Temporary brittle bone disease: a true entity?

Debunking Fringe Beliefs in Child Abuse Imaging: AJR Expert Panel Narrative Review

Child abuse is a global public health concern. Injuries from physical abuse may be clinically occult and not appreciable on physical examination. Imaging is therefore critical in identifying and documenting such injuries. The radiologic approach for a child who has potentially been abused has received considerable attention and recommendations according to decades of experience and rigorous scientific study. Nonetheless, fringe beliefs describing alternative explanations for child abuse-related injuries have emerged and received mainstream attention. Subsequently, imaging findings identified in abused children have been attributed to poorly supported underlying medical conditions, clouding the evidence basis for radiologic findings indicative of nonaccidental trauma. Fringe beliefs that attribute findings seen in child abuse to alternate pathologies such as genetic disorders, birth trauma, metabolic imbalances, vitamin D deficiency, and short-distance falls typically have limited evidence basis and lack professional society support. Careful review of the scientific evidence and professional society consensus statements is important in differentiating findings attributable to child abuse from fringe beliefs used to discount the possibility that a child's constellation of injuries is consistent with abuse. This review refutes fringe beliefs used to provide alternative explanations in cases of suspected child abuse and reinforces the key literature and scientific consensus regarding child abuse imaging.

Thinking fast and slow in the evaluation of injury plausibility in child protection

In evaluating injury in children, child protection paediatricians are tasked with determining whether the history given by parents or caregivers is valid with respect to explaining injury causation. This paper summarises metacognition and in particular the dual processing theory of 'fast and slow thinking' to explain how complex information in contexts of uncertainty is processed to produce decisions and responses, applied to a child protection context. An example is used that resembles abusive head trauma which focuses on understanding the difference between likelihood and plausibility in forensic interpretations of injury causation.

Spontaneous fetal femoral fracture: a case report and literature review

Spontaneous fetal femoral fractures are uncommon in the paediatric setting. The major clinical presentations of a spontaneous fetal femoral fracture are femoral angulation, shortness of the femur and even a marked fracture line. This case report describes a spontaneous fetal femoral fracture of the right femur, which was detected by routine ultrasonography during the 19^th week of gestation in a 24-year-old woman. On routine follow-up visits, the angulation of the right femur in the fetus gradually improved. A caesarean section was undertaken at 39 weeks +5 days of gestation and an X-ray was taken on the second day after birth, which showed that the fracture had healed and the callus had been absorbed. The lengths of the two femurs of the baby were not equal; the right femur was 84 mm, which was 11 mm shorter than the left femur. In cases like this, postnatal follow-up is essential so that an operation can be carried out in a timely manner when the deformity is apparent.

Minimising bias in the forensic evaluation of suspicious paediatric injury

In the rules of evidence in all legal jurisdictions, medical experts are required to maintain objectivity when providing opinions. When interpreting medical evidence, doctors must recognise, acknowledge and manage uncertainties to ensure their evidence is reliable to legal decision-makers. Even in the forensic sciences such as DNA analysis, implicit bias has been shown to influence how results are interpreted from cognitive and contextual biases unconsciously operating. In cases involving allegations of child abuse there has been significant exposure in the media, popular magazines, legal journals and in the published medical literature debating the reliability of medical evidence given in these proceedings. In these cases judges have historically been critical of experts they perceived had sacrificed objectivity for advocacy by having an investment in a 'side'. This paper firstly discusses the issue of bias then describes types of cognitive biases identified from psychological research applied to forensic evidence including adversarial bias, context bias, confirmation bias and explains how terminology can influence the communication of opinion. It follows with previously published guidelines of how to reduce the risk of bias compromising objectivity in forensic practices then concludes with my own recommendations of practices that can be used by child protection paediatricians and within an organisation when conducting forensic evaluations of suspicious childhood injury to improve objectivity in formulation of opinion evidence.

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.

Clinical and laboratory features of temporary brittle bone disease

Temporary brittle bone disease has been described since 1990. It is a syndrome characterised by multiple unexplained fractures in early childhood. There is growing evidence that it has natural causes and does not represent inflicted trauma. We report the clinical and laboratory features of 104 patients investigated personally between 1985 and 2000. These patients had in aggregate 976 fractures or fracture-like lesions. Our patients included disproportionate numbers of infants born preterm or as a result of multiple pregnancy. The fractures were mainly identified in the first 6 months of life and entirely within the first year of life. Most fractures were asymptomatic, particularly the many rib fractures and metaphyseal lesions. Few patients had evidence of bruising at presentation; none had clinical evidence of inflicted injury commensurate with the fractures found. In 22 patients the fractures were found in the course of investigation for unrelated symptoms. In several cases fractures took place while the children were in hospital. Unexplained bruising and sub-conjunctival haemorrhages also occurred in hospital, suggesting collagen defects. Hernias were recorded; in most these resolved spontaneously, again suggesting transient collagen defects. Among the unexplained symptoms of the patients was a history of vomiting, often projectile vomiting. Some patients had unusually blue or grey sclerae for the child's age. Many patients had abnormally large anterior fontanelles. Laboratory findings included anaemia, neutropenia and an exceptionally high serum alkaline phosphatase. Our findings reinforce the view that children with temporary brittle bone disease have a distinctive and identifiable syndrome which probably includes osteopathy of prematurity. These patients do not have osteogenesis imperfecta and are not the victims of non-accidental injury. While the causes of this syndrome remain uncertain, its distinctive features should now be more readily recognised.

Temporary brittle bone disease: relationship between clinical findings and judicial outcome

There is a wide differential diagnosis for the child with unexplained fractures including non-accidental injury, osteogenesis imperfecta and vitamin D deficiency rickets. Over the last 20 years we and others have described a self-limiting syndrome characterised by fractures in the first year of life. This has been given the provisional name temporary brittle bone disease. This work had proved controversial mostly because the fractures, including rib fractures and metaphyseal fractures, were those previously regarded as typical or even diagnostic of non-accidental injury. Some have asserted that the condition does not exist. Over the years 1985 to 2000 we investigated 87 such cases with fractures with a view to determining the future care of the children. In 85 of these the judiciary was involved. We examined the clinical and radiological findings in the 33 cases in which there was a judicial finding of abuse, the 24 cases in which the parents were exonerated and the 28 cases in which no formal judicial finding was made. The three groups of patients were similar in terms of demographics, age at fracturing and details of the fractures. The clinical similarities between the three groups of patients contrast with the very different results of the judicial process.

Temporary brittle bone disease: fractures in medical care

Temporary brittle bone disease is the name given to a syndrome first reported in 1990, in which fractures occur in infants in the first year of life. The fractures include rib fractures and metaphyseal fractures which are mostly asymptomatic. The radiological features of this disorder mimic those often ascribed to typical non-accidental injury. The subject has been controversial, some authors suggesting that the disorder does not exist. This study reports five infants with typical features of temporary brittle bone disease in whom all or most of the fractures took place while in hospital. A non-accidental cause can be eliminated with some confidence, and these cases provide evidence in support of the existence of temporary brittle bone disease.

Vitamin D deficiency rickets and allegations of non-accidental injury

Vitamin D deficiency rickets has long been recognized as a cause of fractures and fracture-like appearances in young children. Often seen in the early 20th century, rickets has recently been regarded as uncommon; the radiological appearances, familiar to previous generations, may not be recognized for what they are. This article reports four children with unexplained fractures initially attributed confidently to non-accidental injury. In each case, the later evidence of vitamin D deficiency led to a reconsideration of that diagnosis.

CONCLUSION

It is important to be aware of this bone disorder in the differential diagnosis of fractures, to investigate appropriately and to recognize that the radiological appearances may be misleading. A mistaken diagnosis of abuse does real harm, not least to the child itself.

A newborn with multiple fractures as first presentation of infantile myofibromatosis

Pathological fractures occur in infancy from a variety of causes, but are a rare condition during neonatal period. We describe the case of a male newborn with a metaphyseal fracture of femur and multiple lytic lesions, diagnosed as infantile myofibromatosis.

Hypothesis: fetal movement influences fetal and infant bone strength

Infants who present with multiple unexplained fractures in which there is no prior trauma, no radiographic evidence of metabolic bone disease, and no biochemical evidence of metabolic bone disease are almost always diagnosed as victims of child abuse, even though parents and caregivers deny wrongdoing. Such a diagnosis has far reaching implications for the infant and family. This article describes the clinical features of 65 such infants with multiple unexplained fractures in which the parents and caregivers deny wrongdoing and in which child abuse was diagnosed. These infants have the phenotype of temporary brittle bone disease that was described by Paterson. A striking observation in these young infants is the pregnancy history of decreased fetal movement. A hypothesis is suggested as an alternative explanation for the mechanism of these fractures in these infants--namely temporary brittle bone disease from fetal immobilization. This hypothesis states that fetal bone loading through fetal movement is essential for the formation of bones of normal strength. This hypothesis is an application of Frost's mechanostat/bone-loading model of bone physiology to the prenatal period of bone formation. This hypothesis explains many of the other observations about temporary brittle bone disease including the early onset of the fractures in the first several months of life, the lack of bruising, the lack of other internal organ injury, and the low risk profile of many of the parents for committing child abuse.

The lesson of temporary brittle bone disease: all bones are not created equal

Temporary brittle bone disease (TBBD) is a recently described phenotype of multiple, unexplained fractures in the first year of life and predominantly in the first 6 months of life. There is usually no other injury such as bruising, subdural hematomas, retinal hemorrhages, or other internal organ injury. The susceptibility to fracture is transient, and there are no other radiographic or biochemical abnormalities noted in the standard evaluation that might suggest an underlying cause. The child abuse and pediatric radiology communities have, for the most part, been unwilling to accept this as a real condition, for they believe it is a ruse for child abuse. This review describes the experience of the author in evaluating infants with multiple unexplained fractures and the hypothesis that has emerged for explaining TBBD. The hypothesis is a prenatal application of the mechanostat/bone loading theory of bone formation and states that TBBD is caused by fetal immobilization which leads to fetal bone unloading and transient, relative osteopenia. Such susceptible infants can fracture with routine handling and present with a pattern of fractures that is similar to that which has been thought to be highly specific for child abuse. The review presents: (a) the evidence that indicates that normal fetal movement is important for normal fetal bone strength, (b) a critique of the radiologic approach in the diagnosis of child abuse in infants with multiple unexplained fractures, (c) observations that would indicate that child abuse is unlikely in infants with TBBD, and (d) new approaches to the infant with multiple unexplained fractures that would assist in accurate diagnosis.

Mid-trimester fracture of femur in a normal fetus

We report a case of an intrauterine fracture of the femur detected at routine mid-trimester sonography in an otherwise normal fetus. There was no associated maternal trauma. At birth, callus formation was palpable and confirmed by radiography. Absence of further fractures despite normal childhood activity and other features precluded a diagnosis of skeletal dysplasia. Although such an event is extremely rare, the possibility of an intrauterine origin should be considered in the differential diagnosis of battered baby syndrome presenting with a single fracture.

The bone disease of preterm birth: a biomechanical perspective

The bone disease of preterm birth has traditionally been explained by a decrease in bone formation from insufficient availability of calcium and phosphorus. However, there is emerging evidence that there is increased bone resorption in the bone disease of preterm birth, an observation that indicates some other explanation for this condition. The biomechanical model of postnatal bone formation states that, through a regulatory feedback system in the bone called the mechanostat, bone is able to respond to increased bone loading by increasing bone strength and to decreased bone loading by decreasing bone strength. It is suggested that this increased bone resorption in the markedly preterm infant compared with the term infant is secondary to decreased bone loading. Application of this model to the fetus and preterm infant suggests that intrauterine bone loading of the fetus from movement and kicking against the uterus is critical for normal fetal bone formation. The associated muscle growth from this activity also contributes to bone loading. The markedly preterm infant is deprived of much of this critical time period of intrauterine bone accretion, and bone formation occurs in the less favorable extrauterine environment, where there is significantly less bone loading.

Imaging of child abuse

Skeletal imaging plays a critical role in the diagnosis of abuse. High-detail radiographs of the entire skeleton, at times supplemented with nuclear imaging, CT, US, and MR imaging, elucidate the variety of findings with this entity. The radiologist's role includes careful analysis of clinical history, familiarity with typical osseous findings in abuse, and awareness of potential normal variants and pitfalls. An accurate diagnosis of abuse can then lead to appropriate measures to protect all family members at risk of serious injury.