Metatarsal Stress Fracture
Description
A metatarsal stress fracture is a complete or incomplete break in the foot involving one or more of the longer foot bones (metatarsals), and is caused by intense exercise or repetitive pressure on the extremity. The wear and injury in the bone exceeds the bone's ability to heal and repair the injury, resulting in a breakdown of the bone, causing a stress or fatigue fracture. This is the second most common bone to sustain a stress fracture in athletes. It can occur anywhere within the metatarsal, although it most commonly affects the lower third of the second metatarsal (next to the big toe's metatarsal).
Common Signs and Symptoms
- Vague, diffuse pain or ache and occasionally tenderness and swelling in the foot
- Uncommonly, bleeding and bruising in the foot
- Weakness and inability to bear weight on the injured extremity
- Paleness and deformity (sometimes)
Causes
Stress fractures are caused by repetitive forces greater than the bone can withstand. They usually occur when there is an imbalance between bone injury and bone remodeling (healing). This usually follows a change in training or performance schedule, equipment, or intensity. It is also associated with a bone's ability to heal and may be associated with loss of menstrual period in women.
Risk Increases With:
- Previous stress fracture
- Military recruits and distance runners
- Bony abnormalities (including osteoporosis and tumors)
- Metabolic disorders, hormone problems, and nutritional deficiencies and disorders (such as anorexia or bulimia)
- Women, especially when there is loss of or irregular menstrual periods
- Poor physical conditioning (strength and flexibility)
- Sudden increase in the duration, intensity, or frequency of physical activity
- Running on hard surfaces
- Poor extremity alignment, including flat feet
- Inadequate footwear with poor shock-absorbing capacity
Preventive Measures
- Appropriately warm up and stretch before practice or competition
- Maintain appropriate conditioning:
- Muscle strength
- Endurance and flexibility
- Wear proper footwear; replace shoes after 300 to 500 miles of running
- Use proper technique with training and activity
- Gradually increase activity and training
- Treat hormonal disorder; birth control pills can be helpful for women with menstrual period irregularity
- Correct metabolic and nutritional disorders
- Wear cushioned arch supports for runners with flat feet
Expected Outcome
With appropriate treatment, this condition is usually curable within 6 to 12 weeks.
Possible Complications
- Failure to heal (nonunion), especially with stress fractures of the upper part of the fifth metatarsal (outer foot)
- Healing in a poor position (malunion)
- Recurrence of stress fracture
- Progression to complete and displaced fracture
- Risks of surgery, including infection, bleeding, injury to nerves (numbness, weakness, paralysis), and need for further surgery
- Repeated stress fracture, not necessarily at the same site (occurs in 1 of every 10 patients)
