Section 5. Bone, Joint, and Muscle Disorders

Chapter 75. Sports Injuries

Topics: Introduction | Stress Fractures of the Foot | Shin Splints | Popliteus Tendinitis | Achilles Tendinitis | Runner's Knee | Hamstring Injury | Lateral Epicondylitis | Medial Epicondylitis | Rotator Cuff Tendinitis

Stress Fractures of the Foot

Stress fractures are small cracks in bones that often develop from chronic, excessive impact, bending, or twisting.

In runners, the bones of the midfoot (metatarsals) are especially prone to stress fractures. The bones most likely to fracture are the metatarsal bones that connect to the middle three toes. The metatarsal bone of the big toe is relatively immune to injury because of its strength and larger size, and the metatarsal bone of the little toe is usually protected because the greatest force from pushing off (toeing off) is exerted on the big toe and the toe next to it. However, when a stress fracture does affect the big or little toe, healing usually takes longer than with the other toes; the person may need to be immobile for a long time or may need surgery.

See the figure What Is a Stress Fracture?

Risk factors for stress fractures in the foot include high arches, running shoes with inadequate shock absorption, and a sudden increase in the intensity or amount of exercise. People with narrow, thin bones are at an increased risk because these bones are not as strong. Postmenopausal women may be particularly susceptible to stress fractures because of osteoporosis (see Section 5, Chapter 60). Younger women athletes may also be susceptible to stress fractures, because the extreme exercise may suppress their ovaries, stop them from having periods, and cause osteoporosis.

The primary symptom is pain in the front part of the foot, usually during a long or intense workout. At first, the pain disappears within minutes of stopping exercise. If workouts are continued, however, the pain returns earlier in the workout and lasts longer after stopping exercise. Ultimately, severe pain may make running impossible, and pain may persist even during rest. The area around the fracture may swell.

A doctor can often make the diagnosis from a history of the symptoms and an examination of the foot. The fracture site hurts when touched. Stress fractures are so fine that they often cannot be seen on x-rays immediately, but doctors can use x-rays to detect the tissue (callus) that forms around the broken bone 2 or 3 weeks after the injury, as the bone heals. A bone scan can confirm the diagnosis earlier but is rarely needed.

Treatment requires that a person not run until the stress fracture has healed, but other exercises can be substituted. After the fracture has healed, wearing athletic shoes with adequate shock-absorbing support and running on grass or other soft surfaces can help prevent a recurrence. A cast is rarely needed. When used, it is removed after 3 weeks to prevent the muscles from becoming weak. Healing generally takes 3 to 12 weeks but may take longer in older people or in people who are bedridden. The smallest toe often takes a long time to heal and sometimes requires surgery.