Ethnic and geographic variations in the epidemiology of childhood fractures in the United Kingdom

Femoral stress is prominently associated with fracture risk in children: The Generation R Study

Bone modeling is an important process in the growing skeleton. An inadequate bone modeling in response to mechanical loads would lead some children to develop weaker bones than others. The resulting higher stresses in the bones would render them more susceptible to fracture. We aimed to examine the association between femoral stress (FS) derived from structural parameters and BMD in relation to incident fractures in children. Bone stress was evaluated at the medial femoral neck, a skeletal site subject to large forces during normal locomotion. This study comprises 1840 children from the Generation R Study, with whole body and hip DXA scans at a mean age of 6.01 years. Hip structural analysis (HSA) was used to measure femur geometry for the FS calculation. Data on fractures occurring over the following 4 years after the DXA assessment were obtained by questionnaire. Incident fracture was observed in 7.6% of the participating children. Cox-multivariate regression analysis, described as hazard ratios (HR), showed that after adjustment for sex, ethnicity, age, weight and lean mass fraction, there was a significant increase in the risk of incident fracture for every standard deviation (SD) decrease in total body BMD (HR: 1.35, 95% CI 1.05-1.74, p-value = 0.021), femoral neck BMD (HR: 1.31, 95% CI 1.09-1.58, p-value = 0.005) and narrow neck BMD (HR: 1.39, 95% CI 1.14-1.68, p-value = 0.001). Whereas, every increment of one SD in femoral stress resulted in 1.33 increased risk of incident fractures (HR: 1.33, 95% CI 1.13-1.57, p-value = 0.001). This association remained (borderline) significant after the adjustment for DXA derived BMD measurements. Our results show that increased bone stress may underlie greater susceptibility to traumatic fractures in children (partially independent of BMD) and underscore the utility of hip DXA scans for the assessment of paediatric bone health and specifically fracture risk.

Fractures in school age children in relation to sex and ethnic background: The Generation R Study

Fracture rate in childhood is increasing and its consequences may affect health and developmental processes and cause school absence and restricted activity days. There are scarce epidemiologic studies regarding fractures in children. The aim of this study was to evaluate if pediatric fractures show disparities across sexes and ethnic groups. This study was conducted based on data from 3632 participants of the Generation R Study. Prevalent fractures were assessed using a questionnaire at a mean age of 9.7 years. Child's ethnicity was determined based on country of birth of the parents using questionnaires (geographic ancestry) or admixture analysis (genetic ancestry). Associations between fracture occurrence and sex or ethnicity were evaluated using logistic regression models adjusted for age, weight, lean mass fraction, bone mineral density (BMD) and sex/ethnicity. Fracture was reported for 525 (14.5%) children. The great majority of these children were classified as European (N = 3164), followed by African (N = 283) and Asian (N = 185) based on geographic ancestry. Similarly, the highest proportion of Europeans was observed based on genetic ancestry. Prevalence of fractures was not different between boys and girls, even after adjustment for possible confounders (OR: 1.03, 95% CI 0.84-1.27, p-value = 0.8). However, odds of prevalent fractures were two times higher in European when compared to Asian children (OR: 2.01, 95% CI 1.17-3.45, p-value = 0.01), and 1.5 times higher when compared to African children (OR: 1.50, 95% CI 1.00-2.26, p-value = 0.05). Overall, in this study, European children showed a highest risk of prevalent fractures independently of factors such as body composition and BMD, while no difference in the prevalence of fractures between boys and girls was observed.

Epidemiologic Features of Traumatic Fractures in Children and Adolescents: A 9-Year Retrospective Study

Purpose

Fractures are common among all types of paediatric injuries, with differences in incidence over time. Here, we present the epidemiologic features of traumatic fractures in a population of youth ≤ 18 years of age who were admitted to our university-affiliated hospitals from 2002 to 2010.

Methods

We retrospectively reviewed 2450 children and adolescents who had traumatic fractures. The data include variables such as age, sex, date of injury, and the mechanism of injury. For the period of 2002-2010, there were 2450 injury events that resulted in at least 1 fracture.

Results

Low falls (1042, 42.5%) and upper limb fractures (1068, 43.6%) were the most common aetiologies and fracture sites. With increasing age, the proportion of injuries due to motor vehicle collisions (MVCs) decreased and the injuries due to being hit by others and due to sprains increased. With increasing age, the proportion of craniofacial fractures (CFFs) decreased, and lower limb fractures (LLFs), spinal fractures (SFs), and fractures of ribs and the sternum (RSFs) increased. Over time, the proportion of injuries due to MVCs and mechanical injury decreased. Male patients presented with a significantly higher proportion of injuries due to low falls, being struck by an object, being hit by others, and due to sprains. There were a significantly lower proportion of injuries due to MVCs in female patients. Male patients presented with a significantly higher proportion of ULFs in the ≤6-year-old age group and a significantly lower proportion of LLFs and SFs in the 12-18-year-old age group than did female patients.

Conclusions

Low falls and upper limb fractures were the leading cause and fracture sites. To further improve the prevention and treatment of traumatic fractures in children and adolescents, policy makers should pay attention to these characteristics.

Traumatic Facial Fractures in Children and Adolescents

This study showed a retrospective analysis of the incidence and pattern of traumatic facial fractures in a pediatric and adolescent population (≤18 years old) in China. The authors retrospectively reviewed 154 children and adolescent who had traumatic facial fractures and who were admitted to our university-affiliated hospitals from 2005 to 2010. This study enrolled 109 males and 45 females aged 11.9 ± 5.2 years old. The incidence peaked around the periods of 12 to 18 years in the male, ≤6 and 16 to 18 years in the female. The most common etiologies were motor vehicle collisions (MVCs) (60, 39.0%), followed by high fall (40, 26.0%), low fall (32, 20.8%). The most common fracture sites were mandible (78, 50.6%) and nose (33, 21.4%), followed by orbit (31, 20.1%). A total of 35 (22.7%) patients suffered neurological deficit. The patients in the 12 to 18 age range group accounted for the largest proportion of 54.5%. Fracture incidence showed peaks between the hours of 12:00 to 16:00 PM (33.7%), during the autumn season (30.5%) and on Friday to Sunday (50.0%). The most common etiology and fracture site were MVCs and mandible, respectively. Etiologies and patterns of traumatic facial fractures vary with age. Continued efforts toward injury prevention of traumatic facial fracture among the children and adolescents are warranted.

Age, gender, and etiology differences of sports-related fractures in children and adolescents: A retrospective observational study

To investigate the age, gender, and etiology differences of sports-related fractures in children and adolescents (6-18 years old).We retrospectively reviewed 410 child and adolescent patients (335 males and 75 females aged 13.5 ± 3.1 years old) with sports-related fractures admitted to our university-affiliated hospitals from 2001 to 2010. The incidence and pattern were summarized with respect to different age groups, genders, etiologies.Playing basketball (97, 23.7%) and running (90, 22.0%) were the most common etiologies. Radius (102, 24.9%) was the most common fracture site. The most common etiologies and fracture sites were biking (19.6%) and humerus fractures (28.0%) in the ≤12 age range group, playing basketball (34.0%) and radius fractures (26.2%) in the 12-15 age range group, playing basketball (31.7%) and radius fractures (23.0%) in the 15-18 age range group. The most common etiologies were playing basketball (27.5%) in the male group and running (24.0%) in the female group. The male presented with significantly higher rate of radius fractures and nerve injury, significantly lower rate of femoral fractures than the female. The most common fracture sites were radius fractures in the basketball group (28.9%) and cricket group (37.5%), humerus fracture in the running group (20.0%), biking group (23.3%), and climbing group (45.0%), tibia fractures in the football group (28.9%) and playing SP bars group (50.0%), and ulna fractures (37.5%) in the ice skating group.Sports-related fractures are common in children and adolescents, particularly in males. Basketball, running, and biking were the most common etiologies; radius, ulna, and humerus were the most common fracture sites.

Anti-inflammatory effect of Resolvin D1 on LPS-treated MG-63 cells

Inflammation reaction plays an important role in the pathogenesis of ankle fracture. The aim of the present study was to investigate the effect of RvD1 on the inflammatory response and underlying molecular mechanisms in MG-63 cells. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and ELISA were used to determine the mRNA and protein expression of cytokines extracted from peripheral blood in children with or without ankle fracture, respectively. MG-63 cells were pre-treated with/without RvD1 and stimulated with 1 µg/ml LPS. The cell viability was detected by MTT assay. The production of cytokines from MG-63 cells was assessed by RT-qPCR and western blot, respectively. The expression of p-p38, NF-κB (p50) and cyclooxygenase-2 (COX-2) mRNA and protein were detected by western blot and/or RT-qPCR. The levels of NLRP3, associated recruitment domain (ASC), cleaved caspase1, caspase-1 were measured by RT-qPCR and/or western blot. The levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF-α) mRNA and protein were up-regulated in children with ankle fracture compared with healthy children. RvD1 treatment did not induce cytotoxicity in MG-63 cells, but it can inhibit LPS induced MG-63 cell proliferation inhibition. RvD1 was able to dose-dependently reverse LPS induced up-regulation of TNF-α, IL-1β, IL-6 mRNA and protein expression. Furthermore, the LPS induced up-regulation of p-p38, NF-κB (p50), and NLRP3, ASC, cleaved caspase-1/caspase-1, and COX-2 was dose-dependently reversed by RvD1. In conclusion, The present study demonstrated that RvD1 inhibited inflammation though inhibiting MAPKp38/NF-κB pathway and NLRP3 inflammasome expression in MG-63 cells, indicating that it may be an effective drug for the treatment of ankle fracture.

Cumulative radiation exposure from medical imaging and associated lifetime cancer risk in children with osteogenesis imperfecta

OBJECTIVES

To estimate the cumulative effective dose of radiation (E) and additional lifetime attributable risk (LAR) of cancer from ionizing radiation in children with osteogenesis imperfecta (OI), who require frequent imaging for fractures and bone densitometry (DXA) surveillance. Also, to evaluate the pattern of long bone fractures.

METHODS

We reviewed all imaging (x-rays, DXA and computed tomography [CT]) conducted in a cohort of children with OI with a minimum observation period of 5 years. For each image, E was estimated using age-dependent local data, and LAR of cancer was extrapolated. LAR and fracture data were compared among children with mild, moderate and severe OI. LAR was allocated to cancer risk categories, and the moderate risk group (1 in 1000 to 1 in 100) was evaluated further.

RESULTS

Results from 106 children with OI (50% females, 5747 images) are presented, with a median (range) observation period of 11.7 (5.2-15.6) years. CT accounted for 0.8% of total imaging procedures but contributed to 66% of total E. The overall LAR of cancer was minimal, averaging an additional 8.8 cases per 100,000 exposed patients (0.8-403). LAR was significantly lower in children with mild OI compared to those with moderate (p = 0.006) and severe OI (p = 0.001). All patients with a moderate LAR of cancer (n = 8) had undergone CT scans and 88% had scoliosis or vertebral fractures. The cohort experienced 412 long bone fractures, with the most common site being the femur (26.5%). OI severity correlated positively with long bone fracture rates (p < 0.001).

CONCLUSIONS

When compared to baseline LAR of cancer (50%) the additional cancer risk from ionizing radiation imaging in our paediatric OI cohort was small (0.0088%). To reduce additional cancer risk, we recommend replacing spinal x-rays with vertebral fracture assessments on DXA and exercising caution with CT imaging.

Appendicular fracture epidemiology of children and adolescents: a 10-year case review in Western Australia (2005 to 2015)

Fracture incidence data of Australian children and adolescents have not been reported in the literature. A 10-year case review of fracture presentations in Western Australia is provided. Between 2005 and 2015, fracture incidence increased relative to population growth. This is concerning, and interventions are required to reverse this trend.

PURPOSE

Fracture incidence in 0-16-year-olds is high and varies between countries. Boys have a 1.5:1 ratio of fracture incidence compared to girls. There are no specific data for Australia. Western Australia is a state with unique geography and population distribution having only a single tertiary paediatric hospital (Princess Margaret Hospital, PMH, in Perth) managing the majority of children and adolescents with fractures in the Emergency Department (ED). The aims of this study were to characterise fracture presentations to PMH-ED and compare the incidence to population data.

METHODS

A database audit of fracture presentations between 2005 and 2015 for fracture rates with a sub-analysis for gender, fracture site and age and a comparison to Perth Metropolitan and Western Australian population data was performed.

RESULTS

Analysis included 31,340 presentations. Fracture incidence, adjusted for the annual population size, increased from 0.63% in 2005 to 0.85% in 2015 (p < 0.001). The month of May reported the highest fracture rate (p < 0.001) corresponding with the start of the winter sports season. Males had a 1.5 times higher fracture incidence than females (p < 0.001), with upper limb fractures three times more common than lower limb fractures (p < 0.001). Fracture incidence increased with age until the early teenage years (15 years for males; 12 years for females) when a decline occurred.

CONCLUSIONS

Increased fracture incidence in Western Australia between 2005 and 2015 identifies a concerning trend for bone health in children and adolescents. Further research is needed to identify potential lifestyle factors that impact fracture incidence translating into evidence-based strategies to reverse these trends and improve bone health.

N-methyl pyrrolidone promotes ankle fracture healing by inhibiting inflammation via suppression of the mitogen-activated protein kinase signaling pathway

N-methyl pyrrolidone (NMP), a small bioactive molecule, has the potential to stimulate bone formation and inhibit osteoclast differentiation. The aim of the present study was to investigate the effect of NMP on the inflammatory response and underlying molecular mechanisms in MG-63 cells. The mRNA and protein expression of cytokines from peripheral blood in children with or without ankle fracture were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and ELISA, respectively. MG-63 cells were pre-treated with/without NMP and stimulated with 1 µM bradykinin (BK). The production of cytokines from MG-63 cells was assessed by western blotting and RT-qPCR. The expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA and protein were measured using western blotting and/or RT-qPCR. Western blotting was used to examine the activation level of mitogen activated protein kinase. Compared with healthy children, levels of tumor necrosis factor (TNF-α), interleukin (IL)-1β and IL-6 mRNA and protein were upregulated in children with ankle fracture. NMP treatment did not induce cytotoxicity in MG-63 cells. The BK-induced upregulation of TNF-α, IL-1β, IL-6, iNOS and COX-2 mRNA and protein was reversed in a dose-dependent manner by NMP. Furthermore, NMP downregulated the activation of c-Jun NH2-terminal kinase and p38 pathways, but not the extracellular signal-related kinase pathway. Therefore, the results of the current study demonstrate that NMP inhibits inflammation dependent on the mitogen-activated protein kinase pathway in MG-63 cells, indicating that it may be beneficial in the healing of fractures.

UK clinical guideline for the prevention and treatment of osteoporosis

INTRODUCTION

In 2008, the UK National Osteoporosis Guideline Group (NOGG) produced a guideline on the prevention and treatment of osteoporosis, with an update in 2013. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women and men age 50 years or over.

METHODS

Where available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence.

RESULTS

Review of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment, lifestyle measures and pharmacological interventions, duration and monitoring of bisphosphonate therapy, glucocorticoid-induced osteoporosis, osteoporosis in men, postfracture care and intervention thresholds.

CONCLUSION

The guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals who are involved in its management.

Muscle-Bone Interactions in Pediatric Bone Diseases

PURPOSE

Here, we review the skeletal effects of pediatric muscle disorders as well as muscle impairment in pediatric bone disorders.

RECENT FINDINGS

When starting in utero, muscle disorders can lead to congenital multiple contractures. Pediatric-onset muscle weakness such as cerebral palsy, Duchenne muscular dystrophy, spinal muscular atrophy, or spina bifida typically are associated with small diameter of long-bone shafts, low density of metaphyseal bone, and increased fracture incidence in the lower extremities, in particular, the distal femur. Primary bone diseases can affect muscles through generic mechanisms, such as decreased physical activity or in disease-specific ways. For example, the collagen defect underlying the bone fragility of osteogenesis imperfecta may also affect muscle force generation or transmission. Transforming growth factor beta released from bone in Camurati Engelman disease may decrease muscle function.

FUTURE DIRECTIONS

Considering muscle-bone interactions does not only contribute to the understanding of musculoskeletal disorders but also can identify new targets for therapeutic interventions.

Time trends in pediatric fracture incidence in Sweden during the period 1950-2006

Background and purpose - Pediatric fracture incidence may not be stable. We describe recent pediatric fracture epidemiology and etiology and compare this to earlier data. Patients and methods - The city of Malmö (population 271,271 in 2005) in Sweden is served by 1 hospital. Using the hospital diagnosis registry, medical charts, and the radiographic archive, we identified fractures in individuals <16 years that had occurred during 2005 and 2006. We also retrieved previously collected fracture data from between 1950 and 1994, from the hospital's pediatric fracture database. We used official population data to estimate period-specific fracture incidence (the number of fractures per 10⁵ person-years) and also age- and sex-adjusted incidence. Differences are reported as rate ratios (RRs) with 95% confidence intervals. Results - The pediatric fracture incidence during the period 2005-2006 was 1,832 per 10⁵ person-years (2,359 in boys and 1,276 in girls), with an age-adjusted boy-to-girl ratio of 1.8 (1.6-2.1). Compared to the period 1993-1994, age-adjusted rates were unchanged (RR =0.9, 95% CI: 0.8-1.03) in 2005-2006, with lower rates in girls (RR =0.8, 95% CI: 0.7-0.99) but not in boys (RR =1.0, 95% CI: 0.9-1.1). We also found that the previously reported decrease in unadjusted incidence in Malmö from 1976-1979 to 1993-1994 was based on changes in demography, as the age-adjusted incidences were similar in the 2 periods (RR =1.0, 95% CI: 0.9-1.1). Interpretation - In Malmö, pediatric fracture incidence decreased from 1993-1994 to 2005-2006 in girls but not in boys. Changes in demography, and also other factors, influence the recent time trends.

Neonatal vitamin D status from archived dried blood spots and future risk of fractures in childhood: results from the D-tect study, a population-based case-cohort study

Background: Whether antenatal and neonatal vitamin D status have clinical relevance in fracture prevention has not been examined extensively, although observational studies indicate that fetal life may be a sensitive period in relation to bone growth and mineralization during childhood.Objective: We examined whether 25-hydroxyvitamin D₃ [25(OH)D₃] concentrations in stored neonatal dried blood spot (DBS) samples are associated with pediatric fracture risk. We hypothesized that in particular, low neonatal vitamin D status may be a risk factor for fracture incidence among children.Design: In a register-based case-cohort study design, the case group was composed of 1039 individuals who were randomly selected from a total of 82,154 individuals who were born during 1989-1999 and admitted to a Danish hospital with a fracture of the forearm, wrist, scaphoid bone, clavicle, or ankle at age 6-13 y. The subcohort was composed of 1600 individuals randomly selected from all Danish children born during 1989-1999. The neonatal 25(OH)D₃ concentrations in DBS samples were assessed by using highly sensitive chromatography-tandem mass spectrometry.Results: The mean ± SD 25(OH)D₃ concentration for all subjects was 27.7 ± 18.9 nmol/L [median (IQR): 23.5 nmol/L (13.3, 37.3 nmol/L)] and showed significant monthly variation (P < 0.0001) with the highest values in July and August. Individuals in the middle quintile of neonatal 25(OH)D₃ had lower odds of sustaining a fracture than did those in the lowest quintile (adjusted OR: 0.75; 95% CI: 0.58, 0.96), but a global test did not show any significant overall association (adjusted P = 0.13).Conclusions: This study suggested that neonatal vitamin D status does not influence subsequent fracture risk in childhood. This is in accordance with studies that report no association between antenatal maternal vitamin D status and childhood fractures. Further studies are needed to examine fracture risk in relation to prenatal vitamin D status in a randomized controlled setting.

Prenatal exposure to vitamin D from fortified margarine and risk of fractures in late childhood: period and cohort results from 222 000 subjects in the D-tect observational study

Prenatal low vitamin D may have consequences for bone health. By means of a nationwide mandatory vitamin D fortification programme, we examined the risk of fractures among 10-18-year-old children from proximate birth cohorts born around the date of the termination of the programme. For all subjects born in Denmark during 1983-1988, civil registration numbers were linked to the Danish National Patient Registry for incident and recurrent fractures occurring at ages 10-18 years. Multiplicative Poisson models were used to examine the association between birth cohort and fracture rates. The variation in fracture rates across birth cohorts was analysed by fitting an age-cohort model to the data. We addressed the potential modification of the effect of vitamin D availability by season of birth. The risk of fractures was increased among both girls and boys who were born before the vitamin D fortification terminated in 1985 (rate ratio (RR) exposed v. non-exposed girls: 1·15 (95 % CI 1·11, 1·20); RR exposed v. non-exposed boys: 1·11 (95 % CI 1·07, 1·14). However, these associations no longer persisted after including the period effects. There was no interaction between season of birth and vitamin D availability in relation to fracture risk. The study did not provide evidence that prenatal exposure to extra vitamin D from a mandatory fortification programme of 1·25 µg vitamin D/100 g margarine was sufficient to influence the risk of fractures in late childhood, regardless of season of birth. Replication studies are needed.