The effect of calcaneus and metatarsal head offloading insoles on healthy subjects' gait kinematics, kinetics, asymmetry, and the implications for plantar pressure management: A pilot study

BACKGROUND

The global number of people with diabetes is estimated to reach 643 million by 2030 of whom 19-34% will present with diabetic foot ulceration. Insoles which offload high-risk ulcerative regions on the foot, by removing insole material, are the main contemporary conservative treatment to maintain mobility and reduce the likelihood of ulceration. However, their effect on the rest of the foot and relationship with key gait propulsive and balance kinematics and kinetics has not been well researched.

PURPOSE

The aim of this study is to investigate the effect of offloading insoles on gait kinematics, kinetics, and plantar pressure throughout the gait cycle.

METHODS

10 healthy subjects were recruited for this experiment to walk in 6 different insole conditions. Subjects walked at three speeds on a treadmill for 10 minutes while both plantar pressure and gait kinematics, kinetics were measured using an in-shoe pressure measurement insole and motion capture system/force plates. Average peak plantar pressure, pressure time integrals, gait kinematics and centre of force were analysed.

RESULTS

The average peak plantar pressure and pressure time integrals changed by -30% (-68% to 3%) and -36% (-75% to -1%) at the region of interest when applying offloading insoles, whereas the heel strike and toe-off velocity changed by 15% (-6% to 32%) and 12% (-2% to 19%) whilst walking at three speeds.

CONCLUSION

The study found that offloading insoles reduced plantar pressure in the region of interest with loading transferred to surrounding regions increasing the risk of higher pressure time integrals in these locations. Heel strike and toe-off velocities were increased under certain configurations of offloading insoles which may explain the higher plantar pressures and supporting the potential of integrating kinematic gait variables within a more optimal therapeutic approach. However, there was inter-individual variability in responses for all variables measured supporting individualised prescription.

Genetic Variants in WNT16 and PKD2L1 Locus Affect Heel Ultrasound Bone Stiffness: Analyses from the General Population and Patients Evaluated for Osteoporosis

Osteoporosis, a complex chronic disease with increasing prevalence, is characterised by reduced bone mineral density (BMD) and increased fracture risk. The high heritability of BMD suggests substantial impact of the individual genetic disposition on bone phenotypes and the development of osteoporosis. In the past years, genome-wide association studies (GWAS) identified hundreds of genetic variants associated with BMD or osteoporosis. Here, we analysed 1103 single nucleotide polymorphisms (SNPs), previously identified as associated with estimated BMD (eBMD) in the UK Biobank. We assessed whether these SNPs are related to heel stiffness index obtained by quantitative ultrasound in 5665 adult participants of the Study of Health in Pomerania (SHIP). We confirmed 45 significant associations after correction for multiple testing. Next, we analysed six selected SNPs in 631 patients evaluated for osteoporosis [rs2707518 (CPED1/WNT16), rs3779381 (WNT16), rs115242848 (LOC101927709/EN1), rs10239787 (JAZF1), rs603424 (PKD2L1) and rs6968704 (JAZF1)]. Differences in minor allele frequencies (MAF) of rs2707518 and rs3779381 between SHIP participants (higher MAF) and patients evaluated for osteoporosis (lower MAF) indicated a protective effect of the minor allele on bone integrity. In contrast, differences in MAF of rs603424 indicated a harmful effect. Co-localisation analyses indicated that the rs603424 effect may be mediated via stearoyl-CoA desaturase (SCD) expression, an enzyme highly expressed in adipose tissue with a crucial role in lipogenesis. Taken together, our results support the role of the WNT16 pathway in the regulation of bone properties and indicate a novel causal role of SCD expression in adipose tissue on bone integrity.

On the morphological relations of the Achilles tendon and plantar fascia via the calcaneus: a cadaveric study

Current treatments of plantar fasciitis are based on the premise that the Achilles tendon (AT) and plantar fascia (PF) are mechanically directly linked, which is an area of debate. The aim of this study was to assess the morphological relationship between the AT and PF. Nineteen cadaveric feet were x-ray imaged, serially sectioned and plastinated for digital image analyses. Measurements of the AT and PF thicknesses and cross-sectional areas (CSA) were performed at their calcaneal insertion. The fiber continuity was histologically assessed in representative subsamples. Strong correlations exist between the CSA of the AT and PF at calcaneal insertion and the CSA of PF's insertional length (r = 0.80), and between the CSAs of AT's and PF's insertional lengths. Further correlations were observed between AT and PF thicknesses (r = 0.62). This close morphological relationship could, however, not be confirmed through x-ray nor complete fiber continuity in histology. This study provides evidence for a morphometric relationship between the AT and PF, which suggests the presence of a functional relationship between these two structures following the biological key idea that the structure determines the function. The observed morphological correlations substantiate the existing mechanical link between the AT and PF via the posterior calcaneus and might explain why calf stretches are a successful treatment option for plantar heel pain.

Knee Osteoarthritis Grade does not Correlate with Quadriceps Muscle Strength or Bone Properties of the Calcaneus in Men Aged 80 Years or More who Can Walk independently

Purpose: Muscle weakness and bone deterioration in the elderly are related to falls and fractures, resulting in decreased mobility. Knee osteoarthritis also may contribute to falls and fractures and thereby affect mortality rates. The Kellgren–Lawrence (KL) classification is widely used in the radiographic evaluation of knee osteoarthritis. Aims: This study aimed to evaluate the quadriceps strength and bone properties of the calcaneus for each KL grade, and to clarify the impact of knee osteoarthritis grade on quadriceps strength and bone properties. Methods: This prospective cross-sectional study included data on 108 male patients (213 knees), aged ≥80 years, who could walk independently. A handheld dynamometer was used to measure quadriceps strength. Bone properties were evaluated using broadband ultrasound attenuation with a portable bone densitometer. Weight-bearing standing knee radiographs were evaluated using KL classification. Quadriceps strength and bone properties were evaluated for each KL grade and the correlations between the grade and quadriceps strength and bone properties were assessed simultaneously. Results: The numbers of participants in KL grades I–IV were 46, 102, 45, and 20, respectively. There were no differences among grades for either quadriceps strength or bone properties. Conclusions: Participants exhibited good quadriceps strength and bone properties regardless of their KL grade. Relatively high mechanical loading of muscle and bone incurred while walking independently, likely explaining this result. Clinically, this study demonstrated the absence of correlations between KL grade and quadriceps strength and bone properties, as was previously reported in studies showing the absence of a correlation between KL grade and pain.

Combined Effect of Osteoporosis and Poor Dynamic Balance on the Incidence of Sarcopenia in Elderly Chinese Community Suburban-Dwelling Individuals

OBJECTIVES

Given the increasing prevalence of osteoporosis and the important role dynamic balanced plays in the assessment of muscle function, we aimed to examine the joint and separate effects of osteoporosis and poor dynamic balance on the incidence of sarcopenia in Chinese elderly individuals.

DESIGN

This study was conducted on 658 (44.4% male) Chinese suburban-dwelling participants with a mean age of 68.42 ± 5.43 years who initially had no sarcopenia and were aged ≥60 years. A quantitative ultrasound scan of each participant's calcaneus with a T score less than -2.5 was used to identify the prevalence of osteoporosis. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia criteria. We assessed dynamic balance using the Timed Up and Go Test (TUGT). Participants who scored in the top 20% on the TUGT were defined as having poor dynamic balance.

RESULTS

After a follow-up of three years, the incidence of sarcopenia in the general population was 8.1% (9.6% in males, 6.8% in females). The incidence of sarcopenia was progressively greater in people suffering from both osteoporosis and poor dynamic balance (OR=2.416, 95%CI=1.124-5.195) compared to those who only had osteoporosis (OR=0.797, 95%CI=0.378-1.682) or poor dynamic balance (OR=1.226, 95%CI=0.447-3.363) in models without adjustments. Even after adjusting for potential confounders, the result still held true (OR=2.431, 95%CI=1.053-5.614).

CONCLUSIONS

In our study, we found individuals who suffered from both osteoporosis and poor dynamic balance simultaneously had a significantly higher incidence of sarcopenia than those who suffered from either one or the other.

Microwave tomography with phaseless data on the calcaneus by means of artificial neural networks

The aim of this study is to use a multilayer perceptron (MLP) artificial neural network (ANN) for phaseless imaging the human heel (modeled as a bilayer dielectric media: bone and surrounding tissue) and the calcaneus cross-section size and location using a two-dimensional (2D) microwave tomographic array. Computer simulations were performed over 2D dielectric maps inspired by computed tomography (CT) images of human heels for training and testing the MLP. A morphometric analysis was performed to account for the scatterer shape influence on the results. A robustness analysis was also conducted in order to study the MLP performance in noisy conditions. The standard deviations of the relative percentage errors on estimating the dielectric properties of the calcaneus bone were relatively high. Regarding the calcaneus surrounding tissue, the dielectric parameters estimations are better, with relative percentage error standard deviations up to ≈ 15%. The location and size of the calcaneus are always properly estimated with absolute error standard deviations up to ≈ 3 mm. Microwave tomography of the calcaneus using phaseless data. Simulations were inspired in Computed Tomography images from real heels (above). Inverse problem was solved using Multilayer Perceptron Artificial Neural Network (below).

Tea consumption and bone health in Chinese adults: a population-based study

Tea is a worldwide drink with controversial effect on bone health. The sex-specific associations are unrevealed among general population. This study showed that prolonged moderate tea consumption benefited bone health in women, while no additional benefit with stronger tea. However, tea consumption was not associated with bone health in men.

INTRODUCTION

Tea consumption has been shown a potentially beneficial effect on bone health in postmenopausal women. However, little is known about such association in men, and whether stronger tea instead harms bone health due to elevated urinary excretion of calcium associated with caffeine in the tea. The aim of this study was to examine the association between various metrics of tea consumption and bone health.

METHODS

The present study included 20,643 participants from the China Kadoorie Biobank (CKB), who have finished both baseline survey (2004-2008) and a re-survey (2013-2014). They were aged 38-86 years at re-survey. Tea consumption was self-reported at both baseline and re-survey. Bone mineral density (BMD) was measured using calcaneal quantitative ultrasound once at re-survey.

RESULTS

Compared with non-consumers, prolonged weekly tea consumers in women was associated with higher calcaneus BMD measures, with β (95% CI) of 0.98 (0.22, 1.74) for BUA, 4.68 (1.74, 7.61) for SOS, and 1.95 (0.81, 3.10) for SI. Among prolonged weekly tea consumers, no linear increase in BMD measures with the amount of tea leaves added was observed. The SOS and SI were higher in consumers with tea leaves 3.0-5.9 g/day than in those with < 3.0 g/day, but were reduced to non-significant for those with ≥ 6.0 g/day. Tea consumption was not associated with calcaneus BMD measures in men.

CONCLUSION

Prolonged moderate tea consumption benefited bone health in women but not in men. For stronger tea consumption with more tea leaves added, neither benefit nor harm to bone health was observed.

A nearly complete foot from Dikika, Ethiopia and its implications for the ontogeny and function of Australopithecus afarensis

The functional and evolutionary implications of primitive retentions in early hominin feet have been under debate since the discovery of Australopithecus afarensis. Ontogeny can provide insight into adult phenotypes, but juvenile early hominin foot fossils are exceptionally rare. We analyze a nearly complete, 3.32-million-year-old juvenile foot of A. afarensis (DIK-1-1f). We show that juvenile A. afarensis individuals already had many of the bipedal features found in adult specimens. However, they also had medial cuneiform traits associated with increased hallucal mobility and a more gracile calcaneal tuber, which is unexpected on the basis of known adult morphologies. Selection for traits functionally associated with juvenile pedal grasping may provide a new perspective on their retention in the more terrestrial adult A. afarensis.

Calcaneus range of motion underestimated by markers on running shoe heel

BACKGROUND

The measurement of rearfoot kinematics by placing reflective markers on the shoe heel assumes its motion is identical to the foot's motion. Studies have compared foot and shoe kinematics during running but with conflicting results. The primary purpose of this study was to compare shoe and calcaneus three-dimensional range of motion during running. A secondary purpose was to determine the effect of a less rigid heel counter on tibia motion.

RESEARCH QUESTION

Do markers placed on the shoe heel accurately represent calcaneus kinematics during running?

METHODS

Three-dimensional coordinate data were collected on 14 subjects (M/F: 9/5) who ran on an instrumented treadmill at 3.35 m/s under four conditions: modified/intact neutral shoes, and modified/intact support shoes. Shoes were modified by placing holes through the heel to allow for shoe heel and calcaneus coordinate data to be collected simultaneously via reflective markers on the shoe and on the skin of the heel within the shoe. Calcaneus, shoe heel, and tibia ROM were calculated from 0 to 50% stance phase and compared across shoe conditions.

RESULTS

Calcaneal frontal plane ROM was significantly greater than neutral and support shoe heel ROM (p < 0.001). Calcaneus ROM was also significantly greater than shoe heel ROM in the transverse (p < 0.001) and sagittal (p < 0.001) planes. No change in tibial transverse plane ROM was observed (p = 0.346) across shoe heel conditions.

SIGNIFICANCE

Shoe markers significantly underestimated calcaneus ROM across all planes of motion. These findings suggest calcaneus kinematics cannot be accurately measured with markers placed solely on the shoe heel. Additionally, the required modifications to the shoe's heel had no effect on tibia ROM in the transverse plane.

Trabecular bone in the calcaneus of runners

Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6), rearfoot-striking runners (n = 6), and non-runners (n = 6), all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (<0.80). Trabecular thickness was positively correlated with weekly running distance (r2 = 0.417, p<0.05) and years running (r2 = 0.339, p<0.05) and negatively correlated with age at onset of running (r2 = 0.515, p<0.01) Trabecular thickness, mineral density and bone volume ratio of nonrunners were highly correlated with body mass (r2 = 0.824, p<0.05) and nonrunners were significantly heavier than runners (p<0.05). Adjusting for body mass revealed significantly thicker trabeculae in the posterior calcaneus of forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the posterior calcaneus.

Relationships among ultrasonic and mechanical properties of cancellous bone in human calcaneus in vitro

Clinical bone sonometers applied at the calcaneus measure broadband ultrasound attenuation and speed of sound. However, the relation of ultrasound measurements to bone strength is not well-characterized. Addressing this issue, we assessed the extent to which ultrasonic measurements convey in vitro mechanical properties in 25 human calcaneal cancellous bone specimens (approximately 2×4×2cm). Normalized broadband ultrasound attenuation, speed of sound, and broadband ultrasound backscatter were measured with 500kHz transducers. To assess mechanical properties, non-linear finite element analysis, based on micro-computed tomography images (34-micron cubic voxel), was used to estimate apparent elastic modulus, overall specimen stiffness, and apparent yield stress, with models typically having approximately 25-30 million elements. We found that ultrasound parameters were correlated with mechanical properties with R=0.70-0.82 (p<0.001). Multiple regression analysis indicated that ultrasound measurements provide additional information regarding mechanical properties beyond that provided by bone quantity alone (p≤0.05). Adding ultrasound variables to linear regression models based on bone quantity improved adjusted squared correlation coefficients from 0.65 to 0.77 (stiffness), 0.76 to 0.81 (apparent modulus), and 0.67 to 0.73 (yield stress). These results indicate that ultrasound can provide complementary (to bone quantity) information regarding mechanical behavior of cancellous bone.

Clinical usefulness of hindfoot assessment for total knee arthroplasty: persistent post-operative hindfoot pain and alignment in pre-existing severe knee deformity

PURPOSE

The purpose of this study was to compare the hindfoot alignment and symptoms in patients with pre-existing moderate and severe knee deformities after total knee arthroplasty (TKA).

METHODS

Eighty knees of 75 patients who underwent TKA for varus osteoarthritis were enrolled retrospectively and evaluated the following pre-operatively and at 2 years post-operatively: the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale (pain and function scores), calcaneal pitch, and naviculocuboid overlap as an indicator of hindfoot alignment. The knees were divided into two groups according to the pre-operative hip-knee-ankle angle defined as the angle between the mechanical axis of the femur and the tibia: group M with genu varus of ≤6°, and group S with varus >6°.

RESULTS

The pain (p = 0.03) and function (p = 0.02) scores improved in group M; however, in group S, these measures did not change. The differences between the groups were not significant concerning the pre-operative calcaneal pitch and naviculocuboid overlap. The post-operative pitch (p = 0.03) and the overlap (p = 0.04) in group M was significantly greater and less than those in group S, respectively. Although the pitch (p < 0.01) and the overlap (p = 0.03) increased in group M, these did not change in group S. Post-operative hindfoot pain and valgus remained in patients in group S.

CONCLUSIONS

For pre-existing moderate knee deformities, a relationship was observed between post-operative knee alignment and compensatory hindfoot alignment, whereas patients with severe deformities experienced persistent post-operative hindfoot pain and valgus alignment. It was concluded that evaluations and managements of residual symptoms after TKA including the hindfoot are important. These findings are clinically relevant that perioperative evaluation of the hindfoot should be required in knee surgery. To help improve the outcomes of TKA, clinicians may consider perioperative intervention in the insole and/or physical therapy of the foot and ankle.

LEVEL OF EVIDENCE

Therapeutic study, Level III.

No Associations of 25-Hydroxycholecalciferol and Parathyroid Hormone Concentrations with Calcaneal Bone Characteristics in Community-Dwelling Elderly Subjects: A Cross-Sectional Study

OBJECTIVE

This study examined the associations of 25-hydroxycholecalciferol [25(OH)D3] and intact parathyroid hormone (iPTH) concentrations with bone status parameters in elderly subjects.

DESIGN/SETTING

Cross-sectional data based on the follow-up 2008 of the longitudinal study on nutrition and health status of senior citizens in Giessen, Germany.

PARTICIPANTS

One hundred eighty-eight independently living subjects aged 66-96 years.

MEASUREMENTS

Serum concentrations of 25(OH)D3, iPTH, N-terminal propeptide of type 1 collagen (P1NP) and activity of alkaline phosphatase (ALP) were assessed. Broadband ultrasound attenuation, speed of sound and stiffness index were determined by calcaneal quantitative ultrasound (QUS). Multiple linear regression analyses were performed to analyse associations of 25(OH)D3 and iPTH with bone status parameters.

RESULTS

Median (range) 25(OH)D3 and iPTH concentrations were 62.8 (29.9-106.7) nmol/L and 4.6 (1.3-21.0) pmol/L, respectively. Neither 25(OH)D3 nor iPTH was associated with calcaneal bone characteristics measured by QUS, whereas negative associations between 25(OH)D3 and bone formation markers (P1NP and ALP) were found. In a sub analysis, 25(OH)D3 was negatively associated with ALP only in subjects with iPTH concentrations > 4.59 pmol/L.

CONCLUSION

The present study provides no evidence for independent associations of 25(OH)D3 and iPTH with calcaneal bone characteristics in community-dwelling elderly subjects with 25(OH)D3 concentrations between 30 and 107 nmol/L. However, 25(OH)D3 interacts with bone formation markers, particularly in subjects with high iPTH concentrations.

Peak Bone Mass and Quantitative Ultrasound Bone Properties in Young Adulthood: A Study in the PEAK-25 Cohort of Women

Peak bone mass is normally reached in the third decade of life. Previously, in the population-based PEAK-25 cohort (n = 1061, age 25.5 ± 0.2), we demonstrated that bone mineral density in the population-based PEAK-25 cohort is comparatively high; therefore, this study aimed to determine if the calcaneus microarchitecture mirrored this. In the process, we describe normative quantitative ultrasound (QUS) values for 25-yr-old women and the relationship between QUS values and extremes of body weight. QUS variables speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index were measured. Young adult values were based on the manufacturer-supplied QUS reference values. Analyses were performed in the cohort as a whole, and additionally, to understand the relationship between body weight and QUS values in young women, the variables were categorized into octiles for weight or body mass index (BMI) and the lowest and highest octiles were compared. In the cohort, SOS values, reflecting bone density, were higher (108 ± 18%), whereas BUA values, reflecting bone complexity, were lower (90 ± 14%) compared to the young adult reference population. SOS did not correlate with body weight or BMI. In the cohort, overall correlations between BUA weight, and BMI were small and positive (Pearson's r coefficients 0.261 and 0.197, respectively; p < 0.001), although in the low-weight group, r coefficients were higher (r = 0.313 and 0.268; p < 0.05). In contrast, in the high-weight group, correlation with BUA values tended to be small, negative, and nonsignificant. Correlation between QUS and dual-energy X-ray absorptiometry-measured bone mineral density was low to moderate and significant at all skeletal sites (r = 0.37-0.52). Whereas coefficients tended to be higher in the low-weight group, the reverse was apparent for the low-BMI group. In these 25-yr-old women, a comparatively high dual-energy X-ray absorptiometry-measured bone mass is offset by less complex bone structures assessed by QUS. This may have implications for later osteoporosis assessment and future fracture risk.

Lessons from the Bone Chapter of the Malaysian Aging Men Study

Male osteoporosis in Malaysia is a largely neglected problem. Therefore, a bone health study in men using quantitative ultrasonometry was launched as part of the Malaysian Aging Men Study in 2009–2012. This review aimed to summarize the findings of the aforementioned bone health study. The study examined the bone health of Chinese and Malaysian men aged 20 years and above living in Kuala Lumpur using a quantitative ultrasound device. Participants answered a questionnaire on their demographic details and physical activity status. Body anthropometry of the participants was measured and their blood collected for biochemical analysis. Results showed that a significant proportion of the Malaysian Chinese and Malay men had suboptimal bone health indicated by calcaneal speed of sound and vitamin D status. Age-related decline of the calcaneal speed of sound in these men was gradual and biphasic without ethnic difference. Body anthropometry such as height, weight, body mass index, and body fat percentage contributed to the variation of the calcaneal speed of sound in Malaysian men. Age-related changes in testosterone, insulin-like growth factor 1, and thyroid stimulating hormone also influenced the calcaneal speed of sound in these men. This study serves as a reminder that male osteoporosis in Malaysia should be an issue of concern. It is also a basis for a more comprehensive study on bone health in men in the future.

Polymorphisms of the WNT16 gene are associated with the heel ultrasound parameter in young adults

SUMMARY

Bone mineral content is influenced by genetic factors. We investigated the role of WNT16 in bone properties determined using quantitative ultrasound (QUS) on young adults. Three WNT16 genetic markers (rs2908007, rs2908004, and rs2707466) were found to have a significant association with the broadband ultrasound attenuation (BUA) measurement, suggesting that WNT16 influences bone mass in young adults.

INTRODUCTION

The aim of this study was to investigate whether genetic markers on the WNT16 gene are associated with bone mass, as assessed using QUS in a population of healthy young Spanish adults.

METHODS

A cross-sectional study was conducted on 575 individuals (mean age 20.41 ± 2.69). Bone quality was assessed using BUA measurements (dB/MHz) on the right calcaneus. Six single nucleotide polymorphisms (SNPs) (rs2908007, rs2908004, rs3801387, rs3801385, rs2707466, and rs2536184) covering the WNT16 gene were selected as genetic markers and genotyped to test their association with BUA variations.

RESULTS

The rs2908007, rs2908004, and rs2707466 SNPs were found to have a significant association with BUA (p = 0.004, p = 0.001, and p = 0.004, respectively).

CONCLUSION

We demonstrate for the first time that WNT16 genetic polymorphisms influence QUS traits in a population of young adults. This finding suggests that WNT16 might be an important genetic factor in determining peak bone mass acquisition.

Meta analysis identifies a novel susceptibility locus associated with heel bone strength in the Korean population

INTRODUCTION

Calcaneal quantitative ultrasound has been recognized as a non-invasive method for evaluation of bone strength and prediction of osteoporotic fracture.

METHODS

To extend a thorough genetic catalog for osteoporotic bone properties, we performed a genome-wide association study (rural cohort I, n=1895) of speed of sound (SOS) using the 1000 genome-based imputation in the discovery stage and then carried out in silico lookups (rural cohort II and III, n=2,967) and de novo genotyping (rural cohort IV, n=4,296) in the replication stage.

RESULTS

In the combined meta-analysis (n=9,158), we identified a novel variant associated with SOS (rs2445771 in the GLDN gene, P=2.27×10(-9)) reaching genome-wide significance in the Korean population. We further demonstrated that allele-specific regulatory modifications found to be associated with functional enrichments by ENCODE annotations.

CONCLUSION

Our findings could provide additional insights into understanding of genetic and epigenetic regulations on bone metabolism.

Serum uric acid is associated with quantitative ultrasound parameters in men: data from the Camargo cohort

This study analyzes the association between serum uric acid levels and heel quantitative ultrasound (QUS) parameters in men aged 50 or more from the Camargo cohort. We found that higher serum uric acid levels are positively associated with all QUS measurements, suggesting a better bone quality in men with elevated serum uric acid values.

INTRODUCTION

Higher serum uric acid concentrations have been associated with higher bone mineral density and lower prevalence of fractures. However, there are no studies that have assessed the bone quality properties in Caucasians. Therefore, we have analyzed the association between quantitative ultrasound (QUS) and serum uric acid levels in adult men from a population-based cohort.

METHODS

A total of 868 men older than 50 were recruited from a larger cohort (Camargo Cohort) after excluding those with any known condition or drug treatment with a possible influence on bone metabolism, or those with a previous diagnosis of gout or taking hipouricemic agents. Bone turnover markers (PINP and CTX), 25OH-vitamin D and PTH levels were measured by electrochemiluminiscence. BMD was determined by DXA, and heel QUS with a gel-coupled device.

RESULTS

Lumbar, femoral neck and total hip BMD was significantly higher in men with higher serum uric acid levels. QUS parameters were also significantly higher in men with high uric acid levels than those with lower values, and increased continuously across quartiles after adjustment for confounding variables. In multiple regression analysis, serum uric acid was significantly associated with all QUS parameters. Finally, men with serum acid levels above median showed higher values in all the QUS parameters than men with lower values.

CONCLUSIONS

Higher serum uric acid levels in men older than 50 years are positively associated with QUS parameters. These data might suggest a better bone quality in men with elevated serum uric acid values.

Low mineral density of a weight-bearing bone among adult women in a high fertility population

Evolutionary theories of aging posit that greater reproductive effort causes somatic decline given a fundamental trade-off between investing energy in reproduction and repair. Few studies in high fertility human populations support this hypothesis, and problems of phenotypic correlation can obscure the expected trade-off between reproduction and somatic condition. This cross-sectional study investigates whether greater reproductive effort is associated with reduced calcaneal bone mineral density (BMD) among female Tsimane forager-farmers of lowland Bolivia. We also investigate whether female Tsimane BMD values are lower than sex- and age-matched US reference values, despite the fact that Tsimane engage in higher physical activity levels that can increase mechanical loading. To measure calcaneal BMD, quantitative ultrasonography was performed on 130 women (mean ± SD age = 36.6 ± 15.7, range = 15-75) that were recruited regardless of past or current reproductive status. Anthropometric and demographic data were collected during routine medical exams. As predicted, higher parity, short inter-birth interval, and earlier age at first birth are associated with reduced BMD among Tsimane women after adjusting for potential confounders. Population-level differences are apparent prior to the onset of reproduction, and age-related decline in BMD is greater among Tsimane compared with American women. Greater cumulative reproductive burden may lower calcaneal BMD individually and jointly with other lifestyle and heritable factors. Fitness impacts of kin transfers in adulthood may determine the value of investments in bone remodeling, and thus affect selection on age-profiles of bone mineral loss.

Insulin-like growth factor-1 is a mediator of age-related decline of bone health status in men

OBJECTIVE

The role of insulin-like growth factor-1 (IGF-1) in bone health in men is debatable. This study aimed to determine whether IGF-1 is a mediator in age-related decline of bone health status measured by calcaneal speed of sound (SOS) in Malaysian men.

METHODS

The study recruited 279 Chinese and Malay men. Their demographic data, weight, height, calcaneal SOS were taken and fasting blood was collected for total testosterone, sex-hormone binding globulin and IGF-1 assays. The associations between the studied variables were assessed using multiple linear regression (MLR) analysis. Mediator analysis was performed using Sobel test.

RESULTS

There was a significant and parallel decrease of IGF-1 and SOS with age (p < 0.05). Serum IGF-1 was significantly and positively associated with SOS (p < 0.05) but after further adjustment for age, the significance was lost (p > 0.05). The strength of the association between age and SOS decreased after adjusting for IGF-1 level but it remained significant (p < 0.05). Sobel test revealed that IGF-1 was a significant partial mediator in the relationship between age and SOS (z = -4.3).

CONCLUSION

Serum IGF-1 is a partial mediator in the age-related decline of bone health in men as determined by calcaneal ultrasound. A prospective study should be performed to validate this relationship.

Discontinuation of leisure time impact-loading exercise is related to reduction of a calcaneus quantitative ultrasound parameter in young adult Japanese females: a 3-year follow-up study

A 3-year follow-up study on 334 young Japanese females enrolled in a university at the age of 18 years revealed that discontinuation of leisure time impact-loading exercises performed in junior high and/or high school was associated with increased risk of reduction in calcaneus osteo-sono assessment index (OSI).

INTRODUCTION

Bone strength rapidly increases during puberty and reaches its peak by the end of adolescence. The aim of this study was to determine the lifestyle factors that influence the maintenance of calcaneus OSI in young adult females around the time when peak bone mass is attained.

METHODS

Annual health checkups including OSI measurements, anthropometrics, lifestyle analysis, and blood examination were performed 4 times on 334 Japanese females enrolled in a university at the age of 18 years. According to the slope of OSI change during the 3-year follow-up, the subjects were grouped into two categories: OSI loss (the lowest tertile) and OSI gain/stable (the second and third tertiles).

RESULTS

At the baseline assessment, the OSI loss group had higher OSI and height and an earlier menarche age than the OSI gain/stable group. Performing leisure time impact-loading exercise in junior high and/or high school but discontinuing it at university was associated with increased risk of OSI loss, independent of OSI, height and weight at the age of 18 years, weight change during follow-up, age of menarche, energy-adjusted nutrient intake, and alcohol drinking; the odds ratios were 4.1-4.9 compared with those performing impact-loading exercise at university. In particular, duration, frequency, and subjective intensity of impact-loading exercise during high school were positively associated with OSI loss.

CONCLUSION

Discontinuation of leisure time impact-loading exercises performed during late adolescence is associated with an increased risk of OSI loss in young adult females during the 3-year follow-up period.

Anatomy and biomechanical properties of the plantar aponeurosis: a cadaveric study

Objectives

To explore the anatomy of the plantar aponeurosis (PA) and its biomechanical effects on the first metatarsophalangeal (MTP) joint and foot arch.

Methods

Anatomic parameters (length, width and thickness of each central PA bundle and the main body of the central part) were measured in 8 cadaveric specimens. The ratios of the length and width of each bundle to the length and width of the central part were used to describe these bundles. Six cadaveric specimens were used to measure the range of motion of the first MTP joint before and after releasing the first bundle of the PA. Another 6 specimens were used to evaluate simulated static weight-bearing. Changes in foot arch height and plantar pressure were measured before and after dividing the first bundle.

Results

The average width and thickness of the origin of the central part at the calcaneal tubercle were 15.45 mm and 2.79 mm respectively. The ratio of the length of each bundle to the length of the central part was (from medial to lateral) 0.29, 0.30, 0.28, 0.25, and 0.27, respectively. Similarly, the ratio of the widths was 0.26, 0.25, 0.23, 0.19 and 0.17. The thickness of each bundle at the bifurcation of the PA into bundles was (from medial to lateral) 1.26 mm, 1.04 mm, 0.91 mm, 0.84 mm and 0.72 mm. The average dorsiflexion of the first MTP joint increased 10.16° after the first bundle was divided. Marked acute changes in the foot arch height and the plantar pressure were not observed after division.

Conclusions

The first PA bundle was not the longest, widest, or the thickest bundle. Releasing the first bundle increased the range of motion of the first MTP joint, but did not acutely change foot arch height or plantar pressure during static load testing.

Composition and microarchitecture of human trabecular bone change with age and differ between anatomical locations

The microarchitecture of trabecular bone adapts to its mechanical loading environment according to Wolff's law and alters with age. Trabecular bone is a metabolically active tissue, thus, its molecular composition and microarchitecture may vary between anatomical locations as a result of the local mechanical loading environment. No comprehensive comparison of composition and microarchitecture of trabecular bone in different anatomical locations has been conducted. Therefore, the objective of this study was to compare the molecular composition and microarchitecture, evaluated with Fourier transform infrared (FTIR) microspectroscopy and micro-computed tomography (μCT), respectively, in the femoral neck, greater trochanter and calcaneus of human cadavers. Specimens were harvested from 20 male human cadavers (aged 17-82 years) with no known metabolic bone diseases. Significant differences were found in composition and microarchitecture of trabecular bone between the anatomical locations. Compositional differences were primarily observed between the calcaneus and the proximal femur sites. Mineralization was higher in the greater trochanter than in the calcaneus (+2%, p<0.05) and crystallinity was lowest in the calcaneus (-24%, p<0.05 as compared to the femoral neck). Variation in the composition of trabecular bone within different parts of the proximal femur was only minor. Collagen maturity was significantly lower in greater trochanter than in femoral neck (-8%, p<0.01) and calcaneus (-5%, p<0.05). The greater trochanter possessed a less dense trabecular bone microarchitecture compared to femoral neck or calcaneus. Age related changes were mainly found in the greater trochanter. Significant correlations were found between the composition and microarchitecture of trabecular bone in the greater trochanter and calcaneus, indicating that both composition and microarchitecture alter similarly. This study provides new information about composition and microarchitecture of trabecular bone in different anatomical locations and their alterations with age with respect to the anatomical loading environments.

Bone mineral density, hip bone geometry, and calcaneus trabecular bone texture in obese and normal-weight children

Our study aimed at comparing bone mineral density (BMD), geometric indices of hip bone strength, and indices of trabecular bone texture at the calcaneus in obese and normal-weight children. Fifty-three obese children (10.3 ± 1.4 yr) and 24 normal-weight children (10.4 ± 1.5 yr) participated in this study. Body composition, bone mineral content, and BMD at whole body (WB), lumbar spine (L2-L4), total forearm, and proximal femur (total hip [TH] and femoral neck [FN]) were measured by dual-energy X-ray absorptiometry (DXA). Bone geometry of the hip was evaluated by the hip structure analysis (HSA) program. DXA scans were analyzed at the FN at its narrowest region and the femoral shaft (FS) by the HSA program. Cross-sectional area (CSA) and section modulus (Z) were measured from hip BMD profiles. Texture analysis was performed on digitized radiographs of the calcaneus to assess trabecular bone microarchitecture, and the result was expressed as Hmean. WB BMD, L2-L4 BMD, TH BMD, and FN BMD were significantly higher in obese children compared with normal-weight peers (p < 0.05). FN Z and FS Z were not significantly different between the 2 groups, whereas Hmean parameter was significantly lower in obese children compared with normal-weight peers (p < 0.001). After adjustment for body weight, obese children displayed lower WB BMD, FN CSA, FN Z, FS CSA, and FS Z compared with normal-weight children. This study suggests that BMD of WB and geometric indices of hip bone strength are not adapted to the increased body weight in obese children.

Calcaneal ultrasound reference ranges for Australian men and women: the Geelong Osteoporosis Study

Heel ultrasound is a more portable modality for assessing fracture risk than dual-energy X-ray absorptiometry and does not use ionising radiation. Fracture risk assessment requires appropriate reference data to enable comparisons. This study reports the first heel ultrasound reference ranges for the Australian population.

INTRODUCTION

This study aimed to develop calcaneal (heel) ultrasound reference ranges for the Australian adult population using a population-based random sample.

METHODS

Men and women aged≥20 years were randomly selected from the Barwon Statistical Division in 2001-2006 and 1993-1997, respectively, using the electoral roll. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were measured at the heel using a Lunar Achilles Ultrasonometer. Gender-specific means and standard deviations for BUA, SOS and SI were calculated for the entire sample (men 20-93 years, n=1,104; women 20-92 years, n=914) and for participants aged 20-29 years (men, n=157; women, n=151). Associations between ultrasound measures and age were examined using linear regression.

RESULTS

For men, mean±standard deviation BUA, SOS and SI were 118.7±15.8 dB/MHz, 1,577.0±43.7 m/s and 100.5±20.7, respectively; values for women were consistently lower (111.0±16.4 dB/MHz, P<0.001; 1,571.0±39.0 m/s, P=0.001; and 93.7±20.3, P<0.001, respectively). BUA was higher in young men compared with young women (124.5±14.4 vs 121.0±15.1 dB/MHz), but SOS (1,590.1±43.1 vs 1,592.5±35.0 m/s) and SI (108.0±19.9 vs 106.3±17.7) were not. The relationships between age and each ultrasound measure were linear and negative across the age range in men; associations were also negative in women but non-linear.

CONCLUSION

These data provide reference standards to facilitate the assessment of fracture risk in an Australian population using heel ultrasound.

Discrepancy between the quantitative ultrasound value of Malaysian men and the manufacturer's reference and the impact on classification of bone health status

The local normative value in quantitative ultrasound (QUS) equipment needs to be established for wider application and accurate classification of patients into respective fracture risk groups. The present study aimed to establish the calcaneal speed of sound (SOS) value for Chinese and Malay men in Malaysia and determine the difference between calcaneal SOS of the local population and the reference values provided by the manufacturer for each age group. This study will also determine the effect of using the manufacturer's young adult (20-29yr) reference or the local young adult reference to classify the subjects into the respective risk groups. Eight hundred forty Malay and Chinese men residing in central peninsular Malaysia were recruited and their calcaneal QUS value was determined using the CM-200 machine (Furuno Electric, Nishinomiya City, Japan). The results showed that the differences in SOS values between Chinese and Malay men were not significant across all the age groups studied (p>0.05). The age-dependent reduction of SOS value assumed a biphasic form, which was evident at 30-39yr and older than 60yr. The calcaneal SOS of the subject under study was significantly higher as compared with the manufacturer's reference (based on Japanese population) in all groups aged 40yr and older (p<0.05). A significant proportion of the subjects in the osteoporosis group was misclassified using the manufacturer's young adult reference as compared with using the local young adult reference (p<0.05). In conclusion, the overall normative value of SOS obtained was suitable for Chinese and Malay men in Malaysia, and a local reference value should be applied to avoid misclassification of subjects into the respective risk groups.

Metric analysis of loading magnitudes at articular and non-articular weight-bearing surfaces in human calcaneus

The calcaneus is axially loaded at its articular interface with the talus. A large bulk of this load is transmitted to the ground across the non-articular tubercles at the plantar surface of the bone. A small part of the incumbent load sustained by the calcaneus is directed towards the forefoot at the calcaneo-cuboid junction. This study investigates the proportion of load distributed across the articular and non-articular surfaces of the calcaneus. The present study demonstrates strong and significant correlation between some of the load bearing variables and suggests the need for further investigations to understand the effect of angular aspects of axial loading on the calcaneus. Accounting for the relative distribution of weight across the articular and non-articular areas may enable us to appreciate the internal trabecular structure of the calcaneus in light of its clinical importance.

Associations of homoarginine with bone metabolism and density, muscle strength and mortality: cross-sectional and prospective data from 506 female nursing home patients

In female nursing home patients, homoarginine was associated with lower bone turnover, higher bone density, lower mortality and, by trend, with muscle strength.

INTRODUCTION

Homoarginine, a cationic amino acid, may be relevant for muscusloskeletal health because it inhibits alkaline phosphatases (AP) and is involved in nitric oxide and energy metabolism. We aimed to evaluate whether homoarginine serum concentrations are associated with bone density and metabolism, muscle strength, fractures and mortality.

METHODS

We examined a cohort of female nursing home patients that underwent quantitative bone ultrasound (QUS) measurements and assessments of knee extensor strength. Measurements of serum homoarginine, C-terminal telopeptide cross-links (β-CTxs) and osteocalcin were also performed at baseline. Thereafter, patients were followed-up with respect to fractures and mortality.

RESULTS

Serum homoarginine concentrations were determined in 506 female study participants (mean age: 83.9 ± 6.0 years). Homoarginine was inversely correlated with β-CTxs (r = -0.26; p < 0.001) and osteocalcin (r = -0.21; p < 0.001), and these associations remained significant in multiple regression analyses. Multivariate regression analyses showed that homoarginine is significantly associated with calcaneus stiffness (beta coefficient = 0.11; p = 0.020) and by trend with knee extensor strength (beta coefficient = 0.09; p = 0.065). During a mean follow-up time of 27 ± 8 months, we recorded 119 deaths (23.5%) and 63 fractures (12.5%). In multivariate analyses, homoarginine was associated with significantly reduced risk of mortality and the combined endpoint of fractures and mortality.

CONCLUSIONS

Whether homoarginine metabolism is critically involved into the pathogenesis of musculoskeletal diseases and fatal events warrants further studies.

A European multicenter comparison of quantitative ultrasound measurement variables: the OPUS study

Quantitative ultrasound (QUS) measurement variables vary between European countries in a different way to hip bone mineral density. Standardization of data can be achieved through statistical approaches to reduce any between-center differences in QUS measurement variables. However, further validation of this method is required before it can be widely applied.

INTRODUCTION

European between-center differences in hip bone mineral density (BMD) have been shown to exist; however, little is known about the geographical heterogeneity of QUS measurement variables. We aimed to examine the differences in QUS variables between three different European countries.

METHODS

Five calcaneal and phalangeal QUS devices in Sheffield, Aberdeen (UK), Kiel and Berlin (Germany), and three devices in Paris (France) were used to measure QUS variables in younger (n = 463, 20-39 years old) and older (n = 2,399, 55-79 years old) women participating in the European multicenter Osteoporosis and Ultrasound (OPUS) study. Broadband ultrasound attenuation, speed of sound, stiffness index, amplitude-dependent speed of sound, bone transmission time, and ultrasonic bone profiler index data were collected. Between-center differences were examined using ANOVA followed by post hoc Fisher's least significant difference tests, and ANCOVA with linear contrasts. p < 0.05 indicated statistical significance.

RESULTS

Between-center differences in nonstandardized QUS measurement variables existed for younger (p = 0.0023 to p < 0.0001) and older women (p < 0.001). Anthropometric characteristics exerted a significant influence on nonstandardized data (p = 0.045 to p < 0.001). However, following statistical standardization, based on height and weight or based on measurements made in young people, geographical heterogeneity in QUS measurement variables was no longer apparent.

CONCLUSIONS

QUS measurement variables vary between European countries in a different way to those for hip BMD. Standardization of data can be achieved through statistical approaches to reduce any between-center differences in QUS measurement variables. However, further validation of this method is required before it can be widely applied.

Microarchitecture and bone quality in the human calcaneus: local variations of fabric anisotropy

The local variability of microarchitecture of human trabecular calcaneus bone is investigated using high-resolution micro-computed tomography (µCT) scanning. The fabric tensor is employed as the measure of the microarchitecture of the pore structure of a porous medium. It is hypothesized that a fabric tensor-dependent poroelastic ultrasound approach will more effectively predict the data variance than will porosity alone. The specific aims of the present study are as follows: (1) to quantify the morphology and local anisotropy of the calcaneus microarchitecture with respect to anatomical directions; (2) to determine the interdependence, or lack thereof, of microarchitecture parameters, fabric, and volumetric bone mineral density (vBMD); and (3) to determine the relative ability of vBMD and fabric measurements in evaluating the variance in ultrasound wave velocity measurements along orthogonal directions in the human calcaneus. Our results show that the microarchitecture in the analyzed regions of human calcanei is anisotropic, with a preferred alignment along the posterior-anterior direction. Strong correlation was found between most scalar architectural parameters and vBMD. However, no statistical correlation was found between vBMD and the fabric components, the measures of the pore microstructure orientation. Therefore, among the parameters usually considered for cancellous bone (ie, classic histomorphometric parameters such as porosity, trabecular thickness, number and separation), only fabric components explain the data variance that cannot be explained by vBMD, a global mass measurement, which lacks the sensitivity and selectivity to distinguish osteoporotic from healthy subjects because it is insensitive to directional changes in bone architecture. This study demonstrates that a multidirectional, fabric-dependent poroelastic ultrasound approach has the capability of characterizing anisotropic bone properties (bone quality) beyond bone mass, and could help to better understand anisotropic changes in bone architecture using ultrasound.

Heel bone mass of a young South Indian population with a Nigerian population residing in a South Indian suburban neighborhood: a comparative study

This cross-sectional cohort emphasized the impact of heel bone mass in the South Indian population and its comparison with Nigerian ethnicity, residing in South India. Peak bone mass, however, evidenced a significant decrease of around 30% compared to that of Nigerian ethnicity.

INTRODUCTION

In the South Indian population, the local folks do not seem to be well informed about the relative association of bone mass with osteoporosis. Hence, there is an acute necessity to assess the same with respect to the ethnic population, presumed to have possessed high bone mass, i.e., the Nigerian population.

METHODS

The calcaneus of the right foot was measured with a quantitative ultrasound device (Sahara, Hologic Inc., USA) for a total population of 734, out of which 314 were Indian males, 348 Indian females, 41 Nigerian males, and 30 Nigerian females, whose ages ranged from 18 to 35 years.

RESULTS

The peak bone mass in Indian males and females is 0.507 ± 0.1 and 0.479 ± 0.1 g cm(-2), respectively, and it is 0.714 ± 0.2 and 0.682 ± 0.2 g cm(-2) with regard to Nigerian male and female populations, respectively. Indian males and females who were within the age group of 26-30 and ≤ 20 years, respectively, represented high bone mass, and the same was the situation with respect to Nigerian counterparts who were within the age group of 21-25 years. Indian and Nigerian non-vegetarian population of both the genders demonstrated a high significance value of p < 0.000001, deciphered by means of unpaired t test.

CONCLUSION

Peak bone strength was dominant in the Nigerian population compared to that of Indians. The Indian population is approximately lagging by 28-30% with respect to peak bone mass behind their Nigerian equivalents. Indian non-vegetarian male and female populations lagged by 6.15% and 6.16% behind the Indian vegetarian male and female populations, respectively.

Influence of birth weight on calcaneal bone stiffness in Belgian preadolescent children

The aim of this study was to investigate the relation between birth weight and calcaneal bone stiffness in a large sample of Belgian, healthy, preadolescent children. Participants were 827 children (3.6-11.2 years, 51.6 % boys) from the Belgian cohort of the IDEFICS study. Birth weight was obtained using a parental questionnaire, and quantitative ultrasound (QUS) measurements were performed to determine calcaneal broadband ultrasound attenuation (BUA), speed of sound (SOS), and stiffness index (SI) using the Lunar Achilles device. Average birth weights were 3435.7 ± 512.0 g for boys and 3256.9 ± 471.1 g for girls. Average calcaneal QUS measurements were 89.6 ± 24.0 (23.3-153.9) dB/MHz for BUA, 1621.4 ± 49.6 (1516.3-1776.5) m/s for SOS, and 92.8 ± 15.6 (49.0-163.0) for SI. Birth weight was positively associated with BUA (r = 0.13, p = 0.002) and SOS (r = -0.16, p < 0.001). The associations remained after correcting for age and sex in multiple regression analyses but disappeared after correcting for anthropometric covariates. Our findings suggest that birth weight, as a rough proxy indicator for genetic and environmental influences during intrauterine life, is associated with BUA and SOS in preadolescent children and may therefore influence the risk of osteoporosis later in life. Further studies using QUS are needed to investigate the consistency of the results of this study.

Resistive vibration exercise retards bone loss in weight-bearing skeletons during 60 days bed rest

Countermeasures are desirable to retard bone loss during long-term space flight. We evaluated the effect of an intervention protocol on bed rest-induced bone loss.

INTRODUCTION

We developed a resistive vibration exercise (RVE) platform to test if an intervention RVE protocol would be effective to protect bed rest-induced bone loss.

METHODS

Fourteen male subjects were assigned randomly to either the RVE group (n = 7) that performed daily supervised resistive vibration exercise or to the no any exercise control (CON) group (n = 7). Both dual-energy X-ray absorptiometry and peripheral quantitative computed tomography were used to monitor changes in bone mineral density.

RESULTS

RVE significantly prevented bone loss at multiple skeletal sites, including calcaneus, distal tibia, hip, and lumbar spine (L2-L4). The ratio of urinary calcium and creatinine was found higher after starting bed rest in CON group while no significant changes were observed in RVE group. No significant temporal change was found for osteocalcin-N during and after bed rest in CON group. However, a significant increase was shown after bed rest in RVE group. In both groups, the urinary concentration of bone resorption markers, such as C-telopeptide of type I collagen (CTX-I) and deoxypyridinoline (DPD), were significantly elevated after bed rest. In the CON group, no significant temporal effect was found for hydroxyproline (HOP), CTX-I, and DPD during bed rest and the serum concentration of HOP and TGF-β significantly increased about 52.04% and 24.03%, respectively only after bed rest. However, all these markers tended to decrease in the RVE group.

CONCLUSIONS

Our results might imply that the intervention of RVE retarded bone loss induced by simulated microgravity in humans that was mainly attributed to its anabolic effects.

Serum testosterone, sex hormone-binding globulin and total calcium levels predict the calcaneal speed of sound in men

OBJECTIVES

Variations in sex hormones and the calcium balance can influence bone health in men. The present study aimed to examine the relationship between the calcaneal speed of sound and biochemical determinants of bone mass, such as sex hormones, parathyroid hormones and serum calcium.

METHODS

Data from 549 subjects from the Malaysian Aging Male Study, which included Malay and Chinese men aged 20 years and older residing in the Klang Valley, were used for analysis. The subjects' calcaneal speed of sound was measured, and their blood was collected for biochemical analysis. Two sets of multiple regression models were generated for the total/bioavailable testosterone and estradiol to avoid multicollinearity.

RESULTS

The multiple regression results revealed that bioavailable testosterone and serum total calcium were significant predictors of the calcaneal speed of sound in the adjusted model. After adjustment for ethnicity and body mass index, only bioavailable testosterone remained significant; the total serum calcium was marginally insignificant. In a separate model, the total testosterone and sex hormone-binding globulin were significant predictors, whereas the total serum calcium was marginally insignificant. After adjustment for ethnicity and body mass index (BMI), the significance persisted for total testosterone and SHBG. After further adjustment for age, none of the serum biochemical determinants was a significant predictor of the calcaneal speed of sound.

CONCLUSION

There is a significant age-dependent relationship between the calcaneal speed of sound and total testosterone, bioavailable testosterone and sex hormone-binding globulin in Chinese and Malay men in Malaysia. The relationship between total serum calcium and calcaneal speed of sound is ethnicity-dependent.

Scaling and mechanics of the felid calcaneus: geometric similarity without differential allometric scaling

Six mechanically significant skeletal variables were measured on the calcanei from 60 Felidae specimens (22 species) to determine whether these variables were scaled to body mass, and to assess whether differential scaling exists. The power equation (y = a · x(b) ) was used to analyse the scaling of the six variables to body mass; we compared traditional regression methods (standardised major axis) to phylogenetically independent contrasts. In agreement with previous studies that compared these methodologies, we found no significant differences between methods in the allometric coefficients (b) obtained. Overall, the scaling pattern of the felid calcaneus conformed to the predictions of the geometric similarity hypothesis, but not entirely to those of the elastic similarity hypothesis. We found that the moment arm of the ankle extensors scaled to body mass with an exponent not significantly different from 0.40. This indicated that the tuber calcanei scaled to body mass faster than calcaneus total length. This explained why the effective mechanical advantage of the ankle extensors increased with body mass, despite the fact that limb posture does not change in felid species. Furthermore, this finding was consistent with the hypothesis of the isometric scaling of ground reaction forces. No evidence for differential scaling was found in any of the variables studied. We propose that this reflected the similar locomotor pattern of all felid species. Thus, our results suggested that the differences in allometric coefficients for 'large' and 'small' mammals were in fact caused by different types of locomotion among the species included in each category.

The mechanical and histological estimation of calcaneal tendon callus in rats after PRP injection

BACKGROUND

The study investigated the potential impact of platelet-rich plasma on tendon healing.

MATERIAL/METHODS

The study was conducted in 88 young, sexually mature rats, Wistar strain. The animals were randomly divided into two groups. The animals from the examined group (n=44) with an operated calcaneal tendon were given subcutaneously allogeneic PRP. The animals from the control group (n=44) were given 0.9% NaCl solution within the area of calcaneal tendon damage. After 7, 14, 21, and 42 days, the tendons were tested mechanically using the universal testing machines (UTM, Lloyd LRX), and were subjected to histological evaluation.

RESULTS

The study evaluated the maximum breaking force (Fmax), the force at the end of the proportional range (Fs) and stiffness of the tendons (H). After 7 days of the experiment, there were significant differences in H (P=0.021), between the examined and control groups. There were no significant differences in Fmax (P=0.53) and Fs (P=0.48) after 7 days. Mean values of Fmax, Fs and H after 14, 21, and 42 days in the study group were significantly higher compared to the control group (P<0.05). In the histological evaluation, the tendons of the examined groups were characterized by higher cellular and vascular density and a more orderly arrangement of collagen fibers compared to the control groups.

CONCLUSIONS

Growth factors in allogeneic PRP increased the mechanical strength of regenerating calcaneal tendons after 14, 21, and 42 days from injury. PRP resulted in the increased histological maturity of the tendon callus in examined groups, at each stage of the experiment.

Kinematics of the ankle and foot. In vivo roentgen stereophotogrammetry

Roentgen stereophotogrammetric analysis has been used to study ankle/foot kinematics in eight healthy volunteers. All the joints between the tibia and the first metatarsal as well as the talo-calcaneal and tibio-fibular joints were analysed in input plantar flexion/dorsiflexion and pronation/supination of the foot as well as internal/external rotation of the leg. The findings included the following: INDIVIDUAL JOINTS 1. The joint axis of the talo-crural joint varied with varying kinds of input motion. Substantial amounts of rotation occurred about axes close to the vertical; this occurred particularly when the input motion was in the internal rotation part of the arc of leg rotation and in pro-/supination of the foot. 2. The total amount of rotation in the talo-calcaneal joint was small in internal rotation of the leg and in pronation of the foot compared to external rotation of the leg and supination of the foot. 3. The talo-navicular joint showed a limited ball-and-socket joint pattern in all subjects. The total amounts of rotation were larger than in the talo-calcaneal joint in all subjects. Plantar flexion axes were more transverse than the axes seen in other kinds of input motion. 4. The talo-calcaneal and talo-navicular joint axes were seldom parallel, indicating that these joints do not necessarily behave as a simple hinge. JOINT INTERACTION Joint interaction varied in different qualities of input motion. Plantar flexion induced rotation in the talo-crural joint, and to some extent in the joints of the arch. Dorsiflexion mainly induced talo-crural joint motion. Pronation/supination induced motion in all joints. The distal joints of the arch displayed more rotation in pronation than in supination, while the talo-calcaneal joint showed less motion in pronation than in supination. Internal leg rotation induced little rotation in the joints of the ankle/foot complex. External rotation induced external rotation, dorsiflexion, and supination in the talo-navicular and talo-calcaneal joints. The distal joints of the arch displayed compensatory plantar flexion and pronation. TRANSFERRAL OF ROTATION The ankle/foot complex showed ability to transform leg rotation into pro-/supination and vice versa. This function was most pronounced in external leg rotation. MOTIONS OF THE FIBULA The fibula showed consistent lateral and posterior translation from input plantar flexion to dorsiflexion of the foot.

Elderly men with a history of distal radius fracture have significantly lower calcaneal bone density and free androgen index than age-matched controls

BACKGROUND

Age related bone loss is widely accepted as related to decreased serum levels of circulating sex hormones. Epidemiological data also show distal radius fractures in men to be a sensitive marker of bone fragility. The aim of this study was to assess if men with a history of distal radius fracture have lower bone mass density (BMD), lower free androgen index (FAI), lower total testosterone (T) and lower bio-available testosterone (Bio-T) than healthy age-matched controls.

PATIENTS AND METHODS

A case-control study is based on consecutive cases treated for low energy distal radius fracture at our department and age-matched controls. Thirty-nine men treated between 1997-2004 and 45 age-matched controls underwent calcaneal bone density measurements (t-score) and analyses of T, Bio-T and serum hormone binding globulin (SHBG).

RESULTS

The fracture group had lower BMD (p < 0.01) and lower FAI (p = 0.01). Linear regression analysis showed a correlation between Bio-T and t-scores (p = 0.03). Using analysis of covariance, a significant difference with lower Bio-T in the fracture group was shown.

CONCLUSION

Bio-T seems to correlate with BMD in elderly men and may serve as a marker for increased fracture risk in this patient group.

Relationships of quantitative ultrasound parameters with cancellous bone microstructure in human calcaneus in vitro

Ultrasound parameters (attenuation, phase velocity, and backscatter), bone mineral density (BMD), and microarchitectural features were measured on 29 human cancellous calcaneus samples in vitro. Regression analysis was performed to predict ultrasound parameters from BMD and microarchitectural features. The best univariate predictors of the ultrasound parameters were the indexes of bone quantity: BMD and bone volume fraction (BV/TV). The most predictive univariate models for attenuation, phase velocity, and backscatter coefficient yielded adjusted squared correlation coefficients of 0.69-0.73. Multiple regression models yielded adjusted correlation coefficients of 0.74-0.83. Therefore attenuation, phase velocity, and backscatter are primarily determined by bone quantity, but multiple regression models based on bone quantity plus microarchitectural features achieve slightly better predictive performance than models based on bone quantity alone.

Do regional modifications in tissue mineral content and microscopic mineralization heterogeneity adapt trabecular bone tracts for habitual bending? Analysis in the context of trabecular architecture of deer calcanei

Calcanei of mature mule deer have the largest mineral content (percent ash) difference between their dorsal 'compression' and plantar 'tension' cortices of any bone that has been studied. The opposing trabecular tracts, which are contiguous with the cortices, might also show important mineral content differences and microscopic mineralization heterogeneity (reflecting increased hemi-osteonal renewal) that optimize mechanical behaviors in tension vs. compression. Support for these hypotheses could reveal a largely unrecognized capacity for phenotypic plasticity - the adaptability of trabecular bone material as a means for differentially enhancing mechanical properties for local strain environments produced by habitual bending. Fifteen skeletally mature and 15 immature deer calcanei were cut transversely into two segments (40% and 50% shaft length), and cores were removed to determine mineral (ash) content from 'tension' and 'compression' trabecular tracts and their adjacent cortices. Seven bones/group were analyzed for differences between tracts in: first, microscopic trabecular bone packets and mineralization heterogeneity (backscattered electron imaging, BSE); and second, trabecular architecture (micro-computed tomography). Among the eight architectural characteristics evaluated [including bone volume fraction (BVF) and structural model index (SMI)]: first, only the 'tension' tract of immature bones showed significantly greater BVF and more negative SMI (i.e. increased honeycomb morphology) than the 'compression' tract of immature bones; and second, the 'compression' tracts of both groups showed significantly greater structural order/alignment than the corresponding 'tension' tracts. Although mineralization heterogeneity differed between the tracts in only the immature group, in both groups the mineral content derived from BSE images was significantly greater (P < 0.01), and bulk mineral (ash) content tended to be greater in the 'compression' tracts (immature 3.6%, P = 0.03; mature 3.1%, P = 0.09). These differences are much less than the approximately 8% greater mineral content of their 'compression' cortices (P < 0.001). Published data, suggesting that these small mineralization differences are not mechanically important in the context of conventional tests, support the probability that architectural modifications primarily adapt the tracts for local demands. However, greater hemi-osteonal packets in the tension trabecular tract of only the mature bones (P = 0.006) might have an important role, and possible synergism with mineralization and/or microarchitecture, in differential toughening at the trabeculum level for tension vs. compression strains.

Impact of age, anthropometric data and body composition on calcaneal bone characteristics, as measured by quantitative ultrasound (QUS) in an older German population

The impact of fat-free mass (FFM), fat mass (FM), body mass index (BMI), body mass and body height on calcaneal bone characteristics as measured with quantitative ultrasound (QUS) was investigated in 137 women and 85 men aged 62-92 years, considering age, smoking, waist-to-hip ratio (WHR) and physical activity level (PAL). In regression analyses using various models, in women, age was a negative predictor of speed of sound (SOS), broadband ultrasound attenuation (BUA) and stiffness index (SI) and smoking was a negative predictor of SOS; positive predictors of SOS, BUA, and SI were BMI, body mass and FFM. In men, smoking was a negative predictor and BMI, body mass and FFM were positive predictors of BUA and SI. In both sexes, PAL, body height, WHR and FM had no effect on QUS parameters. The influence of BMI on calcaneal bone characteristics in elderly people depends on FFM rather than on FM.

Longitudinal changes in calcaneal quantitative ultrasound measures during childhood

This longitudinal study examined how calcaneal quantitative ultrasound (QUS) measures change during childhood while taking into account skeletal maturation, body mass index (BMI), and physical activity. The study reported sex differences in QUS growth curves and an inverse relationship between BMI and speed of sound (SOS) measures.

INTRODUCTION

The aim of this study was to examine how calcaneal QUS parameters change over time during childhood and to determine what factors influence these changes.

METHODS

The study sample consisted of a total of 192 Caucasian children participating in the Fels Longitudinal Study. A total of 548 calcaneal broadband ultrasound attenuation (BUA) and SOS observations were obtained between the ages of 7.6 and 18 years. The best fitting growth curves were determined using statistical methods for linear mixed effect models.

RESULTS

There are significant sex differences in the pattern of change in QUS parameters (p < 0.05). The relationship between QUS measures and skeletal age is best described by a cubic growth curve in boys and a linear pattern among girls. Boys experience their most rapid growth in BUA and SOS in early and late adolescence, while girls experience constant growth throughout childhood. Adiposity levels were significantly associated with the changes in SOS among boys (p < 0.001) and girls (p < 0.01), indicating that children with higher BMI are likely to have lower SOS over time compared to children with lower BMI. For girls, physical activity levels showed positive associations with changes in QUS measures (p < 0.05).

CONCLUSION

This study documents significant sex differences in the pattern of change in QUS measures over childhood and adolescence. Our study also shows significant influences of adiposity and physical activity on the pattern of change in QUS measures during childhood.

The influence of parity on quantitative ultrasound evaluation of the calcaneus and hand phalanges in Polish postmenopausal women

The aim of the retrospective study was to assess the influence of parity on the skeletal status in 760 postmenopausal women. Women with factors affecting their bone status, or those treated for osteoporosis, were not included. Quantitative ultrasound measurements were performed at the heel (Achilles, n = 465) or at hand phalanges (DBM Sonic 1200, n = 295). Regarding hand phalanges, Z score values were significantly lower in women with three, four, and five or six deliveries in comparison to nonparous women and in women with four deliveries versus women with one or two deliveries. Calcaneus ultrasound variables did not differ in regard to the number of deliveries. Stepwise multiple regression analysis has shown that the main factors, affecting the bone status, were postmenopause duration and body weight. We concluded the increasing number of deliveries negatively influences ultrasound measurements at hand phalanges, which suggests their role as a qualitative feature factor of cortical non-weight-bearing bone.

Effects of surgical correction for the treatment of adult acquired flatfoot deformity: a computational investigation

Computational models of the foot/ankle complex were developed to predict the biomechanical consequences of surgical procedures that correct for stage II adult acquired flatfoot deformity. Cadaveric leg and foot bony anatomy was captured by CT imaging in neutral flexion and imported to the modeling software. Ligaments were approximated as tension only springs attached at insertion sites. Muscle contraction of the gastrocnemius/soleus complex was simulated through force vectors and desired external loads applied to the model. Ligament stiffnesses were modified to reflect stage II flatfoot damage, followed by integration of corrective osteotomies-medializing calcaneal osteotomy (MCO) and Evans and calcaneocuboid distraction arthrodesis (CCDA)--to treat flatfoot. Joint angles, tissue strains, calcaneocuboid contact force, and plantar loads were analyzed. The flatfoot simulation demonstrated clinical signs of disease evidenced by degradation of joint alignment. Repair states corrected these joint misalignments with MCO having greatest impact in the hindfoot, and Evans/CCDA having greatest effect in the mid- and forefoot. The lateral procedures unevenly strained plantar structures, while offloading the medial forefoot, and increased loading on the lateral forefoot, which was amplified by combining with MCO. The Evans procedure raised calcaneocuboid joint contact force to twice intact levels. Computational results are in agreement with clinical and experimental findings. The model demonstrated potential precursors to such complications as lateral tightness and arthritic development and may thus be useful as a predictor of surgical outcomes.

Association between alcohol consumption and bone strength in Korean adults: the Korean Genomic Rural Cohort Study

Previous studies have reported an inconsistent relationship between alcohol consumption and bone health. A growing body of research has shown that chronic alcoholism leads to osteopenia and increased incidence of skeletal fractures, but some studies have concluded that alcohol consumption may be associated with higher bone mineral density in elderly populations. However, most studies showing a significant relationship between alcohol consumption and bone status have been in Western countries; and subjects have usually been postmenopausal women. The purpose of the present study was to investigate the association of alcohol consumption with bone strength in Korean adults. Data were from the Korean Genomic Rural Cohort Study, which is an ongoing population-based study of adults aged 40 to 70 years from 5 regions. A total of 7713 participants (3368 men, 4345 women) were surveyed about their annual consumption of alcohol such as soju, beer, makkolli, wine, and whisky. Bone strength was measured by stiffness index using the calcaneal quantitative ultrasound method. Overall, the annual age-specific decrease rate in the stiffness index of women was 2.7 times higher than that of men (0.463% for women, 0.169% for men).After adjustment for eligible covariates, the association between alcohol consumption and risk of reduced bone strength showed a J-shaped curve for both men and women. Compared with nondrinkers, the relative risk of reduced bone strength was 0.52 (95% confidence interval, 0.33-0.83) in men who drank 4 to 5 cups of soju for an amount of 29.626 to 49.375 g of alcohol per day and 0.61 (95% confidence interval, 0.38-0.86) in men who drank 6 to 7 cups of soju for an amount of 49.376 to 69.125 g of alcohol per day. We found no significant relationship between alcohol consumption and bone strength in any other group of men. For women, results suggested that the risk of reduced bone strength was lower in the moderate-consumption group; but no significant relationship was found between alcohol consumption at any level and bone strength. Among Korean adults, alcohol consumption has a J-shaped relationship with risk of reduced bone strength.

Oral contraceptive use and bone mass in women aged 26-36 years

INTRODUCTION

The association between hormonal contraceptive use and bone mineral density remains controversial.

HYPOTHESIS

Hormonal contraceptive use is positively associated with bone mass in young premenopausal women.

METHODS

Cross-sectional analysis of data collected from women aged 26-36 years (n = 687) in the Childhood Determinants of Adult Health study-a longitudinal study investigating childhood determinants of cardiovascular disease, diabetes, and other chronic diseases in adulthood. Participants were not currently pregnant or breast-feeding. Contraceptive use was obtained by self-administered questionnaire. Women were categorized as combined oral contraceptive users (n = 219), progestogen-only contraceptive users (n = 43), and non-users of hormonal contraceptives (n = 425). Bone mass was measured by quantitative ultrasound.

RESULTS

Compared with women who were not using any hormonal contraceptives, women using combined oral contraceptives had significantly higher values of broadband ultrasound attenuation (BUA), speed of sound, and quantitative ultrasound index. These associations remained after adjustment for confounders. Progestogen-only contraceptive users had higher BUA than non-users, but the differences were not statistically significant in this small group.

CONCLUSION

Combined oral contraceptive use was associated with higher bone mass measured by quantitative ultrasound in this population-based sample of premenopausal women aged 26-36 while progestogen-only contraceptives appeared to have no deleterious effect on bone mass.

The influence of foot geometry on the calcaneal osteotomy angle based on two-dimensional static force analyses

BACKGROUND

Malalignment of the hindfoot can be corrected with a calcaneal osteotomy (CO). A well-selected osteotomy angle in the sagittal plane will reduce the shear force in the osteotomy plane while walking. The purpose was to determine the presence of a relationship between the foot geometry and loading of the calcaneus, which influences the choice of the preferred CO angle.

METHODS

A static free body force analysis was made of the posterior calcaneal fragment in the second half of the stance phase to determine the main loads: the plantar apeunorosis (PA) and Achilles tendon (AT). The third load is on the osteotomy surface which should be oriented such that the shear component of the force is zero. The force direction of the PA and AT was measured on 58 MRIs of the foot, and the force ratio between both structures was taken from the literature. In addition the PA-to-AT force ratio was estimated for different foot geometries to identify the relationship.

RESULTS

Based on the wish to minimize the shear force during walking, a mean CO angle was determined to be 33° (SD8) relative to the foot sole. In pes planus foot geometry, the angle should be higher than the mean. In pes cavus foot geometry, the angle should be smaller.

CONCLUSION

Foot geometry, in particular the relative foot heights is a determinant for the individual angle in performing the sliding calcaneal osteotomy. It is recommended to take into account the foot geometry (arch) when deciding on the CO angle for hindfoot correction.

The mechanical relationship between the rearfoot, pelvis and low-back

The purpose of this study was first to investigate whether foot pronation (measured as calcaneal eversion) induced an anterior tilt of the pelvis and increased the degree of lumbar lordosis. Second the study investigated whether foot supination (measured as calcaneal inversion) induced a posterior pelvic tilt and a decreased lumbar lordosis. Participants placed their feet in 18 different foot positions while standing on a rigid platform. Seven of these positions ranged from 15 degrees of foot eversion to 15 degrees of foot inversion and 11 positions ranged from 40 degrees of external foot rotation to 40 degrees of internal foot rotation. Pelvic tilt and lumbar lordosis were estimated using a 3D motion analysis system. Foot pronation and supination did not have a significant relationship with pelvic tilt (r=0.3) and lumbar lordosis (r=0.05). Internally rotating the legs caused the pelvis to tilt anteriorly and externally rotating the legs caused the pelvis to tilt posteriorly (r=0.58). There was no relationship between leg rotation and lumbar lordosis (r=0.24). Since the effects of pelvic tilt on the lumbar spine were only noticeable when pelvic tilt was exaggerated beyond values seen this study it seems unlikely that there is a link between induced foot pronation and an increase in lumbar lordosis.