A metatarsal stress fracture is a fracture of the long bones of the foot, between the toes and the heel. It is the most common of all foot injuries caused by trauma, and typically begins as a small crack in the outer shell of one of the five metatarsal bones. These bones aid in balancing, propelling and supporting the body. Left untreated, the initial crack can progress into a fracture which travels all the way through the bone, resulting in serious pain and immobility.
Metatarsal stress fractures were originally termed march fractures, because they were common amongst soldiers in the early 19th century. Today, they occur most frequently in professional athletes, and are second only to the incidence of tibial fractures. A metatarsal stress fracture is caused by direct trauma or repetitive stress to the foot, such as while jumping, dancing, marching or running. Improper footwear, a rapid increase in activity, weak muscles, and low bone density can all contribute to the development of a metatarsal stress fracture.
Overactivity without rest is also a cause of stress fractures in the metatarsal bones. The bones in the human body are continuously breaking down and rebuilding, and repair themselves naturally during rest periods. When there is high-impact activity or unusual stress to the bones without rest, the body is sometimes unable to keep up with the rebuilding process. This results in a stress fracture, or several small cracks in the bone.
Symptoms of a metatarsal stress fracture include gradually increasing pain on the top of the foot, which may be accompanied by swelling or bruising. In the beginning, the pain is felt only after sports or activity. Over time, the pain will become severe and felt during daily activities, or when no stress is placed upon the foot at all. In many instances, the sufferer will have no memory of sustaining an injury, as the pain is not usually felt at the time of impact.
Diagnosis of stress fractures requires an examination of the foot, and a review of the symptoms. An X-ray may be performed, but is not always an accurate tool for diagnosis. If the X-ray reveals no fracture, but the symptoms are indicative of metatarsal stress, a bone scan may be used to confirm the diagnosis.
Treatment of a metatarsal stress fracture includes at least three weeks of rest from activity, and if pain is severe, crutches or a special walking boot may be prescribed for performing daily activities. After the initial rest period, a gradual return to normal activity over the course of two to four weeks is expected. In some cases, physical therapy, special foot inserts or calcium supplements may be required to expedite healing. Surgery is rarely necessary, but may be required in extreme cases.