Pediatric Stress Fracture

Etiology:
— Application of repetitive microtrauma or chronic abnormal stress to normal bone
— Insufficiency fracture is stress fracture that occurs in weakened bone
Imaging Radiograph: May see marked cortical thickening in area of injury or periosteal new bone formation while thin fracture line through cortex appears later
Note: Difficult to identify on radiograph
Imaging MRI:
— More sensitive than radiograph
— Periosteal and marrow edema
— May show fracture line
DDX: Ewing sarcoma – absence of extra osseous soft tissue mass favors stress fracture over Ewing sarcoma
Complications:
Treatment:
Clinical: Occur most commonly in lower extremity in children – tibia, metatarsals, cuboid

Radiology Cases of Stress Fracture

Radiology Cases of Stress Fracture of Femur

Radiograph of stress fracture of the femur — AP and lateral radiographs of the femur show on the AP view a transverse non-displaced healing fracture through the distal femoral diaphysis that on the lateral view has periosteal reaction and marked cortical thickening along the posterior aspect of the femur.

Radiology Cases of Stress Fracture of Tibia

Radiograph of stress fracture of proximal tibia — AP (left) and lateral (right) radiographs of the tibia and fibula show a double density in the tibial metaphysis which has periosteal reaction associated with it medially and posteriorly.

Radiology Cases of Stress Fracture of Metatarsal

Radiograph of stress fracture — AP radiograph of the foot obtained at presentation (left) shows a mild amount of perisoteal reaction around the diaphysis of the second metatarsal that is much better seen on the repeat radiograph from 1 month later (right).

MRI of stress fracture of the fourth metatarsal — AP radiograph of the foot (above left) shows subtle cortical thickening in the diaphysis of the fourth metatarsal. Coronal (above center) and sagittal (above right) and axial (below) T2 MRI of the foot shows bright signal in the diaphysis of the fourth metatarsal.