Stress Fractures

STRESS, fatigue, boot, cough, and march fractures are some of the more common synonyms for a particular type of fracture which occurs in individuals with seemingly normal form and structure of bone, but an apparent susceptibility to development of fractures under conditions of unaccustomed stress and physical activity. Stress fractures are relatively infrequent in average radiological practice. The usual roentgen appearance offers no special diagnostic challenge, but of particular concern is the fact that certain of the clinical and radiographic features of stress fractures may on occasion mimic malignant bone tumors (5). The large military training facility affords a most unique opportunity to definitively study this problem. This is due to the large number of reasonably healthy young males sub jected to vigorous training conditions, which for most participants fulfill the criteria for unaccustomed physical activity. This report concerns our analysis of 250 fatigue fractures of bone encountered in 219 patients over an arbitrary ten-month period at one of the largest troop-training centers within the United States. All patients studied were otherwise healthy young males without underlying abnormality of bone, and serial roentgenograms were available for analysis in all cases. Clinical Findings In our selected population of military trainees, the onset of clinical findings was generally during the first two weeks of basic training, frequently occurring during the first several days. In those patients suitable for retrospective study of originally negative roentgenograms, symptoms preceded the onset of positive radiographic findings by from one to several weeks. The most common presenting symptom was pain, which was usually described initially as an aching or soreness. However, the pain and discomfort invariably became progressively more intense with the passage of time. Although a few patients felt that light activity alleviated their symptoms, the consensus was that more intense physical activity aggravated pain and discomfort. Positive physical findings included localized tenderness, swelling, and discoloration. A limping gait was invariably present when the stress fracture occurred in the lower extremity. A frequent finding later in the course of healing of metatarsal stress fractures was the presence of a palpable mass, due to the formation of exuberant callus. Radiographic Findings Retrospective analysis of these 250 stress fractures suggested to us that the initial roentgen features could be categorized into one of four basic patterns. The dominant pattern depended not only upon the bone involved, but also upon the period in the evolution of the process when roentgenograms were first obtained. These four patterns were: TYPE I: Fracture line only demonstrable, with no evidence of endosteal callus or periosteal reaction