MedPix 2.0 Atlas

Stress fractures are classified into either fatigue or insufficiency type fractures. Fatigue type fractures result from the application of unusual force/torque onto a normal bone, this is common among athletes (especially long distance runners or ballet dancers) or in military members (especially recruits in basic training or undergoing parachute training). Insufficiency type fractures results from the application of normal stress on an abnormal bone. The underlying abnormality of the bone arises from a diverse array of causes, including osteoporosis, Paget's disease, osteomalacia, hyperparathyroidism, renal osteodystrophy, rheumatoid arthritis, fibrous dysplasia, irradiation, and so forth. Clinically the patient complains of activity-related pain that is relieved by rest. There also may be a localized soft tissue swelling or tenderness, though the specific site and activity being engaged in influences these variables. The most common site of fatigue-type stress fractues is the metatarsals (march fracture) with the second most frequent location being the calcaneus. These calcaneal stress fractures are usually found with a vertical or oblique orientation in the posterior or posterosuperior portion of calcaneus. Radiographs are often normal initially though MR and bone scan offer increased sensitivity and can be used with a high index of clinical suspsion even if the plain radiograph is normal.