Stress fractures, also known as hairline fractures, are quite common in the feet and ankles of athletes and people who engage in repetitive movements or spend a lot of time standing since many stress fractures are overuse injuries. They occur over time when repetitive forces result in microscopic damage to the bone. The repetitive force that causes a stress fracture is not great enough to cause an acute fracture — such as a broken ankle caused by a fall.
Stress fractures can be difficult to identify. Diagnosis is typically confirmed with imaging scans such as an X-ray or MRI. However, they do come with a few symptoms that should prompt a trip to the doctor’s office.
What is a Stress Fracture?
A stress fracture is a type of bone break or crack in the bone that occur when a small or moderate amount of force is applied to a bone repeatedly and over time. It differs from a typical broken bone caused by a sudden injury in that a stress fracture develops in response to chronic stress on the bone.
Stress fractures are common in foot and ankle bones because we continually place force on them by standing, walking, running and jumping. In a stress fracture, the bone breaks but usually does not shift position (become “displaced”).
Runners have a higher than average risk of tibial stress fractures, and activities that involve a lot of stress on the forefoot, such as dancing or track and field, bring an increased risk of stress fractures of the metatarsals or navicular bone of the foot.
The forces that cause a stress fracture in the foot or ankle are similar to those when you bend a paper clip. If you gently bend a paper clip once, it will not break. However, continually bending it back and forth, the metal will weaken and eventually break.
Which Bones Are Affected By a Stress Fracture?
Stress fractures occur most often in the second and third metatarsals in the foot, which are thinner (and often longer) than the adjacent first metatarsal. This is the area of greatest impact on your foot as you push off when you walk or run.
Stress fractures are also common in the calcaneus (heel); fibula (the outer bone of the lower leg and ankle); talus (a small bone in the ankle joint); and the navicular (a bone on the top of the midfoot).
The most commonly affected bones are:
- The metatarsals, which connect the toes to the midfoot.
- The calcaneus (heel bone).
- The navicular, a bone near the ankle. Navicular stress fractures take a long time to heal.
- The bones that make up the ankle joint – particularly the tibia and fibula.
Causes
The foot and ankle are the most common parts of the body to experience a stress fracture because we are on our feet much of every day. Typically, stress fractures are caused by high-impact activities like exercise and sports. Although it is not as common, stress fractures can happen to those who are not involved in high-intensity workouts or sports, particularly if they are suffering from osteoporosis or other bone diseases. Shoes that provide poor support, such as high heels – which place a lot of pressure on the toes – as well as old, stiff shoes can also put a person at risk.
Athletes who participate in sports such as running, basketball, tennis, gymnastics and dance are usually at a higher risk for foot and ankle stress fractures because of repetitive stress placed on their feet and ankles. A lack of conditioning, proper equipment or technique can also disrupt the mechanics of the foot and ankle and result in a stress fracture.
Finally, people with foot deformities that change their load bearing can develop stress fractures. For example, in a foot with a bunion, the big toe may be repositioned such that stops supporting the weight it should normally should bear. This places more load force on the other toes, which can lead to a stress fracture in one or more of them. In such cases, the second toe (next to the big toe) is the most likely to fracture.
Risk Factors
Stress fractures are most often associated with athletic activity, but other factors increase the risk as well. Any condition that causes a decreased bone mass will increase the risk of a stress fracture, including:
- Abnormalities of foot structure or foot biomechanics, such as a high-arched or flat foot
- Post-menopausal women and women who have irregular menstrual cycles, resulting in amenorrhea
- Medications such as corticosteroids and DMPA (Depo-Provera)
- Tobacco use
- Moderate to heavy alcohol use
- Lower body mass
- Inadequate levels of calcium and vitamin D
Symptoms and Diagnosis
The key symptom of a stress fracture is pain that is brought on or made worse with weight-bearing activity. Pain may also be felt with direct pressure on the bone. If left untreated, the pain will usually worsen, and continued stress on the bone could cause a hairline fracture to develop into a more unstable fracture.
Depending on the bone affected, it tends to hurt in very specific, pinpoint areas, and it will hurt when you touch the exact area where the bone is broken. Recent changes or increased activity in conjunction with pain in a specific area of the foot or ankle might indicate the presence of a stress fracture. The pain usually becomes more intense when performing impact activities and gets better during periods of rest.
A stress fracture that is developing may not always show up on an X-ray, which can make diagnosis difficult. It is not uncommon for initial X-rays of bone to show no fracture, while a follow-up X-ray will reveal that a stress fracture has in fact occurred. If you think you may have a stress fracture in your foot or ankle, the most important thing to do is to immediately stop all activities that cause pain. If an untreated stress fracture worsens, the pain will be felt more quickly during activity that puts stress on the affected bones than when the stress fracture first appeared.
If your pain continues after several days of rest or if your pain goes away but then returns even after several weeks of rest, you should see an orthopedic foot and ankle surgeon.
Treatment
Most stress fractures will heal on their own if you reduce your level of activity and wear protective footwear for a period of time. Treatment for a suspected or confirmed stress fracture will involve rest or a change in athletic activity that’s sufficient enough to allow for healing. Immobilization in a walking cast or hard-soled shoe may be prescribed for a few weeks, depending on the degree of fracture and symptoms.
Icing and elevating the affected leg immediately following a stress fracture can help decrease swelling and pain. Pain management can include acetaminophen (Tylenol) instead of nonsteroidal anti-inflammatory drugs (NSAIDs), which includes ibuprofen (Advil) and naproxen (Aleve). This is because some data suggests that taking NSAIDs can reduce the ability of bone to heal.
Your orthopedist may also recommend wearing a stiff-soled shoe, a wooden-soled sandal, or a removable “walking boot,” also known as a short leg-fracture brace shoe.
Some stress fractures require surgery to heal properly. In most cases, this involves supporting the bones by inserting a type of fastener. This is called internal fixation. Pins, screws, and/or plates are most often used to hold the small bones of the foot and ankle together during the healing process.
Recovery
In most cases, it takes from 6 to 8 weeks for a stress fracture to heal. More serious stress fractures can take longer, depending on which bone is broken. Some foot bones, such as the navicular or the fifth metatarsal, can take a much longer time to heal than do others.
Once your pain has subsided, your doctor may confirm that the stress fracture has healed by taking x-rays. A computed tomography (CT) scan can also be useful in determining healing, especially in bones where the fracture line was initially hard to see.
After weeks of rest, and once the pain is completely gone, you may gradually ease back into physical activity and sports. You may want to switch to a sport that puts less stress on the foot and leg, such as swimming or cycling, until you have fully recovered. The worst choices for resumed activity while you recover from a foot or ankle stress fracture are running or even walking on hard surfaces. Do not do too much too soon.
During recovery, wear comfortable, supportive shoes without a raised heel. Footwear should be flexible, not stiff.
Prevention
The following principles can help you lead a healthy lifestyle and avoid problems with stress fractures:
- Eat calcium-rich foods and ensure you get enough daily Vitamin D to help maintain bone density.
- Wear good shoes that are comfortable, well-padded and supportive. It is usually a good idea to wear shoes made specifically for the sport you would like to do. Avoid high heels whenever possible.
- Do not smoke as this can lead to problems with healing. Keep in mind that the nicotine is what creates the problem, so other gum and products containing nicotine will still prevent the bone from healing.
- Alternate activities. For example, switch between jogging, swimming or cycling during the week to minimize the risk of repetitive activity injuries.
- Slowly ease into new activities. Gradually increase the time, speed and distance.
Ask Your Doctor
A fracture can be painful and can lead to significant functional loss and disability. Depending on the severity of the injury, the loss may be temporary or permanent. Working to gain mobility and strength after a fracture should be your main goal after a fracture. Physical therapy can help you return to optimum functional mobility as quickly as possible.
To learn more about bone health or to schedule an appointment with one of our specialists, call us at 800-698-1280.
