Recognizing a Stress Fracture Can Be a Challenge

Recognizing Stress Fractures Can Be a Challenge

Stress fracture. Fatigue fracture. Bone strain. March fracture. All are names used to describe the epitome of an overuse injury: a tiny break in a bone.

While stress fractures typically plague runners, this painful condition also afflicts dancers and such athletes as volleyball, basketball and football players because of the bone-jarring motion associated with each sport. Stress fractures most commonly occur in the lower leg, with the shinbone suffering the greatest number. Specific sports tend to cause site-specific stress fractures. In runners, fractures tend to occur on the shin near the ankle, while volleyball and basketball players experience fractures near the knee. Stress fractures in the foot are more common in dancers and football players.

How Stress Fractures Happen
Bone is a dynamic, living tissue. Under normal conditions, bone repairs itself and adapts to stress. When stress increases to the point that bone cannot repair micro-fractures as fast as they occur, bone integrity is compromised. When activity stresses bone without adequate rest, the bone can weaken or eventually fracture.

According to some sports medicine experts, stress fractures occur when an athlete or coach fails to increase training volumes or intensity safely. In theory, if bone is allowed to adapt to stress, strengthening, not weakening, should occur. In reality, research indicates stress fractures occur for many reasons. Some athletes' anatomy predispose them to stress fractures. Environmental factors, such as running surface, footwear and diet play a role. Many athletes who experience a fracture report a one to two month increase in training intensity, frequency and duration. Some report a change in training surface or equipment. Gender is important too. Female athletes are at increased fracture risk because of the impact of diet and hormones on normal bone growth. In a study of 240 collegiate female track athletes, 49 percent of women with five or less menstrual cycles annually experienced a stress fracture (Clement, DB. American Journal of Sports Medicine, 1974).

Symptoms and Diagnosis
Stress fractures often begin with pain after activity, characterized by a tender spot in the affected area accompanied by swelling, redness and a thickening beneath the skin. The pain subsides with rest and the athlete continues his or her sport. Without treatment however, the pain soon becomes constant, leading athletes to stop activity voluntarily and seek medical advice.

Unfortunately, stress fractures are difficult to detect on X-ray. As a result, the time to diagnosis averages about 13 weeks. Bone scans are more sensitive and are considered the “gold standard” for diagnosis. Magnetic resonance (MR) imaging also offers an excellent diagnostic tool.

Treatment
Once diagnosed, treatment for a fracture can take up to eight weeks and occurs in two phases. Phase one includes modified rest and cross training activities that rest the injured bone yet maintain cardiovascular fitness. Medication and ice help to reduce pain. Stretching and bracing the affected area also helps to promote healing. In phase two, clinicians address biomechanical, environmental and other predisposing factors that may have contributed to the fracture. Foot orthotics, proper nutrition, eating disorders and gradual “reintroduction” to activity are among the interventions that occur in phase two.

Health care providers carefully monitor athletes once they return to play. If pain returns, the athlete must stop activity for one to two weeks. Some stress fractures don’t heal well, particularly those located in the toes or mid-shin. In rare cases, electrical stimulation or bone grafting become necessary.

Because stress fractures are a common overuse injury in athletes, it's important for health professionals and athletes alike to know the signs of stress fracture, and to practice well-known injury prevention strategies that include adequate rest and diet, appropriate footwear and cross-training.

For more information about stress fractures, call the Minnesota Sports Medicine at 612-273-4800.