Hip Structure Research Articles

Hip geometry and strength remain stable the first year after kidney transplantation – an ibandronate/placebo post hoc analysis

Abstract The sensitivity of bone mineral density (BMD) to identify patients with high fracture risk after kidney transplantation is low, wherefore alternative tools are needed. Hip Structure Analysis (HSA) provides an estimation of hip structural geometry and strength based on conventional DXA scans for hip analyses. We aimed to investigate the effect of antiresorptive therapy on hip geometrical and strength parameters by HSA. In a post hoc analysis of a 12-month randomized, double-blind, placebo-controlled trial evaluating the effect of ibandronate in addition to active vitamin D and calcium in kidney transplant recipients (KTR), we re-analyzed dual total hip and femoral neck DXA scans to measure cortical bone thickness (CBT) in the femoral neck (CBTNECK), calcar (CBTCALCAR), and shaft (CBTSHAFT), along with femur neck width, hip axis length, and to estimate Buckling Ratio and Strength Index. DXA measurements were performed within 5 weeks after transplantation and repeated at 10 weeks and 1-year post-transplant. The study included a total of 127 de novo KTR with eGFR >30 mL/min at baseline. The five geometrical and the strength and stability hip parameters remained stable over the first post-transplant year irrespective of antiresorptive therapy. We detected no statistically significant between-group differences in any of the HSA measures. Change in geometrical hip parameters and Buckling Ratio over the study duration was not correlated with change in plasma parathyroid hormone or change in dual total hip BMD. In this study, the so far largest of HSA in KTR, antiresorptive therapy with ibandronate for 12 months did not affect measures of hip geometry or strength. Clinical Trial Registration: www.clinicaltrials.gov as NCT00423384, EudraCT number 2006-003884-30.

Incidence of hip problems in developmental central hypotonia: A scoping review.

To describe what is known about hip problems in individuals with developmental central hypotonia. Searches were conducted in five databases to October 2023. Down syndrome was excluded from this analysis of less well-known genetic diagnoses. At least two reviewers independently screened titles, abstracts, read full-text articles, and extracted data. Of 89 full-text articles, 79 met inclusion criteria. Studies included 544 individuals aged 1 month to 63 years with Kabuki, 49, XXXXY, Prader-Willi, PURA, Koolen de Vries, Emanuel, TRPM3, Wolf-Hirschhorn, and other rare syndromes. Most diagnoses may be associated with a combination of differences in hip structure or stability that are evident at birth, or develop in early infancy, with increasing hip dysplasia and subluxation over time. Joint or ligamentous laxity was most reported along with hypotonia and hypermobility as risk factors. Limited data were identified about conservative or surgical intervention and outcomes in these populations. Children with significant hypotonia, with or without a confirmed genetic diagnosis, are at increased risk of hip problems that may be missed with standard neonatal screening. Ultrasound is recommended between 6 weeks and 6 months, and annual orthopaedic review with regular radiographs for older children and adults with significant and persistent hypotonia.

Impact of Bone Mineral Density and Bone Structural Properties on Postmenopausal Women With Rheumatoid Arthritis in Japan: A Cross-Sectional Study.

Introduction There has been no study on bone structural properties in postmenopausal women with rheumatoid arthritis (RA) in Japan. This study investigated bone mineral density (BMD) and bone structural properties in Japanese postmenopausal women with RA. Methods The study had a cross-sectional design and included 119 postmenopausal women aged 50-80 years with RA symptoms for more than five years. BMD, trabecular bone score (TBS), and results of hip structure analysis (HSA) were measured on dual-energy X-ray absorptiometry scans. The control group consisted of 288 women aged 50-80 years without RA. The RA group and control group using bisphosphonates were compared after propensity score matching for age, body mass index, and fracture history. Women in the RA group were also compared according to the use of glucocorticoids (GCs). Results After the propensity matching score, there were no other significant differences in BMD, TBS, and HSA parameters between the RA group and the control group. In the RA group, the TBS was lower in patients on GCs than those not on GCs (1.272 vs 1.313, p=0.008). There were no other significant differences in BMD and HSA parameters between patients in the RA group according to the use of GCs. Conclusion Although there were no differences in BMD, the TBS was lower in patients on GCs than those not on GCs in the RA group. It is thus important for physicians who administer GCs to treat patients with RA to be aware of not only BMD but also TBS.

Lost in research translation: Female athletes are not male athletes, especially at the hip.

Altered shape of the proximal femur (cam morphology) or acetabulum (pincer morphology) is indicative of femoroacetabular impingement, which can result in hip pain and osteoarthritis of the hip. As mechanical load during growth affects the resulting bone shape, there is strong evidence in males that cam morphology develops during skeletal growth while physes are open, rather than as an adaptation after growth plates are closed (skeletal maturity). This adaptation is particularly evident in athletes who participate at elite levels prior to skeletal maturity. The research providing this evidence, however, has primarily focused on male athletes. Despite the lack of inclusion in the research, females consistently comprise two thirds of the clinical and surgical populations with structural hip pain or pathology. Knowledge gained from male-dominated cohorts may not appropriately transfer to female athletes, especially at the hip. This perspectives article briefly reviews differences between females and males in femoral and acetabular structure, hormones, timing of puberty/maturation, hypermobility, activity level and movement control-factors which affect hip structure development and loading. Without female-focused research, the application of research findings from male athletes to female athletes may lead to ineffective or even inappropriate recommendations and treatments. Thus, there is a critical need for investment in research to promote life-long hip health for females.

3D-modeling from hip DXA shows improved bone structure with romosozumab followed by denosumab or alendronate.

Romosozumab treatment in women with postmenopausal osteoporosis increases bone formation while decreasing bone resorption, resulting in large BMD gains to reduce fracture risk within 1yr. DXA-based 3D modeling of the hip was used to assess estimated changes in cortical and trabecular bone parameters and map the distribution of 3D changes in bone parameters over time in patients from 2 randomized controlled clinical trials: FRAME (romosozumab vs placebo followed by denosumab) and ARCH (romosozumab vs alendronate followed by alendronate). For each study, data from a subset of ~200 women per treatment group who had TH DXA scans at baseline and months 12 and 24 and had provided consent for future research were analyzed post hoc. 3D-SHAPER software v2.11 (3D-SHAPER Medical) was used to generate patient-specific 3D models from TH DXA scans. Percentage changes from baseline to months 12 and 24 in areal BMD (aBMD), integral volumetric BMD (vBMD), cortical thickness, cortical vBMD, cortical surface BMD (sBMD), and trabecular vBMD were evaluated. Data from 377 women from FRAME (placebo, 190; romosozumab, 187) and 368 women from ARCH (alendronate, 185; romosozumab, 183) with evaluable 3D assessments at baseline and months 12 and 24 were analyzed. At month 12, treatment with romosozumab vs placebo in FRAME and romosozumab vs alendronate in ARCH resulted in greater increases in aBMD, integral vBMD, cortical thickness, cortical vBMD, cortical sBMD, and trabecular vBMD (P < .05 for all). At month 24, cumulative gains in all parameters were greater in the romosozumab-to-denosumab vs placebo-to-denosumab sequence and romosozumab-to-alendronate vs alendronate-to-alendronate sequence (P < .05 for all). 3D-SHAPER analysis provides a novel technique for estimating changes in cortical and trabecular parameters from standard hip DXA images. These data add to the accumulating evidence that romosozumab improves hip bone density and structure, thereby contributing to the antifracture efficacy of the drug.

Design and optimization of a new integrated hip and knee prosthesis structure.

Conventional hip disarticulation prostheses (HDPs) are passive devices with separate joint structures, limiting amputees' ability to control and resulting in abnormal gait patterns. This study introduces a new HDP integrating the hip and knee joints for amputees' natural gait. The new HDP restores the physiological rotation center of the hip with a remote center of motion (RCM) structure, and simulates the knee motion with a four-bar structure. Nonlinear programming was employed to optimize the hip-knee joint structure. A hybrid multi-objective drive structure with a series-parallel connection was also designed to ensure motion synergy between the hip and knee joints. Finally, a prototype of the prosthesis was tested using the HDP test system. The optimization results demonstrate that the new HDP accurately restores the rotation center of the femur in amputees, with the knee's instantaneous center of rotation (ICR) trajectory closely resembling that of the human knee (Pearson correlation coefficient is 0.999). The study shows that the new HDP achieves a motion reproduction accuracy of over 95% for the human hip joint at walking speeds above 1.5 km/h, 38% higher than conventional prosthesis. Similarly, at the same walking speed, the new HDP replicates the motion of the human knee at 82.89%, surpassing conventional prosthesis by 57.85%. The new HDP restores symmetry and replicates synergistic movement in amputees' lower limbs, exhibiting superior movement characteristics compared to conventional prostheses. This innovative HDP has the potential to enhance the quality of life for amputees.

Endocortical Trabecularization in Acromegaly: The Cause for the Paradoxically Increased Vertebral Fracture Risk?

Growth hormone (GH) is nonphysiologically increased in acromegaly, stimulating target tissues directly and indirectly via insulin-like growth factor type 1 (IGF-1). Despite GH having anabolic effects on bone growth and renewal, the risk of vertebral fractures is paradoxically increased in acromegaly. We hypothesized that bone tissue compartments were differentially affected by hormonal alterations in active and controlled acromegaly. We aimed to study the effect of sex and gonadal status on long-term outcome of bone mass and structure to understand the biomechanical competence of bone. We followed 62 patients with newly diagnosed acromegaly longitudinally (median 4.8 years after pituitary surgery) to investigate changes assessed by dual X-ray absorptiometry (DXA), trabecular bone score (TBS), and hip structure analysis (HSA). At diagnosis, patients had increased bone mineral density (BMD) in most compartments compared with normative data (Z-scores). Conversely, TBS Z-score was decreased (Z = -0.64 (SD 1.73), p = 0.028). Following treatment of acromegaly, BMD increased further in compartments containing predominantly trabecular bone, such as the lumbar spine, in eugonadal and male subjects, while compartments with predominantly cortical bone, such as the hip and femoral neck, were unchanged. Total body measurements showed further increase in BMD independent of sex and gonadal status. TBS did not change. HSA revealed a significant decrease in cortical thickness in both sexes independent of gonadal status, whereas the overall size of bone (hip axis length and neck width) did not change over time. In conclusion, patients with acromegaly had increased bone mass and dimensions by DXA. Following normalization of disease activity, BMD increased mainly in compartments rich in trabecular bone, reflecting a closure of the remodeling space. However, HSA revealed a significant decrease in cortical thickness, implying endocortical trabecularization, potentially explaining the increased risk for incident vertebral fractures following treatment. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Associations Among Hip Structure, Bone Mineral Density, and Strength Vary With External Bone Size in White Women.

Bone mineral density (BMD) is heavily relied upon to reflect structural changes affecting hip strength and fracture risk. Strong correlations between BMD and strength are needed to provide confidence that structural changes are reflected in BMD and, in turn, strength. This study investigated how variation in bone structure gives rise to variation in BMD and strength and tested whether these associations differ with external bone size. Cadaveric proximal femurs (n= 30, White women, 36-89+ years) were imaged using nanocomputed tomography (nano-CT) and loaded in a sideways fall configuration to assess bone strength and brittleness. Bone voxels within the nano-CT images were projected onto a plane to create pseudo dual-energy X-ray absorptiometry (pseudo-DXA) images consistent with a clinical DXA scan. A validation study using 19 samples confirmed pseudo-DXA measures correlated significantly with those measured from a commercially available DXA system, including bone mineral content (BMC) (R 2 = 0.95), area (R 2 = 0.58), and BMD (R 2 = 0.92). BMD-strength associations were conducted using multivariate linear regression analyses with the samples divided into narrow and wide groups by pseudo-DXA area. Nearly 80% of the variation in strength was explained by age, body weight, and pseudo-DXA BMD for the narrow subgroup. Including additional structural or density distribution information in regression models only modestly improved the correlations. In contrast, age, body weight, and pseudo-DXA BMD explained only half of the variation in strength for the wide subgroup. Including bone density distribution or structural details did not improve the correlations, but including post-yield deflection (PYD), a measure of bone material brittleness, did increase the coefficient of determination to more than 70% for the wide subgroup. This outcome suggested material level effects play an important role in the strength of wide femoral necks. Thus, the associations among structure, BMD, and strength differed with external bone size, providing evidence that structure-function relationships may be improved by judiciously sorting study cohorts into subgroups. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Hip structure analysis and femoral osteodensitometry in aged postmenopausal women with hip osteoarthritis and femoral neck fracture.

Osteoarthritis (OA), osteoporosis, and bone fractures are frequent aging-related conditions. Regardless of the growing research interest in the effects of hip OA on femoral fracture risk, data about the region specificity of osteodensitometric and hip structure analysis (HSA) parameters of the proximal femora are lacking in aged postmenopausal women with hip OA compared to individuals with femoral neck fragility fracture. This study included 76 postmenopausal women admitted for total hip arthroplasty due to non-traumatic femoral neck fracture (FN_Fx group, n = 39) and hip osteoarthritis (OA group, n = 37). Osteodensitometric parameters differed significantly between the OA and FN_Fx groups, depicting lower bone mineral density in the FN_Fx group (p < 0.05). The most significant increase in these parameters was registered in the intertrochanteric region of the OA group. Moreover, the OA-induced changes in HSA-derived parameters displayed significant regional heterogeneity, with the intertrochanteric region showing the most notable difference between OA and FN_Fx group. Our data may indicate that OA displayed the most prominent positive effect on the intertrochanteric femoral region, revealing the regional heterogeneity in structural geometry and biomechanical indices of proximal femora in OA individuals. Since we did not observe significant differences in the femoral neck region, we may speculate that OA does not have a substantial protective effect on the femoral neck fracture risk in aged postmenopausal women.

Age Related Trends in Structural Indices of Proximal Femur in Women Aged 20-70 in Southern Sri Lanka

Age related trends of the indices of hip structure help understanding how bone strength changes with age and the increased bone fragility in old age. Community-dwelling women aged 20-70years (n = 419) were selected by stratified random method and divided into age categories; 20-29years (n-69), 30-39years (n = 60), 40-49years (n = 69), 50-59years (n = 107) and 60-70years (n = 114). All subjects underwent dual energy x-ray absorptiometry (DXA) and hip structure analysis using Hologic Discovery scanner (Hologic Inc, Bedford, USA). Measured indices included hip axis length (HAL) and neck shaft angle (NSA) of the proximal femur. Cross sectional area (CSA), cross sectional moment of inertia (CSMI), section modulus (SM), cortical thickness (CT), buckling ration (BR) of three regions of interest; narrow neck, intertrochanteric region and femoral shaft, were also measured. Age related trends of all indices were studied with Locally Weighted Scatterplot Smoothing lines (LOESS) and ANOVA. Mean HAL and NSA values were not different between age categories. CSA, CSMI, SM and CT in three different regions showed curvilinear relationships with age. These indices gradually increased with age between 20-50 years and the maximum values were seen in the 40-49years age category and they declined afterwards. The decline of these indices was more rapid in the narrow neck and intertrochanter regions when compared with femoral shaft and the lowest mean CSA, CSMI, SM and CT in these two regions were seen in the 60-70 age category. BR showed a gradual decrease with age between 20-50 years and the lowest mean value was seen in the 40-49 age category. BR increased afterwards and the maximum mean value was seen in the 60-70 age category. This study demonstrates the dynamics of structural properties of proximal femur in the three selected cross sections of community-dwelling women aged 20-70 years and the increased bone fragility in old age.

Osteosarcopenia-The Role of Dual-Energy X-ray Absorptiometry (DXA) in Diagnostics.

Osteoporosis and sarcopenia lead to increased mortality, but their early diagnosis allows preventive measures and treatment to be implemented. The dual-energy X-ray absorptiometry (DXA) method enables the assessment of both bone mineral density (BMD) and bone quality based on the trabecular bone score (TBS), the Bone Strain Index (BSI), hip structure analysis (HSA), and comprehensive hip axis length (HAL). The main complications of osteoporosis are fractures, and a BMD value or T-score together with TBS can be also applied in fracture risk calculation using the Fracture Risk Assessment Tool (FRAX). In recent years, the interest in sarcopenia has increased. There are many methods for assessing the quality, quantity and function of muscles. Total body DXA provides information not only about the BMD of the whole skeleton or the amount of lean tissue (identified as fat-free mass), but also about the amount and distribution of adipose tissue. Some parameters obtained from DXA measurements related to muscle and/or fat mass are used in the assessment of osteosarcopenia. The following article presents a wide range of possibilities for the use of the DXA method in the diagnosis of osteosarcopenia because DXA is a useful technique for the diagnosis of bone density and body composition together.

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.

Hip Landmark Detection With Dependency Mining in Ultrasound Image.

Developmental dysplasia of the hip (DDH) is a common and serious disease in infants. Hip landmark detection plays a critical role in diagnosing the development of neonatal hip in the ultrasound image. However, the local confusion and the regional weakening make this task challenging. To solve these challenges, we explore the stable hip structure and the distinguishable local features to provide dependencies for hip landmark detection. In this paper, we propose a novel architecture named Dependency Mining ResNet (DM-ResNet), which investigates end-to-end dependency mining for more accurate and much faster hip landmark detection. First of all, we convert the landmark detection to the heatmap estimation by ResNet to build a strong baseline architecture for fast and accurate detection. Secondly, a dependency mining module is explored to mine the dependencies and leverage both the local and global information to decline the local confusion and strengthen the weakening region. Thirdly, we propose a simple but effective local voting algorithm (LVA) that seeks trade-off between long-range and short-range dependencies in the hip ultrasound image. Besides, a dataset with 2000 annotated hip ultrasound images is constructed in our work. It is the first public hip ultrasound dataset for open research. Experimental results show that our method achieves excellent precision in hip landmark detection (average point error of 0.719mm and successful detection rate within 1mm of 79.9%).

Topological Analysis of a Novel Compact Omnidirectional Three-Legged Robot with Parallel Hip Structures Regarding Locomotion Capability and Load Distribution

In this study, a novel design for a compact, lightweight, agile, omnidirectional three-legged robot involving legs with four degrees of freedom, utilizing an spherical parallel mechanism with an additional non-redundant central support joint for the robot hip structure is proposed. The general design and conceptual ideas for the robot are presented, targeting a close match of the well-known SLIP-model. CAD models, 3d-printed prototypes, and proof-of-concept multi-body simulations are shown, investigating the feasibility to employ a geometrically dense spherical parallel manipulator with completely spherically shaped shell-type parts for the highly force-loaded application in the legged robot hip mechanism. Furthermore, in this study, an analytic expression is derived, yielding the calculation of stress forces acting inside the linkage structures, by directly constructing the manipulator hip Jacobian inside the force domain.

Bending Resistance at Hip and Fractures Risk in Postmenopausal Women Independent of Bone Mineral Density

Several studies suggest that aging loss of bone mass is not necessarily associated with reduced mechanical proprieties as bending resistance. Since postmenopausal women with fracture and without osteoporosis might have an impairment in the bending mechanisms at hip, our aim was to assess if women with and without fractures differ in the femoral parameters of resistance to bending, independent of the bone loss. In this cross-sectional study we enrolled 192 postmenopausal women who underwent X-ray absorptiometry scan to measure bone mineral density as well as cross-sectional geometry parameters at the hip (Hip structure analysis). Among women with osteoporosis, a higher odds ratio for fracture was found in the first tertile of NN-Dmax, a parameter linked to the resistance to bending forces in a cross-section (tertile I, OR = 6.7, p = 0.03; CI 1.19–38.01; reference tertile III). We also found a significantly higher risk for major fracture in the first tertile of NN-Dmax (tertile I, OR = 6.0, p = 0.02; CI 1.26−28.4; reference tertile III). Among women without osteoporosis, a significantly higher odds ratio for fracture was found in the first tertile of IT-CSA, a parameter of resistance to axial load (tertile I, OR = 7.2, p = 0.002; CI 2.04–25.9; reference tertile III). We also found a significantly higher risk for major fracture in the first tertile of IT-CSA (OR = 18.4, p = 0.001; CI 1.52−221.8; tertile III reference). We demonstrate that some hip structural parameters are independently associated to the fracture risk in postmenopausal women.

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

BackgroundThe 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).MethodsAll 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.ResultsThe 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).ConclusionsProximal 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.

Predictors of total hip replacement in community based older adults: a cohort study

The purpose of this study is to describe predictors of total hip replacement (THR) in community dwelling older adults. A better understanding of predictors of THR can aid in triaging patients and researching preventative strategies. At baseline, participants had assessment of radiographic OA and cam morphology (from pelvic radiographs), shape mode scores and hip bone mineral density (BMD; from dual energy X-ray absorptiometry (DXA)). After 2.6 and 5 years, participants reported hip pain using WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), and had hip structural changes assessed using magnetic resonance imaging (MRI). Risk of THR was analysed using mixed-effect Poisson regression. Incidence of THR for OA over 14 years was 4.6% (37/801). As expected, WOMAC hip pain and hip radiographic OA both predicted risk of THR. Additionally, shape mode 2 score (decreasing acetabular coverage) (RR 1.83/SD; 95% CI 1.1-3.04), shape mode 4 score (non-spherical femoral head) (RR 0.59/SD; 95% CI 0.36-0.96), cam morphology (α>60°) (RR 2.2/SD; 95% CI 1.33-3.36), neck of femur BMD (RR 2.09/SD, 95% CI 1.48-2.94) and bone marrow lesions (BMLs) increased risk of THR (RR 7.10/unit; 95% CI 1.09-46.29). In addition to hip pain and radiographic hip OA, measures of hip shape, cam morphology, BMD and BMLs independently predict risk of THR. This supports the role of hip bone geometry and structure in the pathogenesis of end stage hip OA and has identified factors that can be used to improve prediction models for THR.

Current Applications and Selected Technical Details of Dual-Energy X-Ray Absorptiometry.

The application of dual-energy X-ray absorptiometry (DXA) examinations in the assessment of bone mineral density (BMD) in the lumbar spine, hip, and forearm is the basic diagnostic method for recognition of osteoporosis. The constant development of DXA technique is due to the aging of societies and the increasing importance of osteoporosis as a public health problem. In order to assess the degree of bone demineralization in patients with hyperparathyroidism, forearm DXA examination is recommended. The vertebral fracture assessment (VFA) of the thoracic and lumbar spine, performed by a highly-skilled technician, is an interesting alternative to the X-ray examination. The DXA total body examination can be useful in the evaluation of fat redistribution among patients after bariatric surgery, in patients infected with HIV and receiving antiretroviral therapy, and in patients with metabolic diseases and suspected to have sarcopenia. The assessment of visceral adipose tissue (VAT) and detection of abdominal aortic calcifications may be useful in the prediction of cardiovascular events. The positive effect of anti-resorptive therapy may affect some parameters of DXA hip structure analysis (HSA). Long-term anti-resorptive therapy, especially with the use of bisphosphonates, may result in changes in the DXA image, which may herald atypical femur fractures (AFF). Reduction of the periprosthetic BMD in the DXA measurements can be used to estimate the likelihood of loosening the prosthesis and periprosthetic fractures. The present review aims to present current applications and selected technical details of DXA.

Bone mineral density and hip structure changes over one-year in collegiate distance runners and non-athlete controls

Modification of bone is continuous throughout life and influenced by many factors, including physical activity. This study investigated changes in areal bone mineral density (aBMD) and hip structure among male and female collegiate distance runners and non-athlete controls over 12 months. Using dual-energy x-ray absorptiometry (DXA) and hip structure analysis (HSA) software, aBMD at the posterior-anterior (PA) and lateral spine, femoral neck, total hip (TH), whole body (WB), and bone geometry at the narrow neck (NN) of the femur was measured three times over 12 months. HSA included cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), and Z-section modulus (Z). Male runners had significantly higher aBMD at TH and WB and greater CSA, CSMI, and Z than male controls at the end of 12 months. Female controls had higher aBMD at the PA spine than female runners at the end of 12 months. Male runners had significant increases in aBMD at the PA (p = 0.003) and lateral spine (p = 0.002), and TH (p = 0.002), female runners had significant decreases in aBMD at TH (p = 0.015) and WB (p = 0.002), male controls had significant increases in aBMD at the PA spine (p < 0.001) and WB (p < 0.001), and female controls had significant decreases in aBMD at lateral spine and TH (p = 0.008) over the year. When applying covariates of bone-free lean mass and vitamin D, male distance runners demonstrated significant improvement in CSA (3.602 ± 0.139 vs. 3.675 ± 0.122 cm2, p = 0.05), CSMI (3.324 ± 0.200 to 3.467 ± 0.212 cm4, p < 0.05), and Z (1.81 ± 0.08 to 1.87 ± 0.08 cm3, p = 0.05) during the study. No other changes in hip structure occurred over the year. Distance running may be beneficial to aBMD and hip structure in college-age males but not females. Further research is needed on potential influences of weight-bearing activity, energy availability, and hormonal status on aBMD and hip structure in males and females.

Development of Hip Bone Geometry During Gender-Affirming Hormone Therapy in Transgender Adolescents Resembles That of the Experienced Gender When Pubertal Suspension Is Started in Early Puberty.

ABSTRACTBone geometry can be described in terms of periosteal and endocortical growth and is partly determined by sex steroids. Periosteal and endocortical apposition are thought to be regulated by testosterone and estrogen, respectively. Gender‐affirming hormone (GAH) treatment with sex steroids in transgender people might affect bone geometry. However, in adult transgender people, no change in bone geometry during GAH was observed. In this study, we investigated changes in bone geometry among transgender adolescents using a gonadotropin‐releasing hormone agonist (GnRHa) and GAH before achieving peak bone mass. Transgender adolescents treated with GnRHa and subsequent GAH before the age of 18 years were eligible for inclusion. Participants were grouped based on their Tanner stage at the start of GnRHa treatment and divided into early, mid, and late puberty groups. Hip structure analysis software calculating subperiosteal width (SPW) and endocortical diameter (ED) was applied to dual‐energy X‐ray absorptiometry scans performed at the start of GnRHa and GAH treatments, and after ≥2 years of GAH treatment. Mixed‐model analyses were performed to study differences over time. Data were visually compared with reference values of the general population. A total of 322 participants were included, of whom 106 were trans women and 216 trans men. In both trans women and trans men, participants resembled the reference curve for SPW and ED of the experienced gender but only when GnRHa was started during early puberty. Those who started during mid and late puberty remained within the reference curve of the gender assigned at birth. A possible explanation might be sought in the phenomenon of programming, which conceptualizes that stimuli during critical windows of development can have major consequences throughout one's life span. Therefore, this study adds insights into sex‐specific bone geometry development during puberty of transgender adolescents treated with GnRHa, as well as the general population. © 2021 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.