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Bone mineral content in preterm infants at age 4 to 16.

date: 03/01/1985
author: Helin I, Landin LA, Nilsson BE.
publication: Acta Paediatr Scand. 1985 Mar;74(2):264-7.
pubmed_ID: 3993373

Using photon absorptiometry the forearm bone mineral content (BMC) was determined in 75 children aged 4 to 16, who all had a low birth weight. Forty-five of them were born preterm AGA (27 boys, 18 girls, mean weight 1 580 g; range 920-2 060 g) and 30 preterm SGA (17 boys, 13 girls, mean weight 1510; range 940-2130 g). The results were compared with a control group of children of the same age, and analyses of covariance with age, height and weight as the covariant factors were performed. The BMC, weight and height did not differ between the children born AGA or SGA. Irrespective of AGA or SGA, the BMC was significantly decreased in boys but the difference was less pronounced and less significant when height and weight were used as covariant factors. Boys who had been born preterm had a less BMC than the control boys for their age but they were also somewhat shorter and lighter than expected with regard to their age.

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Bone density and other possible predictors of fracture risk in children and adolescents with spastic quadriplegia.

author: Henderson RC.
publication: Dev Med Child Neurol. 1997 Apr;39(4):224-7.
pubmed_ID: 9183259
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.

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Bisphosphonates to treat osteopenia in children with quadriplegic cerebral palsy: a randomized, placebo-controlled clinical trial.

date: 11/01/2002
author: Henderson RC, Lark RK, Kecskemethy HH, Miller F, Harcke HT, Bachrach SJ.
publication: J Pediatr. 2002 Nov;141(5):644-51.
pubmed_ID: 12410192

OBJECTIVE: To evaluate in a double-blind, placebo-controlled clinical trial the safety and efficacy of intravenous pamidronate to treat osteopenia in nonambulatory children with cerebral palsy. STUDY DESIGN: Six pairs of subjects generally matched within each pair for age, sex, and race completed the protocol. One member of each pair randomly received plain saline placebo, the other pamidronate. Drug/placebo was administered intravenously daily for 3 consecutive days, and this 3-day dosing session was repeated at 3-month intervals for one year. Evaluations were continued for 6 months after the year of treatment. Bone mineral density (BMD) was measured in the distal femur, a site specifically developed for use in this contracted population, and the lumbar spine. RESULTS: In the metaphyseal region of the distal femur, BMD increased 89% +/- 21% (mean +/- SEM) over the 18-month study period in the pamidronate group compared with 9% +/- 6% in the control group. Age-normalized z scores increased from -4.0 +/- 0.6 to -1.8 +/- 1.0 in the pamidronate group and did not significantly change in the control group (-4.2 +/- 0.3 to -4.0 +/- 0.3). The first dosing with pamidronate caused a transient drop in serum calcium that was asymptomatic and not treated. No other potentially adverse effects were noted. CONCLUSIONS: In this small controlled clinical trial, pamidronate was found to be a safe and very effective agent to increase BMD in nonambulatory children with cerebral palsy.

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Effect of standing on spasticity, contracture, and osteoporosis in paralyzed males.

date: 01/01/1993
author: Kunkel CF, Scremin AM, Eisenberg B, Garcia JF, Roberts S, Martinez S.
publication: Arch Phys Med Rehabil. 1993 Jan;74(1):73-8.
pubmed_ID: 8420525

The effect of “standing” in a frame on spasticity (clinical assessment and H-reflex), contracture (lower extremity joint range of motion), and osteoporosis (dual photon absorptiometry) was studied in six paralyzed males (mean age 49 yr) who had been confined to wheelchairs for an average of 19 years. Standing time averaged 144 hours over a mean of 135 days. Clinical Assessment measured reflexes, tone, and clonus in the legs. Results revealed no important differences between initial and final scores for clinical assessment and joint range of motion. In three subjects for whom H-reflexes were found, latency and amplitude were not altered by “standing.” Bone density was normal in the lumbar spine but significantly reduced in the femoral neck. “Standing” did not modify the bone density in any site. A follow-up interview revealed that 67% of subjects continued to “stand” and felt healthier because of it. In summary, “standing” had no ill effects, did not alter measured variables, and had a positive psychological impact.

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Bone mineral density and fractures in boys with Duchenne muscular dystrophy.

date: 02/01/2000
author: Larson CM, Henderson RC.
publication: J Pediatr Orthop. 2000 Jan-Feb;20(1):71-4.
pubmed_ID: 10641693

The relationships between bone density, mobility, and fractures were assessed in 41 boys with Duchenne muscular dystrophy. Bone density in the lumbar spine was only slightly decreased while the boys were ambulatory (mean z-score, -0.8), but significantly decreased with loss of ambulation (mean z-score, -1.7). In contrast, bone density in the proximal femur was profoundly diminished even when gait was minimally affected (mean z-score, -1.6), and then progressively decreased to nearly 4 standard deviations below age-matched normals (mean z-score, -3.9). These are consistent with the findings that 18 (44%) of the boys sustained a fracture, 66% of these fractures involved the lower extremities, and there were no spinal compression fractures. Furthermore, four (44%) of nine boys who were walking with aids or support at the time of fracture never resumed walking after the fracture. Osteoporosis is most profound in the lower extremities of boys with Duchenne muscular dystrophy, and begins to develop early while still ambulating. Frequent fractures that may result in loss of ambulation are the clinical consequences.

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Bone density and metabolism in children and adolescents with moderate to severe cerebral palsy.

date: 07/01/2002
author: Henderson RC, Lark RK, Gurka MJ, Worley G, Fung EB, Conaway M, Stallings VA, Stevenson RD.
publication: Pediatrics. 2002 Jul;110(1 Pt 1):e5.
pubmed_ID: 12093986

OBJECTIVES: Diminished bone density and a propensity to fracture with minimal trauma are common in children and adolescents with moderate to severe cerebral palsy (CP). The purpose of this study was to provide a detailed evaluation of bone mineral density (BMD) and metabolism in this population and to assess the relationship of these measures to multiple other clinical, growth, and nutrition variables. METHODS: The study group consisted of 117 subjects ages 2 to 19 years (mean: 9.7 years) with moderate to severe CP as defined by the Gross Motor Functional Classification scale. Population-based sampling was used to recruit 62 of the participants, which allows for estimations of prevalence. The remaining 55 subjects were a convenience sampling from both hospital- and school-based sources. The evaluation included measures of BMD, a detailed anthropometric assessment of growth and nutritional status, medical and surgical history, the Child Health Status Questionnaire, and multiple serum analyses. BMD was measured in the distal femur, a site specifically developed for use in this contracted population, and the lumbar spine. BMD measures were converted to age and gender normalized z scores based on our own previously published control series (n > 250). RESULTS: Osteopenia (BMD z score <-2.0) was found in the femur of 77% of the population-based cohort and in 97% of all study participants who were unable to stand and were older than 9 years. BMD was not as low in the lumbar spine (population-based cohort mean +/- standard error z score: -1.8 +/- 0.1) as in the distal femur (mean z score: -3.1 +/- 0.2). Fractures had occurred in 26% of the children who were older than 10 years. Multiple clinical and nutritional variables correlated with BMD z scores, but interpretation of these findings is complicated by covariance among variables. In stepwise regression analyses, it was found that severity of neurologic impairment as graded by Gross Motor Functional Classification level, increasing difficulty feeding the child, use of anticonvulsants, and lower triceps skinfold z scores (in decreasing order of importance) all independently contribute to lower BMD z scores in the femur. CONCLUSIONS: Low BMD is prevalent in children with moderate to severe CP and is associated with significant fracture risk. The underlying pathophysiology is complex, with multiple factors contributing to the problem and significant variation between different regions of the skeleton.

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Modulation of bone loss during calcium insufficiency by controlled dynamic loading.

date: 04/01/1986
author: Lanyon LE, Rubin CT, Baust G.
publication: Calcif Tissue Int. 1986 Apr;38(4):209-16.
pubmed_ID: 3085898

Changes in the midshaft cross-sectional area of the ulna were measured in egg-laying turkeys on a diet insufficient in calcium. Left:right comparisons were used to assess the bone loss over a six-week period due to 1) calcium insufficiency, 2) calcium insufficiency plus disuse, and 3) calcium insufficiency and disuse interrupted by a short daily period of intermittent loading applied from an external device. Calcium insufficiency alone in the intact ulna resulted in a 15% reduction in cross-sectional area. In the functionally deprived bones this loss was increased to 32%. In bones where the disuse was interrupted by a single short daily period of loading, the degree of bone loss was significantly modified (P less than 0.006) to 25%. No significant difference in the modulating effect of loading was achieved by varying the peak strain from 0.0015 to 0.003, the strain rate from 0.01 to 0.05, or the duration of the single loading period from 100 sec per day to 25 minutes. All the loading regimes employed had been demonstrated to be osteogenic in mature male birds on a diet sufficient in calcium.

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Static vs dynamic loads as an influence on bone remodeling.

date: 01/01/2004
author: Lanyon LE, Rubin CT.
publication: J Biomech. 1984;17(12):897-905.
pubmed_ID: 6520138

Remodeling activity in the avian ulna was assessed under conditions of disuse alone, disuse with a superimposed continuous compressive load, and disuse interrupted by a short daily period of intermittent loading. The ulnar preparation consisted of the 110mm section of the bone shaft between two submetaphyseal osteotomies. Each end of the preparation was transfixed by a stainless steel pin and the shaft either protected from normal functional loading with the pins joined by external fixators, loaded continuously in compression by joining the pins with springs, or loaded intermittently in compression for a single 100s period per day by engaging the pins in an Instron machine. Similar loads (525 N) were used in both static and dynamic cases. The strains engendered were determined by strain gauges, and at their maximum around the bone’s midshaft were -0.002. The intermittent load was applied at a frequency of 1 Hz as a ramped square wave, with a rate of change of strain during the ramp of 0.01 s-1. Peak strain at the midshaft of the ulna during wing flapping in the intact bone was recorded from bone bonded strain gauges in vivo as -0.0033 with a maximum rate of change of strain of 0.056 s-1. Examination of bone sections from the midpoint of the preparation after an 8 week period indicated that in both non-loaded and statically loaded bones there was an increase in both endosteal diameter and intra cortical porosity. These changes produced a decrease in cross sectional area which was similar in the two groups (-13%).(ABSTRACT TRUNCATED AT 250 WORDS)

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Calcium balance in paraplegic patients: influence of injury duration and ambulation.

date: 10/01/1978
author: Kaplan PE, Gandhavadi B, Richards L, Goldschmidt J.
publication: Arch Phys Med Rehabil. 1978 Oct;59(10):447-50.
pubmed_ID: 718407

Calcium metabolic balance determinations, which have been done in various clinical and experimental conditions, were applied to the study of 8 spinal cord injured patients receiving a diet with 1600 mg calcium and 85 to 120 gm protein daily. All of the patients had hypercalciuria prior to ambulation. Those with spinal cord injuries of less than 3 months duration (early group) had a calcium balance of -27 mg before ambulation and 235 mg after ambulation. Patients with spinal cord injuries of 6 months or more duration (late group) had calcium balances of 55 mg before ambulation and 175 mg after ambulation. Ambulation significantly decreased the hypercalciuria and modified the calcium balance in a positive direction. Smaller changes were noted in the responses of the late group than in those of the early group. Early ambulation will probably prevent bone loss, calcium stones in the genitourinary tract, and other sequellae of negative calcium balance.

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The effect of a weight-bearing physical activity program on bone mineral content and estimated volumetric density in children with spastic cerebral palsy.

date: 07/01/1999
author: Chad KE, Bailey DA, McKay HA, Zello GA, Snyder RE.
publication: J Pediatr 1999 Jul;135(1):115-7.
pubmed_ID: 10393617

After an 8-month physical activity intervention in children with cerebral palsy, increases in femoral neck bone mineral content (BMC) (9.6%), volumetric bone mineral density (v BMD) (5.6%), and total proximal femur BMC (11.5%) were observed in the intervention group (n = 9) compared with control subjects (n = 9; femoral neck BMC, -5. 8%; v BMD, -6.3%; total proximal femur BMC, 3.5%).

Publication Types:
? Clinical Trial
? Randomized Controlled Trial