Rachitic changes, demineralization, and fracture risk in healthy infants and toddlers with vitamin D deficiency

Serum 25-hydroxyvitamin D threshold and risk of rickets in young children: a systematic review and individual participant data meta-analysis to inform the development of dietary requirements for vitamin D

PURPOSE

The objective of this systematic review was to determine a minimum serum 25-hydroxyvitamin D (25OHD) threshold based on the risk of having rickets in young children. This work was commissioned by the WHO and FAO within the framework of the update of the vitamin D requirements for children 0-3 years old.

METHODS

A systematic search of Embase was conducted to identify studies involving children below  4 years of age with serum 25OHD levels and radiologically confirmed rickets, without any restriction related to the geographical location or language. Study-level and individual participant data (IPD)-level random effects multi-level meta-analyses were conducted. The odds, sensitivity and specificity for rickets at different serum 25OHD thresholds were calculated for all children as well as for children with adequate calcium intakes only.

RESULTS

A total of 120 studies with 5412 participants were included. At the study-level, children with rickets had a mean serum 25OHD of 23 nmol/L (95% CI 19-27). At the IPD level, children with rickets had a median and mean serum 25OHD of 23 and 29 nmol/L, respectively. More than half (55%) of the children with rickets had serum 25OHD below 25 nmol/L, 62% below 30 nmol/L, and 79% below 40 nmol/L. Analysis of odds, sensitivities and specificities for nutritional rickets at different serum 25OHD thresholds suggested a minimal risk threshold of around 28 nmol/L for children with adequate calcium intakes and 40 nmol/L for children with low calcium intakes.

CONCLUSION

This systematic review and IPD meta-analysis suggests that from a public health perspective and to inform the development of dietary requirements for vitamin D, a minimum serum 25OHD threshold of around 28 nmol/L and above would represent a low risk of nutritional rickets for the majority of children with an adequate calcium intake.

Vitamin D-A Risk Factor for Bone Fractures in Children: A Population-Based Prospective Case-Control Randomized Cross-Sectional Study

BACKGROUND

Vitamin D is an essential component in calcium metabolism. Seasonality, advanced age, sex, dark skin pigmentation, and limited exposure to sunlight were reported as causes of vitamin D deficiency. This study aims to determine whether children with lower levels of vitamin D suffer more fractures than those with sufficient levels.

MATERIALS AND METHODS

Our institution underwent a prospective case-control randomized cross-sectional single-blinded study that included 688 children. They were split into two groups: the study group and the control group. The study group received supplements of vitamin D and calcium for 6 months. Another reference cohort was observed, which comprised 889 patients in the pediatric ward for different respiratory or gastroenterological conditions without a history of fractures. This group was used for age-sex matching tests.

RESULTS

Logistic regression showed that with every one unit increase of vitamin D level, the chance of having a middle third fracture in both bones of the forearm decreased by 7% (OR 1.07); distal third fracture incidence decreased by 1.03 times; middle third radius fracture incidence decreased by 1.03 times; distal third radius fracture incidence decreased by 1.06 times. The risk of having a distal third both-bone forearm fracture increased by 1.06 times with every year of age. Comparing the healing process, we noticed an improvement in bony callus formation for patients in the study group.

CONCLUSIONS

Dosing the serum level of 25-OH-vitamin D should be taken into consideration for pediatric low-energy trauma fractures. Supplementing with vitamin D and calcium throughout childhood can be a solution for healthy bones. Our preliminary results show that the normal level of vitamin D in children should start at 40 ng/mL.

Vitamin D Supplementation and Its Impact on Different Types of Bone Fractures

Vitamin D helps to balance the levels of calcium and phosphorus to maintain proper bone structure. It is also involved in essential biological roles and displays a wide spectrum of potential benefits in the human body. Since there are many types of fractures that occur at specific ages and due to different circumstances, the influence of vitamin D on the frequency of a particular fracture may differ. Thus, the authors investigated the possible preventive effect of vitamin D on the risks of vertebral fractures, hip fractures, stress fractures and pediatric fractures. Additional aspects of vitamin D, especially on recuperation after injures and its impact on the severity of particular fractures, were also discussed. It was suggested that vitamin D supplementation may contribute to a reduction in hip fracture risk due to reduced bone turnover, decreased frequency of falls and improved muscle function. Furthermore, vitamin D appears to lower the risk of stress fractures in athletes and military recruits. Due to a nonunified protocol design, presented investigations show inconsistencies between vitamin D supplementation and a decreased risk of vertebral fractures. However, a vitamin D preventive effect on pediatric fractures seems to be implausible.

Radiologists' Diagnostic Performance in Differentiation of Rickets and Classic Metaphyseal Lesions on Radiographs: A Multicenter Study

BACKGROUND. Despite evidence supporting the specificity of classic metaphyseal lesions (CML) for the diagnosis of child abuse, some medicolegal practitioners claim that CML result from rickets rather than trauma. OBJECTIVE. The purpose of this study was to evaluate radiologists' diagnostic performance in differentiating rickets and CML on radiographs. METHODS. This retrospective seven-center study included children younger than 2 years who underwent knee radiography from January 2007 to December 2018 and who had either rickets (25-hydroxyvitamin D level < 20 ng/mL and abnormal knee radiographs) or knee CML and a diagnosis of child abuse from a child abuse pediatrician. Additional injuries were identified through medical record review. Radiographs were cropped and zoomed to present similar depictions of the knee. Eight radiologists independently interpreted radiographs for diagnoses of rickets or CML, rated confidence levels, and recorded associated radiographic signs. RESULTS. Seventy children (27 girls, 43 boys) had rickets; 77 children (37 girls, 40 boys) had CML. Children with CML were younger than those with rickets (mean, 3.7 vs 14.2 months, p < .001; 89.6% vs 5.7% younger than 6 months; 3.9% vs 65.7% older than 1 year). All children with CML had injuries in addition to the knee CML identified at physical examination or other imaging examinations. Radiologists had almost perfect agreement for moderate- or high-confidence interpretations of rickets (κ = 0.92) and CML (κ = 0.89). Across radiologists, estimated sensitivity, specificity, and accuracy for CML for moderate- or high-confidence interpretations were 95.1%, 97.0%, and 96.0%. Accuracy was not significantly different between pediatric and nonpediatric radiologists (p = .20) or between less experienced and more experienced radiologists (p = .57). Loss of metaphyseal zone of provisional calcification, cupping, fraying, and physeal widening were more common in rickets than CML, being detected in less than 4% of children with CML. Corner fracture, bucket-handle fracture, subphyseal lucency, deformed corner, metaphyseal irregularity, and subperiosteal new bone formation were more common in CML than rickets, being detected in less than 4% of children with rickets. CONCLUSION. Radiologists had high interobserver agreement and high diagnostic performance for differentiating rickets and CML. Recognition that CML mostly occur in children younger than 6 months and are unusual in children older than 1 year may assist interpretation. CLINICAL IMPACT. Rickets and CML have distinct radiographic signs, and radiologists can reliably differentiate these two entities.

Parathyroid hormone changes in infants investigated for inflicted injury; an observational retrospective single centre cohort study

BACKGROUND

Biochemical and haematological testing is recommended in the United Kingdom when inflicted injury is suspected. We examined the associations of test results with radiologically-confirmed fracture(s), and between test results, in a large retrospective observational cohort.

METHODS

Infants up to age two years presenting with suspected inflicted injury, without clinically or radiologically apparent bone disease, and where a skeletal survey was undertaken during the period 1st August 2013 to 31st December 2020, were included. Biochemical parameters: corrected calcium (cCa); phosphate (P); alkaline phosphatase (ALP); parathyroid hormone (PTH); 25-hydroxyvitamin D (25D); and haematological parameters: haemoglobin (Hb); mean corpuscular haemoglobin (MCH); mean corpuscular haemoglobin content (MCHC); mean corpuscular volume (MCV); platelet count were collated together with the results of the radiological assessments.

FINDINGS

Of 332 eligible infants (190 male), 142 (84 male) had fracture(s) and/or intracranial injury. Mean PTH in the non-fracture group (n measured 50/190) was 27.3 ng/l; in those with intracranial injury alone (n measured 9/23) was 39.4 ng/l; in those with fracture alone (n measured 62/84) was 45.0 ng/l; and in those with fracture and intracranial injury (n measured 20/35) 51.8 ng/l. F-test of multiple means = 0.0369. There was no difference in 25D between the groups.

INTERPRETATION

PTH was raised in infants who had fracture(s), intracranial injury or both. A single raised PTH may not necessarily be an indicator of prior disturbed skeletal health in these circumstances. The relevance of vitamin D status and interpretation of data from biochemical testing should be informed by the overall presentation in suspected inflicted injury cases. A single raised PTH may be a consequence of the child's injuries rather than prior disturbed bone health.

Multi-modality imaging characteristics of costochondral fractures, a highly specific rib fracture for child abuse

BACKGROUND

Rib fractures in young children are strongly associated with nonaccidental trauma (NAT). Costochondral junction (CCJ) fractures are unique with most being identified in the healing phase on radiographs. NAT-associated CCJ fractures, therefore, may be underdiagnosed. Improved diagnoses of CCJ fractures may lead to better identification of NAT.

OBJECTIVE

To document the association of CCJ fractures with NAT, and improve CCJ fracture recognition by documenting the imaging features with multiple radiologic modalities.

MATERIALS AND METHODS

Children, ages 0-4 years, with CCJ fractures on radiologic reports were identified over a 10-year period. All available radiographic skeletal surveys, chest radiographs, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US) studies were reviewed. We chose CT as the radiologic gold standard. Imaging patterns of the primary fracture and healing changes were documented. The diagnosis of NAT by the child protective team was documented.

RESULTS

One hundred and nine CCJ fractures were found in 22 patients, 21 of whom were diagnosed with NAT (95.5%). Radiographic skeletal survey identified 34.6% of CCJ fractures (P < 0.0001) with a sensitivity of 32.5% and specificity of 99.2%. MRI identified 50.0% of CCJ fractures with a sensitivity of 42.9% and specificity of 98.1%.

CONCLUSION

CCJ fractures are highly specific for NAT. As sensitivity is low for radiographic skeletal survey in CCJ fracture diagnosis compared with CT, CT may have a role in confirming a clinical suspicion of NAT.

Evolving forensic controversies in child abuse imaging

Child abuse is a common cause of morbidity and mortality in the pediatric population. Despite well-defined evidence establishing bona fide clinical and imaging indicators of child abuse, denialists have emerged on behalf of defendants utilizing unaccepted scientific positions based on literature that they have often authored themselves. This manuscript describes many of the trends in recent legal proceedings while highlighting the importance of consensus statements and professional ethics as they pertain to child abuse imaging. Knowledge of these cases and legal defense strategies is valuable to potential expert witnesses in relevant proceedings.

Vitamin D, rickets and child abuse: controversies and evidence

Suboptimal vitamin D status is a global health issue that affects children and adults worldwide. The prevalence of vitamin D deficiency and insufficiency has been well documented in the pediatric population in the United States. Although vitamin D deficiency is common, radiographic findings are uncommon and can be subtle. Additionally, because of the high prevalence of pediatric vitamin D insufficiency, it is commonly identified in young children with fractures. However, the majority of pediatric fractures are caused by trauma to healthy bones. Some, especially in infants and toddlers, are caused by non-accidental trauma. A small percentage is related to medical disease, including those associated with disorders of collagen, disorders of mineralization, and non-fracture mimics. Despite the scientific evidence, among disorders of mineralization, non-rachitic disorders of vitamin D have become a popular non-scientific theory to explain the fractures identified in abused children. Although infants and young children with rickets can fracture bones, the vast majority of fractures identified in abused infants are not caused by bone disease. Here we present a review of the literature on bone disease in the setting of accidental and non-accidental trauma. This context can help physicians remain vigilant about identifying vulnerable young children whose injuries are caused by non-accidental trauma.

Diagnostic Imaging for Physical Abuse in Children

신체적 학대로 인한 손상은 소아에서 이환율과 사망률의 중요한 원인이 된다. 특히, 1세 이하의 영아가 신체적 학대의 위험이 높다. 신체적 학대가 의심되는 경우 영상의학과 의사의 역할은 매우 중요한데 학대가 의심되는 영상의학적 소견을 찾고 다른 질환과의 감별을 통해 신속하고 정확한 진단을 내려야 한다. 본 논문에서는 신체적 학대를 받은 아동에서 흔히 보일 수 있는 특징적인 손상인 골절, 머리 손상, 척추 손상, 흉부와 복부의 손상 등의 여러 영상의학적 소견을 설명하고 이러한 손상이 유발되는 생체 역학적 힘의 기전에 대해 알아보고자 한다.

Rachitic change and vitamin D status in young children with fractures

OBJECTIVE

To examine the association between rachitic changes and vitamin D levels in children less than 2 years old with fractures.

METHODS

Children less than 2 years old who were admitted to a large children's hospital for a fracture and underwent a skeletal survey were included. Two pediatric radiologists blinded to the children's vitamin D levels independently reviewed the skeletal surveys for the following rachitic findings: demineralization, widened sutures, rachitic rosary, Looser zones, and metaphyseal changes. Kappa coefficients were calculated to assess inter-rater agreement. Logistic regression was used to test the association between vitamin D level and rachitic findings.

RESULTS

There were 79 subjects (40 female and 39 male) with a median age of 4 months. Vitamin D levels ranged from 11.6 to 88.9 ng/ml and were low in 27. Questionable demineralization was noted in seven subjects; mild to moderate demineralization was observed in four subjects. Widened sutures were noted in seven subjects, many also with concurrent intracranial hemorrhage. Lower vitamin D levels were associated with increased odds of demineralization after adjusting for age, gender, and prematurity (P < 0.015). An association was not found between the vitamin D level and suture widening (P = 0.07). None of the cases demonstrated Looser zones, rachitic rosary, or metaphyseal changes of rickets.

CONCLUSIONS

Infants and toddlers with fractures frequently have suboptimal vitamin D levels, but radiographic evidence of rickets is uncommon in these children.

Rickets severity predicts clinical outcomes in children with X-linked hypophosphatemia: Utility of the radiographic Rickets Severity Score

The Rickets Severity Score (RSS) was used to evaluate X-linked hypophosphatemic rickets (XLH), a genetic disorder mediated by increased circulating FGF23. The reliability of the RSS was assessed using data from a randomized, phase 2 clinical trial that evaluated the effects of burosumab, a fully human anti-FGF23 monoclonal antibody, in 52 children with XLH ages 5 to 12 years. Bilateral knee and wrist radiographs were obtained at baseline, week 40, and week 64. We evaluated the relationships of the RSS to the Radiographic Global Impression of Change (RGI-C), serum alkaline phosphatase (ALP), height Z-score, 6-minute walk test (6MWT) percent predicted, and the Pediatric Orthopedic Society of North America Pediatric Outcomes Data Collection Instrument (POSNA-PODCI). The RSS showed moderate-to-substantial inter-rater reliability (weighted kappa, 0.45-0.65; Pearson correlation coefficient (r), 0.83-0.89) and substantial intra-rater reliability (weighted Kappa, 0.66; r = 0.91). Baseline RSS correlated with serum ALP (r = 0.47). Baseline RSS identified two subgroups (higher [RSS ≥1.5] and lower RSS [RSS <1.5]) that discriminated between subjects with greater and lesser rachitic disease. Higher RSS was associated with more severe clinical features, including impaired growth (Z-score, -2.12 vs -1.44) and walking ability (6MWT percent predicted, 77% vs 86%), more severe self-reported pain (29.9 [more severe] vs 45.3 [less severe]) and less physical function (29.6 [more severe] vs 40.9 [less severe]). During burosumab treatment, greater reductions in RSS corresponded to higher RGI-C global scores (r = -0.65). Improvements in RSS correlated with decreased serum ALP (r = 0.47). These results show the reliability of the RSS in XLH, and demonstrate that higher RSS values are associated with greater biochemical, clinical, and functional impairments in children with XLH.

Randomised Controlled Trial Comparing Daily Versus Depot Vitamin D3 Therapy in 0-16-Year-Old Newly Settled Refugees in Western Australia Over a Period of 40 Weeks

Vitamin D deficiency is highly prevalent in newly settled refugees in Western Australia (WA). If adherence to daily vitamin D therapy is problematic, depot therapy is a therapeutic alternative. The aim of this study was to compare daily versus depot treatment and factors influencing the therapeutic outcome. Newly settled refugees (n = 151) with 25(OH)D levels less than 78 nmol/L were randomised to receive daily or depot vitamin D therapy with eight weekly interval follow up to 40 weeks. Biochemical and clinical parameters were collected at each visit. Generalized Linear Mixed Models (GLMM) examined the longitudinal changes over time controlling for confounders including age, gender, treatment arm, season, country of refuge/origin and sun exposure score. Participants were aged 5.5 months to 16.0 years (75 males, 83 females). Both treatment groups achieved vitamin D sufficiency. The daily treatment group had significantly higher 25(OH)D levels at each visit post baseline and a higher proportion of participants with levels above 50 nmol/L at all time points. Time, treatment group, calcium and sun exposure score were significant predictors of 25(OH)D serum levels. Depot vitamin D therapy is an alternative to daily treatment in this at-risk group of children and adolescents in whom treatment adherence is problematic.

Vitamin D Insufficiency and Fracture Risk in Urban Children

BACKGROUND

Investigation into the role of vitamin D in fractures in the pediatric population has been limited despite estimates that as many as 70% of American children have inadequate vitamin D levels (measured as 25-hydroxyvitamin D, 25(OH)D). The purpose of this study was to evaluate vitamin D's role in pediatric fracture risk by comparing 25(OH)D between fractured and nonfractured cohorts.

METHODS

A 12-month prospective case-control study was completed in children aged 2 to 14 years in an urban, academic hospital. Sixty fractured children requiring conscious sedation or general anesthesia for management were compared with 60 nonfractured controls. All participants and their guardians were surveyed for low bone density risk factors, and total serum 25(OH)D was measured. Statistical analysis was completed using Student t tests, χ tests, analysis of variance, and logistic regression models.

RESULTS

After controlling for age and daily sun exposure, lower total serum 25(OH)D was associated with higher fracture risk (odds ratio=0.94; 95% confidence interval, 0.90-0.99; P=0.023). In the fractured cohort, 6 (10%) patients were deficient (25(OH)D<20 ng/mL) and 33 (55%) were insufficient (25(OH)D, 20 to 30 ng/mL). Of the nonfractured population, 8 (13%) were deficient and 19 (32%) were insufficient. There were more insufficient patients in the fractured than in the nonfractured cohort (odds ratio=2.99; 95% confidence interval, 1.27-7.0; P=0.037).

CONCLUSIONS

Higher fracture incidence is associated with serum 25(OH)D insufficiency. Hypovitaminosis D may place the pediatric population at increased risk for fracture. Consideration should be given to routine assessment of vitamin D in fractured children.

LEVEL OF EVIDENCE

Prognostic level III-prospective case-control study.

Multiple fractures in infants who have Ehlers-Danlos/hypermobility syndrome and or vitamin D deficiency: A case series of 72 infants whose parents were accused of child abuse and neglect

Objective: To increase the level of awareness that Ehlers-Danlos/hypermobility syndrome (EDS) and vitamin D deficiency are associated with infantile fragility fractures and radiologic features that may be mistakenly reported to be caused by non-accidental trauma due to Child Abuse and Neglect (CAN).

Patients and Methods: We constructed a case series, the largest to date, of infants with EDS who were vitamin D sufficient, insufficient and deficient and infants without EDS but with documented vitamin D deficiency and radiologic evidence of rickets who presented with multiple fractures originally diagnosed as being non-accidental and caused by child abuse. These infants were referred to the outpatient Bone Health Care Clinic at Boston University Medical Campus over a 6-year (2010–2015) period. We also present 6 index cases in which the court concluded that there was no convincing evidence of child abuse and the infants were returned to their parents. Institutional Review Board (IRB) approval was obtained.

Results: We present 72 cases of infants with multiple fractures diagnosed to be caused by non-accidental trauma. All infants were younger than one year of age. Among them, 93%(67) had clinical evidence of EDS and/or a family history with a confirmed clinical diagnosis of at least one parent having EDS and the other 7%(5) without evidence of EDS had vitamin D deficiency/infantile rickets. Three of the EDS infants were diagnosed as osteogenesis imperfecta (OI)/EDS overlap syndrome. The most common fractures noted at diagnosis were ribs and extremity fractures (including classic metaphyseal lesions). Serum levels of 25-hydroxyvitamin D [25(OH)D] were reported in 48 infants (18.0 ± 8.5 ng/ml) and in 30 mothers (21.3 ± 11.7 ng/ml). Sixty-three percent (27) of the EDS infants who had their serum 25(OH)D measured were vitamin D deficient 25(OH)D<20 ng/ml and 5 were vitamin D sufficient 25(OH)D>30 ng/ml. The mean serum level for infants with vitamin D deficiency/rickets was (10.2 ± 3.0 ng/ml)

Conclusion: EDS, OI/EDS and vitamin D deficiency/infantile rickets are associated with fragility fractures in infants that can be misinterpreted as caused by non-accidental trauma due to child abuse.

Vitamin D Deficiency in Pediatric Fracture Patients: Prevalence, Risk Factors, and Vitamin D Supplementation

OBJECTIVE

Although vitamin D levels are not routinely monitored in pediatric fracture patients, identification of children with a vitamin D deficiency may be clinically relevant because of the potential role of vitamin D in fracture healing. This study aimed to determine the prevalence of vitamin D deficiency in a pediatric fracture population and to identify risk factors for deficiency.

METHODS

All pediatric patients (<18 years) who were treated for a fracture of the upper or lower extremity from September 2012 to October 2013 in the outpatient setting of a level one trauma center were included in this cross-sectional study. Vitamin D deficiency was defined as a serum calcidiol <50 nmol/L. Potential risk factors for vitamin D deficiency were analysed using multivariable logistic regression analysis.

RESULTS

A total of 108 boys (58%) and 79 girls, of a mean age 11.1 years (standard deviation 3.9), who had undergone 189 fractures were included in the study. Sixty-four children (34%) were vitamin D deficient. Of those with follow-up measurements, 74% were no longer deficient after supplementation. Vitamin D status did not influence the occurrence of complications during fracture treatment. Independent risk factors for vitamin D deficiency were older age, season (spring), and a non-Caucasian skin type.

CONCLUSION

Clinicians who treat children with a fracture should inform patients and parents on vitamin D supplementation. Vitamin D measurement and supplementation may be needed for children with a non-Caucasian skin type or for those who present with a fracture during spring months.

Are There Hallmarks of Child Abuse? I. Osseous Injuries

Fractures are commonly found in cases regarded as child abuse. The most commonly encountered fractures are to the ribs and the metaphyses. This paper examines the specificity of the classical metaphyseal lesion (CML) and rib fractures as hallmarks of child abuse. Recently, vitamin D deficiency (rickets) has been proposed as an alternative cause for the appearances typically described in CML. The literature in this area is examined. Rib fractures have also been highly associated with child abuse, particularly posterior rib fractures. As well as metabolic bone disease, resuscitation has been examined as a cause of rib fractures in young children. The current literature remains strongly supportive of rib fractures and metaphyseal fractures being indicators of child abuse.

The etiology and significance of fractures in infants and young children: a critical multidisciplinary review

This paper addresses significant misconceptions regarding the etiology of fractures in infants and young children in cases of suspected child abuse. This consensus statement, supported by the Child Abuse Committee and endorsed by the Board of Directors of the Society for Pediatric Radiology, synthesizes the relevant scientific data distinguishing clinical, radiologic and laboratory findings of metabolic disease from findings in abusive injury. This paper discusses medically established epidemiology and etiologies of childhood fractures in infants and young children. The authors also review the body of evidence on the role of vitamin D in bone health and the relationship between vitamin D and fractures. Finally, the authors discuss how courts should properly assess, use, and limit medical evidence and medical opinion testimony in criminal and civil child abuse cases to accomplish optimal care and protection of the children in these cases.

A witnessed case of a classic metaphyseal fracture caused during IV line placement in a child: Insight into mechanism of injury

Recent publications argue that classic metaphyseal fractures are caused by rickets as opposed to trauma. Previous case reports of accidental traumatic classic metaphyseal fractures have been discounted due to lack of identification of the fracture at the time of the traumatic event, and lack of an evaluation for boney metabolic disorders. We report a case of a 20 day old male with a diagnosis of congenital vertical talus who sustained a classic metaphyseal fracture of the distal tibia during manipulation in preparation for intravenous line placement. The mechanics of the event causing the classic metaphyseal fracture were witnessed and accompanied by an audible "pop". Prior x-rays of the tibia demonstrate normal osseous morphology, and an evaluation for boney metabolic disorders was normal. This case identifies a traumatic classic metaphyseal fracture and provides insight into the types of forces necessary to cause such a fracture.

Absence of rickets in infants with fatal abusive head trauma and classic metaphyseal lesions

PURPOSE

To determine if rickets is present in cases of infant homicide with classic metaphyseal lesions (CMLs) and other skeletal injuries.

MATERIALS AND METHODS

This study was exempt from the institutional human subjects board review because all infants were deceased. An archival review (1984-2012) was performed of the radiologic and histopathologic findings of 46 consecutive infant fatalities referred from the state medical examiner's office for the evaluation of possible child abuse. Thirty infants with distal femoral histologic material were identified. Additional inclusion criteria were as follows: (a) The medical examiner determined that the infant had sustained a head injury and that the manner of death was a homicide, (b) at least one CML was evident at skeletal survey, (c) CMLs were confirmed at autopsy, and (d) non-CML fractures were also present. Nine infants (mean age, 3.9 months; age range, 1-9 months) were identified. Two pediatric radiologists independently reviewed the skeletal surveys for rachitic changes at the wrists and knees. A bone and soft tissue pathologist reviewed the distal femoral histologic slices for rickets.

RESULTS

There were no radiographic or pathologic features of rickets in the cohort.

CONCLUSION

The findings provide no support for the view that the CML is due to rickets. Rather, they strengthen a robust literature that states that the CML is a traumatic injury commonly encountered in physically abused infants.

Vitamin D and skeletal health in infancy and childhood

During growth, severe vitamin D deficiency in childhood can result in symptomatic hypocalcaemia and rickets. Despite the suggestion from some studies of a secular increase in the incidence of rickets, this observation may be driven more by changes in population demographics than a true alteration to age, sex and ethnicity-specific incidence rates; indeed, rickets remains uncommon overall and is rarely seen in fair-skinned children. Additionally, the impact of less severe vitamin D deficiency and insufficiency has received much interest in recent years, and in this review, we consider the evidence relating vitamin D status to fracture risk and bone mineral density (BMD) in childhood and adolescence. We conclude that there is insufficient evidence to support the suggestion that low serum 25-hydroxyvitamin D [25(OH)D] increases childhood fracture risk. Overall, the relationship between 25(OH)D and BMD is inconsistent across studies and across skeletal sites within the same study; however, there is evidence to suggest that vitamin D supplementation in children with the lowest levels of 25(OH)D might improve BMD. High-quality randomised trials are now required to confirm this benefit.

Vitamin D deficiency in children with fractures

OBJECTIVE

This study aimed to determine whether healthy children with fractures resulting from minor accidental trauma have a higher prevalence of vitamin D deficiency than that of healthy children without fractures.

METHODS

This was a prospective case-control study of ambulatory children younger than 18 years with and without fractures in a pediatric emergency department. Evaluation included serum 25-hydroxyvitamin D (25(OH)D) level, complete metabolic panel, and phosphorus level. Vitamin D deficiency was defined as a 25(OH)D level of less than 20 ng/mL and insufficiency less than 30 ng/mL but 20 ng/mL or greater. A level of 30 ng/mL or greater was considered sufficient. Fisher exact test was used to test for association between 25(OH)D level and fracture status. Logistic regression was used to examine the relationship between 25(OH)D levels and the odds of fracture, conditioned on season, age, race, body weight percentile, history of fracture, multivitamin use, and estimated daily milk intake.

RESULTS

The sample included 100 case and 100 control patients. There was no statistical difference in median 25(OH)D levels between fracture and control groups (26.7 vs 25.45 ng/mL, P = 0.84). There was no difference in the proportion of patients with sufficient 25(OH)D levels or in the distribution of sufficient, insufficient, and deficient. After adjusting for male sex and season of enrollment, vitamin D sufficiency was not a significant predictor of fracture status in a multiple variable logistic model (odds ratio, 0.94; 95% confidence interval, 0.51-1.77; Wald P = 0.859).

CONCLUSIONS

We found no relationship between vitamin D deficiency and fracture risk in our study population.

Does low vitamin D have a role in pediatric morbidity and mortality? An observational study of vitamin D in a cohort of 52 postmortem examinations

Vitamin D is required for calcium absorption and normal bone mineralization; it has a key role in immune regulation against infections and is believed to be involved in immunomodulation in asthma. We did a retrospective analysis of 52 postmortem cases (aged 2 days to 10 years). Seventeen children had vitamin D deficiency (<25 nmol/L); 24 children had vitamin D insufficiency (25-49 nmol/L); 10 children had suboptimal vitamin D levels (50-79 nmol/L); and only 1 child had adequate levels (≥80 nmol/L). Three infants had fractures. Growth plate histology was abnormal in 10 cases with vitamin D deficiency (59%), but radiology was abnormal in only 3 of those cases. Eight infants (33%) with vitamin D insufficiency had abnormal histology, but radiology was normal in all cases. In 3 children hypocalcemia due to vitamin D deficiency was considered accountable for death; they all showed radiological and histological rickets: 2 babies had cardiomyopathy and a 3-year-old had hypocalcemic seizures. Children from all ethnic groups had a high proportion of low vitamin D levels. Vitamin D deficiency (the most common form of pediatric metabolic bone disease) is preventable and treatable. Profound hypocalcemia due to severe vitamin D deficiency can cause unexpected death in babies and young children. Measuring serum vitamin D levels postmortem may provide invaluable information on sudden unexplained death in 'at-risk' children. Vitamin D deficiency may be relevant in childhood asthma and in children with multiple infections and babies with bone fractures. Postmortem vitamin D levels are stable and easy to measure.

Evaluating children with fractures for child physical abuse

Fractures are common injuries caused by child abuse. Although the consequences of failing to diagnose an abusive injury in a child can be grave, incorrectly diagnosing child abuse in a child whose fractures have another etiology can be distressing for a family. The aim of this report is to review recent advances in the understanding of fracture specificity, the mechanism of fractures, and other medical diseases that predispose to fractures in infants and children. This clinical report will aid physicians in developing an evidence-based differential diagnosis and performing the appropriate evaluation when assessing a child with fractures.

Fractures in hospitalized children

Hospitalized children have multiple risk factors for fragility fractures, related to disease pathophysiology, treatments, nutritional status and immobilization. Recognition and treatment of these risk factors are important to prevent morbidity associated with fractures and to promote current and future bone health. Many knowledge gaps remain regarding the ideal nutrition, physical activity, and medication regimens needed to optimize bone health and reduce the risk of fractures over the life course. This article reviews the pathogenesis, risk factors, treatment and prevention strategies for fractures in hospitalized infants and children.

Increasing incidence of nutritional rickets: a population-based study in Olmsted County, Minnesota

OBJECTIVE

To determine temporal trends in incidence and risk factors of nutritional rickets in a community-based population.

PATIENTS AND METHODS

Rochester Epidemiology Project data were used to identify all children (aged <18 years) residing in Olmsted County, Minnesota, between January 1, 1970, and December 31, 2009, with diagnostic codes corresponding to rickets, vitamin D deficiency, hypovitaminosis D, rachitis, osteomalacia, genu varum, genu valgum, craniotabes, hypocalcemia, hypocalcemic seizure, and tetany. Record abstraction was performed to select individuals with radiographic confirmation of rickets. Age- and sex-matched controls were identified for the evaluation of risk factors. The main outcome measure was radiographic evidence of rickets without identifiable inherited, genetic, or nonnutritional causes. Incidence rates were calculated using Rochester Epidemiology Project census data.

RESULTS

Of 768 children with eligible diagnostic codes, 23 had radiographic evidence of rickets; of these, 17 children had nutritional rickets. All 17 children were younger than 3 years, and 13 (76%) were of nonwhite race/ethnicity. Clinical presentation included poor growth (n=12), leg deformity (n=8), motor delay (n=5), leg pain (n=3), weakness (n=3), and hypocalcemia or tetany (n=2). The incidence of nutritional rickets in children younger than 3 years was 0, 2.2, 3.7, and 24.1 per 100,000 for the decades beginning in 1970, 1980, 1990, and 2000, respectively (P=.003 for incidence trend). Nutritional rickets was associated with black race, breast-feeding, low birth weight, and stunted growth (P<.05 for all). Four of 13 patients (31%) who underwent 25-hydroxyvitamin D testing had values less than 10 ng/mL.

CONCLUSION

Nutritional rickets remains rare, but its incidence has dramatically increased since 2000. Not all cases of rickets can be attributed to vitamin D deficiency.

Rickets: Part II

This is the continuation of a two-part review of rickets. This part emphasizes the specific pathophysiology, clinical features, pathoanatomy and radiographic findings of vitamin D deficiency rickets. Other forms of rickets, differential diagnostic considerations and the potential relationship between low levels of vitamin D metabolites and unexplained fractures in infants are also discussed.