Bone-mineral density in children and adolescents who have spastic cerebral palsy

[Bone mineral density in a population with severe infantile cerebral palsy]

OBJECTIVE

To determine the bone mineral density (BMD) values in children and adolescents with moderate and severe infantile cerebral palsy (ICP) in our catchment area, and compare these values with a healthy population.

MATERIAL AND METHOD

A prognostic study of cases and controls for the assessment of BMD in patients from 2 to 18 years old with infantile cerebral palsy belonging to the Gross Motor Function Classification System (GMFCS) Groups IV and V. The BMD measurements were performed at distal femur level, dividing this region into 3 areas following the forearm protocol.

RESULTS

The BMD for each of the three areas studied results in the final sample of 69 patients were much lower than the reference levels. There was a statistically significant difference (P<.05) between the BMD values in the two sub-groups studied.

DISCUSSION

The greater the involvement, from a neurological point of view, in patients classified as Group V shows a very low BMD compared to patients of similar sex and age. The acquisition of bone capital in patients with ICP does not follow the normal pattern of the healthy population.

Scurvy: An unusual presentation of cerebral palsy

Scurvy is caused by prolonged severe dietary deficiency of ascorbic acid, in which the breakdown of intercellular cement substances leads to capillary hemorrhages and defective growth of fibroblasts, osteoblasts and odontoblasts, resulting in impaired synthesis of collagen, osteoid and dentine. It is characterized by hemorrhagic gingivitis, subperiosteal hemorrhages, perifollicular hemorrhages, and frequently petechial hemorrhages (especially on the feet). People with abnormal dietary habits, mental illness or physical disability are prone to develop this disease. Epiphyseal separation is known to occur in scurvy but is rarely seen now. Epiphyseal separation from the metaphysis is always through the zone of calcified cartilage, known as “scorbutic lattice”, which in the radiographs is represented as “the white line of Frenkel”. We report a case of multiple epiphyseal separations in a cerebral palsy child because of vitamin C deficiency. The child was treated with splintage of extremity and nutritional supplementation. All physeal separation healed completely without any deformity.

Efficacy of alendronate in the treatment of low bone density in the pediatric and young adult population

BACKGROUND

Pediatric osteoporosis is uncommon but can result in painful and debilitating insufficiency fractures. Treatment options for osteoporosis in children are few. Bisphosphonate therapy for children has not been approved by the Food and Drug Administration (FDA) in the United States, but its use in that population has been increasing. Randomized controlled studies have not been done because of the small subject pool and the difficulty in randomizing a child with an insufficiency fracture to a placebo arm of a study. This retrospective case-control study of a population of children with primarily neuromuscular disease was done to review changes in bone mineral density as reflected by dual x-ray absorptiometry (DXA) scanning.

METHODS

Medical records and DXA scans were screened to identify children with low bone density who had been treated with alendronate as well as similar control subjects with low bone density for their age who had not received alendronate. Medication acquisition was confirmed by refill records, and cumulative exposure was calculated. Interval DXA scans were reviewed to correlate bone mineral density change in grams per square centimeter as well as the percent change and percent change over time for both alendronate-treated and control subjects.

RESULTS

Twenty-eight alendronate-treated subjects and thirty control subjects met the inclusion criteria. No significant improvement in bone mineral density was seen in the alendronate-treated subjects as compared with the control subjects. Some patients in both groups exhibited marked improvement, with improvement of >31% seen only in the alendronate-treated subjects.

CONCLUSIONS

Alendronate does not reliably improve bone density in children and young adults with primarily neuromuscular disease and without osteogenesis imperfecta. Individual patients treated with bisphosphonates must be carefully followed to ensure medication compliance and appropriate response.

Relationships of muscle strength and bone mineral density in ambulatory children with cerebral palsy

SUMMARY

This work explores the relationships of muscle strength and areal bone mineral density (aBMD) in ambulatory children with cerebral palsy (CP). The knee extensor strength, but not motor function, was related to aBMD. Thus, muscle strength, especially antigravity muscle strength, was more associated with aBMD in these children than motor function.

INTRODUCTION

Muscle strength is related to bone density in normal children. However, no studies have examined these relationships in ambulatory children with CP. This work explores the relationships of muscle strength and aBMD in ambulatory children with CP.

METHODS

Forty-eight ambulatory children with spastic CP, aged 5-15 years, were classified into two groups based on Gross Motor Function Classification System levels: I (n = 28) and II (n = 20). Another 31 normal development (ND) children were recruited as the comparison group for the aBMD. Children with CP underwent assessments of growth, lumbar and distal femur aBMD, Gross Motor Function Measure-66 (GMFM-66), and muscle strength of knee extensor and flexor by isokinetic dynamometer.

RESULTS

The distal femur aBMD, but not lumbar aBMD, was lower in children with CP than in ND children (p < 0.05). Children with level I had greater knee flexor strength and GMFM-66 scores than those with level II (p < 0.001). However, the knee extensor strength and distal femur and lumbar aBMD did not differ between two groups. Regression analysis revealed the weight and knee extensor strength, but not GMFM-66 scores, were related positively to the distal femur and lumbar aBMD (adjusted r (2) = 0.56-0.65, p < 0.001).

CONCLUSIONS

These results suggest the muscle strength, especially antigravity muscle strength, were more associated with the bone density of ambulatory children with CP than motor function. The data may allow clinicians for early identifying the ambulatory CP children of potential low bone density.

Nutritional rehabilitation increases the resting energy expenditure of malnourished children with severe cerebral palsy

AIM

The aim of this study was to measure resting energy expenditure (REE) and energy intake in children with quadriplegic cerebral palsy (CP), to relate these to anthropometric measurements, and to determine the influence of nutritional rehabilitation on REE.

METHODS

Fifty-six children (20 females, 36 males; age range 3y 11mo-18y; mean age 10y; SD 3y 11mo) with CP (Gross Motor Function Classification System level V) participated in this cross-sectional study. Children were excluded if they had a known metabolic disorder, genetic syndrome, or chromosomal abnormality. Thirty-three of the children were tube fed and 23 were fed orally. A comparison group comprised 111 (42 females, 69 males) healthy children who had undergone anthropometric and REE measurements and were of similar age to the children with CP (4-19y). REE was measured by indirect calorimetry and energy intake was determined from weighed food records.

RESULTS

The REE in the children with CP was low (79.5%) compared with that predicted and highly variable (SD 38.4%). Fat-free mass was the strongest predictor of REE, accounting for 27% of the variation. Energy intake as a percentage of REE in was greatly overestimated in oral-fed children with CP (293%). In a subset of children with CP (n=14), an increased energy intake by gastrostomy tube feeding resulted in an increase in REE from 70.0% to 101.9% of that predicted.

INTERPRETATION

The REE of children with CP is low and variable and is not strongly related to any one anthropometric measurement. Food records in oral-fed children with CP are of little value owing to their inaccuracy. This study provided support for the hypothesis that the low REE found in malnourished children with CP is partly due to a low energy intake.

Informing evidence-based clinical practice guidelines for children with cerebral palsy at risk of osteoporosis: a systematic review

AIM

The aim of this systematic review was to inform evidence-based clinical practice guidelines for children with cerebral palsy (CP) and low bone mineral density (BMD).

METHOD

A computer-assisted literature search was focused on low BMD in children with CP, and was limited to the following interventions: weight-bearing activities, bisphosphonate use, and vitamin D or calcium supplementation. Articles were classified according to American Academy of Neurology guidelines and recommendation classifications were given based on the evidence for the intervention increasing BMD and decreasing fragility fractures. Studies were included if they were English-language full-text studies, focused on children with CP, and included at least 10 participants receiving the studied interventions.

RESULTS

Twenty-one articles underwent full-text review and data abstraction, including seven studies of weight-bearing activities, five studies of vitamin D or calcium supplementation, and nine studies of bisphosphonates administration. Overall, the evidence that bisphosphonates administration increases BMD was assessed as level B (probable) while the evidence that vitamin D or calcium supplementation does so was assessed as level C (possible); there was insufficient evidence to suggest that weight-bearing activities are an effective intervention to improve BMD. The evidence that bisphosphonates help to prevent fragility fractures was assessed as level C (possible); there was inadequate evidence to support the use of weight-bearing activities or vitamin D or calcium supplementation to decrease fragility fractures.

INTERPRETATION

Evidence-based clinical practice guidelines were created outlining the suggested role of weight-bearing activities, vitamin D and calcium supplementation, and bisphosphonate use for children with CP with low BMD at risk of fragility fractures.

Lumbar spine and total-body dual-energy X-ray absorptiometry in children with severe neurological impairment and intellectual disability: a pilot study of artefacts and disrupting factors

BACKGROUND

Children with severe neurological impairment and intellectual disability (ID) are susceptible for developing low bone mineral density (BMD) and fractures. BMD is generally measured with dual-energy X-ray absorptiometry (DXA).

OBJECTIVE

To describe the occurrence of factors that may influence the feasibility of DXA and the accuracy of DXA outcome in children with severe neurological impairment and ID.

MATERIALS AND METHODS

Based on literature and expert opinion, a list of disrupting factors was developed. Occurrence of these factors was assessed in 27 children who underwent DXA measurement.

RESULTS

Disrupting factors that occurred most frequently were movement during measurement (82%), aberrant body composition (67%), small length for age (56%) and scoliosis (37%). The number of disrupting factors per child was mean 5.3 (range 1-8). No correlation was found between DXA outcomes and the number of disrupting factors.

CONCLUSION

Factors that may negatively influence the accuracy of DXA outcome are frequently present in children with severe neurological impairment and ID. No systematic deviation of DXA outcome in coherence with the amount of disrupting factors was found, but physicians should be aware of the possible influence of disrupting factors on the accuracy of DXA.

Protein levels in enteral feeds: do these meet requirements in children with severe cerebral palsy?

Children with cerebral palsy (CP) have been documented to have feeding difficulties, which increase in line with condition severity and result in lowered growth potential. Much nutrition literature surrounds energy intake and expenditure in these children, with less information available on other parameters such as protein and micronutrients, which are also important for growth and development. We examined differences in protein intake and a variety of protein metabolism indices in children with CP compared with controls. A total of twenty-four children aged 4–12 years with marked CP fed orally (O, n 15) or enterally (E, n 9) were recruited, including age-matched typically developing children (C, n 24). Fasting blood samples were analysed for levels of albumin, creatinine, urea and urate. Parents collected an exact food replica for three consecutive days of their child's actual intake, which were directly analysed for protein content. Significant differences were found in protein intakes between the groups (mean percentage minimum requirements: E = 178 (sd 47); O = 208 (sd 95); C = 311 (sd 119), P = 0·005). Despite all children consuming over recommended levels, children with CP had significantly reduced levels of the protein metabolic indices compared with controls. These include as z-scores: albumin mean C = 0·71 (sd 1·04) and CP = − 0·17 (sd 1·60), P = 0·03; creatinine C = − 2·06 (sd 0·46) and CP = − 3·11 (sd 0·98), P < 0·001; urate C = 0·18 (sd 0·62) and CP = − 0·58 (sd 0·93), P = 0·002. Post hoc analysis, the present data show potentially greater protein metabolism issues in enterally fed children, compared with the other groups. This may also support recent literature that suggests shortfalls in current recommendations.

Tolerance and effectiveness on pain control of Pamidronate® intravenous infusions in children with neuromuscular disorders

Osteoporosis is a common complication in children with motor impairments. They have a higher risk of fractures (20% during their lifetime) mostly at femoral level. Furthermore, these children have pain yet no clear relation has been established between osteoporosis and pain. The efficacy of bisphosphonates has been validated in adults and for children with osteogenesis imperfecta (OI). However, its use in children with motor impairments has not yet been validated.

PATIENTS AND METHODS

Retrospective study on the medical charts of children presenting neurological diseases and motor impairments associated to secondary symptomatic osteoporosis. These children underwent treatment with Pamidronate(®) intravenous infusions (I.V.) in Lyon and Valence between 2002 and 2008. Data were collected on pain control, incidence and frequency of fractures and bone mass density (BMD). Data on adverse events were also collected to evaluate treatment's tolerance.

RESULTS

Twelve children's charts were studied for a total of 50 Pamidronate(®) I.V. infusions. Regarding treatment's efficacy, we observed a clear decrease and even total relief of the pain with improvement reported after 98% of perfusions. Regarding BMD, there was a real improvement after the treatment (e.g., lumbar BMD measures, -46.5% before treatment and -27% after treatment). The adverse events, flu-like syndrome, muscle pain and asymptomatic hypocalcemia, were minor and quickly reversible.

CONCLUSION

It seems quite essential to screen for osteoporosis-related pain in these children and treat them quickly to avoid a negative impact on their quality of life. Treatment with I.V. bisphosphonates has shown its relevance, yet practical modalities still need to be defined. It would be interesting but quite difficult to implement, in light of the positive effect of this study, a prospective, randomized, controlled, double-blind vs. placebo study on a large enough sample of patients.

Anthropometric and fitness variables associated with bone mineral density and broadband ultrasound attenuation in ambulatory children with cerebral palsy

We investigated anthropometric and fitness variables associated with areal bone mineral densities and broadband ultrasound attenuation in ambulatory children with cerebral palsy. Thirty-four children with cerebral palsy, aged 4-12 years, and 33 normal development children were collected. There were significant differences in femoral bone densities and calcaneus broadband ultrasound attenuation, but not in lumbar bone densities, between cerebral palsy and normal groups. Regression analysis revealed that different anthropometric and fitness variables were linked to bone densities of different skeletal regions in children with cerebral palsy (adjusted r(2) = .41-.67). Growth variables were mainly related to femoral and lumbar bone densities, while muscular endurance was mainly related to femoral and calcaneus bone densities. These findings suggest multiple complex variables can contribute to bone density variations among different skeleton areas in these children. These data can allow clinicians to identifying early these children at risk for low bone density.

Factors associated with bone density in different skeletal regions in children with cerebral palsy of various motor severities

AIM

To analyse factors associated with bone density in different skeletal regions in children with cerebral palsy (CP) of various motor severities.

METHOD

We examined 56 children with spastic CP (10 diplegia, 12 hemiplegia and 34 quadriplegia) aged 4 to 12 years (35 males, 21 females) and 29 typically developing children. Children with CP were stratified into three groups based on Gross Motor Function Classification System (GMFCS) levels I to II (n = 22), III (n = 8), and IV to V (n = 26). Growth and clinical variables, bone markers, distal femur and lumbar areal bone mineral density (BMDa), and calcaneal broadband ultrasound attenuation (BUA) were assessed.

RESULTS

The femur BMDa and calcaneal BUA values were lower in children in low GMFCS levels than in children in high GMFCS levels (p<0.05; femur BMDa: levels I-III, 0.6-0.7 g/cm(2); levels IV-V, 0.5 g/cm(2); calcaneal BUA: levels I-II, 39 db/MHz; levels III-V, 20-21 db/MHz). Lumbar BMDa and most bone markers did not differ significantly among CP and healthy groups. Regression analysis revealed that growth variables and GMFCS level were mainly associated with lower limb BMDa and BUA, and growth variables were mainly associated with lumbar BMDa (adjusted r(2) = 0.48-0.56). None of the bone markers were associated with bone density.

INTERPRETATION

Bone densities vary and are associated with a number of factors in different skeletal regions in children with CP with a range of motor severities.

The effect of gastrostomy tube feeding on body protein and bone mineralization in children with quadriplegic cerebral palsy

AIM

The aim of this study was to investigate the effect of gastrostomy tube feeding on body protein and bone mineralization in malnourished children with cerebral palsy (CP).

METHOD

Children aged between 4 and 18 years with spastic quadriplegic CP (Gross Motor Function Classification System level V) were recruited from the Children's Hospital at Westmead to participate in this prospective cohort study. The children had measurements of anthropometry (weight, height, and skinfold), bone mineral content (BMC) by dual-energy X-ray absorptiometry, and total body protein (TBP) by neutron activation analysis before and after gastrostomy tube feeding. Comparison data were collected prospectively from age-matched healthy children and extracted from databases for this study.

RESULTS

A total of 21 children (nine females, 12 males) participated in the study (median age 8 y 5 mo; interquartile range [IQR] 6 y 9 mo-11 y 10 mo). The median length of time of gastrostomy feeding was 19.4 months (IQR 7.7-29.9 mo). Significant (p<0.05) improvements were found in the median values for weight (15.4-23.3 kg), weight standard deviation scores (SDS; -4.8 to -3.0), height (105.4-118.3 cm), per cent body fat (10.7-16.3), TBP (2.4-3.4 kg), TBP per cent predicted for height (83.4-99.0), and BMC (469-626 g). No significant increases were found in height SDS, TBP per cent predicted for age, or BMC SDS for age or height.

INTERPRETATION

Malnourished children with quadriplegic CP showed significant increases in body fat and protein with gastrostomy tube feeding. No significant change in bone mineralization predicted for age or height was observed.

Bone mineral density and functional measures in patients with arthrogryposis

BACKGROUND

Patients with arthrogryposis often report decreased ambulation and physical activity. Given that skeletal mineralisation is responsive to force, we identified the need to characterize bone mineral density and functional measures in this population, and conducted a cross-sectional study to establish a reference for future investigations.

METHODS

Thirty consecutive patients aged 5 to 18 years with either the diagnosis of amyoplasia or nonsyndromic arthrogryposis with predominantly lower extremity involvement underwent bone densitometry testing, and lumbar spine Z-scores were calculated against an age and sex-matched control population as is customary in children. Pediatric outcomes data collection instrument (PODCI) and functional independence measure for Children (WeeFIM) assessment forms were completed. Mean Z-scores, PODCI, and WeeFIM scores were calculated. Statistical analysis was performed to compare lumbar spine Z-scores between patients divided by ambulatory status and to correlate WeeFIM and PODCI scores.

RESULTS

Mean lumbar spine Z-score was -0.47, with 73% of Z-scores being <0. Mean Z-score among nonambulators or home ambulators was -1.05, as compared to a mean Z-score among limited and unlimited community ambulators of -0.14 with a trend toward significance (P=0.10), and a dose-response relationship between higher bone density and increasing ambulatory function. Mean WeeFIM self-care and mobility quotient scores were 67.5/100 and 70.9/100, respectively. PODCI normative scores were decreased for upper extremity (10/50), transfer/basic mobility (-17/50), and sports/physical function (4/50), but normal in pain/comfort (45/50) and happiness (49/50). A linear relationship was noted between functional ambulation level and WeeFIM quotient and PODCI normative scores. There was good correlation between WeeFIM mobility and PODCI transfers and basic mobility standardised scores (R=0.86).

CONCLUSIONS

This is the first study to measure bone mineral density in children with arthrogryposis, and shows it to be lower than age-matched means, especially in patients with limited ambulation. Objective measures of functional ability (WeeFIM and PODCI) are decreased and demonstrate a linear relationship with ambulatory level. Further investigation is needed to quantify long-term effects of entering adulthood with below average bone mineral density in patients with arthrogryposis.

LEVEL OF EVIDENCE

Level II.

Fixation of subtrochanteric extending/derotational femoral osteotomies with the Locking Compression Plate in ambulatory neuro-orthopaedic patients

PURPOSE

Patients with neuro-orthopaedic disorders often develop hip flexion contractures or rotational hip deformities. Increasing deformities impair the already diminished walking abilities and proximal femoral osteotomies are often performed to maintain/improve walking abilities. Fixation of the osteotomies with condylar plates has been successfully used but does often not allow immediate postoperative full weight bearing. To avoid a substantial postoperative rehabilitation deficit and additional bone loss due to inactivity, a postoperative treatment with full weight bearing is, therefore, wishful. Newer fixed-angled implants with stronger anchoring in osteopenic bone might fit these demands. The objective of this study was to evaluate bone healing and the complication rate after proximal extending and/or derotational femoral osteotomy fixed with 3.5/4.5 Locking Compression Plate (LCP; Synthes(®)) and postoperative full weight bearing in ambulatory neuro-orthopaedic patients.

METHODS

Fifteen ambulatory neuro-orthopaedic patients (12 cerebral palsy [CP], 1 trisomy 21, 2 hemiparesis) with a mean age of 13.7 years (range 7-22) with hip flexion contractures and/or rotational deformities underwent subtrochanteric (n = 26) osteotomy between July 2004 and October 2007. All patients were allowed to bear their full weight postoperatively. We investigated the fusion rate, implant failure, and general complication rate until union had occurred.

RESULTS

Fourteen patients (mean weight 42.0 kg [range 21.8-59]) uneventfully achieved solid fusion. One patient (19 years of age, 73 kg) needed revision surgery due to implant failure with consecutive varus deformity and achieved solid fusion after the second intervention. Besides one superficial wound infection, no other complications occurred.

CONCLUSIONS

Subtrochanteric extending and/or derotational osteotomies fixed with an LCP are a reliable procedure in neuro-orthopaedic patients. Most patients can be treated with early postoperative full weight bearing. However, in heavier patients, possible implant failure must be considered.

Infantile scurvy: two case reports

Background. Ascorbic acid (vitamin C) is necessary for the formation of collagen, reducing free radicals, and aiding in iron absorption. SCURVY, a disease of dietary ascorbic acid deficiency, is uncommon today. It still exists in high risk groups including economically disadvantaged populations with poor nutrition. The incidence of SCURVY in the pediatric population is very low. Cases Report. Here we report two cases of SCURVY revealed by subperiosteal hematoma in children with cerebral palsy and developmental delay. Conclusion. SCURVY is extremely rare in children. Musculoskeletal manifestations are prominent in pediatric SCURVY. Multiple subperiosteal hematomas are an important indicator for diagnosis.

Pediatric rehabilitation: 1. Common medical conditions in children with disabilities

OBJECTIVE

This self-directed learning module focuses on the physiatric management of the common morbidities associated with pediatric traumatic brain injury and cerebral palsy. It is part of the study guide on pediatric rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation and pediatric medicine. The goal of this article is to enhance the learner's knowledge regarding current physiatric management of complications related with pediatric traumatic brain injury and cerebral palsy.

The relationship between fractures and DXA measures of BMD in the distal femur of children and adolescents with cerebral palsy or muscular dystrophy

Children with limited or no ability to ambulate frequently sustain fragility fractures. Joint contractures, scoliosis, hip dysplasia, and metallic implants often prevent reliable measures of bone mineral density (BMD) in the proximal femur and lumbar spine, where BMD is commonly measured. Further, the relevance of lumbar spine BMD to fracture risk in this population is questionable. In an effort to obtain bone density measures that are both technically feasible and clinically relevant, a technique was developed involving dual-energy X-ray absorptiometry (DXA) measures of the distal femur projected in the lateral plane. The purpose of this study is to test the hypothesis that these new measures of BMD correlate with fractures in children with limited or no ability to ambulate. The relationship between distal femur BMD Z-scores and fracture history was assessed in a cross-sectional study of 619 children aged 6 to 18 years with muscular dystrophy or moderate to severe cerebral palsy compiled from eight centers. There was a strong correlation between fracture history and BMD Z-scores in the distal femur; 35% to 42% of those with BMD Z-scores less than -5 had fractured compared with 13% to 15% of those with BMD Z-scores greater than -1. Risk ratios were 1.06 to 1.15 (95% confidence interval 1.04-1.22), meaning a 6% to 15% increased risk of fracture with each 1.0 decrease in BMD Z-score. In clinical practice, DXA measure of BMD in the distal femur is the technique of choice for the assessment of children with impaired mobility.

Effect of high-frequency, low-magnitude vibration on bone and muscle in children with cerebral palsy

BACKGROUND

Children with cerebral palsy (CP) have decreased strength, low bone mass, and an increased propensity to fracture. High-frequency, low-magnitude vibration might provide a noninvasive, nonpharmacologic, home-based treatment for these musculoskeletal deficits. The purpose of this study was to examine the effects of this intervention on bone and muscle in children with CP.

METHODS

Thirty-one children with CP ages 6 to 12 years (mean 9.4, SD 1.4) stood on a vibrating platform (30 Hz, 0.3 g peak acceleration) at home for 10 min/d for 6 months and on the floor without the platform for another 6 months. The order of vibration and standing was randomized, and outcomes were measured at 0, 6, and 12 months. The outcome measures included computed tomography measurements of vertebral cancellous bone density (CBD) and cross-sectional area, CBD of the proximal tibia, geometric properties of the tibial diaphysis, and dynamometer measurements of plantarflexor strength. They were assessed using mixed model linear regression and Pearson correlation.

RESULTS

The main difference between vibration and standing was that there was a greater increase in the cortical bone properties (cortical bone area and moments of inertia) during the vibration period (all P's ≤ 0.03). There was no difference in cancellous bone or muscle between vibration and standing (all P's > 0.10) and no correlation between compliance and outcome (all r's < 0.27; all P's > 0.15). The results did not depend on the order of treatment (P > 0.43) and were similar for children in gross motor function classification system (GMFCS) 1 to 2 and GMFCS 3 to 4.

CONCLUSIONS

The primary benefit of the vibration intervention in children with CP was to the cortical bone in the appendicular skeleton. Increased cortical bone area and the structural (strength) properties could translate into a decreased risk of long bone fractures in some patients. More research is needed to corroborate these findings, to elucidate the mechanisms of the intervention, and to determine the most effective age and duration of the treatment.

LEVEL OF EVIDENCE

Level II, prospective randomized cross-over study.

Official positions of the International Society for Clinical Densitometry (ISCD) on DXA evaluation in children and adolescents

Dual-energy X-ray absorptiometry (DXA) is the most widely used technical instrument for evaluating bone mineral content (BMC) and density (BMD) in patients of all ages. However, its use in pediatric patients, during growth and development, poses a much more complex problem in terms of both the technical aspects and the interpretation of the results. For the adults population, there is a well-defined term of reference: the peak value of BMD attained by young healthy subjects at the end of skeletal growth. During childhood and adolescence, the comparison can be made only with healthy subjects of the same age, sex and ethnicity, but the situation is compounded by the wide individual variation in the process of skeletal growth (pubertal development, hormone action, body size and bone size). The International Society for Clinical Densitometry (ISCD) organized a Pediatric Position Development Conference to discuss the specific problems of bone densitometry in growing subjects (9-19 years of age) and to provide essential recommendations for its clinical use.

Bone fracture in physically disabled children attending schools for handicapped children in Japan

OBJECTIVE

Very few epidemiologic studies on bone fracture have been conducted in schools for handicapped children (Yogo schools). The aim of this study was to clarify the frequency and risk factors of bone fracture in physically disabled children in Japan.

METHODS

We used a cross-sectional design to examine 525 physically disabled children in 38 Yogo schools in the Hokuriku-Koshinetsu District of Japan. The questionnaire surveyed information on participant sex, age, level of physical disability, and bone fracture history. Information on fractures was obtained, including number of fractures over participant lifetime, age when fractures occurred, location, and cause. One-year-period prevalence and lifetime prevalence were defined as the proportion of subjects with incident fractures in the previous year and with a history of fracture, respectively.

RESULTS

Participant ages ranged from 6 to 15 years, and 66.3% had cerebral palsy (CP). The 1-year-period prevalence was 3.6% and lifetime fracture prevalence was 9.7%. The 1-year-period prevalence in the age groups of 6-9, 10-12, and 13-15 years was 2/184 (1.1%), 5/171 (2.9%), and 12/164 (7.3%), respectively (P for trend = 0.0031). There were no differences in period prevalence between sexes, and this was not associated with presence of CP. Multiple logistic regression analysis showed that age and presence of one joint contracture in the lower limbs or hip were independently associated with occurrence of bone fracture over participant lifetime.

CONCLUSIONS

Physically disabled children are at high risk of bone fracture, and further risk factors should be determined.

Bone density in cerebral palsy

This article discusses the problem of osteoporosis in cerebral palsy. Osteoporosis remains a major health problem worldwide. Cerebral palsy is the most prevalent childhood condition associated with osteoporosis. Bone density is significantly decreased. Children with cerebral palsy often sustain painful fractures with minimal trauma that impair their function and quality of life. This article addresses the anatomy and structure of bone and bone metabolism, the clinical assessment of bone mass, the causes of osteoporosis and its evaluation and treatment in children with cerebral palsy.

Epidemiology of low bone mineral density and fractures in children with severe cerebral palsy: a systematic review

AIM

Children with severe cerebral palsy (CP) are at risk for developing low bone mineral density (BMD) and low-impact fractures. The aim of this study was to provide a systematic literature review of the epidemiology of fractures and low BMD in children with severe CP, with an emphasis on risk factors. Gross Motor Function Classification System (GMFCS) levels IV and V were criteria for severe cerebral palsy.

METHOD

The literature (PubMed) was searched and eligible studies were given a level of evidence score using the Scottish Intercollegiate Guidelines Network criteria.

RESULTS

Seven studies were found concerning epidemiology of fractures, 11 studies described epidemiology of low BMD, and 14 studies concerned risk factors. The methodological quality of most of these studies was poor. Five studies were considered well-conducted with low risk of confounding and bias. In these studies, the incidence of fractures in children with moderate to severe CP approached 4% per year, whereas the prevalence of low BMD in the femur was 77%. Limited ambulation, feeding difficulties, previous fractures, anticonvulsant use, and lower body fat mass were associated with low BMD z-scores.

INTERPRETATION

There is only a limited amount of high-quality evidence on low BMD and fractures in children with severe CP.

Osteoporosis in adults with cerebral palsy

Life expectancy for the 400 000 adults with cerebral palsy (CP) in the USA is increasing. Although there is a perception of increased fractured rate in the adult with CP, it has not been well studied. Low bone mineral density is found in more than 50% of adults with a variety of disabilities, including CP. Dual-energy X-ray absorptiometry scanning is commonly used to assess bone mineral density, but is limited by positioning and other artifacts in adults with CP. Novel scanning regions of interest, such as the distal femur, are not yet standardized in adults. Nutritional assessment and physical activity, the basis of most fracture prevention programs, are difficult to do in the adult with CP. A better understanding of the 'muscle-bone unit' physiology and its exploitation may lead to better treatment modifications. Clinical research trials with bisphosphonates (e.g. pamidronate), estrogen, selective estrogen receptor modulators, parathyroid hormone analogs, and growth hormone need to be targeted to the adult with CP. Longitudinal studies of fracture risk factors, genetic research in bone and neuromuscular biology, and the development of treatment surrogates for physical activity are additional areas of needed expertise. This could be facilitated by an adult CP registry and the centralization of clinical research efforts.

Evidence-based review of bone strength in children and youth with cerebral palsy

Children with cerebral palsy have various risk factors for compromised bone health. Evidence concerning their bone fragility is gathering; however, there is no consensus regarding risk factors, indications for evaluation, follow-up, or treatment. We performed an evidence-based review targeted to address the following questions concerning children with cerebral palsy: Is bone strength impaired and what are the risk factors? Are these children at increased risk for bone fractures? What are the relations between bone mineral density and fracture risk? What methods can be used for bone health assessment? How can bone strength be improved? Currently, the most acceptable method for evaluating bone status in children is dual-energy x-ray absorptiometry. Evidence demonstrates reduced bone mass in children with cerebral palsy; yet, no clear association with fractures. Preventive methods are suggested.

Treatment of femur fractures in children with cerebral palsy

PURPOSE

Children with cerebral palsy may have low bone density stemming from various etiologies and are, thereby, at risk for fractures. The treatment of femur fractures in children with cerebral palsy may need to be tailored to address the management of spastic muscle tone and multiple medical co-morbidities.

METHODS

Our study is a retrospective review that evaluates the treatment of 47 femur fractures in children with cerebral palsy in both ambulatory and non-ambulatory patients.

RESULTS

Thirty-two fractures in non-ambulators were treated non-operatively, 11 of which resulted in malunions and five developed pressure sores. Six fractures in non-ambulators were treated operatively, one of which resulted in a malunion. In ambulators, five fractures were treated non-operatively; one of these fractures lost reduction after 2 weeks and required surgical intervention. One of four fractures in ambulators treated operatively developed a malunion.

CONCLUSION

Our study results suggest that femur fractures in children with cerebral palsy can be treated non-operatively; however, because of the high risk of malunion in this patient population, fracture alignment needs to be followed closely during healing. Careful attention during casting is necessary to prevent pressure sores. Strong consideration should be given to initial operative treatment in ambulatory patients in order to preserve function.

The efficacy of alendronate in wheelchair-bound patients: a 1-year prospective study

The aim of the study was to establish the efficacy of 1-year alendronate treatment in 10 wheelchair-bound participants. In the study were included participants with z-score lower than -2.0 in one of three skeletal sites. Bone status was assessed using dual-energy X-ray absorptiometry at calcaneus and forearm and using quantitative ultrasound at hand phalanges at baseline and after a year. Laboratory variables included serum carboxyterminal telopeptide of type I collagen (ICTP) and bone alkaline phosphatase. Mean values of bone measurements did not differ between baseline and follow-up, the mean value of ICTP nonsignificantly increased and bone alkaline phosphatase significantly dropped (P<0.01). No patient treated revealed the increase in three bone densitometric variables and only one showed a decrease in ICTP exceeding 40% of baseline value. Concluding, in wheelchair-bound participants short-term alendronate therapy does not reduce bone resorption and does not improve the skeletal status.

Bone density and fragility fractures in patients with developmental disabilities

We investigated prior fractures, osteoporosis risk factors, and bone mineral density (BMD) in 107 institutionalized adults with developmental disabilities. We found a very high prevalence of BMD in the osteoporotic range and a significant correlation between lower BMD and prior fragility fractures.

INTRODUCTION

The purpose of this study was to investigate factors contributing to osteoporosis and fragility fractures among developmentally disabled adults.

METHODS

Adults from a residential center participated in a prospective study in which bone mineral density (BMD) at the forearm and heel were measured with a portable X-ray densitometer. Prior fragility fractures were identified from chart review.

RESULTS

Among 107 participants, 84 (78.5%) had a measurement within the osteoporotic range. The heel was more severely abnormal (mean T-score -3.1 +/- 1.5) than the forearm (-1.6 +/- 1.3, p < .0.0001). Radiographically confirmed prior fragility fractures (17 [16.3%]) were associated with lower heel (p = 0.0155) and forearm (p = 0.0172) T-scores. In multiple regression analysis, there were independent associations between forearm BMD and prior fragility fractures (p = 0.0126) and between heel BMD and prior fragility fractures (p = 0.0291). The odds ratio for prior fracture increased by 2.02 (95% CI 1.12-3.64) for each standard deviation (SD) decrease in heel T-score and by 2.39 (95% CI 1.08-5.32) for each SD decrease in forearm T-score.

CONCLUSIONS

We found a very high prevalence of osteoporotic BMD measurements in institutionalized adults with developmental disabilities. Lower heel and forearm BMD measurements were significantly and independently associated with prior fragility fractures in this population.

Contribution of stepping while standing to function and secondary conditions among children with cerebral palsy

PURPOSE

To explore the feasibility and efficacy of stepping while standing and its effect on function and prevalence of secondary conditions among children with severe cerebral palsy.

METHODS

Of 22 children with severe cerebral palsy, 11 underwent treatment using a Hart Walker (HW) device, and the other 11 underwent a passive standing program. Constipation prevalence and adverse events were recorded. Bone quantitative ultrasound was performed for the tibia. The Pediatric Evaluation of Disability Inventory was used to assess activities of daily life.

RESULTS

Children exposed to the HW improved bowel function, but no added quantitative benefit to bone was observed when compared with passive standing. Children using the HW were able to take steps independently in the device, but did not reach a functional walking level.

CONCLUSIONS

Providing a child who is nonambulatory the opportunity to walk may be important both for participation in activities of daily living and social roles and for preventing secondary conditions.

Growth and nutrition disorders in children with cerebral palsy

Growth and nutrition disorders are common secondary health conditions in children with cerebral palsy (CP). Poor growth and malnutrition in CP merit study because of their impact on health, including psychological and physiological function, healthcare utilization, societal participation, motor function, and survival. Understanding the etiology of poor growth has led to a variety of interventions to improve growth. One of the major causes of poor growth, malnutrition, is the best-studied contributor to poor growth; scientific evidence regarding malnutrition has contributed to improvements in clinical management and, in turn, survival over the last 20 years. Increased recognition and understanding of neurological, endocrinological, and environmental factors have begun to shape care for children with CP, as well. The investigation of these factors relies on advances made in the assessment methods available to address the challenges inherent in measuring growth in children with CP. Descriptive growth charts and norms of body composition provide information that may help clinicians to interpret growth and intervene to improve growth and nutrition in children with CP. Linking growth to measures of health will be necessary to develop growth standards for children with CP in order to optimize health and well-being.

Dual-energy X-ray aborptiometry assessment in children and adolescents with diseases that may affect the skeleton: the 2007 ISCD Pediatric Official Positions

The Task Force focusing on the use of dual energy X-ray absorptiometry (DXA) in children and adolescents with diseases that may affect the skeleton reviewed over 300 articles to establish the basis for the Official Positions. A significant number of studies used DXA-based outcome measures to assess the effects of specific interventions and charted the natural history of incremental changes in bone size and mass in specific disease states in children. However, the utility of DXA in clinical practice has not been evaluated systematically, in large part due to the lack of a workable definition for childhood osteoporosis. Thus, in combination with the Official Positions addressing the diagnosis of osteoporosis in children, and the reporting of DXA results in children, this document presents clear guidelines from which clinicians and researchers alike can work. This report delineates a set of disorders in which it is appropriate to use DXA as part of the comprehensive assessment of skeletal health in children and adolescents, and provides guidance concerning the initiation of assessment and the frequency of monitoring. Importantly, this document also highlights significant gaps in our knowledge, emphasizing areas for future research.

Effects of stretching and heat treatment on hamstring extensibility in children with severe mental retardation and hypertonia

Objectives: To examine the effect of heat and duration of stretching on the extensibility of hamstring muscles and their electromyographic responses to passive stretch in children with hypertonia and severe mental retardation.

Design: Randomized cross-over trial.

Setting: Developmental disability unit in a local hospital.

Participants: Twenty-nine subjects (9 females) with ages ranged from 4 to 13 years with spastic and/or dystonic hypertonia and hamstring tightness.

Interventions: Subjects received four treatment sessions in random order with each consisting of five repetitions of stretching: (A) 10-second stretching, (B) 30-second stretching, (C) hot pack followed by 10-second stretching, and (D) hot pack followed by 30-second stretching. Each treatment session comprised five repetitions of stretch and successive treatments were separated by at least 24 hours.

Main outcome measures: The distance between greater trochanter and lateral malleolus and hamstring electromyographic (EMG) activity during passive knee extension stretching.

Results: Two-way ANOVA showed a larger increase in hamstring extensibility in conditions C and D (1.3 ± 1.1 cm) than conditions A and B (0.7 ± 0.9 cm) (P<0.001). For the EMG recordings, conditions B and D (-25.1 ± 58.4μV) had greater decrease than conditions A and C (-3.5 ± 36.6 μV) (P= 0.039).

Conclusions: Heat application to the hamstrings before stretching could result in greater increase in extensibility than stretching alone in children with hypertonia and severe mental retardation. Stretching could promote relaxation of the hamstring muscles regardless of prior heat treatment. Stretching sustained for 30 seconds led to greater relaxation than that for 10 seconds.

Spinal bone mineral density, IGF-1 and IGFBP-3 in children with cerebral palsy

BACKGROUND/AIMS

Childhood cerebral palsy (CP) is associated with osteopenia and the GH-IGF axis plays an important role in bone metabolism. We studied the relationship between spinal bone mineral density (BMD) and serum IGF-1 and IGFBP-3 in children with CP.

METHODS

Cross-sectional study of 30 children (9 F and 21 M, ages 4.5-15) with CP. Subjects underwent dual-energy x-ray absorptiometry scans (spinal BMD), blood tests (IGF-1, IGFBP-3, Ca, P, PTH, vitamin D, osteocalcin) and urine tests (N-telopeptide).

RESULTS

Spinal BMD was decreased in children with CP (average Z-score -2.14 +/- 1.08) compared to age- and gender-matched norms. IGF-1 and IGFBP-3 were also decreased compared to age-matched norms (average IGF-1 Z-score -0.74 +/- 1.2, average IGFBP-3 Z-score -0.68 +/- 1.2). All other blood and urine tests, including measures of calcium and vitamin D status, were normal. In 25 CP children with osteopenia (Z-score >-1), there was a trend towards correlation between spinal BMD Z-score and serum IGF-1 SDS score (r = 0.328, p = 0.09). IGFBP-3 Z-scores were available in 24 of these patients and had a statistically significant correlation with spinal BMD Z-score (r = 0.386, p = 0.05).

CONCLUSION

Osteopenia is common in children withCP and may be associated with lower IGF-1 and IGFBP-3 levels.

Pediatric dual-energy X-ray absorptiometry: technique, interpretation, and clinical applications

This article reviews the dual-energy x-ray absorptiometry (DXA) technique, its interpretation, and clinical applications with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist," monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist," aware of the DXA findings in a large number of clinical diseases, providing the referring clinician with a meaningful context for the numeric result obtained with DXA.

Bone mineral density correlation with fractures in nonambulatory pediatric patients

Although bone mineral density (BMD) as related to T score (comparison with young adult) is well correlated with fracture risk in adults, no such correlation has been confirmed in children. Quadriparetic children have lower BMD than age-matched controls, as well as a higher rate of fragility fracture. This study examines a cohort of children with quadriparesis and other nonambulatory children to correlate BMD with fragility fractures.We hypothesize that fracture in these children is related to BMD as correlated with patient size and that age comparison (Z-score) is less important. Review of all children with a dual-energy x-ray absorptiometry scan from August 2003 to June 2005 identified 101 nonambulatory pediatric patients (excluding children with osteogenesis imperfecta or metabolic bone disease). Sixteen patients had insufficient data, leaving 85 patients, 26 of whom had experienced fragility fractures. Lateral femoral dual-energy x-ray absorptiometry scan was performed on one or both legs, then regions were averaged. Data was evaluated for statistical correlation between BMD and body size as evidenced by body mass index (BMI). Other factors, including age, Z-score, and height and weight independently were secondarily evaluated for correlation with fracture risk. Correlation was demonstrated between history of fracture and BMD when related to BMI (P = 0.002). In conclusion, in these nonambulatory children, the combination of the BMD of the distal femur and BMI correlates well with occurrence of fragility fracture and may relate to fracture risk. This relationship is independent of the child's chronological age and Z-score. This information may be helpful prognostically to define a treatment algorithm for low bone density on a case-by-case basis.

Pediatric DXA: clinical applications

Normal bone mineral accrual requires adequate dietary intake of calcium, vitamin D and other nutrients; hepatic and renal activation of vitamin D; normal hormone levels (thyroid, parathyroid, reproductive and growth hormones); and neuromuscular functioning with sufficient stress upon the skeleton to induce bone deposition. The presence of genetic or acquired diseases and the therapies that are used to treat them can also impact bone health. Since the introduction of clinical DXA in pediatrics in the early 1990s, there has been considerable investigation into the causes of low bone mineral density (BMD) in children. Pediatricians have also become aware of the role adequate bone mass accrual in childhood has in preventing osteoporotic fractures in late adulthood. Additionally, the availability of medications to improve BMD has increased with the development of bisphosphonates. These factors have led to the increased utilization of DXA in pediatrics. This review summarizes much of the previous research regarding BMD in children and is meant to assist radiologists and clinicians with DXA utilization and interpretation.

Advanced skeletal maturity in ambulatory cerebral palsy patients

INTRODUCTION

Both advanced and delayed bone age relative to chronological age have been described in non ambulatory children with moderate to severe cerebral palsy (CP). The purpose of our study was to assess skeletal maturation in an ambulatory CP population and determine the affects of body mass index (BMI), type of CP, and Gross Motor Function Classification System (GMFCS) on skeletal maturity.

METHODS

A retrospective chart and radiograph review was performed on 51 patients with ambulatory CP. A control group of 50 patients was also analyzed. Age, sex, height, weight, type of CP, and GMFCS were recorded from the chart. The height and weight were used to calculate BMI. Bone age was determined using the Oxford method. Statistical analysis for the data included descriptive statistics with bivariate and multivariate regression analyses. Significance was determined as P < 0.05.

RESULTS

There were 26 boys and 25 girls. All CP patients were independent ambulators. The mean chronological age was 7.1 years for boys and 8.6 years for girls. The mean bone age was 9.9 years for boys and 10.6 years for girls. Overall, 48 (94%) of 51 patients had advanced bone age compared with chronological age. Bone age was significantly advanced compared with chronological age for boys (P = 0.033) and showed a trend toward significance in girls (P = 0.079). Bone age was advanced compared with our control population in both sexes. In multivariate analysis, quadriplegic CP type showed a trend toward significance (P = 0.066), and GMFCS III was significantly associated with advanced bone age in boys (P = 0.011). In girls, quadriplegic CP type and BMI of less than 15 were significantly associated with advanced bone age (P < 0.05 in both).

CONCLUSION

Our results demonstrated that most of the ambulatory CP patients had advanced bone age compared with chronological age. Quadriplegic CP type in boys and girls contributed to advanced bone age. GMFCS III and a low BMI also contributed to advanced bone age in boys and girls, respectively. Understanding factors that lead to either delayed or advanced skeletal maturation is important in planning the appropriate timing for orthopaedic surgical intervention.

Epiphyseal separations in spastic cerebral palsy

Metaphyseal and diaphyseal fractures have been reported in children with severe spastic cerebral palsy, but there is no reference to epiphyseal separations in these patients. We report nine epiphyseal separations involving the distal femur and proximal humerus in four severely affected children with spastic quadriplegic cerebral palsy. The clinico-radiological features confirmed the cause to be scurvy. These epiphyseal separations have a good prognosis unlike the physeal injuries reported in children with myelodysplasia. Treatment with vitamin C and splintage resulted in rapid healing with excellent remodeling. Scurvy should be considered a potential cause for an epiphyseal slip in a child with severe spastic cerebral palsy. Routine dietary supplementation of vitamin C is recommended for these malnourished and nonambulant children.

Body mass index in ambulatory cerebral palsy patients

Malnutrition is a common problem in children with cerebral palsy. Although malnutrition is often recognized in patients with severe cerebral palsy, it can be unrecognized in less severely affected patients. The consequences of malnutrition are serious, and include decreased muscle strength, poor immune status, and depressed cerebral functioning. Low body mass index has been used as a marker for malnutrition. The purpose of this study was to determine which patients in an ambulatory cerebral palsy patient population were at risk for low body mass index. A retrospective chart review was performed on 75 patients. Age, sex, height, weight, type of cerebral palsy, and functional status [gross motor functional classification system (GMFCS) level] was recorded from the chart. Descriptive statistics with bivariate and multivariate regression analyses were performed. Thirty-eight boys and 37 girls with an average age of 8.11 years were included in the study. Unique to our patient population, all cerebral palsy patients were independent ambulators. Patients with quadriplegic cerebral palsy had a significantly lower body mass index than those with diplegic and hemiplegic cerebral palsy. Patients with a GMFCS III had significantly lower body mass index than those with GMFCS I and II. When multivariate regression analysis to control for age and sex was performed, low body mass index remained associated with quadriplegic cerebral palsy and GMFCS III. Malnutrition is a common health problem in patients with cerebral palsy, leading to significant morbidity in multiple organ systems. We found that in an ambulatory cerebral palsy population, patients with lower functional status or quadriplegia had significantly lower body mass index, suggesting that even highly functioning ambulatory cerebral palsy patients are at risk for malnutrition.

Growth hormone therapy improves bone mineral density in children with cerebral palsy: a preliminary pilot study

CONTEXT

Cerebral palsy is associated with osteopenia, increased fracture risk, short stature, and decreased muscle mass, whereas GH therapy is associated with increased bone mineral density (BMD) and linear growth and improvement in body composition.

OBJECTIVE

We conducted a pilot study to evaluate the effect of 18 months of GH therapy on spinal BMD, linear growth, biochemical markers, and functional measures in children with cerebral palsy.

DESIGN AND SETTING

The study was a randomized control trial, conducted from 2002-2005 at the University of California, Los Angeles, Orthopedic Hospital's Center for Cerebral Palsy.

PATIENTS

Patients included 12 males with cerebral palsy, ages 4.5-15.4 yr.

INTERVENTION

We compared 18 months of GH (50 microg daily) vs. no treatment.

PRIMARY OUTCOME MEASURES

Spinal BMD (dual-energy x-ray absorptiometry scan), height, growth factors, and bone markers were assessed.

RESULTS

Ten subjects (five in each group) completed the study. Pre- and post-average height z-scores were -1.47 +/- 0.23 and 0.8 +/- 0.2 (GH-treated group) vs. -1.35 +/- 1.26 and -1.36 +/- 1.27 (control group) (Delta SD score, 0.67 vs. -0.01; P = 0.01). Average change in spinal BMD z-score (Delta SD score corrected for height) was 1.169 +/- 0.614 vs. 0.24 +/- 0.25 in the treated and control groups, respectively (P = 0.03). Osteocalcin, IGF-I, and IGF-binding protein 3 levels increased during GH therapy. There was no change in quality of life scores as measured by the Pediatric Orthopedic Disability Inventory.

CONCLUSIONS

This small pilot study suggests that 18 months of GH therapy is associated with statistically significant improvement in spinal BMD and linear growth.

Fractures in patients with cerebral palsy

Fractures in children with cerebral palsy (CP) constitute a common clinical problem. The purpose of this retrospective study is to analyze the demographics, identify risk factors, and delineate guidelines for treatment in 156 children with CP who were treated for fractures. To identify changes in demographics, children treated before 1992 (56 patients) were compared with those treated from 1992 to 2000. The latter group of children was compared with an age- and gender-matched group of CP children without fractures. Ambulatory status, the presence of contractures, nutritional status, seizure medication, the type of treatment received, final outcomes, and complications were recorded and statistically analyzed. The mean age at the time of the first fracture was 10 years. Sixty-six percent of patients had spastic quadriplegia, of whom 83% were nonambulatory. Eighty-two percent of fractures occurred in the lower limbs. Forty-eight percent were delayed in diagnosis with no cause determined. Children treated after 1992 had higher incidence of multiple fractures, lower incidence contractures, and a younger age at first fracture. This group showed a statistically significant difference for anticonvulsant therapy (P=0.001), CP pattern (P=0.005), ambulatory status (P=0.001), and osteopenia (P=0.001) when compared with the group of CP patients without fractures. Eighty percent of fractures were treated with a soft bulky dressing. Complications occurred in 17% of patients. The greatest risk factor for fracture is the nonambulatory CP child on anticonvulsant therapy. These risk factors seem to have increased, resulting in a higher prevalence of low energy fractures. Future research must focus on the underlying mechanisms and prevention of this condition.

Fracture rate in children with cerebral palsy

OBJECTIVES

To determine the prevalence of previous fracture, the rate of fracture over time and associated risk factors for fracture in children with moderate or severe cerebral palsy (CP).

STUDY DESIGN

Three hundred and sixty-four children with moderate-to-severe motor impairment (Gross Motor Function Classification System III, IV and V) enrolled in a multi-centre, region-based longitudinal study of growth, nutrition and health. Of these, 297 had baseline fracture information and 261 children had at least one follow-up assessment. Median duration of follow-up was 1.6 years, for over 600 person-years of follow-up.

RESULTS

Forty-six (15.5%) children reported 62 previous fractures at baseline assessment. Children with a history of fractures at baseline were older (mean age 11.9 vs. 8.9 years, p<0.0001) and had greater body fat (triceps z-score -0.01 vs. -0.68, p=0.0003) than children with no previous fracture. Twenty children (6.7%) reported 24 fractures during the follow-up period. Factors associated with risk of fracture during the follow-up period were higher body fat (p=0.03), gastrostomy use (p=0.05) and previous fracture (p=0.10). Based on 24 fractures in 604.5 person-years of follow-up, the rate of fracture was 4.0 per hundred children (4.0%) per year. For children with a history of fracture at baseline, the fracture rate was 7.0% per year; for children with gastrostomy, 6.8% per year; and for children with high triceps skinfold, 9.7% per year.

CONCLUSIONS

Children with moderate or severe CP are at high risk for fracture. Children with greater body fat, feeding gastrostomy and prior history of fracture are at highest risk and may benefit most from intervention. Further longitudinal study and clinical trials in children with CP are needed to better understand the factors contributing to fracture risk in this population and the best methods of prevention and treatment.

Advances in the diagnosis and treatment of osteoporosis

Although severely low bone density is relatively rare in the pediatric population, it can be a significant problem in many patients with chronic illness. As peak bone formation occurs during adolescence, it is crucial that pediatricians and other care providers for this patient population recognize the significance of attainment of adequate bone. Dietary intake of vitamin D and calcium should be optimized, and correction of underlying causes of poor bone density should occur whenever possible. Assessment of bone density is difficult, as each technology available has problems, and none of the technologies are well-associated with fracture risk in pediatric patients. Once diagnosis of severely low bone density is established, treatment options are limited and poorly studied. The benefits of bisphosphonate therapy appear to outweigh the risks in patients with low bone density and frequent fragility fractures, and it appears that most improvement with bisphosphonates occurs within the first 2 to 4 years. Evidence, however, is emerging that once off therapy, bone turnover remains decreased for at least several years. During that time, improvements in bone density are decreased. Many questions remain regarding duration of therapy with bisphosphonate therapy and the long-term effects on the children who receive this medication. Anabolic therapies may become important in the future, but there is currently extremely limited information regarding their use in pediatrics.

Fractures in children with cerebral palsy

INTRODUCTION

We studied the fracture history in a large population of patients with cerebral palsy to determine which children were at the highest risk for fracture.

METHODS

The International Classification of Diseases (Ninth Revision) coding identified 763 children with cerebral palsy. Patients and caregivers were contacted for information about fracture history and risk factors for low bone density. Of the 763 children identified, 418 children (54.8%) were available for this study; 243 (58%) had quadriplegia, 120 (29%) diplegia, and 55 (13%) hemiplegia. Three hundred sixty-six children were spastic, 23 mixed tone, 13 athetoid, and 16 classified as others. We identified 50 children (12%) who fractured; 15 of these same children had, over time, multiple fractures.

RESULTS

The number of fractures showed a normal distribution by age, with a mean of 8.6 (SD, 4.0). Children with cerebral palsy with mixed tone had a higher rate of fracture (chi = 14.7, P < 0.01); chi analysis indicated that the children who fractured were, as a group, more likely to use a feeding tube, have a seizure disorder, take valproic acid (VPA), and use standing equipment in therapy. Multiple regression analysis demonstrated older age and VPA use as predictive of fracture and gave the following equation: fracture = -0.01 + (VPA x 0.17) + (age x 0.15). The subgroup that sustained multiple fractures were older at the time of first fracture than the children who had only one reported fracture (t = -2.3, P < 0.05).

CONCLUSIONS

The main finding of our article is that older age at first fracture and use of VPA are predictive of fractures and define a group of children with cerebral palsy who may benefit from treatment interventions to increase bone density.

Low bone mass in children and adolescents

Osteoporosis is a disease characterized by low bone mass and micro architectural alterations of bone tissue leading to enhanced bone fragility and increased fracture risk. Although research in osteoporosis has focused mainly on the role of bone loss in the elderly population, it is becoming increasingly clear that the amount of bone that is gained during growth is also an important determinant of future resistance to fractures. Thus, considerable interest is being placed on defining preventive strategies that optimize the gain of bone mass during childhood and adolescence. Knowledge of the determinants accounting for the physiologic and genetic variations in bone accumulation in children will provide the best means toward the early diagnosis and treatment of osteoporosis. This article reviews the techniques available for bone mass measurements in children and the major determinants and diseases influencing bone accretion during childhood and adolescence.