Current Concepts Regarding Athletic Stress Fractures and Low Bone Density

f all the overuse injuries seen in athletes, stress fractures are among the most perplexing to diagnose and treat. Stress fractures range from the mildly symptomatic athlete with normal x-rays and a positive bone scan (stress reaction) to the relatively acute painful injury with an obvious fracture through an area of remodeling bone. In this article I hope to clear up some of the misconceptions about stress fractures and will explore the risk factor of abnormally low bone density. Much of the early literature on stress fractures came from military boot camps, where relatively unconditioned recruits were exposed to u n a c c u s temporary restriction from painful activity until healing is documented. Nondisplaced stress fractures of the fifth metatarsal or femoral neck sometimes require surgery to promote healing within a time frame that is acceptable for the competitive athlete. Any delay in diagnosis of a stress fracture may result in its progression to a complete fracture. Fractures that are allowed to progress and displace almost always require surgical stabilization with plates, screws, or intramedullary rods. Stress fracture of the femoral neck generally has a poor prognosis, particularly in cases requiring surgery after displacement of the undiagnosed fracture. Female athtomed repetitive stresses (Gilbert &Johnson, 1966). The majority of these "march fractures" occurred in the feet (metatarsaIs and calcaneus) , and it has been suggested that heavy military boots were responsible for many of the injuries. The more recent literature (Matheson et al., 1987)shows that the tibia accounts for about half of the stress fractures seen in athletes. Most stress fractures are innocuous injuries that require only letes are more susceptible to certain acute injuries and stress fractures than male athletes in equivalent sports. A large study by Rice (1993) has shown that girls' cross-country has the highest injury rate of any organized high school sport, surpassing even boys' football and wrestling. Most of the injuries seen in female endurance athletes are overuse injuries and stress fractures. The so-called Female Athlete Triad of amenorrhea, eating disorders, and osteoporosis has been increasingly implicated in this high injury rate. Low bone density is now well recognized as a risk factor for development of stress fractures.