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Anatomy and Physiology of Pediatric Bone
CLINICAL PEARLS AND PITFALLS
During periods of growth, the regions of the pediatric skeleton
undergoing rapid metabolic activity are more susceptible to fracture.
Fracture remodeling in pediatric patients is robust and allows for more
acceptable angulation at the time of casting, and less frequent
operative repair than adult fractures.
Current Evidence
Unique elements of the bony architecture in children include a thick and active
periosteum, a physis (growth plate), and an epiphysis (secondary ossification
center) ( Fig. 111.1 ). Structurally, the bones of a child are much more porous and
pliable than those of an adult. As a result, overall bony strength is less, and the
incidence of fractures is greater in children than in adults. Moreover, ligaments
have greater strength than the physes; thus, a child is more likely to suffer a
fracture from an injury that, in a skeletally mature individual, would result in a
sprain, ligamentous injury, or dislocation.
Unlike in adults, remodeling and anatomic fracture union for pediatric fractures
is the expectation rather than the exception. In general, significant remodeling can
be anticipated both in younger children and when the fracture occurs in the
metaphysis of growing bones. The greatest degree of remodeling is anticipated
with bony injuries occurring in the plane of motion of the adjacent joint. In
contrast, the injuries least likely to correct without intervention include those that
occur in the diaphysis of long bones in adolescents, those with bowing greater
than 10 degrees, and fractures with rotational malalignment. In general, the goal
is to obtain as near an anatomic reduction of the fracture fragments as possible in
all age groups and not to rely on remodeling to align angulated fractures;
however, relative guidelines for acceptable angulation by age are provided.

Physeal Fractures
Salter–Harris type I injuries are frequently diagnosed clinically by point
tenderness at the physis and may not be evident radiographically.

Selective use of radiographs of the contralateral extremity may help with
diagnosing physeal injury.
An important complication of physeal fractures is growth disturbance, which
may result in angular deformity, limb length discrepancy, and/or epiphyseal