While infants often appear delicate, their bones are surprisingly resilient. Fractures can occur, though less commonly than in older children or adults. Understanding the unique properties of infant bones and fracture circumstances helps parents recognize issues and ensure appropriate care.
How Infant Bones Differ
Infant bones possess distinct characteristics compared to adult bones, influencing how they respond to stress. A newborn’s skeleton contains around 300 bones, more than the 206 found in an adult, as many small segments fuse during growth. Much of a baby’s initial skeletal structure is cartilage, a flexible tissue, particularly in the skull where bones are not yet fully fused, allowing flexibility during birth. This cartilage gradually transforms into hardened bone through ossification.
Infant long bones feature growth plates (physes), specialized cartilage areas near bone ends responsible for longitudinal growth. These plates remain open throughout childhood, typically closing during puberty. More cartilage and active growth plates make infant bones more flexible and less brittle than adult bones, meaning they are more likely to bend or buckle than snap. However, growth plates are weaker than solid bone, making them vulnerable to injury that can affect future bone growth if not treated properly.
Causes of Infant Fractures
Infant bone fractures can arise from various situations, from accidental trauma to underlying medical conditions. Birth-related injuries are one cause, with the clavicle (collarbone) most commonly broken during delivery, often due to difficult labor or birthing aids.
Accidental causes account for many fractures, including falls from changing tables, being dropped, or car accidents. For instance, falls down stairs while carrying a child can lead to femur fractures.
Non-accidental trauma, such as child abuse, is a significant cause of fractures in infants, especially those under 6 months. Certain patterns, like multiple rib fractures, specific metaphyseal lesions, or femur fractures in a non-ambulatory child without clear accidental explanation, can raise suspicion. While spiral fractures were once considered highly indicative of abuse, they can also occur accidentally, such as a “toddler’s fracture” of the tibia from rotational force.
Rare medical conditions can predispose infants to bone fragility. Osteogenesis imperfecta (OI), or brittle bone disease, is a genetic disorder where the body produces insufficient or faulty collagen, leading to weaker bones. Infants with severe OI can be born with multiple fractures. Other conditions like metabolic bone disease of prematurity, rickets, or certain genetic disorders also increase fracture risk, necessitating careful medical evaluation for unexplained injuries.
Identifying a Fracture and When to Seek Help
Recognizing a potential fracture in an infant can be challenging since they cannot verbally communicate pain. However, several signs can indicate a bone injury.
Common signs include:
Persistent, inconsolable crying, especially when the affected area is touched or moved.
Swelling, bruising, or redness around the injury site.
Refusal to move a limb.
The affected body part appearing deformed or bent at an unnatural angle.
A snapping sound heard at the time of injury.
Seek immediate medical evaluation if a fracture is suspected, even if minor. If there is obvious limb deformity or severe pain, an emergency room visit is recommended. For an open fracture (bone protruding through skin) or suspected head, neck, or back injury, call emergency services immediately and do not move the baby. While waiting, gently support the injured area to prevent unnecessary movement, using cushions or clothing to stabilize the limb. Do not attempt to straighten or change the position of a suspected broken bone, as this could worsen the injury.
Care and Healing for Infant Fractures
Treatment for infant fractures typically involves immobilizing the injured bone to allow proper healing. Common methods include casts, splints, or slings. Splints are often applied initially to accommodate swelling; once swelling subsides, a full cast may be used. Duration varies by fracture location and severity, but infant bones generally heal quickly due to rapid growth and robust healing capacity.
Infant bones have a superior ability to remodel, correcting misalignment as they grow and reshaping the bone to its normal form. This remodeling potential is a significant advantage in pediatric fracture healing. While some fractures may heal in as few as three weeks, others can take several months. Pediatric orthopedic specialists are often involved, as their expertise addresses unique aspects of growing bones, including protecting growth plates. Following medical advice regarding cast care, activity restrictions, and follow-up appointments is essential for proper healing and preventing complications.