Physical child abuse can result in soft-tissue and bony trauma to any site throughout the body. While no injury or fracture pattern is pathognomonic for abuse, fractures commonly associated with inflicted trauma include fractures of the ribs, skull, and diaphysis and metaphysis of long bones. Awareness and recognition of child abuse are paramount for the orthopaedic surgeon.
Structure and function
Pediatric bone is continually growing and maturing, thus giving it different properties than adult bone. Compared to mature bone, pediatric bone is less dense, more pliable, more porous, and more vascular. This increased vascularity and porosity help prevent the propagation of fractures and enhance the rate of healing. When fractures do occur, the thicker and stronger pediatric periosteum augments the stability of fracture alignment. Pediatric bone can be compared to a young sapling tree; it bends easily but is difficult to break. As children age, their bones become stronger and stiffer.
While juvenile bones have an enormous healing capacity, damage to the epiphyseal plate can potentially cause premature closure resulting in arrested bone growth at the site of injury. Growth plate fractures are classified according to the Salter-Harris classification system, graded types I through V (see figure 1), and the risk of growth arrest increases with the severity of the injury. Very young children, in contrast to adolescent children with less linear growth potential remaining, heal faster and can typically recover from most bony injuries without complication.
Figure 1. Salter-Harris classification system for fractures involving the epiphyseal plate in children (taken from Wikipedia)
The estimated annual incidence of child abuse ranges from 15 to 42 cases per 1,000 children. Roughly one third to one half of these abused children will sustain fractures. Children at increased risk for abuse include children that are first-born, premature, unplanned, stepchildren, or handicapped. 69% percent of abused children are under the age of one; 85% percent are younger than three years old. The abusers are most commonly male (the biological father in 45% of cases). Shaking is the most common form of physical abuse.
Although no infallible method of detecting child abuse exists, clinical suspicion should be raised when the described mechanism of injury is vague, unwitnessed, or inconsistent with clinical findings. Injuries incongruous with the child’s developmental stage, such as a femur fracture or skull fracture before the child can walk, should prompt further investigation. Soft-tissue injury is the most common manifestation of child abuse followed by skeletal fractures. While the incidence of bruises naturally increases with the mobility of the child, bruising over non-bony prominences may indicate maltreatment.
Physical abuse resulting in fracture may consist of one or a combination of punches, kicks, blows, pulling, twisting, shaking, and throwing. Fracture of immature bone requires greater energy than fracture of mature bone, thus any fracture of healthy pediatric bone indicates significant application of force.
While no fracture location or pattern is pathognomonic for child abuse, certain fracture locations and patterns correlate highly with inflicted trauma.
- Multiple fractures in various stages of healing without a past medical history of metabolic or connective tissue bone disease suggest ongoing, repetitive physical abuse.
- Rib fractures have the highest specificity for abuse. Rib fractures can be inflicted by direct blows or squeezing compression. Breaking a child’s ribs requires substantial force, often resulting in potentially life threatening solid organ injuries. Multiple consecutive ribs are often broken corresponding to the abuser’s finger placement. Rib fractures can be difficult to detect on x-ray because they are frequently non-displaced and have overlapping structures. Therefore these fractures may be better visualized on x-rays taken during the healing phase 10-14 days post event.
Figure 2. Arrows point to multiple posterior rib fractures secondary to child abuse (taken from Wikipedia)
- Long bone fractures of the femur, humerus, and tibia are the most common fractures of child abuse, but these are also common with accidental trauma. Isolated long bone fractures in non-ambulatory children are highly suspicious, although not indicative, of inflicted trauma. In contrast, a “toddler’s fracture” of the femur is a common non-inflicted fracture in ambulating children. Spiral, oblique, or transverse fracture patterns are possible with both non-accidental and accidental injury.
- Diaphyseal fractures can have a spiral or transverse fracture pattern. Spiral fractures result from direct torsional forces on an extremity, such as twisting the leg. Transverse fractures result from a direct impact to the bone. Diaphyseal fractures are more common than metaphyseal fractures with inflicted trauma, but less specific.
- Metaphyseal (“bucket handle” or “corner”) fractures result from pulling or twisting an extremity suddenly and forcibly. This action causes separation of a peripheral metaphyseal bone fragment with attached subpereostal bone collar, forming a mobile concave disk shaped bone fragment
Figure 3. Please use figure like this one
- Skull fractures are most commonly linear and parietal in both intentional and unintentional trauma. However, skull fractures in children younger than 18 months are suggestive of inflicted trauma.
- Spinal fractures are uncommon and often asymptomatic. Compression or burst fracture of the lower spine may result from significant downward force into a sitting position.
- Sternum, scapula, and pelvis fractures are typically caused by high-energy accidents such as a motor vehicle crash. Child abuse should be suspected when these fractures occur in a child lacking a plausible history of a high-energy accident.
Health care providers are required by law to report suspected child abuse to the appropriate governmental authorities. Suspected abuse should also prompt involvement of child protective services (CPS) if available.
Identifying child abuse can be quite difficult. Frequently the children are too young to verbalize a history or the location of their injury. Parents or caretakers usually do not openly confess to abusing their children, but they can present to the Emergency Department seeking care for their child after inflicting an injury. Therefore, physicians must be aware and recognize the signs of abuse. Even with a high clinical suspicion for abuse, it may be impossible to definitively attribute an injury to abuse if the abuser has a reasonable cover story. Furthermore, the accusation and investigation of child abuse is highly sensitive as it can have profound consequences on the family unit and custody of the child. Therefore, other explanations for pediatric fractures must be considered and ruled out. The differential for possible inflected trauma includes:
- Accidental trauma
- Normal anatomical bony variants
- Birth trauma
- Metabolic Bone disease including Cu deficiency, rickets, osteopenia of prematurity, and chronic illness
- Connective tissue disorders including osteogenesis imperfecta and Caffey’s disease
- Infections including osteomyelitis, syphilis, and neoplasms
- Drug toxicity
- Congenital insensitivity to pain
A radiographic skeletal survey is the recommended diagnostic imaging modality and is mandatory for any child under two years of age for whom child abuse is suspected. Surveying the whole skeleton of an infant or young child may also provide evidence of previous fractures in addition to current injuries. A skeletal survey includes AP and lateral views of the skull and chest; an AP view of the pelvis, long bones of the extremities, and feet; lateral views of the spine; and a PA oblique view of the hands. While not required, oblique views of the ribs enhance the likelihood of identifying subtle fractures. Two additional, more detailed views should be obtained of any part that is suspicious for lesions on skeletal survey. A skeletal survey is not indicated in children greater than five years old because they can typically verbalize the mechanism of their injury.
A pediatric radiologist with experience imaging child abuse injuries should review the films and can usually help sort through the likelihood of each diagnosis on the differential. They look for signs of current fracture, hematoma, and periosteal reaction. The radiologist should be familiar with the stages of bone healing to better approximate the age of injuries.
In cases where lesions cannot be identified on the initial skeletal survey but clinical suspicion for abuse remains high, a repeat skeletal survey taken two weeks after the initial incident is recommended to increase diagnostic yield. Periosteal reaction of healing fractures may make previously unseen fractures more visible and may help determine the age of injuries.
While skeletal survey is the standard of care, additional imaging may include ultrasound, radionucleotide scan, and CT.
To rule out organic causes of bone fracture, a metabolic workup can be done. These labs should include serum levels of levels of alkaline phosphatase, calcium and phosphorous, PTH, and urinary calcium and phosphorous levels.
Risk factors and prevention
While little can be done to prevent child abuse from occurring, physician vigilance and early intervention with a CPS team may help prevent child abuse from recurring.
The primary goal of treatment for child abuse fractures is to minimize motion at the site of fracture to allow for deposition and maturation of new bone. This can usually be accomplished through non-operative management with splinting or casting. Occasionally open reduction and internal fixation are necessary to achieve appropriate healing and restore function. Physical therapy with appropriate weight bearing will help with the bone remodeling process.
Long-term orthopaedic prognosis is excellent. The pediatric population has high bone turnover resulting in a high capacity to heal. Untreated fractures may heal with non-anatomic bony angulations or articulations. Long-term complications of both treated and untreated fractures include non-union or osteoarthritis of injured joints.
Without proper intervention, abused children are at a significant risk for repetitive injury or even death.
Activity level may be restricted and some school may be missed while fractures are healing. More importantly, pediatric victims of physical abuse may have long lasting psychosocial impacts throughout development and adulthood.
Child abuse, multiple fractures, metaphyseal fracture, long bone fracture, rib fracture, skeletal survey
Recognize a history and physical exam suspicious for child abuse. Appreciate child developmental stage and plausibility of reported mechanism of injury. Identify lesions on radiographs suspicious of abuse.