Purpose or Case Report: Stress injuries occur when normal bone is subjected to chronic and repeated mechanical loading. Children are at particularly increased risk for these types of injuries compared to adults, due to weaker chondro-osseous junctions, increased physical activity, less muscle mass, narrower bones with thinner cortices, hormonal changes, and decreased mineral content of bones.

Pediatric stress injuries consist of physeal and apophyseal stress injuries and stress fractures. When the primary physes of the long bones sustain repetitive workloads, endochondral ossification is impeded, and unmineralized cartilage extends into the metaphysis. Such repetitive workloads also affect associated apophyses, leading to chondrocyte proliferation, hypertrophy, and inflammation. Stress fractures, also known as fatigue fractures, occur when bone remodeling is given insufficient time to repair “micro-trauma” damage and additional mechanical loading cycles enable damage to accumulate in the bone, ultimately leading to a fracture.

This educational exhibit will review the imaging findings associated with stress injuries of the axial and appendicular skeleton commonly seen in older children and adolescents. The exhibit will draw on case examples of children participating in a wide range of activities to illustrate the range of stress injuries in the pediatric population and their diagnostic findings, including cheerleading, dancing, baseball pitching, climbing, and even bowling and competitive yoga.
Methods & Materials: Case material was drawn from patients seen at a tertiary-care children's hospital with an active pediatric orthopedic service.
Results: Cases featured illustrate findings of stress injuries on various imaging modalities, including radiographs, computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine bone scan.
Conclusions: Prompt diagnosis of stress injuries is necessary in order to recommend timely cessation of activity and allow healing. The appearance of stress injuries, particularly on MR imaging, can mimic osteomyelitis or an aggressive neoplasm. Diagnosis based on clinical history is difficult in children, so imaging characteristics that reliably discern stress injuries from other causes with similar appearances can be very helpful in guiding management.