "normal study" by the registered radiologist. This study was carried out in the Department of Anatomy, Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh from March 2019 to February 2020. A total of 200 femoral neck-shaft angles were analyzed from 100 patients' radiographs comprising 50 males and 50 females. The average NSA of adult Bengali Bangladeshi is 128.74°±5.83° with a mean value of 128.68°±6.20° for the right and 128.81°±5.66° for the left. The mean value of NSA is 129.64°±5.90° and 127.85°±5.64° in adult males and females respectively. The femoral neck-shaft angle in adult Bengali Bangladeshi males was significantly higher than the females.

As one of the leading causes of elderly patients' hospitalisation, proximal femur fractures (PFFs) will present an increasing socioeconomic problem in the near future. This is a result of the demographic change that is expressed by the increasing proportion of elderly people in society. Peri-operative management must be handled attentively to avoid complications and decrease mortality rates. To deal with the exceptional needs of the elderly, the development of orthogeriatric centres to support orthogeriatric co-management is mandatory. Adequate pain medication, balanced fluid management, delirium prevention and the operative treatment choice based on comorbidities, individual demands and biological rather than chronological age, all deserve particular attention to improve patients' outcomes. The operative management of intertrochanteric and subtrochanteric fractures favours intramedullary nailing. For femoral neck fractures, the Garden classification is used to differentiate between non-displaced and displaced fractures. Osteosynthesis is suitable for biologically young patients with non-dislocated fractures, whereas total hip arthroplasty and hemiarthroplasty are the main options for biologically old patients and displaced fractures. In bedridden patients, osteosynthesis might be an option to establish transferability from bed to chair and the restroom. Postoperatively, the patients benefit from early mobilisation and early geriatric care. During the COVID-19 pandemic, prolonged time until surgery and thus an increased rate of complications took a toll on frail patients with PFFs. This review aims to offer surgical guidelines for the treatment of PFFs in the elderly with a focus on pitfalls and challenges particularly relevant to frail patients., (© 2021. The Author(s).)

Extinct sloths represent a wide range of morphological, locomotor, and body size variation. Researchers have examined femoral neck angle in two dimensions to hypothesize locomotor behaviors in this group; however, this measure does not account for femoral neck anteversion. Here, we present a new method for quantifying femoral neck anteversion angle, in addition to femoral neck angle, to capture the 3D position of the femoral head/neck. Femora of extant (n = 21; Bradypus and Choloepus) and extinct (n = 49; Acratocnus, Megalocnus, Neocnus, and Parocnus) sloths were surface scanned and their surface models used to calculate three angles of femoral neck anteversion and femoral neck angle. Femoral neck anteversion was calculated as the angle between the femoral neck axis and the geometric axis of the femoral condyles (GA), the 35% cross section axis, and a trochanter axis. Femoral neck angle was calculated as the angle between the femoral neck and shaft axes. Genera were compared using ANOVAs with post hoc multiple comparisons for each angle. Femoral neck angle and femoral neck anteversion relative to the cross section were also analyzed. Significant differences among genera exist for all angles, (p < .001) but not all angles separate all genera. Femoral neck and anteversion angles typically yield different results, demonstrating the utility of analyzing both angles. The GA and cross section angles are highly correlated in sloths, with the exception of comparisons among Megalocnus, Parocnus, and Neocnus, suggesting morphological variation in the distal femur. While this method was applied to sloths, it has broad applicability to mammalian groups., (© 2020 American Association for Anatomy.)

Objectives: To investigate the cross-section shape of the femoral neck isthmus (FNI) in three-dimensional reconstruction model of the femoral neck., Methods: From December 2009 to December 2012, computed tomography (CT) data of bilateral hip joint from 200 consecutive patients (137 males and 63 females, 69.41 ± 9.21 years old, ranged from 50-85 years old) who underwent surgical treatments for proximal femoral fracture were retrospectively reviewed. The 3D model of the proximal femur was reconstructed, and the "inertia axis" method, which was applied to measure the long and short axes of the cross-section of the FNI, was established. The cross-sectional area and perimeter were calculated by a formula using the length of the long and short axes and then compared with the actual measured values by the software. Correlation between the descriptive parameters of the FNI cross-section (area, perimeter, and eccentricity) and patients' demographics (age, height, and weight) was analyzed. Stepwise linear regression analysis was used to determine the main relevant factors., Results: The ICC results showed excellent data reproducibility ranged from 0.989 to 0.996. There was no significant difference in the cross-sectional area of the FNI between the actual measured values and the predicted values using the formula (732.83 ± 126.74 mm 2 vs 731.62 ± 128.15 mm 2 , P = 0.322). The perimeter using the two methods showed narrow while significant difference (97.86 ± 8.60 mm vs 92.84 ± 8.65 mm, P < 0.001), the actual measured values were about 5 mm greater than the predicted values. The parameters (area, perimeter, and eccentricity) were significantly larger in male than female (P < 0.001). A positive correlation between the cross-sectional area, perimeter, height, and weight was observed. The stepwise linear regression analysis showed that the regression equation of the FNI area was as follows: Y = -1083.75 + 1033.86 × HEIGHT + 1.92 × WEIGHT, R 2 = 0.489., Conclusion: The cross-section shape of the FNI appears to be oval-like in the 3D model, which is separated according to the inertia axis, and the findings proposed an anatomical basis for the further study of the spatial configuration of cannulated screws in the treatment of femoral neck fractures., (© 2021 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

Context: Among patients with type 1 diabetes (T1D), the risk of hip fracture is up to 6-fold greater than that of the general population. However, the cause of this skeletal fragility remains poorly understood., Objective: To assess differences in hip geometry and imaging-based estimates of bone strength between youth with and without T1D using dual-energy x-ray absorptiometry (DXA)-based hip structural analysis., Design: Cross-sectional comparison., Participants: Girls ages 10 to 16 years, including n = 62 with T1D and n = 61 controls., Results: The groups had similar age, bone age, pubertal stage, height, lean mass, and physical activity. Bone mineral density at the femoral neck and total hip did not differ in univariate comparisons but was lower at the femoral neck in T1D after adjusting for bone age, height, and lean mass. Subjects with T1D had significantly lower cross-sectional area, cross-sectional moment of inertia, section modulus, and cortical thickness at the narrow neck, with deficits of 5.7% to 10.3%. Cross-sectional area was also lower at the intertrochanteric region in girls with T1D. Among those T1D subjects with HbA1c greater than the cohort median of 8.5%, deficits in hip geometry and strength estimates were more pronounced., Conclusions: DXA-based hip structural analysis revealed that girls with T1D have unfavorable geometry and lower estimates of bone strength at the hip, which may contribute to skeletal fragility and excess hip fracture risk in adulthood. Higher average glycemia may exacerbate effects of T1D on hip geometry., (• The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The practice of sports during the growth phase has a positive influence on bone mineral accrual. However, the effects of different sports are still not fully understood. The aim of this study was to evaluate the bone geometry in adolescent handball players. This is a cross-sectional study in which 53 female adolescents (12-17 years old) were divided into two groups: handball players (HG: n = 26), who must have had at least six months of participation in official competitions, and a control group (CG: n = 27). Bone geometry properties, such as cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (Z), and femoral strength index (FSI) were measured using DXA. Tanner's sexual maturity, menarche, peak height velocity, sun exposure, and calcium intake were assessed. An unpaired Student's t test or the Mann-Whitney test and multivariate analyzes were used to compare variables differences between groups. The HG group showed a significantly higher body mass index, weight and lean mass (LST), CSA, CSMI, Z, and FSI than the CG group. When the values were adjusted for LST, the differences disappeared. The LST has been shown to be relevant to the strength and bone stiffness of the femurs of female adolescents, and the competitive practice in handball may have contributed to its increase.

The aim of the present study was to explore the influence of physical activity level on composite indices of femoral neck strength (compression strength index [CSI], bending strength index, and impact strength index) in a group of young overweight men. To do so, we compared composite indices of femoral neck strength in active overweight men and insufficiently active overweight men. They were divided into 2 groups based on their physical activity level: 70 active overweight men (engaging in more than 150 minutes of physical activity per week; 8.7 ± 4.8 h/wk) and 26 insufficiently active overweight men (engaging in less than 150 minutes of physical activity per week; 1.2 ± 0.7 h/wk). Height (m) and weight (kg) were measured, and body mass index (kg/m 2 ) was calculated. Bone mineral density was measured by dual-energy X-ray absorptiometry at whole body, lumbar spine, total hip, and femoral neck. Body weight, lean mass, fat mass, and body mass index were not significantly different between the 2 groups. CSI, bending strength index, and impact strength index were significantly higher in active overweight men compared to insufficiently active overweight men. After adjustment for age, physical activity (h/wk) and lean mass, only CSI remained higher in active overweight men compared to insufficiently active overweight men. This study suggests that, in young overweight men, being active (engaging in more than 150 minutes of physical activity per week) is associated with greater composite indices of femoral neck strength. To our knowledge, this is the first study that finds a significant difference regarding composite indices of femoral neck strength between 2 groups of young overweight men with different levels of physical activity., (Copyright © 2020 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Background: Arthroscopic osteochondroplasty may improve range of motion and relieve pain in patients with symptomatic hip impingement. Femoral neck fracture is a risk of this procedure because of the weakening of the proximal femur. To our knowledge, there are no biomechanical studies in young human cadaveric bone evaluating the effect of osteochondroplasty on femoral neck strength., Purpose/hypothesis: The purpose was to evaluate loads to fracture in young human cadavers after resection depths of 25% and 40% at the head-neck junction. We hypothesized that both depths will maintain ultimate loads to failure above previously published loads, as well as above physiologic weightbearing loads., Study Design: Descriptive laboratory study., Methods: Cadaveric proximal femoral specimens (6 matched pairs, under the age of 47 years) were divided into 2 groups: 25% or 40% of the diameter at the head-neck junction was resected. The length of the resection was 2 cm and the width of the resection was determined by the length of the anterolateral quadrant at the head-neck junction in all cases. A compressive load was applied directly to the femoral head. Peak load, stiffness, and energy to fracture were compared between groups., Results: The average peak load to fracture after 25% resection (7347 N) was significantly higher than after the 40% resection (5892 N) ( P = .010). The average energy to fracture was also significantly higher in the 25% resection group (30.2 J vs 19.2 J; P = .007). The average stiffness was higher in the 25% group, although not statistically significant ( P = .737)., Conclusion: Resection depths of 25% and 40% at the anterolateral quadrant of the femoral head-neck junction may be safe at previously described functional loads such as standing and walking in the age range more typically seen in patients undergoing hip arthroscopy. Loads to fracture were significantly higher than previously reported using older cadaveric specimens., Clinical Relevance: Currently, most surgeons limit weightbearing after femoral osteochondroplasty in part because of risk of femoral neck fracture. Given the higher observed loads to fracture, young patients could possibly bear weight sooner after surgery, although postoperative protocols should be individualized based on patient age, weight, bone density, amount of bone resected, concomitant procedures, and potential compliance with activity restrictions.

In the past, researchers have attempted to model trabecular bone using computational techniques. However, only a few of these models are visually similar, but not representative of the microstructural characteristics of real trabecular bones. In this study, we hypothesized that probabilistic modeling approaches could be used to generate representative digital models that capture the microstructural features of real trabecular bones. To test this hypothesis, we proposed a novel mathematical framework to build the digital models and compared the digital models to real bone specimens. First, an initial three-dimensional cellular structure was generated using Voronoi tessellation, with the faces and edges of the Voronoi cells considered as a pool of potential trabecular plates and rods, respectively. Then, inverse Monte Carlo simulations were performed to select, delete, or reassign plates and rods until the underlying size, orientation, and spatial distributions of the plates and rods converged to the target distributions obtained from real trabecular bone microstructures. Next, digital graphics techniques were used to define the thickness of trabecular plates and the diameter of trabecular rods, followed by writing the model into a Standard Tessellation Language file and then smoothing the model surfaces for a more natural appearance. To verify the efficacy of the digital model in capturing the microstructural features of real trabecular bones, forty-six digital models with a large variation in microstructural features were generated based on the target distributions obtained from trabecular bone specimens of twelve human cadaveric femurs. Then, the histomorphological parameters of the digital models were compared with those of the real trabecular bone specimens. The results indicate that the digital models are capable of capturing major microstructural features of the trabecular bone samples, thus proving the hypothesis that the proposed probabilistic modeling approach could render real trabecular bone microstructures.

Analyses using newly developed structural measures of minimal model (aBMD, W, Sigma, Delta) in a Chinese female age-matched cohort of femoral neck fracture patients and non-fracture community controls resulted in improved fracture prediction, suggesting the usefulness of new variables, extending the value of widely available DXA technology., Introduction: We have developed a new approach to evaluate 2D femoral neck (FN) structure, the minimal model (MM). This model includes FNaBMD and FNWidth with two new internal structural measures, the standard deviation of normalized mineral mass projection profile distribution (FNSigma) and the displacement between center of mineral (CoM) mass and geometric center of mineral mass projection profile (FNDelta)., Methods: Differences in these four structural measurements together with age, weight, and height were compared in the contralateral hip of 285 FN fracture Chinese female patients and 261 age-matched community controls. Structural variables were calculated from DXA equivalent 2D images obtained from QCT scans analyzed using Mindways Software., Results: Review of FN scanned profiles of fracture patients and controls identified substantial reduction in mineral mass in the superior segment of FN. Fracture participants were taller, weighed less, and had lower FNaBMD and larger FNDelta, due to a larger inferior displacement in the CoM, consistent with greater reduction in superior segment bone. Logistic regression identified increased height, reduced FNaBMD, increased FNDelta, and reduced FNSigma per SD as significant independent contributors to differentiating fracture from non-fracture. Area under ROC analysis identified significant improvement in discrimination with the addition of FNDelta and FNSigma to the model including age, height, weight, and FNaBMD (C statistic 0.87 and 0.84 respectively)., Conclusions: These data extend previous data that identified the benefit of 2D FN internal structural information in discriminating those at increased future fracture risk from recently fractured individuals. These data support continuing investigation of MM analysis as a straightforward analytical approach adding value to DXA hip aBMD in predicting fracture risk.

Background: The femoral neck torsion angle (FNTA) is an important but often neglected parameter in assessments of the anatomical morphology of the femoral neck, which is often confused with the femoral neck anteversion angle (FNAA) in the current literature. Currently, the measurement methods reported in the literature all adopt the naked eye or two-dimensional (2D) visualization method, and the measurement parameters and details are not clearly defined. The objection of this research was to provide a reliable 3D method for determining the femoral neck axis, to improve the measurement method of the FNTA, and to analyze the anatomical and clinical significance of the results., Methods: Computed tomography (CT) data of 200 patients who received a lower extremity CT angiography examination were selected, and the bilateral femurs were reconstructed with three dimensional CT (3D CT). First, the 3D axis of the femoral neck was built. Second, the long axis of the cross section the femoral neck isthmus (FNI) and femoral neck basilar part (FNB) were confirmed by the "inertia axes" method, and the plane consisting of the long axis of the cross-section and the center of the femoral head was defined as the long axial plane. Third, the coronal plane of the proximal femur was determined through the long axis of the proximal femur and the femoral coronal. Finally, the FNTAs (the angles between the long axial planes and the coronal plane of the proximal femur) of FNI and FNB were measured. The size of FNTA was compared between the sexes and sides and different locations, the correlation between the parameters and age, height, and weight were evaluated., Results: The difference in FNTA was statistically significant between the isthmus and the basilar part (isthmus 30.58 ± 8.90° vs. basilar part 23.79 ± 3.98°; p < 0.01). Significant difference in the FNTA was observed between the sexes (males 31.99 ± 9.25° vs. females 27.49 ± 7.19°; p < 0.01). The increase in FNTA from the basilar part to the isthmus was 6.79 ± 8.06°, and the male (7.87 ± 8.57°) was greater than the female (4.44 ± 6.23°, p < 0.01). However, no significant difference in the values was observed between sides. Height exerted the greatest effect on the FNTA according to the correlation analysis (r = 0.255, p< 0.001)., Conclusions: This study found a reliable 3D method for the determination of the femoral neck axis improved the measurement method of the FTNTA and made it more accurate and repeatable. The results provided a methodological basis and theoretical support for the research and development of internal fixation device for femoral neck fracture and the spatial configuration of implants in treatment. And the optimal opening point of the femoral medullary cavity was recommended to locate at the posterior position of the top of the femoral neck cross-section during hip replacement.

Background and purpose - The neck-shaft angle (NSA) is valuable for diagnostics and therapy of the hip, but current reference values derive mostly from studies on anatomic specimens, small cohorts, or are hospital-based. Moreover, associated factors such as age, sex, or anthropometric data have rarely been considered. Therefore, we determined associated factors for NSA and reassessed the historical reference values in a general adult population.Methods - NSAs on both sides of 3,226 volunteers from the population-based Study of Health in Pomerania (SHIP) were measured with MRI. SHIP drew a representative sample of the population of Pomerania (northeastern Germany). NSAs were compared with sex, age, and anthropometric data by bivariable linear regression models. Reference values were assessed by quantile regressions for 2.5th and 97.5th percentiles.Results - The mean NSA was 127° (SD 7), while men had a lower NSA than women (95% confidence interval [CI] 0.4°-1.4°). The reference range was 114°-140°. Age was inversely associated with NSA (CI -0.2 to -0.1). Body height was positively associated with the NSA, while BMI and waist circumference showed a negative association. There was no association between body weight and NSA.Interpretation - The historical lower limit of 120° might be too high, so the radiological prevalence of hip pathology might have been overestimated. The previously reported influence of age, sex, and body height on the NSA has been confirmed.

Objective: This paper aims to (i) identify differences in measures of hip morphology between four racial groups using anteroposterior (AP) hip x-rays, and (ii) examine whether these differences vary by sex., Methods: 912 hip x-rays (456 individuals) from four racial groups (European Caucasians, American Caucasians, African Americans and Chinese) were obtained. Males and females (45-75 years) with no radiographic hip OA (Kellgren and Lawrence < Grade 2 or Croft < Grade 1) were included. Eleven features of hip joint morphology were analysed. Linear regression with generalised estimating equations (GEE) was used to determine race and sex differences in hip morphology. Post-hoc Bonferroni procedure was used to adjust for multiple comparisons., Results: The final analysis included 875 hips. Chinese hips showed significant differences for the majority of measures to other racial groups. Chinese were characterised by more shallow and narrow acetabular sockets, reduced femoral head coverage, smaller femoral head diameter, and a lesser angle of alignment between the femoral neck and shaft. Variation was found between other racial groups, but with few statistically significant differences. The average of lateral centre edge angle, minimum neck width and neck length differed between race and sex (p-value for interaction < 0.05)., Conclusions: Significant differences were found in measures of morphology between Chinese hips compared to African Americans or Caucasian groups; these may explain variation in hip OA prevalence rates between these groups and the lower rate of hip OA in Chinese. Sex differences were also identified, which may further explain male-female prevalence differences for OA., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To cross-calibrate dual energy X-ray absorptiometry machines when replacing GE Lunar DPX-Pro with GE Lunar iDXA., Methods: A cross-sectional study was conducted in 126 children (3-19 years) and 135 adults (20-66 years). Phantom cross calibration was carried out using aluminum phantom provided with each of the machines on both machines. Total body less head (TBLH), lumbar spine (L2-L4) and left femoral neck bone mineral density (BMD), bone mineral content (BMC), and bone area were assessed for each patient on both machines. TBLH lean and fat mass were also measured. Bland-Altman analysis, linear regressions, and independent sample t test were performed to evaluate consistency of measurements and to establish cross-calibration equations., Results: iDXA measured 0.33% lower BMD and 0.64% lower BMC with iDXA phantom as compared to DPX-Pro phantom (p < 0.001). In children, TBLH-BMC, femoral BMC and area were measured 10%-14% lesser, TBLH area was higher by 1%-2% and L2-L4 area by 10%-14% by iDXA as compared to DPX-Pro. iDXA measured higher TBLH fat [15% (girls), 31% (boys)] than DPX-Pro. In adults, TBLH-BMD (1.7%-3.4%), BMC (6.0%-10.9%) and area (4.2%-7.6%) were measured lesser by iDXA than DPX-Pro. L2-L4 BMD was higher [2.7% (men), 1.8% (women)] by iDXA than DPX-Pro. Femoral BMC was 2.11% higher in men and 4.1% lower in women by iDXA as compared to DPX-Pro. In children, R 2 of cross-calibration equations, ranged from 0.91 to 0.96; in adults, it ranged from 0.93 to 0.99 (p < 0.01). After the regression equations were applied, differences in BMD values between both machines were negligible., Conclusion: A strong agreement for bone mass and body composition was established between both machines. Cross-calibration equations need to be applied to transform DPX-Pro measurements into iDXA measurements to avoid errors in assessment. This study documents a need for use of cross-calibration equations to transform DPX-Pro body composition data into iDXA values for clinical diagnosis., (Copyright © 2019 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Background: A detailed understanding of the blood supply to the femoral head is required to plan the surgery in the femoral neck and head area. However, information about the blood vessel networks in the femoral head is inadequate., Methods: The surface of the femoral neck of 100 dry cadaveric adult femur specimens was scanned using a 3D scanner. The scanning distance was 200 mm, precision 0.01 mm, and measuring point 0.04 mm. The images were acquired at a resolution of 1,310,000 pixels. Digital imaging data were recorded from the femoral neck surface. The diameters of the nutrient foramina of the superior, inferior and anterior retinacular arteries, and the ligamentum teres arteries were determined and divided into five groups., Results: The mean cumulative cross-sectional area of the nutrient foramina was as follows: canals of the superior, inferior, anterior, and ligamentum retinacular arteries were 15.59 mm 2 , 3.63 mm 2 , 4.32 mm 2 , and 1.58 mm 2 , respectively. Next, we analyzed the canals of the superior, inferior, anterior and ligamentum retinacular arteries, respectively, via 3D scanner. We found that the canals of the superior retinacular arteries appear to supply more blood to the femoral head than the canals of the other three types of arteries., Conclusions: Our results demonstrated that surgeries of the femoral neck and femoral head will be improved with prior 3D scanning and lead to better outcomes in surgeries involving the hip area.

Conventional methods have limitations in measuring femoral neck torsion angle (FNTA) of patients with femoral deformities. A new method of three-dimensional (3D) reconstruction technology based on computer tomography (CT) was proposed to enhance measurement accuracy and applicability in this study.Bilateral FNTA of 50 developmental dysplasia of the hip (DDH) patients (DDH group) and 81 volunteers (normal group) were measured by Mimics software based on CT data with the marker lines determined by centerline and curvature. Each FNTA was measured by observer A and observer B for twice separately. 50 DDH patients were classified into 3 groups (group I, II, III) according to Hartofilakidis classification. The statistical analysis of the differences was made among the measurements of the FNTA.The FNTA values were 27.56° ± 12.48° in DDH group and 21.22° ± 8.14° in normal group with significant difference (t = 4.516, P < .001). The FNTA values were 24.53° ± 2.40° in group I, 29.78° ± 1.83° in group II and 39.08° ± 3.13° in group III, with significant difference (F = 7.568, P = .001).The accuracy, reliability and applicable scope of FNTA measurement can be improved by 3D reconstruction in clinical practice. The applicable scope of this method included normal people and patients with femoral deformities. The FNTA of DDH patients is significantly larger than normal volunteers with a positive correlation between the severity of classification. This study will also provide references for preoperative design of Chinese population.

Only a few postcranial remains have been assigned to the Miocene great ape Dryopithecus fontani, leading to uncertainties in the reconstruction of its overall body plan and positional behavior. Here we shed light on the locomotor repertoire of this species through the study of the femoral neck cortical bone (FNCB) distribution of IPS41724, a partial proximal femur from the Abocador de Can Mata locality ACM/C3-Az (11.9 Ma, middle Miocene; Vallès-Penedès Basin, Spain) attributed to this taxon. This specimen was scanned through computed tomography to measure the superior (SUP) and inferior (INF) cortical thicknesses at the middle and the base of the femoral neck. Measurements were compared with a sample of extant primates and the femur IPS18800.29 from the younger great ape Hispanopithecus laietanus from Can Llobateres 2 (9.6 Ma, late Miocene; Vallès-Penedès Basin), previously shown to display a homogeneous FNCB distribution at the midneck section coupled with postcranial adaptations to below-branch suspensory behaviors. Our analyses indicate an asymmetric FNCB distribution for IPS41724 (SUP/INF index = ∼0.4 at the midneck and base of the neck sections), comparable with that of quadrupedal primates and bipedal hominins (including early australopiths), but contrasting with the homogeneous FNCB distribution of Hispanopithecus and extant great apes. An asymmetrical FNCB distribution has been associated with stereotyped loads at the hip joint (as in both quadrupedal and bipedal taxa). Our results therefore support a significant quadrupedal component of the positional behavior of Dryopithecus, thus strengthening the argument that plesiomorphic generalized quadrupedalism was still a major locomotor behavior for Miocene great apes. If that were the case, it could have deep implications for the origins of hominin bipedalism., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: The knowledge of proximal femur geometry is essential in the understanding and treatment of hip pathologies. Our aim is to evaluate the range of "normal anatomical values of the proximal femur" and their relationship to age, gender, and ethnicity in a cohort of healthy population, using a 3-dimensional computed tomography automated software., Methods: The pelvis and bilateral femora of 628 healthy individuals (394 males/234 females, mean age 61.5 ± 16.5 years, mean body mass index [BMI] 26.9 ± 5.2 kg/m 2 ) including 2 ethnicities (226 Asians and 406 Caucasians) were assessed with a 3-dimensional computed tomography scan-based system using algorithm-calculated landmarks. The demographic parameters recorded were age, gender, BMI, and ethnicity. The femoral neck-shaft angle (NSA), femoral neck version, femoral offset (FO), and femoral canal flare index (fCFI) were calculated for each individual. Analyses were performed using SPSS version 22. P-values <.05 were considered to indicate statistical significance., Results: Overall, the mean NSA was 124.7° (standard deviation [SD] 6.2), mean femoral neck version was 14.5° (SD 8.1), mean FO was 42.9 mm (SD 6.8), and mean fCFI was 3.4 (SD 0.5). Gender was associated with all parameters, with the females presenting more valgus and anteverted hips. Multivariate analysis revealed a lower NSA and fCFI and a higher FO for older individuals. Ethnicity and BMI were not associated with any parameters., Conclusion: Our results showed that there is a direct relationship of age and gender to the variations in the investigated proximal femur anatomical parameters in a large cohort of healthy individuals. Those important gender-based and age-based differences might advocate for more varus and lateralized component to reproduce preoperative anatomy of male and patients older than 50 years., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Studies of the australopith (Australopithecus and Paranthropus) proximal femur have increasingly integrated information from the local arrangement of the cortical and cancellous bone to allow functional-biomechanical inferences on the locomotor behavioral patterns. In Australopithecus africanus and Paranthropus robustus, the cancellous bone organization at the center of the femoral head shows principal strut orientation similar to that of fossil and recent humans, which indicates that australopiths were human-like in many aspects of their bipedalism. However, by combining outer morphology with superoinferior asymmetry in cortical bone thickness at the base of neck and mid-neck, it has been suggested that, while adapted for terrestrial bipedality, australopiths displayed a slightly altered gait kinematics compared to Homo. We used techniques of 2D and 3D virtual imaging applied to an X-ray microtomographic record to assess cortical bone distribution along the entire femoral neck compartment in four upper femora from Swartkrans, South Africa (SK 82, SK 97, SK 3121, and SWT1/LB-2) and compared the results to the extant human and chimpanzee conditions. Our results support and extend previous evidence for more symmetric superior and inferior femoral neck cortical thicknesses in P. robustus than in modern humans and show that the differences are even greater than previously reported. However, P. robustus and humans still share a trend of lateral-to-medial decrease in asymmetry of the superior/inferior cortical thickness ratio, while this pattern is reversed in chimpanzees. We also identified two features uniquely characterizing P. robustus: an accentuated contrast between the relatively thicker anterior and the thinner posterior walls, and a more marked lateral-to-medial thinning of both cortices compared to extant humans and chimpanzees, which indicate wider interspecific differences among hominids in structural organization of the proximal femur than previously reported. It remains to be ascertained if, and to what extent, these features also characterize the femoral neck of Australopithecus., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The femoral neck-preserving ratio is crucial in arthroplasty with a collum femoris-preserving (CFP) stem. The aim of our study was to analyze the relationships between the neck-preserving ratio and the short-term radiologic and clinical outcomes of patients who underwent total-hip arthroplasty (THA) with a CFP stem.The data of 325 hips from January 2015 to December 2016 were retrospectively reviewed. The demographic and radiologic data before and after surgery were obtained from patients. The neck-preserving ratio was defined as the ratio of the preserved femoral neck length to the preoperative femoral neck length. Correlations between the neck-preserving ratio and the radiologic and clinical outcomes of patients were analyzed.The mean neck-preserving ratio was 66.38 ± 6.91% in the current study. We divided patients into 3 groups according to the neck-preserving ratio: group A (neck-preserving ratio ≤60.00%), group B (60.00% < neck-preserving ratio < 70.00%), group C (neck-preserving ratio ≥70.00%). Radiologic features, including the neck-shaft angle ratio (0.96 ± 0.05), canal fill ratio (0.64 ± 0.07), anterior-posterior offset ratio (1.04 ± 0.10), and lateral offset ratio (2.55 ± 1.56) (ratios of the postoperative values to the preoperative values), and the prevalence of complications was significantly different among the groups (χ = 21.173, P < .001). In the correlation analysis, we found a moderate negative correlation between the neck-preserving ratio and neck-shaft angle ratio (r = -0.308, P < .001) and a slight positive correlation of the neck-preserving ratio with the anterior-posterior offset ratio (r = 0.415, P < .001) and the lateral offset ratio (r = 0.164, P = .003). In the linear regression analyses, the neck-preserving ratio was significantly linearly correlated with the neck-shaft angle ratio (B = -0.232, 95% confidence interval [CI] = -0.311 to -0.154, P < .001), anterior-posterior offset ratio (B = 0.589, 95% CI = 0.447-0.730, P < .001), and lateral offset ratio (B = 3.693, 95% CI = 1.256-6.131, P = .003). However, there was no significant linear correlation between the neck-preserving ratio and the canal fill ratio (B = 0.073, 95% CI = -0.033 to 0.180, P = .174). Logistic regression analyses also showed that a sufficient neck-preserving ratio was a protective factor for periprosthetic femoral fractures (odds ratio [OR] = 0.924, 95% CI = 0.859-0.994, P = .035), dislocations (OR = 0.892, 95% CI = 0.796-0.999, P = .048), and thigh pain (OR = 0.886, 95% CI = 0.818-0.960, P = .003).For CFP stems, an insufficient neck-preserving ratio is significantly correlated with poor radiologic and clinical outcomes. Therefore, surgeons should be cognizant to preserve a sufficient femoral neck length during surgery to improve the outcomes for patients undergoing THA with CFP stems.

The abundant femoral assemblage of Homo naledi found in the Dinaledi Chamber provides a unique opportunity to test hypotheses regarding the taxonomy, locomotion, and loading patterns of this species. Here we describe neck and shaft cross-sectional structure of all the femoral fossils recovered in the Dinaledi Chamber and compare them to a broad sample of fossil hominins, recent humans, and extant apes. Cross-sectional geometric (CSG) properties from the femoral neck (base of neck and midneck) and diaphysis (subtrochanteric region and midshaft) were obtained through CT scans for H. naledi and through CT scans or from the literature for the comparative sample. The comparison of CSG properties of H. naledi and the comparative samples shows that H. naledi femoral neck is quite derived with low superoinferior cortical thickness ratio and high relative cortical area. The neck appears superoinferiorly elongated because of two bony pilasters on its superior surface. Homo naledi femoral shaft shows a relatively thick cortex compared to the other hominins. The subtrochanteric region of the diaphysis is mediolaterally elongated resembling early hominins while the midshaft is anteroposteriorly elongated, indicating high mobility levels. In term of diaphyseal robusticity, the H. naledi femur is more gracile that other hominins and most apes. Homo naledi shows a unique combination of characteristics in its femur that undoubtedly indicate a species committed to terrestrial bipedalism but with a unique loading pattern of the femur possibly consequence of the unique postcranial anatomy of the species., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Introduction: For trochanteric fractures, helical blade placement is crucial to the prognosis of operations. Existing measurement methods used for blade placement include the Cleveland zone, the tip-apex distance (TAD), the calcar-referenced tip-apex distance (CalTAD), and the Parker's ratio. These methods all lack a direct view on blade direction. The current study proposed the axis-blade angle (ABA) to solve direction problem and investigated its clinical applicability., Methods: A retrospective study collected 156 patients between May 2014 and February 2018. The occurrence of mechanical complications was analyzed in relation to age, gender, fracture side, American Society of Anesthesiologists classification, fracture classification, reduction quality, bone quality, the Cleveland zone, the Parker's ratio, the TAD, the CalTAD, and the ABA., Results: 119 patients, including 25 with mechanical complications, were suitable for full analysis. In the univariate analysis, the Cleveland zone, reduction quality, the TAD, the CalTAD and the ABA were statistically associated with mechanical complications. In the multivariate analysis, reduction quality (p = 0.008) and the ABA (p < 0.001; adjusted OR 0.86;95% CI 0.77 to 0.96) showed significant results, which indicated that reduction quality and the ABA were two independent influencing factors for mechanical complications. Calculation of the receiver operating characteristic (ROC) curve indicated that the ABA was a reliable predictor of mechanical complications at the cut-off of -10°., Conclusions: The ABA provides instruction for the intraoperative adjustment of guide wire direction. Placing the helical blade with an ABA > -10° can effectively reduce the risk of mechanical complications., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Multiscale models of bone remodelling which incorporate clinically important features at a wide range of spatial scales are computationally intractable. In addition, there is a large gap in existing bone remodelling literature which deals with Haversian-level cortical bone remodelling behaviour and its effect on whole organ bone strength. In this study, we present an integration between continuum mechanics and surrogate modelling as an efficient circumvention to the problem of intractability, linked with an intricate 3D cortical bone remodelling algorithm which captures realistic microanatomical features at the Haversian level. The surrogate model predicted clear differentiation in long-term bone strength changes in clinically significant cases with extremely high computational efficiency., (© 2019 John Wiley & Sons, Ltd.)

Bisphosphonate use has declined dramatically in recent years, partly because of fear of rare side effects like atypical femur fractures (AFFs). It is therefore desirable to have a diagnostic method to identify those at risk of AFF to prevent this serious complication. We compared trabecular microarchitecture and hip geometry between 30 patients with AFF and 141 controls of similar age and sex, using bisphosphonates. Trabecular bone score (TBS) and hip structural analysis (HSA) were used to assess trabecular microarchitecture and macroscopic hip geometry from dual-energy X-ray absorptiometry images of the lumbar spine and hip, respectively. General characteristics, TBS, and HSA were compared between patients with AFF and controls using Student's t tests and chi-square statistics. Associations between AFF and TBS and femur geometric characteristics by HSA were adjusted for sex, age, height, weight, ethnicity, duration of bisphosphonate use, and glucocorticoid use. Additionally, the analysis of TBS was adjusted for lumbar spine bone mineral density and the time difference between dual-energy X-ray absorptiometry scanning and the diagnosis of AFF. Patients with AFF had significantly higher body mass index than controls, had used bisphosphonates longer, and glucocorticoids and proton pump inhibitors more frequently. Sex-specific T-score was significantly higher in patients with AFF at the lumbar spine (p = 0.004), but not at the femoral neck (p = 0.190) after adjustment for age, height, and weight. TBS did not differ significantly between patients with AFF and controls. Neither neck shaft angle nor any geometric variables at the femoral shaft measured by HSA differed between patients with AFF and controls. At the narrow neck, patients with AFF had lower buckling ratio and higher centroid position, consistent with a lower risk of classical fragility hip fractures. The findings at narrow neck and higher bone mineral density might be explained by the fact that the majority of patients with AFF used bisphosphonates to prevent glucocorticoid-induced osteoporosis. Based on our results, TBS and HSA do not appear to have value in detecting patients at risk of AFF., (Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to explore the relationships between physical performance variables and bone parameters such as bone mineral density (BMD), bone mineral content, hip geometry indices, and trabecular bone score in a group of young overweight and obese adult women. Sixty-eight overweight/obese (body mass index ≥25 kg/m 2 ; 25.5-42.4 kg/m 2 ) young women whose ages range from 18 to 35 yr participated in this study. Body composition and bone outcomes were measured by dual-energy X-ray absorptiometry. Maximum oxygen consumption (VO 2 max, in liter per minute) was determined indirectly using a progressive shuttle run test. One-repetition-maximum half-squat was directly measured. Vertical jump was measured and maximum power (P max) of the lower limbs was calculated. Lean mass was positively correlated to whole body (WB) BMD, total hip BMD, femoral neck (FN) BMD, femoral neck cross-sectional area (FN CSA) and femoral neck cross sectional moment of inertia (FN CSMI) (p < 0.05). VO 2 max (in liter per minute) and muscle power were positively correlated to WB BMD, total hip BMD, FN BMD, FN CSA, and FN CSMI (p < 0.05). One-repetition-maximum half-squat was positively correlated with lumbar spine trabecular bone score, WB BMD, FN BMD, FN CSA and FN CSMI (p < 0.05). This study suggests that lean mass, vertical jump, VO 2 max (liter per minute), muscle power and one-repetition-maximum half squat are positive determinants of BMD and hip geometry indices in young overweight and obese women., (Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to describe femoral neck (FN) geometry among eumenorrheic underweight women around the age of peak bone mass. Proximal femur geometry and body composition were assessed in 12 underweight women and in 24 healthy controls using dual-energy X-ray absorptiometry. The Hip Structural Analysis program was used to determine bone geometry at the FN. The cross-sectional area (CSA) and the cross-sectional moment of inertia (CSMI) were significantly lower in underweight women than in controls (p < 0.05). There was a trend toward lower sectional modulus (Z) and strength index in underweight women (p < 0.15). Body weight, body mass index, and lean mass (LM) were positively correlated with CSA, CSMI, Z, and neck-shaft angle (r = 0.428-0.611, p < 0.05). After controlling for body weight, body mass index, and LM, the differences in CSA, CSMI, Z, and neck-shaft angle were no more statistically significant between the 2 groups. The multivariate analysis retained LM as the main predictor of CSA, CSMI, and Z in the whole population. The present study suggests that thinness is associated with low resistance to axial forces (CSA) and bending load (Z and CSMI) in adult eumenorrheic women. LM seems to be a key determinant of FN geometry in underweight women., (Copyright © 2017 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Background: It is common practice when placing cannulated screws within the femoral head when treating femoral neck fractures to avoid the thread-forms from crossing the fracture line. Despite the widespread use of cannulated screws in internal fixation of femoral neck fractures, there is no study to our knowledge that describes the ideal length of thread-forms., Purpose: The purpose of this study is to determine the thread length that will maximize purchase within the femoral head while minimizing risk of crossing the fracture line. Additional analysis was conducted to identify factors associated with the maximal possible length of treads in minimally and non-displaced femoral neck fractures., Methods: We performed a retrospective study of all patients treated for a minimally or non-displaced femoral neck fracture from April 1, 2004 through December 31, 2017. Only patients who had received a pre-operative CT or MRI scan were included. Fixation was then templated using radiographs and the distance from the subchondral bone to the fracture line was then measured., Results: The study included 127 patients. The average estimated length of lag screw threads was 33.2 ± 6.67 mm, with lower quartile of 29.1 mm and higher quartile of 37.2 mm. The median was 32.0 mm and most frequently encountered estimate was 29 mm. Estimated lag screw size did not differ significantly based on age or BMI, but both height (p < 0.001) and race (0.04) were positively correlated with estimated lag screw size and males had longer measurements compared to females, 37.2 ± 7.0 mm vs 31.4 ± 5.7 mm (p < 0.001), respectively., Conclusion: In conclusion, we propose an additional lag screw thread form with length 26.0 mm to capture 90% of femoral neck fractures., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The aim of this study was to get precise normal values of the femoral neck angle (FNA) in support of developing an optimally functioning total hip prosthesis for medium and large dog breeds. Accordingly, two- and three-dimensional computed tomographic images of the anatomical structures of the proximal femora of 58, hip-dysplasia-free, mature dogs of medium and large breeds were studied. Based on the length of their femora the dogs were allocated to Group I (from 145 to 195 mm) and Group II (from 196 to 240 mm). The FNA was measured on each femur using multi-slice spiral computed tomography (CT). The two- and three-dimensional image data were processed as multi-planar and threedimensional reconstructions using Advantage Workstation software. The CT measurements revealed that Group I had an average femoral neck angle of 147.59° (min. 144.05°, max. 153.35°), while in Group II the average FNA was 147.46° (min. 141°, max. 154.35°). There was no significant correlation between the length of the femur and the FNA in either group. The optimal FNA for a total hip prosthesis is 147.5° for medium and large dog breeds.

Objectives: Recently, more accurate description of the femoral geometry has become of interest to engineers and orthopedic surgeons. However, an appropriate database is lacking. Therefore, the aim of this study is to present morphological parameters and their correlations, which are relevant for medical issues such as impingement after total hip replacement, as well as for implant design and the etiology of hip fractures., Methods: We investigated 12 well-known morphological parameters of the femur in 169 healthy human subjects through evaluation of 3D-reconstructed CT scans. Pearson's coefficients of correlations were calculated using a statistical t-test method for each pair of parameters., Results: The mean, maximum, minimum, median, and standard deviation values are reported for all parameters. Histograms showing the distribution of each morphological parameter are also presented. It is shown that absolute and horizontal offsets, total femur length, and NCVD parameters are normally distributed, but NCDF and NCDS are not. Furthermore, an inter-correlation matrix was reported to reveal statistical correlations between these parameters. The strongest positive correlation existed between absolute offset (OSA) and horizontal offset (OSH), while the least positive correlation was found between NCDF and total femur length (TFL), and also between NCDS and NCDF. Anteversion angle (ATA) and OSA showed the least negative correlation. However, the strongest negative correlation was found between neck-shaft angle (NSA) and greater trochanter height (GTH), as well as between OSA and NCVD., Conclusions: Comprehending patients' native bone morphology, including the variations and correlations, is essential for orthopedic surgeons to undertake preoperative planning and surgery as well as to appropriately design medical devices. Thus, more population-based detailed databases are necessary. We investigated an extensive set of proximal femoral morphology parameters using a statistically standardized method to expand the existing knowledge. The results of our study can be used for diverse medical and biomechanical purposes., (© 2019 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

There is scarcity of population-level data on the bone areal size (BA) that produces the highest bone mineral density (BMD), and how BA relates to BMD among racial groups. We use population-level data to estimate the BA that coincide with the highest BMD among racial groups in the United States. A total of 7425 participants, age 18-75 years, whose BA and BMD were measured in the United States National Health and Nutrition Examination Survey (NHANES) 2009-2014, were assessed in this study. Multiple regression models were used to estimate race-specific relationships between BA and BMD. The critical BA that associates with the highest (peak) BMD among racial groups adjusted for confounders was estimated. Results showed a curvilinear relationship between BA and BMD at the population level such that BMD increases with BA at lower values and then decreases after a peak value. Races combined, BA of about 45 cm 2 seems to correspond to a peak femur BMD in this sample. The peak BMD was different among racial groups. The BA at which BMD peaks was lower among blacks and Mexicans compared to whites. We conclude that femur BMD increases up to a critical femur BA and then decreases thereafter. Persons with femur BA at or close to the critical value may tend to have higher than average BMD.

Osteoporosis is a common metabolic bone disease. The impact of global blood plasma proteins on the risk of osteoporosis remains elusive now. We performed a large-scale polygenic risk score (PRS) analysis to evaluate the potential effects of blood plasma proteins on the development of osteoporosis in 2286 Caucasians, including 558 males and 1728 females. Bone mineral density (BMD) and bone areas at ulna & radius, hip, and spine were measured using Hologic 4500W DXA. BMD/bone areas values were adjusted for age, sex, height, and weight as covariates. Genome-wide SNP genotyping of 2286 Caucasian subjects was performed using Affymetrix Human SNP Array 6.0. The 267 blood plasma proteins-associated SNP loci and their genetic effects were obtained from recently published genome-wide association study (GWAS) using a highly multiplexed aptamer-based affinity proteomics platform. The polygenetic risk score (PRS) of study subjects for each blood plasma protein was calculated from the genotypes data of the 2286 Caucasian subjects by PLINK software. Pearson correlation analysis of individual PRS values and BMD/bone area value was performed using R. Additionally, gender-specific analysis also was performed by Pearson correlation analysis. 267 blood plasma proteins were analyzed in this study. For BMD, we observed association signals between 41 proteins and BMD, mainly including whole body total BMD versus Factor H (p value = 9.00 × 10 -3 ), whole body total BMD versus BGH3 (p value = 1.40 × 10 -2 ), spine total BMD versus IGF-I (p value = 2.15 × 10 -2 ), and spine total BMD versus SAP (p value = 3.90 × 10 -2 ). As for bone areas, association evidence was observed between 45 blood plasma proteins and bone areas, such as ferritin versus spine area (p value = 1.90 × 10 -2 ), C4 versus hip area (p value = 1.25 × 10 -2 ), and hemoglobin versus right ulna and radius area (p value = 2.70 × 10 -2 ). Our study results suggest the modest impact of blood plasma proteins on the variations of BMD/bone areas, and identify several candidate blood plasma proteins for osteoporosis.

Background: Combined anteversion in total hip arthroplasty influences both dislocation risk and range of motion. One of its components, stem version (SV), could be dictated by many factors, from native femoral anatomy to stem geometry and surgeon's choice. In the present multicenter study, robotic technology was used to assess the influence of native femoral version on final SV and combined anteversion using a straight, uncemented stem., Methods: Three hundred sixty-two patients undergoing total hip arthroplasty were enrolled from 3 different orthopedic centers from 2012 and 2016. All patients underwent computed tomography planning with measurement of femoral neck version (FNV) and intraoperative measurement of stem version (SV), acetabular component version (AV), and combined version (CV) with robotic instrumentation., Results: Mean FNV was 5.0° ± 9.6°, and SV was 6.4° ± 9.7°. The average difference between FNV and SV was 1.6° ± 9.8°. A moderate correlation was found between FNV and SV (R = 0.48, P < .001). SV was between 5° and 20° in 174 patients (48%). Mean CV was 28.2° ± 7.9°. A strong correlation was found between SV and CV (R = 0.89, P < .001). A significant difference in SV was found between the 3 centers (P < .001). CV was <25° in 109 patients (30.1%). Relative risk of CV < 25° was 8.6 times greater with SV < 5° (P < .001)., Conclusion: With the use of an uncemented, single-wedge, straight stem, SV is highly variable. Despite being moderately correlated with native FNV, SV can be partially influenced by the surgeon. A low SV could be hardly corrected, bringing high risk of low CV., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The objective of this study was to compare current measurements of bone mineral density (BMD) of the lumbar spine (LS), femoral neck (FN), and total femur (TF) regions with initial values recorded 12 years ago in women from Northwest Mexico, and evaluate their correlation with dietary, anthropometric, and reproductive variables. BMD was assessed by Dual-energy X-ray absorptiometry. Participants were grouped as follows: Nulliparous (G1); women who were mothers 12 years ago (G2); and women who were nulliparous 12 years ago, but are now mothers (G3). In all three groups, current LS BMD was higher than initial ( p ≤ 0.05) and current TF BMD in G2 was higher than initial values ( p ≤ 0.05). When comparing current FN and TF BMD among the three groups, G2 had higher values than G3 ( p ≤ 0.05). G2 also showed higher LS BMD than G1 and G3 ( p = 0.006). Age at menarche was inversely-correlated with FN and TF BMD in G1 ( p < 0.01), while the body mass index (BMI) correlated positively with all three bone regions in G2 ( p < 0.05). This study shows that in women without and with children, age at menarche, BMI, and age were factors associated to BMD in healthy subjects in reproductive age.

Human bone is known to adapt to its mechanical environment in a living body. Both its architecture and microstructure may differ between weight-bearing and non-weight-bearing bones. The aim of the current study was to analyze in three dimensions, the morphology of the multi-scale porosities on human cortical bone at different locations. Eight paired femoral diaphyses, femoral necks, and radial diaphyses were imaged using Synchrotron Radiation µCT with a 0.7 µm isotropic voxel size. The spatial resolution facilitates the investigation of the multiscale porosities of cortical bone, from the osteonal canals system down to the osteocyte lacunar system. Our results showed significant differences in the microstructural properties, regarding both osteonal canals and osteocytes lacunae, between the different anatomical locations. The radius presents significantly lower osteonal canal volume fraction and smaller osteonal canals than the femoral diaphysis or neck. Osteocytes lacunae observed in the radius are significantly different in shape than in the femur, and lacunar density is higher in the femoral neck. These results show that the radius, a non-weight-bearing bone, is significantly different in terms of its microstructure from a weight-bearing bone such as the femur. This implies that the cortical bone properties evaluated on the femoral diaphysis, the main location studied within the literature, cannot be generalized to other anatomical locations., (Copyright © 2018. Published by Elsevier Inc.)

While metrics of pelvis and femur geometry have been demonstrated to influence hip fracture risk, attempts at linking geometry to underlying mechanisms have focused on fracture strength. We investigated the potential effects of femur and pelvis geometry on applied loads during lateral falls on the hip. Fifteen female volunteers underwent DXA imaging to characterize two pelvis and six femur geometric features. Additionally, participants completed low-energy sideways falls on the hip; peak impact force and pressure, contact area, and moment of force applied to the proximal femur were extracted. No geometric feature was significantly associated with peak impact force. Peak moment of force was significantly associated with femur moment arm (p = 0.005). Peak pressure was positively correlated with pelvis width and femur moment arm (p < 0.05), while contact area was negatively correlated with metrics of pelvis width and femur neck length (p < 0.05). This is the first study to link experimental measures of impact loads during sideways falls with image-based skeletal geometry from human volunteers. The results suggest that while skeletal geometry has limited effects on overall peak impact force during sideways falls, it does influence how impact loads are distributed at the skin surface, in addition to the bending moment applied to the proximal femur. These findings have implications for the design of protective interventions (e.g. wearable hip protectors), and for models of fall-related lateral impacts that could incorporate the relationships between skeletal geometry, external load magnitude/distribution, and tissue-level femur loads., (Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.)

BACKGROUND The incidence of hip fracture is steadily increasing. We aimed to establish a creative approach to precisely estimate the risk of hip fracture by exploring the relationship between hip fracture and bone mineral density (BMD)/femur geometry. MATERIAL AND METHODS Sixteen samples of cadaveric female proximal femora were randomly selected. Experiments were performed experimental measurement of the femoral neck BMD and geometric parameters (including neck length, neck diameter, head diameter, and neck-shaft angle). In addition, the experimental measurements contain the failure load, which represents the mechanical strength of the femoral neck, and we calculated the correlation coefficient among BMD, geometric parameters, and failure load. RESULTS Significant correlations were discovered between femoral mechanical properties and femoral neck BMD (r=0.792, r²=0.628, P<0.001), trochanteric BMD (r=0.749, r²=0.560, P=0.001), and head diameter (r=0.706, r²=0.499, P=0.002). Multiple linear regression analyses indicated that the best predictor of hip fracture was the combination of femoral neck BMD, head diameter, and neck diameter (r²=0.844, P<0.001). CONCLUSIONS The results confirmed that, compared with BMD alone, the combination of BMD and geometric parameters of proximal femur is a better estimation of hip fracture. The geometry of the proximal femur played an important role in assessing the biomechanical strength of femur. This method greatly assists in predicting the risk of hip fracture in clinical trials and will assist studies on why the incidence of hip fracture varies among races.

Objectives: This study aims to determine the changing in hip anatomy parameters with age and reveals the reason for the extorsion of lower extremity in the aged., Design: Retrospective study., Participants: One hundred and forty patients who had received imaging check of the femur and acetabulum between October 2013 and October 2016 were included in this study., Main Outcome Measures: The femoral neck torsion angle (FNTA), neck-shaft angle (NSA), and acetabular anteversion angle (AVA) were measured by an experienced orthopedic surgeon. All the patients' demographic and physical characteristics including age, sex, body laterality, height, and weight were recorded. The Student t -test, two-way ANOVA, Pearson correlation, and multiple linear regression were used for the statistical analysis., Results: The mean age for male and female was 45.01±15.38 and 49.30±17.63 years, respectively. Outcomes revealed that the NSA on the right side of the body, 133.46±4.46° in male and 134.36±4.71° in female, was statistically higher than the left side. Female FNTA had significantly higher values than male ( P <0.01). Two-way ANOVA reveals that FNTA and AVA were correlated with age (P<0.05) but not weight, height, or BMI. NSA was correlated with age, weight, and BMI (P<0.05) but not height. Multiple linear regression analysis showed that only age made an independent contribution to NSA., Conclusions: The NSA and FNTA of Asian population may have an obvious decrease whereas AVA increases with ageing, which reveals the reason for the extorsion of lower extremity with elderly. During hip-related surgery in elderly patients, more attention should be paid to these lower extremity anatomic changes.

Sheep hips have a natural non-spherical head similar to a cam-type deformity in human beings. By performing an intertrochanteric varus osteotomy, cam-type femoroacetabular impingement can be induced experimentally. In sheep, the aspherical portion is located superiorly-exactly matching the region where the superior retinacular vessels enter the femoral head-neck junction in human beings. In order to fully exploit the potential of this experimental FAI model, a safe osteochondroplasty of the superior asphericity would need to be done without the risk of avascular necrosis. The aim of this study was to describe the vascular anatomy of the femoral head in sheep from the aorta to the retinacular vessels in order to perform safe femoral osteochondroplasty of the superior femoral asphericity in sheep. Sixty-two ovine hips were analyzed using CT angiography (30 hips), post mortem intravascular latex injection (6 hips), vascular corrosion casting (6 hips), and analysis of the distribution of vascular foramina around the femoral head-neck junction in macerated ovine femora (20 hips). The ovine femoral head receives its blood supply from anterior retinacular arteries from the lateral femoral circumflex artery, and from posterior retinacular arteries from the medial femoral circumflex artery. The superior aspherical portion is free of vessels. Detailed knowledge about vascular anatomy of sheep hips is of clinical significance since it allows to perform osteochondroplasty of the superior aspherical portion in the experimental ovine FAI model safely without the risk of osteonecrosis. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2340-2348, 2018., (© 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

The skeleton of a cricket fast bowler is exposed to a unique combination of gravitational and torsional loading in the form of substantial ground reaction forces delivered through the front landing foot, and anterior-posterior shear forces mediated by regional muscle contractions across the lumbo-pelvic region. The objectives of this study were to compare the hip structural characteristics of elite fast bowlers with recreationally active age-matched controls, and to examine unilateral bone properties in fast bowlers. Dual-energy X-ray absorptiometry of the proximal femur was performed in 26 elite male fast bowlers and 26 normally active controls. Hip structural analysis (GE Lunar; enCORE version 15.0) determined areal bone mineral density (BMD) of the proximal femur, and cross-sectional area, section modulus (Z), cross-sectional moment of inertia, and femoral strength index at the narrow region of the femoral neck. Mean femoral neck and trochanter BMD were greater in fast bowlers than in controls (p <0.001). All bone geometry properties, except for cross-sectional moment of inertia, were superior in fast bowlers (p <0.05) following adjustment for height and lean mass. There were no asymmetries in BMD or bone geometry when considering leg dominance of the fast bowlers (p > 0.05). Elite fast bowlers have superior bone characteristics of the proximal femur, with results inferring enhanced resistance to axial compression (cross-sectional area), and bending (Z) forces, and enhanced strength to withstand a fall impact as indicated by their higher femoral strength index. No asymmetries in hip bone properties were identified, suggesting that both torsional and gravitational loading offer significant osteogenic potential., (Copyright © 2017 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

Objectives: To determine and test mathematical models of the relationship between hip flexion-extension, femoral rotation, and NSA. We hypothesized that hip flexion-extension and femoral rotation would result in NSA measurement error., Methods: Two mathematical models were developed to predict NSA in varying degrees of hip flexion-extension and femoral rotation. The predictions of the equations were tested in vitro using a model that varied hip flexion-extension while keeping rotation constant, and vice versa. The NSA was measured from an anterior-posterior radiograph obtained with a C-arm. Attributable measurement error based on hip positioning was calculated from the models., Results: The predictions of the model correlated well with the experimental data (correlation coefficient = 0.82-0.90). A wide range of patient positioning was found to result in <5-10 degrees error in the measurement of NSA. Hip flexion-extension and femoral rotation had a synergistic effect in measurement error of the NSA. Measurement error was minimized when hip flexion-extension was within 10 degrees of neutral., Conclusions: This study demonstrates that hip flexion-extension and femoral rotation significantly affect the measurement of the NSA. To avoid inadvertently fixing the proximal femur in varus or valgus, the hip should be positioned within 10 degrees of neutral flexion-extension with respect to the C-arm to minimize positional measurement error.

Femur expansion occurs during normal aging in both men and women. Average bone mineral density (BMD) over a region of interest (ROI) on the femur may considerably decrease with age even in healthy people, and therefore, it is inaccurate if used to monitor treatment-induced bone change., Introduction: Areal bone mineral density (BMD), averaged over a region of interest (ROI) on the femur, is widely used in the diagnosis of osteoporosis, assessment of fracture risk, and monitoring of treatment effectiveness. We studied the effect of age-related change in femur geometry on average BMD., Methods: The effect of age-related bone geometric change on averaged BMD was investigated by a cross-sectional study. Total 83 healthy subjects were selected for this study. For each subject, QCT of left femur was scanned using clinical scanner. For each standard volume of interest (VOI), integral/cortical/trabecular bone volume, volumetric BMD (vBMD), and bone mass were measured using QCT Pro; the corresponding areal BMD (aBMD) was projected using CTXA-Hip. Both QCT Pro and CTXA-Hip are commercial software. Correlations between bone volume/density/mass and age were studied., Results: In the studied population, there was no association between body weight/BMI (body mass index) and age, correlation between normalized femoral neck width and age was 0.24 (p < 0.05). Both aBMD and integral vBMD decreased with age (after adjusted by BMI, for aBMD, r = - 0.21 to - 0.24, p ≤ 0.05 except at trochanter; for vBMD, r = - 0.20 to - 0.31, p < 0.05); cortical vBMD had no significant change; trabecular vBMD decreased at all VOIs except at trochanter (after adjusted by BMI, r = - 0.22 to 0.32, p ≤ 0.05). Integral volume showed slight increase but only significant at the trochanter after adjusted by body size, cortical volume showed insignificant decrease, and trabecular volume considerably increased with age in all VOIs (after adjusted by body size, r = 0.27-0.40, p < 0.05). Integral, cortical, and trabecular mass had no significant change in all VOIs, except that at the trochanter trabecular mass slightly increased with age (r = 0.31, p < 0.05)., Conclusions: Even though there is no change in bone mass, average BMD may considerably decrease with age due to bone expansion. Comparatively, aBMD is less affected than vBMD.

The different mechanical stimulus affects the bone mass and bone strength. The aim of this study was to investigate the effect of landing posture of the hoopster and paratrooper on the bone mass. In this study, 39 male participants were recruited including 13 paratroopers, 13 hoopsters, and 13 common students (control groups). Bone area (BA), BMD and BMC of calcaneus, and 1-5th of the metatarsus, hip, and lumbar spine (L 1 -L 4 ) were measured by the dual-energy X-ray absorptiometry. Also, the vertical ground reaction forces (GRFs) of hoopsters and paratroopers were measured by the landing of 1.2 m 3D force platform. BA of hoopsters at the calcaneus, lumbar spine, and hip were significantly higher than the control group. The lumbar spine, hip, calcaneus, the 1st and 2nd metatarsals, BMC of paratroopers, and control groups were significantly lower than hoopsters. BMD of the lumbar spine, hip, and right and left femoral necks in hoopsters were significantly higher than the other participants. BMC and BMD of lower limber showed no significant difference between paratroopers and the control group. Besides, peak GRFs of paratroopers (11.06 times of BW) were significantly higher than hoopsters (6.49 times of BW). The higher GRF in the landing train is not always in accordance with higher BMD and BMC. Variable loads in hoopsters can improve bone remodeling and play an important role in bone expansions for trabecular bones. This will be considered by the method of training to prevent bone loss.

Many researchers are interested in femoral conformation because most orthopaedic problems of the long bones occur in the femur and its joints. The neck-shaft (NSA) and the anteversion (AVA) angles are good predictors for understanding the orientation of the proximal end of the femur. The varus (aLDFA) and procurvatum (CDFA) angles have also been used to understand the orientation of the distal end of the femur. The purposes of this study were to investigate the relationship between the proximal and distal angles of the femur and to compare the distal femoral angles in male and female dogs in order to investigate the sexual dimorphism. The measurements of normal CDFAs, which have not been previously reported, may also provide a database of canine distal femoral morphology. A total of 75 cleaned healthy femora from different breeds or mixed breed of dogs were used. The three-dimensional images were reconstructed from computed tomographic images. The AVA, NSA, aLDFA and CDFA were measured on the 3D images. The correlation coefficients were calculated among the measured angles. The distal femoral angles were also compared between male and female femora. The 95% confidence intervals of the AVA and the NSA were calculated to be 24.22°-29.50° and 144.97°-147.50°, respectively. The 95% confidence intervals of the aLDFA and the CDFA for all studied dogs were 92.62°-94.08° and 89.09°-91.94°, respectively. The NSA showed no correlation with either the aLDFA or CDFA. There was a weak inverse correlation between the AVA and CDFA and a weak positive correlation between the AVA and aLDFA. The differences in the aLDFA and CDFA measurements between male and female dog were not significant. In conclusion, femoral version, regardless of the plane, might have little influence on distal femoral morphology in normal dogs. Besides this, there is no evidence of a sexual dimorphism in the varus and procurvatum angles of the dog distal femur. The data from this study may be used in both orthopaedic studies and for clinical applications related to the distal femur of dogs., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Background Neck-shaft angle (NSA) is one of the prominent features in the proximal femur which is an important determinant of fracture of femoral neck. Present study evaluating the value of neck-shaft angle has relied heavily on radiographs. As knowledge of neck-shaft angle is important to orthopaedic surgeons, there is need to elucidate whether there is significant variation of this angle among the two different genders and various age groups of both right and left femora of Nepalese population. Objective To ascertain the value of neck-shaft angle in the Nepalese population by means of a radiographic study and to correlate the values with regard to right neck-shaft angle/ left neck-shaft angle side (RNSA/LNSA), gender and three different age group. Method Normal pelvic radiographs of 148 patients seen at department of orthopedic and radiology, College of Medical Sciences- Teaching Hospital (COMS-TH), Bharatpur, Chitwan from the month of February 2017 to June 2017 were divided into two different gender and three different age groups (21-40 years, 41-60 years and Above 60 years) and their neck-shaft angle of both right and left sides were recorded. Result The average of RNSA and LNSA were found to be 132.96±6.05° and 131.54±13.66° respectively for male and 134±6.57° and 132.98±6.23° respectively for female. In total the average RNSA and LNSA were 133.51±6.32° and 132.26±10.61° respectively. Similarly, the average RNSA and LNSA for three different age groups (21-40 years, 41-60 years and Above 60 years) were found to be 133.76±6.44°, 133.69±6.36° and 132.50±6.06° and the 133.35±6.29°, 132.47±5.85° and 128.84±21.98° respectively. Conclusion The average neck-shaft angle recorded here shows no significant difference in both RNSA and LNSA in males except for a small and significant difference in LNSA in female of three different age groups.

The aim of this ex vivo study was to test a novel three-dimensional (3D) automated computer-aided design (CAD) method (aCAD) for the computation of femoral angles in dogs from 3D reconstructions of computed tomography (CT) images. The repeatability and reproducibility of three manual radiography, manual CT reconstructions and the aCAD method for the measurement of three femoral angles were evaluated: (1) anatomical lateral distal femoral angle (aLDFA); (2) femoral neck angle (FNA); and (3) femoral torsion angle (FTA). Femoral angles of 22 femurs obtained from 16 cadavers were measured by three blinded observers. Measurements were repeated three times by each observer for each diagnostic technique. Femoral angle measurements were analysed using a mixed effects linear model for repeated measures to determine the levels of intra-observer agreement (repeatability) and inter-observer agreement (reproducibility). Repeatability and reproducibility of measurements using the aCAD method were excellent (intra-class coefficients, ICCs≥0.98) for all three angles assessed. Manual radiography and CT exhibited excellent agreement for the aLDFA measurement (ICCs≥0.90). However, FNA repeatability and reproducibility were poor (ICCs<0.8), whereas FTA measurement showed slightly higher ICCs values, except for the radiographic reproducibility, which was poor (ICCs<0.8). The computation of the 3D aCAD method provided the highest repeatability and reproducibility among the tested methodologies., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Currently, there is no definition or classification system for quadrilateral plate (QLP) fractures; the aim was to anatomically and radiologically characterise the QLP, propose a definition and classify QLP fractures., Methods: This study included an anatomical component and a radiological component. The anatomical study aimed at defining the characteristics of the QLP; the QLP was identified using four articulating bony pelvis specimens. A titanium mesh was placed on the specimens' quadrilateral surface; standard anteroposterior and oblique views were obtained, and axial CT images, to determine the radiological landmarks. The radiological study included the review of images of patients with QLP fractures; fractures involving the QLP were identified in a series of 609 consecutive patients with acetabular fractures., Results: We considered QLP fractures where the QLP is separated from both columns of the acetabulum; this was found in 16% (98 cases). They were mostly encountered with associated both columns fractures (60 cases; 61%), Separation of the QLP could be complete or incomplete, or simple or comminuted, so QLP fractures were divided into three types: QLP1, simple with incomplete separation; QLP2, comminuted with incomplete separation; QLP3, comminuted with complete separation (QLP4), simple with complete separation., Conclusion: The QLP was characterised, and a definition and classification system; Cairo University Hospitals (CUH) Classification was proposed for these fractures. We believe that this classification may prove useful in the future for the identification and management of these fractures., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Dense and stiff metallic femoral stems implanted into femurs for total hip arthroplasties produce a stress shielding effect since they modify the original load sharing path in the bony structure. Consequently, in the long term, the strain adaptive nature of bones leads to bone resorption, implant loosening, and the need for arthroplasty revision. The design of new cementless femoral stems integrating open porous structures can reduce the global stiffness of the stems, allowing them a better match with that of bones and provide their firm fixation via bone ingrowth, and, thus reduce the risk of implantation failure., Methods: This paper aims to develop and validate a simplified numerical model of stress shielding, which calculates the levels of bone resorption or formation by comparing strain distributions on the surface of the intact and the implanted femurs subjected to a simulated biological loading. Two femoral stems produced by laser powder-bed fusion using Ti-6Al-4V alloy are employed: the first is fully dense, while the second features a diamond cubic lattice structure in its core. The validation consists of a comparison of the numerically calculated force-displacement diagrams, and displacement and strain fields with their experimental equivalents obtained using the digital image correlation technique., Results and Conclusions: The numerical models showed reasonable agreement between the force-displacement diagrams. Also, satisfactory results for the correlation analyses of the total displacement and equivalent strain fields were obtained. The stress shielding effect of the implant was assessed by comparing the equivalent strain fields of the implanted and intact femurs. The results obtained predicted less bone resorption in the femur implanted with the porous stem than with its dense counterpart., (Copyright © 2017 Elsevier Ltd. All rights reserved.)