Fractures de contraintes Fractures de fatigue Fractures par insuffisance osseuse

Stress fractures are common lesions that occur without trauma neither focal abnormality. They include fatigue fractures which are caused by the application of abnormal stress or torque to a bone that has normal resistance, and insufficiency fractures which occur when normal activity stresses a bone that is deficient in resistance. Such fractures seem to occur more frequently, this being due to both increased sport participation and improved identification by imaging techniques. Following a review of the pathophysiology, aetiology and clinical features, imaging features are presented: bone scintigraphy, radiography, computed tomography, magnetic resonance imaging (MRI) and ultrasound; the findings are presented according to bone shape and to the site of the fracture. Diagnosis of stress fractures is based on the patient's history of physical activity, early abnormalities on the bone scintigraphy and delay on x-ray features. Earlier diagnosis may be done by performing CT scanning and MRI since these techniques are able to detect a fracture even in difficult cases.