Bone health in Duchenne muscular dystrophy: a workshop report from the meeting in Cincinnati, Ohio, July 8, 2004.
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Bone Density↗
Biomedical subjects
R C Henderson
Publications and source records attributed to R C Henderson.
Health status of children with moderate to severe cerebral palsy.
The aim of the study was to evaluate the health of children with cerebral palsy (CP) using a global assessment of quality of life, condition-specific measures, and assessments of health care use. A multicenter population-based cross-sectional survey of 235 children, aged 2 to 18 years, with moderate to severe impairment, was carried out using Gross Motor Function Classification System (GMFCS) levels III (n = 56), IV (n = 55), and V (n = 122). This study group scored significantly below the mean on the Child Health Questionnaire (CHQ) for Pain, General Health, Physical Functioning, and Impact on Parents. These children used more medications than children without CP from a national sample. Fifty-nine children used feeding tubes. Children in GMFCS level V who used a feeding tube had the lowest estimate of mental age, required the most health care resources, used the most medications, had the most respiratory problems, and had the lowest Global Health scores. Children with the most severe motor disability who have feeding tubes are an especially frail group who require numerous health-related resources and treatments. Also, there is a relationship among measures of health status such as the CHQ, functional abilities, use of resources, and mental age, but each appears to measure different aspects of health and well-being and should be used in combination to reflect children's overall health status.
Activities of Daily Living↗
Dual X-ray absorptiometry assessment of body composition in children with altered body posture.
Many children have contractures and/or deformities that preclude positioning in a fully supine position. The purpose of this study was to evaluate the effects of "poor" positioning on the assessment of body composition with dual X-ray absorptiometry (DXA) in thirty-seven normal child volunteers ages 3-16 yr. Multiple whole-body DXA scans of each child were performed: duplicate scans in the correct fully supine position, two scans while simulating different positions typical of children with contractures, and a scan while positioned in the full lateral position as a "worst-case" scenario. Also evaluated were the precision of duplicate measures in the altered positions, the effect of knee flexion contractures, and the impact of metallic orthopedic fixation devices. Errors in body composition assessment did occur from "poor" positioning. In those positions simulating children with contractures, the mean errors were 4-6% for measures of bone mineral content, 1-3% for lean body mass, and 5-11% for fat mass. Measures in the correct fully supine position and the contracted positions were highly correlated. The errors obtained by altering position were small. If errors of this magnitude are of significance, then corrective equations could be utilized to improve accuracy. Precise and reasonably accurate measures of body composition can be obtained with DXA in children with disabilities and deformities that preclude fully supine positioning.
Absorptiometry, Photon↗
Bone mineral density 6 years after a hip fracture: a prospective, longitudinal study.
The purpose of this prospective study was to extend the results of previous studies to determine if an accelerated rate of loss of bone mineral density (BMD) continues for 6 years after a hip fracture. Eighty-five elderly patients who had sustained a hip fracture had determinations of BMD made at the time of fracture; 55 of these patients were available for reassessment of BMD 1 year later, and 21 were available for reassessment of BMD 6 to 7 years later. The change in BMD from injury to 1 year and from 1 to 6 years was determined and correlated with pre- and postinjury variables, such as ambulatory ability, dietary intake of calcium, serum vitamin D levels, and mental status. There was a marked decrease in BMD in the in the first year after fracture, with the mean change in BMD being -4.3% at the femoral neck and -1.8% at the lumbar spine. Between 1 and 6 years after fracture, however, there was a dramatic increase in the BMD at both the femoral neck and lumbar spine measurement sites. Relative to 1 year after fracture, the mean increases were 7.7% at the femoral neck and 4.5% at the lumbar spine. In many cases, the loss of bone mineral that occurred in the first year after fracture was completely recouped in the subsequent 5 years. Five of the 21 patients (24%) sustained a contralateral hip fracture in the 6 years after the index fracture. Lumbar spine BMD was lower at baseline (p = 0.112), 1 year after fracture (p = 0.007), and 6 years after fracture (p = 0.003) in patients who sustained a second hip fracture than in those who did not. There was a general decrease in the functional activity level of patients in the 6 years after a hip fracture, but there were no statistically significant relationships between changes in BMD and the functional mobility of patients. The mean calcium intake in patients improved remarkably in the 6 years after fracture, but there was no correlation between daily calcium intake and changes in BMD. During the first year after a hip fracture, there is a rapid loss of bone mineral from the lumbar spine and contralateral femoral neck. Between 1 and 6 years after fracture, however, BMD is likely to increase, perhaps to levels greater than those at baseline. Although this investigation is small, the findings of this study point to the importance of further larger studies to further clarify the natural history of BMD after a hip fracture and the potential impact of pharmacological intervention on that natural history.
Aged↗
Bone mineral content and body composition in children and young adults with cystic fibrosis.
With dual energy X-ray absorptiometry (DEXA), it is possible to quantitate important aspects of growth in children with cystic fibrosis (CF), supplementing the usual measures of height and weight. Of particular concern during growth is the accumulation of bone mineral, since osteoporosis and fractures are well-recognized problems in end-stage disease. Various measures of growth and body composition were examined in 40 children and young adults (ages 5.7-20.3 years, mean 11.9 years) and compared to age-, gender-, and race-matched normal controls. The mean (+/- SE) weight Z-score of the 40 CF patients was -0.70 +/- 0.11, and the mean height Z-score was -0.66 +/- 0.15. Relative to their matched normal controls, the CF patients had a deficit in total body bone mineral averaging 19.1% +/- 3.0%. The deficits in total body bone mineral correlated with pulmonary and nutritional measures of disease severity. Serum vitamin D levels, calcium intake, age, gender, use of steroids, and CF genotype were not found to be significant factors. In this group of children and young adults with CF, height and weight measures of growth were not dramatically reduced (mean Z-scores = -0.7), yet large deficits in total body bone mineral averaging nearly 20% were identified.
Absorptiometry, Photon↗
Lateral femoral scan: an alternative method for assessing bone mineral density in children with cerebral palsy.
BACKGROUND: Children with cerebral palsy (CP), often nonambulatory and/or on anticonvulsants, are at increased risk for fractures. Bone mineral density (BMD) measured by the conventional techniques of dual-energy X-ray absorptiometry (DXA) often cannot be reliably or easily measured in these patients. OBJECTIVE: To find an alternative site to whole body, spine and hip that can be conveniently used to measure BMD in CP patients. MATERIALS AND METHODS: Having observed that CP patients prefer to lie on their sides, we explored measuring BMD at the distal femur in the lateral projection. A total of 92 scans were performed without sedation in 34 children and adolescents with CP, aged 4-19 years. Four femoral shaft subregions were created: two trabecular and two cortical. RESULTS: The coefficients of variation (CV %) were generally higher for opposite-side comparisons (n = 12 patients) than for same-side comparisons (n = 16 patients). For intra- and interobserver analyses, CV % were higher for cortical regions than for trabecular regions. Overall, the CV % were similar to those for hip and spine. CONCLUSION: This peripheral site in the femur should be considered as an alternative for patients with CP when whole-body, hip and spine DXA are not practical.
Absorptiometry, Photon↗
The correlation between dual-energy X-ray absorptiometry measures of bone density in the proximal femur and lumbar spine of children.
OBJECTIVE: To assess the correlation between a pediatric patient's proximal femur and lumbar spine bone mineral density (BMD) Z-scores, and the side-to-side difference between proximal femurs. DESIGN: Three hundred and thirty-nine patients aged 2.2-17.0 years with an assortment of underlying conditions underwent dual-energy X-ray absorptiometry (DXA) measures of BMD in both proximal femurs and the lumbar spine. RESULTS: Z-scores in the proximal femur and lumbar spine correlated highly (r = 0.73, P = 0.0001), but for individual patients the difference was often significant, and increased as BMD deviated further from normal. For patients with proximal femur Z-scores of 1 to -1 the mean difference between proximal femur and lumbar spine Z-scores was 0.5; with proximal femur Z-scores of less than -3 the mean difference was increased to 1.7. In conditions which symmetrically involve the lower extremities, the right and left proximal femur Z-scores differed on average by only 0.2. CONCLUSION: BMD measurements for pediatric patients are most easily interpreted by clinicians if converted to Z-scores, yet these are usually available only for the lumbar spine. Age-normalized BMD assessment at more than one site is necessary to provide a more reliable, complete assessment of bone mineral status in pediatric patients.
Absorptiometry, Photon↗
Accelerated bone mineral loss following a hip fracture: a prospective longitudinal study.
The purpose of this prospective study was to monitor the bone mineral density (BMD) of the lumbar spine and contralateral femoral neck in the first year following an osteoporosis-related fracture of the hip. Eighty-three elderly patients (mean age 77 years) who had sustained a hip fracture had determinations of BMD made at the time of fracture; 49 of these patients were available for reassessment of BMD 1 year later. The change in BMD was correlated with pre- and postinjury variables, such as ambulatory ability, dietary intake of calcium, serum vitamin D levels, mental status, and routine serologies. The mean decrease in BMD in the year following fracture was 5.4% from the contralateral femoral neck and 2.4% from the lumbar spine. Calcium intake correlated with the loss of BMD from the femoral neck (p = 0.015), but not the lumbar spine. Patients with daily calcium intakes of less than 500 mg/day had a more than 10% decrease in femoral neck BMD in the year following their hip fracture. Serum 1,25-dihydroxy vitamin D level correlated with loss of MBD from the lumbar spine (p = 0.001), but not from the femoral neck. There was no correlation between the loss of bone mineral from either measurement site and age, sex, level of ambulation, or mental status. The loss of BMD from the femoral neck in the year following a hip fracture is more than five times that reported in the nonfractured population. This accelerated rate of loss can have drastic consequences in an elderly population already exhibiting osteopenia and propensity to fall. Investigation of pharmacologic or other interventions in the first critical year following a hip fracture may potentially blunt this accelerated rate of bone loss and lessen the risk of subsequent fractures.
Aged↗
Vitamin D levels in children with cystic fibrosis.
Serum levels of the important hormone 1,25-dihydroxyvitamin D (1,25-diOHD, calcitriol) have not been extensively evaluated in patients with cystic fibrosis (CF) during the critical period of skeletal growth and development. This study was a cross-sectional, observational assessment of 25-hydroxyvitamin D (25-OHD, calcidiol) and 1,25-diOHD levels in 54 patients with CF. The patients' ages ranged from 4.9 years to 19.5 years (mean, 11.0 years). Levels were correlated with pulmonary function tests, chest x-ray scores, height and weight Z scores, skinfold percentiles, CF genotype, serum chemistries, and use of a vitamin supplement. Levels were compared with those in more than 160 other pediatric patients living in the same region, and all assays were done in the same laboratory. Despite low-normal levels of the 25-OHD precursor, there was a high prevalence of low (18%) and marginal (18%) levels of 1,25-diOHD. None of the various parameters examined correlated with either 25-OHD or 1,25-diOHD levels. The cause, clinical significance, and treatment of low levels of this important hormone in children with CF warrant further study.
Adolescent↗
Calcium intake in children with positive IgG RAST to cow's milk.
OBJECTIVE: This study was made to: (i) identify the prevalence of low calcium intakes in a paediatric population with loosely defined 'milk allergy'; and (ii) assess long-term (mean 21 months later) changes in calcium intake following a single nutrition counselling session with those patients initially found to have a low intake. METHODOLOGY: Calcium intake was assessed in a cross-sectional study of 58 patients ages 5-16 years (mean 9.9 years) with IgG radioallergosorbent test (RAST) class II or higher for cow's milk protein. Those 31 patients found to have a low calcium intake were prospectively re-evaluated 12-30 months later following a single nutrition counselling session. RESULTS: Calcium intake was < recommended dietary allowance (RDA) for 31 of 58 (53%) patients. The patient's perception of their intake was unreliable; 44% of those who rated their calcium intake fair or good did not meet their RDA. Taking a calcium supplement did not ensure adequate intake; 21% of those taking supplements still did not meet their RDA. Milk intake predicted calcium intake; 8% of those who did not drink milk vs 68% of those who did drink at least some milk met their RDA without supplementation. The 31 patients with low intakes received counselling and were re-evaluated at an average follow-up of nearly 2 years. Calcium intake was increased a mean of 360 mg/day and use of supplements increased from 10 to 52% of the group. Despite these positive changes, 48% still did not meet their RDA. CONCLUSION: Limited milk intake is likely to be associated with suboptimal calcium intake. Efforts should be made to educate the family about the importance of calcium and its non-dairy sources. With many families repeated discussions of this issue may be necessary to influence calcium intake.
Adolescent↗
Bone density and other possible predictors of fracture risk in children and adolescents with spastic quadriplegia.
Forty-three patients with spastic quadriplegia (mean age 7.9 years, range 3.3 to 17.2 years) underwent bone mineral density (BMD) measurement of the lumbar spine and were evaluated between 2.6 and 5.5 years (mean 3.8) later to determine whether this measurement had predicted risk of fracture over the subsequent period of observation. Other potential risk factors that were evaluated include body weight z score, serum vitamin D levels, previous fracture, and hip spica casting. The baseline measurements showed that BMD falls further below normal with increasing age and was more than one standard deviation below age-matched normal mean in 38 of the 43 patients. Fracture rate did not differ between those with low and those with very low spinal BMD. Similarly, serum vitamin D levels and body weight z scores were not predictive of fracture. However, fracture rate was over fourfold greater following spica casting and more than threefold greater following an initial fracture. Fracture rates in the study group were similar to those reported for age- and sex-matched normal children, though generally the location of the fractures and mechanisms of injury differed.
Absorptiometry, Photon↗
Vitamin D levels in noninstitutionalized children with cerebral palsy.
Calcitriol (1,25-dihydroxy vitamin D) is an important hormone in calcium and phosphate metabolism. Levels of calcitriol and its precursor, 25-hydroxy vitamin D (calcidiol), were measured in a heterogeneous group of 125 noninstitutionalized children and adolescents with spastic cerebral palsy. Levels of each were correlated with: (1) clinical factors including mobility, prior fracture, and use of anticonvulsants; (2) nutrition and growth parameters including skinfolds, body mass index, and use of vitamin supplements; and (3) other serum analyses including osteocalcin as a marker of bone formation, calcium, and alkaline phosphatase. Levels of calcidiol and calcitriol did not correlate with any of the various clinical, nutritional, or growth parameters examined. The prevalence of low (< 10 ng/mL) levels of calcidiol was significant (19%), and dependent on the season of the year in which the level was measured. In contrast, less than 2% of the patients were found to have a low (< 20 pg/mL) level of calcitriol and the mean was comparable to normal pediatric subjects. Levels of calcitriol are maintained in noninstitutionalized children with cerebral palsy despite anticonvulsants, poor nutrition, and calcidiol levels that vary greatly with the seasons.
Adolescent↗
Bone density in children and adolescents with cystic fibrosis.
OBJECTIVE: To assess bone mineralization in children and adolescents with cystic fibrosis. DESIGN: A cross-sectional, observational study of bone mineral density (BMD) in the lumbar vertebrae and the proximal femur of 62 patients aged 4.9 to 17.8 years (mean, 10.7 years). The age-normalized BMD findings (z scores) were correlated with multiple variables, including measures of pulmonary disease, nutritional status and growth, genotype, calcium intake, and serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels. RESULTS: The mean BMD z score was -1.03 +/- 0.14 (+/- SE) in the lumbar vertebrae and -0.71 +/- 0.17 in the proximal femur. The BMD in this age range declined relative to normal values at a rapid rate of roughly 1 SD every 6 to 8 years. The BMD z scores correlated well with multiple measures of disease severity, particularly weight and forced expiratory volume in 1 second. CONCLUSIONS: Significant osteoporosis in adults with CF results at least in part from a failure to accumulate bone mineral at a normal rate during skeletal growth and development. The cause of this is likely multifactorial. With increasing longevity, the skeletal consequences of CF become an important consideration.
Adolescent↗
Bone density in survivors of childhood malignancies.
PURPOSE: The purpose of this study was to assess bone mineralization in survivors of childhood malignancies. PATIENTS AND METHODS: Bone mineral density (BMD) of the lumbar spine was measured in 60 patients aged 5.5-20.1 years (mean, 12.4 years) who had no known disease 1.0-14.5 years (mean, 4.3 years) after completing treatment for a malignancy. The age-normalized BMD findings (Z scores) were correlated with multiple variables, including measures of growth and nutrition, type of malignancy, and various treatments, including use of steroids, methotrexate, or cranial irradiation. RESULTS: BMD was normal in most patients with a mean Z score of -0.28 + 0.14 (+/- SE). Only 8% of the patients were more than 2 SDs below age-matched normal BMD. Weight Z score was the major determinant of BMD Z score. Calcium intake and height Z score were also important variables. CONCLUSIONS: Most survivors of childhood malignancies will not be left with a clinically significant deficit in BMD. Risk factors for diminished BMD include low-weight and low-height Z scores and low calcium intake. Therapeutic interventions are available to address these risk factors in those patients with significantly diminished BMD.
Adolescent↗
Bone mineralization in the affected extremities of children with spastic hemiplegia.
To assess the impact of neurologic involvement on bone mineralization, dual-energy X-ray absorptiometry was used to quantitate bone mineral content (BMC), bone mineral density (BMD), fat and lean muscle mass in the limbs of 19 children with spastic hemiplegic cerebral palsy. The BMC in the affected limb was on average 26.5% lower (upper limbs) and 15.6% lower (lower limbs) than in the corresponding uninvolved limb. Lean muscle mass was reduced by 15% and BMD by 6% in the involved limbs and did not differ significantly between upper and lower limbs. The fat content of involved and uninvolved limbs did not differ. Children with poor hand function had greater reductions in BMC (39.3%), BMD (11.3%) and lean muscle mass (22.5%) than did children with better hand function. Thus, bone size and density decrease with increasing neurologic involvement, and weight bearing may slightly lessen the effect.
Adolescent↗
Isokinetic strength following knee arthroscopy.
This study objectively evaluates recovery of quadriceps and hamstring strength following knee arthroscopy in a group of 43 patients given rehabilitation instructions, but limited supervised rehabilitation. Although the patients did not complain of weakness or functional limitation, isokinetic testing 1, 3, and 8 weeks following surgery revealed persistent weakness in many patients. Incomplete recovery was most apparent when patients were categorized by the degree to which they had recovered normal strength. Results expressed as a mean for the entire group indicated reasonably good recovery and obscured the significant weakness persisting in some patients. Knee extension strength tested at 60 degrees/sec had returned to normal 8 weeks after arthroscopy in only 32% of the subjects. Hamstring strength recovery was better, with 71% having normal strength. Patients may not recognize or report muscular weakness following arthroscopy, yet following 8 weeks of self-supervised rehabilitation many will have objective evidence of persistent weakness. In asymptomatic patients the clinical significance of this weakness is unknown.
Adult↗
Correlates of bone mineral density in elderly patients with hip fractures.
Ninety-seven elderly patients with acute fractures of the proximal femur sustained as a result of minimal trauma were studied with regard to variables that may potentially influence the incidence or outcome of fractures of the proximal femur. The mean bone mineral density (BMD) measured at the femoral neck was approximately 2 SDs below age- and sex-adjusted normals. There was a preferential loss of bone mineral from the femoral neck in younger patients with hip fractures (Z score -3.10 +/- 0.23) (mean +/- SEM) compared with the lumbar spine (Z score -1.71 +/- 0.41). Mean daily calcium intake was well below the recommended levels and calcium intake < 400 mg/day was associated with lower lumbar spine BMD Z scores (p = 0.01). Ambulatory ability was unassociated with BMD Z scores. The results of this study suggest that the femoral neck is a site of preferential bone loss in younger postmenopausal patients, and screening of patients at risk of hip fracture should measure BMD at this site. Calcium supplementation may play a role in decreasing the incidence of hip fractures.
Age Distribution↗
Metastatic breast carcinoma to the os calcis presenting as heel pain.
A 47-year-old woman who had been treated for breast carcinoma 11 years previously developed significant heel pain of unclear etiology, which ultimately proved to be metastatic adenocarcinoma. A low index of suspicion and falsely negative plain radiographs contributed to a delay in diagnosis. No other osseous metastases besides those to the foot were identifiable at the time of diagnosis. Breast carcinoma is one of the most common malignancies and frequently metastasizes to bone. Despite this, metastases to the hands or feet (acrometastases) have been identified in only a few cases. It is likely that acrometastases are more common than reported but unrecognized.
Adenocarcinoma↗