Stress fractures : Current concepts of diagnosis and treatment

The stress fracture is a common injury seen by healthcare professionals caring for athletes. They have been described in numerous areas of the skeletal system and in multiple sports. However, they are most commonly seen in the lower extremities, with running the reported cause in most cases. Stress fractures result from repetitive, cyclic loading of bone which overwhelms the reparative ability of the skeletal system. Mechanically, three events may lead to stress fractures. First, the applied load can be increased. Secondly, the number of applied stresses can increase. Finally, the surface area over which the load is applied can be decreased. Diagnosis requires thorough clinical evaluation with a high index of suspicion for stress fractures. History must focus on examining the athletes training regimen, especially any changes in distance, running surface and type of shoe. Physical examination varies depending on the location of the stress fracture. Ultrasound is a possible adjunct to the physical examination. Initial plain radiological evaluation may be normal, especially early in the course of a stress fracture. Further radiological evaluation may be necessary to make a definitive diagnosis. Repeating plain radiographs, bone scintigraphy, magnetic resonance imaging and computerised tomography are all possible options. Treatment options begin with rest and cessation of the precipitating activity. This should be 'active rest' in which the athlete continues to exercise depending on the site of the fracture. The athlete should be evaluated from a biomechanical point of view and any abnormalities dealt with prior to rehabilitation. Possible adjuncts to treatment include pneumatic braces and electromagnetic field therapy. There are specific stress fractures that must be considered at-risk for complications of healing. The treatment of these fractures begins with immobilisation and may require surgery pending response to therapy. Stress fractures occur more frequently in female athletes in relation to their male counterparts. There is a demonstrated relationship to eating disorders, amenorrhea and osteoporosis, or the female athlete triad. Thus, stress fractures in the female athlete requires additional investigation into those areas. The diagnosis and treatment of stress fractures is a challenge for the physician caring for the athlete. It requires a high index of suspicion combined with a strong knowledge of the at-risk stress fractures and their complications.