What is a stress fracture?
A stress fracture is a fracture or crack in the bone. Stress fractures occur when small or moderate amounts of force are applied to the bone repeatedly and over time. This differs from traumatic fractures, where large amounts of force are applied suddenly, such as in the case of a severe ankle sprain, which can lead to an acute ankle fracture, or in a car crash, when the bones in the foot can be damaged or crushed).
Stress fractures are common in the bones of the foot and ankle because we constantly put stress on them by standing, walking, running, and jumping. In a stress fracture, the bone breaks but usually doesn't move ("displace").
The force that causes a stress fracture in the foot or ankle is similar to bending a paper clip. If you bend the paper clip lightly once, it won't snap. However, if you keep bending it back and forth many times, the metal will weaken (or "fatigue") and eventually break. Bones subjected to repetitive forces experience a similar type of fatigue, called a "stress response." This increases the risk of the bone eventually breaking, i.e. suffering a stress fracture.
Causes of Foot and Ankle Stress Fractures
Stress fractures usually occur in one of two ways:
People with healthy bones overuse their feet and ankles through frequent, repetitive movements. This is especially true of athletes who participate in high-intensity sports, such as track and field, soccer, basketball, soccer, tennis, gymnastics or cheerleading.
Foot stress fractures can occur in people with very weak bones due to a separate underlying disease, such as osteoporosis, even during fairly low-impact activities such as frequent walking. This type of stress fracture is called a "deficiency fracture" because it occurs in bone that doesn't have "enough" density or strength to withstand the normal force of impact. Insufficiency fractures can sometimes affect young, healthy women who exercise excessively because this activity can lead to irregular or absent menstrual cycles, which in turn affects bone strength.
The feet and ankles are the most prone to stress fractures in the body because we are constantly standing. Stress fractures of the foot and ankle usually occur in people starting a new activity that involves any impact of the foot on the ground, such as hiking or running. Stress fractures can also occur in people who rapidly increase a certain amount of activity. For example, people who typically run for 30 minutes twice a week and then suddenly start running 7 days a week for 1 hour each have an increased risk of stress fractures.
Shoes that provide poor support, such as high heels -- which can put a lot of pressure on the toes -- and old, stiff shoes can put people at risk. Finally, people with foot deformities that alter their ability to carry weight may develop stress fractures. For example, in a foot with a bunion, the big toe may reposition so that it stops supporting the weight it normally should. This puts a higher load on the other toes, which can lead to a stress fracture in one or more of the toes. In this case, the second toe (next to the big toe) is most likely to fracture.
Which bones in the foot and ankle are affected by stress fractures?
Stress fractures can occur in any bone in the lower leg, ankle, and foot. The most commonly affected bones are:
Metatarsal, connecting the toes and the midfoot.
- The calcaneus (calcaneus).
- navicular, a bone near the ankle. Navicular stress fractures take a long time to heal.
- The bones that make up the ankle joint—especially the tibia and fibula.
What are the symptoms of a foot and ankle stress fracture?
The main symptom of a stress fracture is pain. Depending on the bone affected, it tends to hurt in very specific, precise areas, when you touch the exact area of the fracture.
If you have recently changed or increased your activity and feel pain in a specific area of your foot or ankle, you may have a stress fracture. The pain usually gets stronger when you engage in impact activity and gets better with rest.
If you think you may have a stress fracture in your foot or ankle, the most important thing is to immediately stop all activities that cause pain. If an untreated stress fracture worsens (gets bigger), you will start to feel pain sooner during activities that put pressure on the affected bone than when the stress fracture first appeared.
If your pain persists after a few days of rest, or if your pain goes away but returns even after a few weeks of rest, you should see an orthopaedic foot and ankle surgeon (also called an "orthopaedic surgeon" or "orthopaedic surgeon") .
How are stress fractures diagnosed?
Your doctor will start by asking you questions about your pain and activity levels to assess your risk factors above.
Next, he or she will examine you and order X-rays for the area where you are in pain. When a stress fracture is present, it is actually not uncommon for an X-ray to look normal and not show a broken bone. This is because sometimes the bone reacts and grows new bone to heal the crack. (However, injured bones can still be easily re-broken.) When new bone grows, the final step is calcification. A radiologist or orthopedist usually confirms the diagnosis of a stress fracture by seeing calcification of new bone growth on an X-ray.
In some cases, your doctor may order a bone scan or MRI to provide more information than a standard X-ray. However, these more expensive tests are usually not needed to diagnose stress fractures.
How do you treat a stress fracture?
Most stress fractures heal on their own if you reduce your activity and wear protective footwear for a while. As mentioned above, if you have or think you may have a stress fracture in your foot or ankle, the most important thing is to stop the activity that is causing your problem in the first place. You should stop all high-impact activities for a period of time, usually about six weeks.
Ice and elevating the affected leg immediately after a stress fracture can help reduce swelling and pain. As for pain, it's best to take acetaminophen (Tylenol) rather than nonsteroidal anti-inflammatory drugs (NSAIDs), which include ibuprofen (Advil) and naproxen (Aleve). This is because some data suggest that taking NSAIDs reduces the ability of bones to heal.
Your orthopaedic surgeon may recommend hard-soled shoes, clog-soled sandals, or removable "walking boots," also known as short-leg fracture support shoes.
Related reading: Ankle fracture diagnosis, treatment, surgery and rehabilitation
How long does it take for a stress fracture to heal?
Many stress fractures of the foot or ankle develop a heel within 4 to 6 weeks. However, healing time will vary, depending on the broken bone. Some foot bones, such as the navicular or fifth metatarsal, may take longer to heal than others.
After a few weeks of rest, you may gradually return to physical activity and exercise once the pain is completely gone. This period of gradual reintroduction should span approximately 4 to 6 weeks. Switch to exercises that put less pressure on your feet and legs until you are fully recovered. Examples of appropriate low-impact activities include:
- Cycling (cycling or spin lessons)
When you're recovering from a foot or ankle stress fracture, your worst option for returning to activity is running or even walking on a hard surface. You can easily reopen the fracture and have to start the recovery process again.
During recovery, wear comfortable, supportive shoes and don't raise your heels. Footwear should be elastic, not rigid. If you're a runner, start a conservative jogging regimen after you've resumed 4 to 6 weeks of low-intensity activity. Increase your running mileage very slowly over time. Don't do too much, too quickly.
Do I need surgery?
Surgery is rarely required and is usually recommended only after conservative nonsurgical approaches described above have failed.
Stress fracture prevention
The following principles can help you live a healthy lifestyle and avoid stress fracture problems:
- Eat calcium-rich foods and make sure you're getting enough vitamin D each day to help maintain bone density.
- Wear good shoes. Instead of wearing old or stiff shoes, try shoes that are comfortable, well padded and supportive. It's usually a good idea to wear shoes designed for the sport you want to do. Avoid wearing high heels as much as possible.
- do not smoke. This can cause healing problems. It's actually nicotine that's causing the problem, so other gums and products that contain nicotine can still prevent bones from healing.
- cross train. This means you should alternate between activities. For example, you can switch from jogging to swimming or cycling during the week.
- Slowly adjust to previous or new physical activity. Gradually increase time, speed and distance. Many experts recommend increasing exercise time by 10% each week.