Mechanical validation of a tomographic (pQCT) index for noninvasive estimation of rat femur bending strength

Ferretti, J.L.; Capozza, Ricardo Francisco; Zanchetta, J. R.

doi:10.1016/8756-3282(95)00438-6

Cited by 236 publications

(169 citation statements)

References 40 publications

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“…The bone then undergoes increased resorption, with osteoblasts stimulated by the increased muscle-induced strain. In this way, the bone compensates for the increased load by thickening over time (20). Cortical vBMD was normal in our study cohort, consistent with the results of others (18,19).…”

Section: Discussionsupporting

confidence: 92%

“…Quantification by pQCT of bone geometry and density properties in children and adolescents with JRA has been limited to the radius (18,19). We prefer the tibia to the radius for appendicular bone assessment, due to its larger bone size and muscle area and higher rate of bone turnover due to mechanical loading (20). Therefore, this study was undertaken to characterize tibia bone features in patients with JRA as assessed by pQCT in comparison with healthy, age-matched controls, and to identify disease-related factors that predict diminished or altered bone geometry, density, or strength in the 3 JRA subtypes.…”

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confidence: 99%

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Musculoskeletal abnormalities of the tibia in juvenile rheumatoid arthritis

Felin¹,

Prahalad²,

Askew³

et al. 2007

Arthritis & Rheumatism

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Objective. To characterize local bone geometry, density, and strength, using peripheral quantitative computed tomography (pQCT), compared with general bone characteristics as measured using dual x-ray absorptiometry (DXA), and to assess their relationship to disease-related factors in children with juvenile rheumatoid arthritis (JRA).Methods. Forty-eight children ages 4-18 years with JRA (17 pauciarticular, 23 polyarticular, 8 systemic) were compared with age-matched healthy controls (n ‫؍‬ 266). Measurements included cortical and trabecular bone geometry, density, and strength at the distal and midshaft tibia determined by pQCT, and whole-body, lumbar spine, and femoral neck measurements by DXA.Results. Methotrexate (MTX) was prescribed to 23 of 48 patients (47.9%) and glucocorticoids and MTX were prescribed to 15 of 48 patients (31.3%), with the greatest use in children with systemic JRA. All JRA patients had decreased tibia trabecular bone density, cortical bone size and strength, and muscle mass. Children with systemic JRA had lower femoral neck densities. Systemic JRA was associated with a shorter, less mineralized skeleton, while a narrower, less mineralized skeleton was observed in polyarticular JRA. The tibia diaphysis was narrower with decreased muscle mass, but normal, size-adjusted bone mineral in all subtypes indicated a localized effect of JRA on bone. Patients exposed to glucocorticoids and MTX or to glucocorticoids or MTX alone had greatly reduced trabecular density, cortical bone geometry properties, and bone mineral content, muscle mass, and bone strength.Conclusion. Children with JRA have decreased skeletal size, muscle mass, trabecular bone density, cortical bone geometry, and strength. Not surprisingly, these bone abnormalities are more pronounced in children with greater disease severity.

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Section: Discussionsupporting

confidence: 92%

mentioning

confidence: 99%

Musculoskeletal abnormalities of the tibia in juvenile rheumatoid arthritis

Felin¹,

Prahalad²,

Askew³

et al. 2007

Arthritis & Rheumatism

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“…This BSI has been validated by its close correlation with the actual, mechanically tested bending/breaking force of all bones. (30,31) Furthermore, we calculated a new parameter, relative bone strength index (RBSI), in order to reflect the relationship between tibial bone strength and the load applied on it. RBSI was computed as BSI/(tibial length Â body weight).…”

Section: Body Composition and Bone Measurementsmentioning

confidence: 99%

Fat mass accumulation compromises bone adaptation to load in finnish women: A cross-sectional study spanning three generations

Xu¹,

Nicholson²,

Wang³

et al. 2010

Journal of Bone and Mineral Research

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Body weight and lean mass correlate with bone mass, but the relationship between fat mass and bone remains elusive. The study population consisted of 396 girls and 138 premenopausal mothers and 114 postmenopausal grandmothers of these girls. Body composition and tibial length were assessed using dual-energy X-ray absorptiometry (DXA), and bone traits were determined at the tibia using peripheral quantitative computed tomography (pQCT) in the girls at the ages of 11.2 AE 0.8, 13.2 AE 0.9, and 18.3 AE 1.0 years and in the mothers (44.7 AE 4.1 years) and grandmothers (70.7 AE 6.3 years). The values of relative bone strength index (RBSI), an index reflecting the ratio of bone strength to the load applied on the tibia, were correlated among family members (all p < .05). The mean values of RBSI were similar among 11-and 18-year-old girls and premenopausal women but significantly lower in 13-year-old girls and postmenopausal women. However, in each age group, subjects in the highest BMI tertiles had the lowest RBSI values (all p < .01). RBSI was inversely associated with body weight (all p < .01), indicating a deficit in bone strength relative to the applied load from greater body weight. RBSI was inversely associated with fat mass (all p < .001) across age groups and generations but remained relatively constant with increasing lean mass in girls and premenopausal women (all p > .05), indicating that the bone-strength deficit was attributable to increased fat mass, not lean mass. Moreover, the adverse effect of fat mass was age-dependent, with every unit increase in fat mass associated with a greater decrease in RBSI in pre-and postmenopausal women than in girls (all p < .001). This is largely due to the different capacity of young and adult bones to increase diaphyseal width by periosteal apposition in response to increased load. In summary, increasing body weight with fat accumulation is accompanied by an age-dependent relative bone-strength deficit in women because the beneficial effects of increased fat mass on bone, if any, do not compensate for the mechanical burden that it imposes. ß

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“…28 Each femur was tested for mechanical strength in 3-point bending on a small testing machine (QTest-1L with TestWorks-4 software, MTS Systems, Eden Prairie, MN) using conditions from previous studies. 31 The central load was directed at 0.2 mm/min from anterior to posterior and applied at the midshaft, and the two outer supports were placed 15 mm apart positioned on the diaphysis equidistant from the midshaft, near the lesser trochanter and femoral condyles. Supports and load platen were 2.5 mm diameter cylinders.…”

Section: Methodsmentioning

confidence: 99%

Density and structural changes in the bone of growing rats after weekly alendronate administration with and without a methotrexate challenge

Spadaro¹,

Damron²,

Horton³

et al. 2006

Journal Orthopaedic Research

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Alendronate (ALN) and other bisphosphonates have been used successfully in pediatric patients with osteopenia secondary to connective tissue diseases. Loss of growth in height has not been reported, but concerns remain regarding the effect of these potent antiresorptive agents when used in children and adolescents. High-dose methotrexate (MTX) and other chemotherapy drugs have been implicated in osteoporosis and a high fracture incidence in survivors of childhood cancers and are also associated with osteopenia in adult animals. The effect of high dose MTX on bone density during rapid skeletal growth, however, has not been widely studied, nor has the potentially therapeutic effect of bisphosphonates in this setting. We examined the effects of ALN and MTX administration, alone and in combination, on bone density, morphology, mechanical strength, and longitudinal growth in normal growing rats. Sprague-Dawley rats were given ALN once weekly (0.3 mg/kg) from 5 to 11 weeks of age, with and without a course of methotrexate (MTX) given daily in weeks 1 and 3 (0.75 mg/kg/day). Twenty-four animals were randomly divided into four groups: Control (vehicle), ALN alone, ALN þ MTX, and MTX alone. After 6 weeks, the femora, tibiae, and lumbar spine were studied by dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, mechanical strength testing, microradiography, light microscopy, and by determination of ash weights and bone lengths. ALN treatment increased bone mineral density (BMD) by 23% to 68%. The largest increases in the femur occurred in the distal third where endochondral bone growth was greatest and included large increases in trabecular bone and total cross-sectional area. ALN þ MTX produced similar effects to ALN alone. MTX only reduced BMD by 8% in the vertebrae, but not significantly at other sites. MTX also led to femoral length reductions of 2.9%. The small reductions in BMD due to MTX were overwhelmed by the increases due to ALN, whereas the length loss was unaffected. Transverse density banding corresponding to weekly ALN administrations were clearly evident radiographically throughout the growing skeleton, likely due to decreased resorption and possibly increased mineralization in the bands. ALN or ALN þ MTX treatment also led to increases in mechanical strength in the femora. Although MTX administration during growth leads to some BMD reduction, ALN given with MTX eliminates this reduction and in fact bone density and strength increase above control levels. ß

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Mechanical validation of a tomographic (pQCT) index for noninvasive estimation of rat femur bending strength

Cited by 236 publications

References 40 publications

Musculoskeletal abnormalities of the tibia in juvenile rheumatoid arthritis

Musculoskeletal abnormalities of the tibia in juvenile rheumatoid arthritis

Fat mass accumulation compromises bone adaptation to load in finnish women: A cross-sectional study spanning three generations

Density and structural changes in the bone of growing rats after weekly alendronate administration with and without a methotrexate challenge

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