Effect of hand dominance on bone mass measurement in sedentary individuals

Prediction of height using ulna length in African-Caribbean children

Standing height is an essential anthropometric measurement in pediatrics. In children unable to stand upright, measurement of ulna to predict standing height is recommended, but height prediction equations based on the ulna have not been established in children of African ancestry. We hypothesized that such equations would result in lower predicted height compared to using equations derived from non-African children. We measured prospectively standing height and both ulna in 358 African-Caribbean children without bone deformity or muscle disease, referred to two pulmonary function test laboratories. Interobserver variability was low for standing height (n = 54) and ulna measurement (n = 51) (mean biases [95%CI]: -0.02 [-0.99; 0.95] and 0.05 [-0.91; 1.01] cm, respectively), as well as inter-ulna variability (n = 352; mean bias 0.03 95%CI [-0.66; 0.73] cm). We used the mean value of 247 bilateral ulna measurements to calculate prediction equations using a generalized linear model including age, sex, ulna length, and geographic origin group, the latter showing no influence on the model. In the validation population of 107 children, the median difference [inter-quartile range] between standing height and ulna-predicted height was -0.4 [-2.7; 1.0] cm. Of 260 reliable baseline spirometry, there was a strong concordance between bronchial obstruction diagnosis established using standing height or ulna-predicted height (kappa coefficient: 0.85 [0.77; 0.94]) with only 11 (4.3%) children misclassified. The ulna predicted height calculated from African-Caribbean prediction equations resulted in a smaller height than the height calculated using equations derived from non-African children.

Dominant and nondominant distal radius microstructure: Predictors of asymmetry and effects of a unilateral mechanical loading intervention

Most information about distal radius microstructure is based on the non-dominant forearm, with little known about the factors that contribute to bilateral asymmetries in the general population, or what factors may influence bilateral changes over time. Here, we analyzed bilateral high resolution peripheral quantitative computed tomography (HRpQCT) data collected over a 12-month period as part of a clinical trial that prescribed a well-controlled, compressive loading task to the nondominant forearm. Baseline data from 102 women age 21–40, and longitudinal data from 66 women who completed the 12-month trial, were examined to determine factors responsible for side-to-side asymmetries in bone structure and change in structure over time. Cross-sectionally, the dominant radius had 2.4%–2.7% larger cross-sectional area, trabecular area, and bone mineral content than the nondominant radius, but no other differences were noted. Those who more strongly favored their dominant arm had significantly more, thinner, closely spaced trabecular struts in their dominant versus nondominant radius. Individuals assigned to a loading intervention had significant bilateral gains in total bone mineral density (2.0% and 1.2% in the nondominant versus dominant sides), and unilateral gains in the nondominant (loaded) cortical area (3.1%), thickness (3.0%), bone mineral density (1.7%) and inner trabecular density (1.3%). Each of these gains were significantly predicted by loading dose, a metric that included bone strain, number of cycles, and strain rate. Within individuals, change was negatively associated with age, meaning that women closer to age 40 experienced less of a gain in bone versus those closer to age 21. We believe that dominant/nondominant asymmetries in bone structure reflect differences in habitual loads during growth and past ability to adapt, while response to loading reflects current individual physiologic capacity to adapt.

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We examined relationships between physical activity, handedness, demographics, and asymmetries in distal radius structure.

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Trabecular and cross-sectional area were 2.4-2.7% larger in the dominant side.

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We examined factors that predicted 12-month change after a unilateral loading intervention on the nondominant side.

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The intervention caused unilateral (nondominant) increases in most variables, which scaled with loading dose.

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The results also suggest that greater dietary calcium is associated with endosteal bone apposition following loading.

Use of the Contralateral Glenoid for Calculation of Glenoid Bone Loss: A Cadaveric Anthropometric Study

PURPOSE

The purpose of this study was to determine if there are significant side-to-side anthropometric differences between paired glenoids.

METHODS

Forty-six matched-pair cadaver glenoids were harvested, and their glenoid heights (GHs) and glenoid widths (GWs) were measured with digital calipers. The glenoid surface area was calculated using the standard assumption that the inferior two-thirds of the glenoid is a perfect circle.

RESULTS

There was a statistically significant difference between matched-pair GHs of 0.96 ± 3.07 mm (P = .020) and GWs of 0.46 ± 1.64 mm (P = .033). There was a significant difference of glenoid cavity area of 20.30 ± 81.53 mm2 (P = .044), or a difference of ∼3%. A total of 4 of 46 pairs of glenoids (8.6%) showed a difference in width >3 mm.

CONCLUSIONS

This study demonstrates the fallacy of use of the contralateral glenoid in measuring glenoid bone loss. Although many paired samples exhibited similar side-to-side glenoid measurements, the number of cadaveric pairs that showed differences of >3 mm was substantial. Caution should be taken when using calculation methods that include this assumption for surgical decision making, as surface area, GW, and GH were all shown to have statistically significant side-to-side differences in their measurements.

CLINICAL RELEVANCE

Many methods exist for measuring glenoid bone loss after anterior shoulder dislocation, but some of the current methods may be inaccurate and lead to unreliable estimations.

Dominant vs. non-dominant hip comparison in bone mineral density in young sporting athletes

To explore differences in bone mineral density (BMD) between dominant and non-dominant hip within levels of sport impact. BMD was higher in the non-dominant hip in high-impact sports, whereas the dominant hip had increased BMD for low-impact sports. The side-to-side differences were relatively small and not clinically relevant.

PURPOSE

It is unknown whether there is difference in BMD at the hip between dominant and non-dominant sides in young athletes. The aims of this study were to explore the dominant-non-dominant differences in hip BMD in young athletes participating in low- and high-impact sports and to assess the effect of ground force impact on BMD.

METHODS

Data was collected on University of Oxford athletes and controls (CG) between 2016 and 2018. Athletes were classified into two groups: high-impact sports (HIG) and low-impact sports (LIG). Total and regional measurements of both hips' BMD were recorded using a dual-energy X-ray absorptiometry (DXA). Linear regression method was used to assess differences in BMD between and within groups.

RESULTS

One hundred ninety-four athletes (HIG: n = 89, LIG: n = 105) and 48 controls were included in this study. Total hip and femoral neck BMD was higher in athletes compared to the CG (p < 0.01), with HIG recording highest levels of BMD. The BMD difference between the dominant and non-dominant sides was significant in the LIG, with BMD being higher in the dominant side. Conversly, BMD was higher in the non-dominant hip within the HIG. However, the hip asymmetries were not clinically relevant (%BMD difference < 3%). A significant interaction between side and sport group on BMD was observed.

CONCLUSIONS

High-impact sports had significantly higher BMD compared with low-impact sports and CG. BMD in the dominant hip was significantly higher for the LIG and lower in the HIG; however, differences were not clinically relevant.

Diagnostic imaging of osteoporosis and sarcopenia: a narrative review

Osteoporosis and sarcopenia represent two major health problems with an increasing prevalence in the elderly population. The correlation between these diseases has been widely reported, leading to the development of the term "osteosarcopenia" to diagnose those patients suffering from both diseases. Several imaging methods for the diagnosis and management of osteoporosis exist, with dual-energy X-ray absorptiometry (DXA) being the most commonly used for measuring bone mineral density (BMD). Imaging technique other than DXA is represented by conventional radiography, computed tomography (CT) and ultrasound (US). Similarly, the imaging technologies used to detect loss of skeletal muscle mass in sarcopenia include DXA, CT, US and magnetic resonance imaging (MRI). These methods differ in terms of reliability, radiation exposure and costs. CT and MRI represent the gold standard for evaluating body composition (BC), but are costly and time-consuming. DXA remains the most often used technology for studying BC, being quick, widely available and with low radiation exposure.

Does regional loss of bone density explain low trauma distal forearm fractures in men (the Mr F study)?

The pathogenesis of low trauma wrist fractures in men is not fully understood. This study found that these men have lower bone mineral density at the forearm itself, as well as the hip and spine, and has shown that forearm bone mineral density is the best predictor of wrist fracture.

INTRODUCTION

Men with distal forearm fractures have reduced bone density at the lumbar spine and hip sites, an increased risk of osteoporosis and a higher incidence of further fractures. The aim of this case-control study was to investigate whether or not there is a regional loss of bone mineral density (BMD) at the forearm between men with and without distal forearm fractures.

METHODS

Sixty-one men with low trauma distal forearm fracture and 59 age-matched bone healthy control subjects were recruited. All subjects underwent a DXA scan of forearm, hip and spine, biochemical investigations, health questionnaires, SF-36v2 and Fracture Risk Assessment Tool (FRAX). The non-fractured arm was investigated in subjects with fracture and both forearms in control subjects.

RESULTS

BMD was significantly lower at the ultradistal forearm in men with fracture compared to control subjects, in both the dominant (mean (SD) 0.386 g/cm² (0.049) versus 0.436 g/cm² (0.054), p < 0.001) and non-dominant arm (mean (SD) 0.387 g/cm² (0.060) versus 0.432 g/cm² (0.061), p = 0.001). Fracture subjects also had a significantly lower BMD at hip and spine sites compared with control subjects. Logistic regression analysis showed that the best predictor of forearm fracture was ultradistal forearm BMD (OR = 0.871 (0.805-0.943), p = 0.001), with the likelihood of fracture decreasing by 12.9% for every 0.01 g/cm² increase in ultradistal forearm BMD.

CONCLUSIONS

Men with low trauma distal forearm fracture have significantly lower regional BMD at the ultradistal forearm, which contributes to an increased forearm fracture risk. They also have generalised reduction in BMD, so that low trauma forearm fractures in men should be considered as indicator fractures for osteoporosis.

Evaluation of bone microstructure in CRPS-affected upper limbs by HR-pQCT

INTRODUCTION

Complex regional pain syndrome (CRPS) is a major complication after trauma, surgery, and/or immobilization of an extremity. The disease often starts with clinical signs of local inflammation and develops into a prolonged phase that is characterized by trophic changes and local osteoporosis and sometimes results in functional impairment of the affected limb. While the pathophysiology of CRPS remains poorly understood, increased local bone resorption plays an undisputed pivotal role. The aim of this retrospective clinical study was to assess the bone microstructure in patients with CRPS.

METHODS

Patients with CRPS type I of the upper limb whose affected and unaffected distal radii were analyzed by high-resolution peripheral quantitative computed tomography (HR-pQCT) were identified retrospectively. The osteology laboratory data and dual-energy X-ray absorptiometry (DXA) images of the left femoral neck and lumbar spine, which were obtained on the same day as HR-pQCT, were extracted from the medical records.

RESULTS

Five patients were identified. The CRPS-affected upper limbs had significantly lower trabecular numbers and higher trabecular thicknesses than the unaffected upper limbs. However, the trabecular bone volume to total bone volume and cortical thickness values of the affected and unaffected sides were similar. Trabecular thickness tended to increase with time since disease diagnosis.

DISCUSSION

CRPS associated with significant alterations in the bone microstructure of the affected upper limb that may amplify as the duration of disease increases.

Association between bone indices assessed by DXA, HR-pQCT and QCT scans in post-menopausal women

Quantitative computed tomography (QCT), high-resolution peripheral QCT (HR-pQCT) and dual X-ray absorptiometry (DXA) scans are commonly used when assessing bone mass and structure in patients with osteoporosis. Depending on the imaging technique and measuring site, different information on bone quality is obtained. How well these techniques correlate when assessing central as well as distal skeletal sites has not been carefully assessed to date. One hundred and twenty-five post-menopausal women aged 56-82 (mean 63) years were studied using DXA scans (spine, hip, whole body and forearm), including trabecular bone score (TBS), QCT scans (spine and hip) and HR-pQCT scans (distal radius and tibia). Central site measurements of areal bone mineral density (aBMD) by DXA and volumetric BMD (vBMD) by QCT correlated significantly at the hip (r = 0.74, p < 0.01). Distal site measurements of density at the radius as assessed by DXA and HR-pQCT were also associated (r = 0.74, p < 0.01). Correlations between distal and central site measurements of the hip and of the tibia and radius showed weak to moderate correlation between vBMD by HR-pQCT and QCT (r = -0.27 to 0.54). TBS correlated with QCT at the lumbar spine (r = 0.35) and to trabecular indices of HR-pQCT at the radius and tibia (r = -0.16 to 0.31, p < 0.01). There was moderate to strong agreement between measuring techniques when assessing the same skeletal site. However, when assessing correlations between central and distal sites, the associations were only weak to moderate. Our data suggest that the various techniques measure different characteristics of the bone, and may therefore be used in addition to rather than as a replacment for imaging in clinical practice.

Bilateral Asymmetry of Radius and Tibia Bone Macroarchitecture and Microarchitecture: A High-Resolution Peripheral Quantitative Computed Tomography Study

Studies assessing bone health often select the dominant or nondominant limb to scan, but not both, for efficiency reasons. New scanning technology allows 3-dimensional (3D) visualization of the microarchitecture in bone, but it is not well understood whether there are differences between the dominant and nondominant limbs. Using 3D high-resolution peripheral quantitative computed tomography (HR-pQCT), the aim of this study is to investigate the effect of limb dominance on bone macroarchitecture and microarchitecture. Healthy male and female participants (N=100; 59 female, 41 male), mean age 30.7±12.1 years, were scanned at both radii and tibiae using HR-pQCT. Hand and foot dominance were determined by the participant's self-report. Most participants were right hand dominant (94.0%) and right foot dominant (91.0%). In the pooled cohort, the dominant radius had significantly greater cortical area (2.11%; p=0.002) and failure load (3.00%; p=0.001). At the tibia, the dominant foot had significantly lower bone mineral density (-0.77%; p=0.042), cortical area (-1.05%; p=0.031), and thickness (-1.51%; p=0.017). For females, there were no differences at the radius, but at the tibia, the dominant side had greater cross-sectional area (1.03%; p=0.044). Our data suggest that dominance has a small yet significant effect on macroarchitecture at both the ultradistal radius and tibia but not microarchitecture. This work emphasizes that it is important to be consistent in the selection of either dominant or nondominant limbs for HR-pQCT cohort studies; however, in the case where the opposite limb needs to be scanned, there would be small differences in macroarchitecture and no significant differences in microarchitecture anticipated.

Densitometric study of the clavicle: bone mineral density explains the laterality of the fractures

Introduction

Epidemiological studies have shown laterality in clavicle fractures, such that the left side is more frequently fractured. The present study had the aim of evaluating whether the clavicle on the dominant side is denser and thus explaining the greater incidence of fractures on the non-dominant side.

Materials and methods

This was a descriptive study on 52 healthy patients, who were classified according to age, sex and whether the dominant or non-dominant side was affected.

Results

The participants comprised 28 women (53.8%) and 24 men (46.2%). Regarding the dominant side, 30 were right-handed (57.7%) and 22 were left-handed (42.3%). The mean age was 25 years. In this study, it could be seen that the non-dominant side had greater bone mass than the dominant side. It was also observed that the bone density was greater in the middle and distal thirds on the non-dominant side, with a statistically significant difference. In the women, the density was also greater on the non-dominant side; this difference was not significant in relation to the dominant side, but there were significant differences between the middle thirds (p < 0.001) and the distal thirds (p < 0.006).

Conclusion

Variations in bone density, toward higher and lower bone mass, may have been responsible for the fractures. According to the findings from this study, fractures occur more in the middle third of the non-dominant clavicle, as a result of greater bone mineral mass, which gives rise to lower flexibility and fractures in the region.

Evaluation of Bilateral Asymmetry between Upper Limb Masses in Right-Handed Young Adults of Both Sexes

The study introduced a novel precise method for measurement and calculation of upper arm mass and to assess the difference between masses of upper limbs on the dominant and non-dominant sides of the body of right-handed participants. Forty healthy untrained male ( n = 20; M age = 20.8yr., SD = 1.2) and female ( n = 20; M age = 20.7 yr., SD = 1.3) participants without a history of upper-extremity pathology participated. Kinematic and kinetic data were collected during arm motion. The mass of each arm was calculated. Each participant performed 20 movements with each arm. Most often the dominant arm was more massive than the non-dominant in both sex groups; however, mass was more symmetric for female participants than for male participants. Regression equations related to total body mass were calculated for each arm independently.

The analysis of densitometric and geometric parameters of bilateral proximal phalanges in horses with the use of peripheral quantitative computed tompgraphy

BACKGROUND

Proximal phalanges in horses are among bones that are most prone to injuries. So far, the detailed analysis of densitometric and geometric parameters of both front legs proximal phalanges in horses has not been investigated. The aim of this study was to compare the densitometric and geometric parameters between proximal phalanges in equine both front legs with the use of peripheral quantitative computed tomography (pQCT).

METHODS

The study material comprised isolated both front legs proximal phalanges derived from 22 horses. The structure analysis of the proximal phalanges was conducted with the pQCT. The following bone parameters were determined: bone mineral content, volumetric bone mineral density, total bone area, trabecular area, cortical area, cortical thickness, periosteal circumference, endocortical circumference, Strength Strain Index. Tomographic analysis of proximal phalanges was conducted at three levels: at 15%, 50% and 85% of the bone length.

RESULTS

The statistical analysis showed that both the densitometric and geometric parameters of the bone at 50% and 85% of its length, did not present any statistically significant differences for the left or right proximal phalanges of the forelimb. At the same time, all examined parameters measured at 15% of the bone length, in the vicinity of the proximal metaphysis revealed significant statistical differences between both front legs proximal phalanges.

CONCLUSIONS

The proximal phalanx parameters in the forelimbs are significantly different for the left and right proximal phalanx at 15% of the length and they indicate higher Strength Strain Index of the left bone in this location. The densitometric and geometric parameters of the bone at 50% and 85% of its length, did not present any statistically significant differences for the left or right proximal phalanges of the left and right forelimbs. The most serious changes caused by asymmetrical load of the thoracic limbs in horses occur near the proximal metaphysis, where the spongious substance is most abundant. This may happen because the metabolism of the spongious bone tissue is eight times faster compared to the compact bone tissue. Thus, any changes, including those caused by asymmetrical strain exerted on the right and left thoracic limbs, are the earliest to be observed.

Evaluation of bone mineral density in children with perinatal brachial plexus palsy: effectiveness of weight bearing and traditional exercises

PURPOSE

(1) To investigate any evidence of bone mineral density (BMD) changes in children with Perinatal Brachial Plexus Palsy (PBPP). (2) To detect any relationship between these changes and the child age, weight, height, BMI, power index, gender, ethnicity, and the side affected. (3) To determine any possible effects of a designed weight bearing exercise program and the traditional one upon BMD of those children.

STUDY DESIGN

Randomized single blind controlled trial.

METHOD

A convenience sampling strategy was used to obtain 45 children with unilateral PBPP. Their ages ranged from 3 to 10 years. They were randomly divided to three equal groups. Groups were, then, randomly assigned to either interventions [Weight Bearing Exercises Program (WBEP) or Traditional Exercises Program (TEP)] or to the control treatment. Dual Energy X-Ray Absorptiometry (DXA) was used to evaluate BMD for all children at entry and approximately after six months treatment period.

RESULTS

We detected significant low entry level measurements of all BMD parameters of the affected side when compared to that of the unaffected sides (p=0.000). The mean value of the entry level calculated Z score for the affected side of all study children was equal to -1.12 ± 0.327 being in the osteopenic risk range. Furthermore, thirty children (66.7%) recorded less than (-1) Z score being in this risky range. Also, we recorded a significant improvement of all BMD parameters of the affected side after treatment in favor of the WBEP group when compared to that of the control and TEP groups (p=0.02, p=0.03 respectively for the affected both bones BMD parameter).

CONCLUSIONS

BMD is significantly reduced in PBPP children. The retardation of bone accrual increases as the child height and weight decreases and the degree of paralysis increases. WBEP significantly promoted BMD improvement when compared to the TEP.

Upper limb bone mineral density and body composition measured by peripheral quantitative computed tomography in right-handed adults: the role of the dominance effect

BACKGROUND

To investigate the impact on bone and muscle of pathological conditions involving only one of the upper limbs, it is important to know the physiological differences due to the dominance effect.

AIM

To evaluate any physiological differences between dominant and non-dominant upper limbs in terms of bone mineral density (BMD), muscle mass, and muscle density at different levels.

SUBJECTS AND METHODS

The study considered 60 right-handed healthy adults, 30 men and 30 women. Cortical BMD, muscle area, and muscle density were investigated by pQCT-XCT-3000 Stratec at the proximal radius, trabecular and total BMD at the distal radius, and trabecular and cortical BMD at the second phalanx of the third finger. Hand grip strength was also measured.

RESULTS

No significant differences in BMD were found between the dominant and non-dominant upper limbs at any of the sites considered, in men or women. Muscle density was also similar on the two sides, whereas muscle area at the proximal radius was significantly lower on the non-dominant side in both men [4177.5+/-475.1 vs 4009.3+/-552.7 mm2; Delta%: 4.1%; 95% confidence interval (CI) 1.7%-6.5%] and women (2903.9+/-470.9 vs 2720.3+/-411.7 mm2; Delta%: 6.1%; 95%CI 4.3%-7.9%). Hand grip strength proved greater on the right side in both men (48.5+/-8.8 vs 45.2+/-8.7 kg; Delta% 7.1; p<0.001) and women (29.1+/-4.3 vs 27.0+/-5.1 kg; Delta% 7.1; p<0.001).

CONCLUSION

The dominance effect does not seem to influence trabecular or cortical BMD at any of the sites in the upper limb. Muscle density is not modified by dominance, while muscle area is reduced on the non-dominant side and this should be borne in mind when the effect of pathological conditions on the body composition of a single forearm is investigated.

Postpubertal architectural developmental patterns differ between the L3 vertebra and proximal tibia in three inbred strains of mice

An understanding of normal microarchitectural bone development patterns of common murine models is needed. Longitudinal, structural, and mineralization trends were evaluated by in vivo microCT over 12 time points from 6-48 wk of age at the vertebra and tibia of C3H/HeN, C57BL/6, and BALB/C mice. Longitudinal growth occurred rapidly until 8-10 wk, slowed as the growth plate bridged, and fused at 8-10 mo. Structural augmentation occurred through formation of trabeculae at the growth plate and thickening of existing ones. In the vertebrae, BV/TV increased rapidly until 12 wk in all strains. Between 12 and 32 wk, the architecture was stable with BV/TV deviating <1.1%, 1.6%, and 3.4% for the C57BL/6, BALB/C, and C3H/HeN mice. In contrast, the tibial architecture changed continuously but more moderately for BV/TV and TbTh compared with the vertebra and with comparable or larger changes for TbN and TbSp. Age-related trabecular deterioration (decreased BV/TV and TbN; increased TbSp and structure model index) was evident at both sites at 32 wk. In all strains, the cortex continued to develop after trabecular values peaked. The temporal plateau of BMD was variable across mouse strains and site, whereas tissue mineral density was attained at approximately 6 mo for all sites and strains. Geometric changes at the tibial diaphysis occurred rapidly until 8-10 wk, providing the C57BL/6 mice and C3H/HeN mice with the highest torsional and compressive rigidity, respectively. In summary, key skeletal development milestones were identified, and architectural topology at the vertebra was found to be more stable than at the tibia.

High-resolution pQCT analysis at the distal radius and tibia discriminates patients with recent wrist and femoral neck fractures

We depict a fragility bone state in two primitive osteoporosis populations using 3D high-resolution peripheral in vivo QCT (HR-pQCT). Postmenopausal women (C, controls, n = 54; WF, wrist, n = 50; HF, hip, n = 62 recent fractured patients) were analyzed for lumbar and hip DXA areal BMD (aBMD), cancellous and cortical volumetric BMD (vBMD), and microstructural and geometric parameters on tibia and radius by HR-pQCT. Principal component analysis (PCA) allowed extracting factors that best represent bone variables. Comparison between groups was made by analysis of covariance (ANCOVA). Two factors (>80% of the entire variability) are extracted by PCA: at the radius, the first is a combination of trabecular parameters and the second of cortical parameters. At the tibia, we found the reverse. Femoral neck aBMD is decreased in WF (8.6%) and in HF (18%) groups (no lumbar difference). WF showed a approximately 20% reduction in radius trabecular vBMD and number. Radius cortical vBMD and thickness decrease by 6% and 14%, respectively. At the tibia, only the cortical compartment is affected, with approximately 20% reduction in bone area, thickness, and section modulus and 6% reduction in vBMD. HF showed same radius trabecular alterations than WF, but radius cortical parameters are more severely affected than WF with reduced bone area (25%), thickness (28.5%), and vBMD (11%). At the tibia, trabecular vBMD and number decrease by 26% and 17.5%, respectively. Tibia cortical bone area, thickness, and section modulus showed a >30% decrease, whereas vBMD reduction reached 13%. Geometry parameters at the tibia displayed the greatest differences between healthy and fractured patients and between wrist and hip fractures.

Whole bone geometry and bone quality in distal forearm fracture

Fracture of the distal radius is a sentinel for future increased risk of other "osteoporotic" fractures, in which the peak age for incidence of distal radius fracture is 5 to 10 years before that for spine and hip fractures. Mean bone mineral density (BMD) of the distal radius was lower in patients with osteoporosis compared with age- and sex-matched normal subjects. However, it has been shown that to predict the strength of the distal radius at the site where fractures occur requires more than measurement of bone mineral content (BMC) or BMD. Only moderate correlations have been found between forearm sites, which may be a result of differences in bone composition between sites. Different forearm sites may be used interchangeably for diagnostic purposes, but the prognostic value is not known. Using the distal radius as a screening tool for identifying individuals at risk of "osteoporotic" fracture shows that forearm site selection and accuracy of measurement can be important confounders in group studies.Improving resolution of computed tomography (CT) scanners has enabled quantitation of cortical bone density and cortical thickness. These measurements have enabled the mechanism of bone loss in the distal radius to be elucidated and show that, after menopause, bone loss is primarily through thinning of the cortex. CT imaging allows the precise localization of bone changes in individuals and should be of value in the assessment of the severity of osteoporosis. It also shows that this technology has the potential to determine the efficacy of therapeutic interventions. A concerted effort has been made to elucidate the interrelationships between the amount of bone and the geometry and that clinical imaging of BMC and/or cross-sectional area in the radius would provide improved prediction of an individual's risk of fracture.The technological tools are available, in the clinic, to accurately measure the 3-dimensional (3D) geometry of the distal radius and the amount of bone. In addition, the cortical and cancellous bone compartments can be analyzed separately. This capability, along with the easy accessibility of the distal radius to clinical imaging modalities, provides an excellent framework for longitudinal prospective studies to determine morphologic risk factors for osteoporotic fractures of the distal radius.

Is laterality associated with a higher rate of hip arthroplasty on the dominant side?

The authors analyzed data collected by the Registry of the Orthopedic Prosthetic Implantology in Italy. They found a higher rate of total hip arthroplasty on the right side (58%) in comparison with the left side in patients affected by primary coxarthrosis. To test whether laterality was the cause of this, they checked the prevalence of the upper and lower limbs in 262 patients treated for monolateral total hip prosthesis. They found that the percentage of left-handed patients was very low (0.8-6.5%). The percentage of left-footed patients was, instead, 26.5% for power tasks. They observed that, while the rate of arthroplasties on the right side was similar to that of the left side (50.7 and 49.3%) in the right-footed patients, there was a clear-cut prevalence in the number of operations on the right hip (76.8%) in comparison to the left one (23.2%) in the left-footed patients. The authors suggested that, in left-footed patients, the right side was subjected to greater stress.

Bone mineral density and bone markers in patients with a recent low-energy fracture: effect of 1 y of treatment with calcium and vitamin D

BACKGROUND

Low-energy fractures of the hip, forearm, shoulder, and spine are known consequences of osteoporosis.

OBJECTIVE

We evaluated the effect of 1 y of treatment with calcium and vitamin D on bone mineral density (BMD) and bone markers in patients with a recent low-energy fracture.

DESIGN

In a double-blinded design, patients with fracture of the hip (lower-extremity fracture, or LEF) or upper extremity (UEF) were randomly assigned to receive 3000 mg calcium carbonate + 1400 IU cholecalciferol or placebo (200 IU cholecalciferol). BMD of the hip (HBMD) and lumbar spine (LBMD) were evaluated by dual-energy X-ray absorptiometry, and physical performance was assessed by the timed Up & Go test. Serum concentrations of 25-hydroxycholecalciferol, parathyroid hormone (PTH), telepeptide of type I collagen (ICTP), osteocalcin, and N-terminal propeptide of collagen type I were measured.

RESULTS

A total of 122 patients were included (84% women; x +/- SD age: 70 +/- 11 y); 68% completed the study. In an intention-to-treat analysis, LBMD increased in the intervention group and decreased in the placebo group, and the difference between the groups was significant after 12 mo: 0.931 +/- 0.211 compared with 0.848 +/- 0.194 (P<0.05). No significant change was shown for HBMD. The effect of treatment was more pronounced in patients aged <70 y. The intervention decreased bone turnover. PTH was significantly lower in the intervention group (P<0.01) for the LEF patients. ICTP and change in LBMD were significantly related to physical performance.

CONCLUSIONS

A 1-y intervention with calcium and vitamin D reduced bone turnover, significantly increased BMD in patients younger than 70 y, and decreased bone loss in older patients. The effect of treatment was related to physical performance.

Side differences in the bone density of the distal radius and calcaneus in Koreans aged 4-86 years

Although bone mineral density (BMD) measurements of peripheral bone have been widely used due to practical and economic factors, a consensus does not exist as to whether the dominant or nondominant side is preferable for diagnosing osteoporosis and predicting fracture risk. Thus, we evaluated BMD differences of the distal radius and calcaneus between dominant and nondominant sides in the Korean population. Data were collected from 1794 subjects (979 females and 815 males) aged 4-86 yr, who were not taking any medication that affected bone metabolism or had a history of fracture. All subjects completed a questionnaire, and anthropometric and BMD measurements were taken. BMD values at the distal radii and calcanei were measured by dual-energy X-ray absorptiometry using a Lunar instrument. Significant correlations were observed between the dominant and nondominant distal radii (r=0.92; p<0.0001) and calcanei (r=0.94; p<0.0001). A side difference for the distal radius was not observed, whereas a significant side difference for the calcaneus was detected (p<0.05). Our findings provide information for recommending a sampling site upon measuring the distal radius and calcaneus during clinical or community-based studies.

Comparison of the femoral neck bone density, quantitative ultrasound and bone density of the heel between dominant and non-dominant side

Our study was initiated to evaluate whether there are differences between the two sides, depending on hand dominance, in densitometry values and quantitative ultrasound parameters (QUS) of the lower limb. One hundred and six women and 44 men were involved. The hand dominance was determined by interview. The bone mineral density (BMD) of the left and the right femoral necks and the calcanei were measured by dual-energy X-ray absorptiometry (DXA). The QUS examination consisted of measuring the attenuation (BUA), the speed of the ultrasound (SOS) and quantitative ultrasound index (QUI) transversing the left and right calcanei. The density of the neck of femur of the non-dominant side did not differ from that of the dominant side. On the other hand, BMD, BUA and the QUI of the calcaneus were higher on the non-dominant side in both genders (p<0.05 for each parameter). No similar differences were seen for the SOS values. Our study has confirmed the side-to-side differences of the calcaneus in both genders, lower values were found on the dominant side. No similar differences were seen on the femur. The AUC values seemed to be higher on the dominant side, however, these differences were not strictly significant. In the case of peripheral site (heel) measurements, the practical significance of our observations is that they raise the possibility of performing peripheral DXA and QUS examinations of the calcaneus on the dominant side of the patient according to handedness.

Short-term and long-term site-specific effects of tennis playing on trabecular and cortical bone at the distal radius

Mechanical loading during growth magnifies the normal increase in bone diameter occurring in long bone shafts, but the response to loading in long bone ends remains unclear. The aim of the study was to investigate the effects of tennis playing during growth at the distal radius, comparing the bone response at trabecular and cortical skeletal sites. The influence of training duration was examined by studying bone response in short-term (children) and long-term (young adults) perspectives. Bone area, bone mineral content (BMC), and bone mineral density (BMD) of the radius were measured by DXA in 28 young (11.6 +/- 1.4 years old) and 47 adult tennis players (22.3 +/- 2.7 years old), and 70 age-matched controls (12 children, 58 adults) at three sites: the ultradistal region (trabecular), the mid-distal region, and the third-distal region (cortical). At the ultradistal radius, young and adult tennis players displayed similar side-to-side differences, the asymmetry in BMC reaching 16.3% and 13.8%, respectively (P < 0.0001). At the mid- and third-distal radius, the asymmetry was much greater in adults than in children (P < 0.0001) for all the bone parameters (mid-distal radius, +6.6% versus +15.6%; third-distal radius, +6.9% versus +13.3%, for BMC). Epiphyseal bone enduring longitudinal growth showed a great capacity to respond to mechanical loading in children. Prolonging tennis playing into adulthood was associated with further increase in bone mineralization at diaphyseal skeletal sites. These findings illustrate the benefits of practicing impact-loading sports during growth and maintaining physical activity into adulthood to enhance bone mass accrual and prevent fractures later in life.

Cortical and trabecular bone at the forearm show different adaptation patterns in response to tennis playing

Bone responds to impact-loading activity by increasing its size and/or density. The aim of this study was to compare the magnitude and modality of the bone response between cortical and trabecular bone in the forearms of tennis players. Bone area, bone mineral content (BMC), and bone mineral density (BMD) of the ulna and radius were measured by dual-energy X-ray absorptiometry (DXA) in 57 players (24.5 +/- 5.7 yr old), at three sites: the ultradistal region (50% trabecular bone), the mid-distal regions, and third-distal (mainly cortical bone). At the ultradistal radius, the side-to-side difference in BMD was larger than in bone area (8.4 +/- 5.2% and 4.9 +/- 4.0%, respectively, p < 0.01). In the cortical sites, the asymmetry was lower (p < 0.01) in BMD than in bone area (mid-distal radius: 4.0 +/- 4.3% vs 11.7 +/- 6.8%; third-distal radius: 5.0 +/- 4.8% vs 8.4 +/- 6.2%). The asymmetry in bone area explained 33% of the variance of the asymmetry in BMC at the ultradistal radius, 66% at the mid-distal radius, and 53% at the third-distal radius. The ulna displayed similar results. Cortical and trabecular bone seem to respond differently to mechanical loading. The first one mainly increases its size, whereas the second one preferentially increases its density.

Bilateral measurement of femoral bone mineral density

Both femora were measured on 61 normal adults using dual X-ray absorptiometry (DXA). In a subset of 31 subjects, each femur was scanned once using the conventional leg-positioning device supplied with the densitometer, and once using a new positioning device and software that allowed both legs to be measured simultaneously. In another subgroup (n = 30), subjects were measured three times using the new dual-femur approach to better assess precision error. The data were analyzed for differences owing to the different positioning devices and for differences between right and left sides. The correlation between results with the old and new positioners was high (r > 0.99, standard error of the estimate [SEE] = 0.01-0.02 g/cm(2)). There was no significant difference in the average bone mineral density (BMD) values between the old and new positioner. The precision errors for each femur alone with the dual-femur approach were similar to those reported for the single-femur scans (1 to 2%), but the precision errors for the combined femora were reduced by 30% as expected. The correlation between right and left sides was high (r = 0.94-0.96), and the SEE in predicting one side from the other was moderate for total, trochanteric, and femoral neck BMD (0.05, 0. 05, and 0.06 g/cm(2), respectively). These SEE equate to about 0.5 standard deviation in terms of T-score. Differences in many individual cases between the right and left sides were significantly greater than the precision error. The new dual-femur software and leg positioner allows rapid measurement and analysis of both femora, thereby eliminating the uncertainty between sides.

In vivo detection of structural differences between dominant and nondominant radii using peripheral quantitative computed tomography

This cross-sectional study identifies differences in distal radial trabecular bone structure related to habitual loading patterns in the upper extremities using high-resolution peripheral quantitative computed tomography. As well, it determines whether measurements of these indices in one limb serve as satisfactory surrogates for the contralateral limb. The dominant and nondominant forearms of 106 adult volunteers (mean age [SD], 44.3[17.5] yr) were scanned and indices of trabecular bone structure (connectivity index [CI], maximum hole size [H(M)], and mean hole size [H(A)]) were determined at the distal radius. The images were also analyzed to determine bone density. For all subjects, H(M) is significantly smaller in the dominant radius (p < 0.01). Right-handed subjects (n = 96) have greater CI (p < 0.05) and smaller H(M) (p < 0.01) in the dominant radius. For the total group, the dominant limb has a greater mass (total and cortical bone mineral content, p < 0.01 and p < 0.05, respectively) and greater total bone volumetric density (p < 0.05). There are no significant differences between limbs for the group of left-handed subjects &lapr;n = 10). As expected, significant associations exist between side-to-side measurements of bone structure and density (p < 0.001). The correlation coefficients for connectivity index, H(M), and H(A) are 0.86, 0.85, and 0.87, respectively. For bone density, the between-limb associations are 0. 90, 0.73, and 0.92 for the total, cortical, and trabecular bone compartments at the distal radius. Differences in the structure of the trabecular bone network suggest that differential loading of the dominant limb preserves bone strength.