Stress fractures

Stress fracture

Stress fractures are tiny cracks in a bone that occur from overuse or repetitive application of an outside force, such as your feet might experience if you repeatedly jump up and down or if you consistently run long distances. These fractures also can arise from normal use of a bone that's been weakened by a condition such as osteoporosis.

Stress fractures can occur in any bone, but they most often afflict the weight-bearing bones of your lower leg and foot. For athletes, stress fractures are among the most common injuries. Track and field athletes are particularly susceptible, with well over half of such injuries occurring in these athletes. Women athletes are particularly susceptible to stress fractures, and individuals with flat feet or high, rigid foot arches may also be at increased risk. But anyone can experience a stress fracture; for example, a nonathlete who's starting a new exercise program or taking a prolonged hike may be at risk if they do "too much too soon."

Your doctor might use an X-ray or bone scan to diagnose a stress fracture. At its simplest, treatment of a stress fracture involves icing the affected area and plenty of rest. More severe cases may require splinting or casting, and at times surgical insertion of a pin to help a bone heal.

Signs and symptoms

The most common signs and symptoms of stress fracture include:

bulletA dull ache following physical activity
bulletSwelling
bulletPain that decreases with rest and increases with activity
bulletPain that occurs earlier in your workout each successive workout
bulletPain that increases over time
bulletA spot that feels tender or painful when you apply pressure

A stress fracture may be barely noticeable at first — you may feel it only during longer, more intense workouts. Or, the pain you feel may simply be a precursor to fracture known as a stress reaction — a weakening of the bone at the cellular level. In either case, without proper self-care and treatment, the bone may continue to weaken and a crack or break could develop.

Stress fractures are sometimes mistaken for shinsplints, an inflammation along the inner shinbone that commonly afflicts runners. The two conditions may also exist at the same time, but stress fractures are more serious and require more restriction of activity to heal.

Causes

Stress fractures are caused by the repetitive application of force to your body. The fracture occurs when your muscles become tired and are no longer able to absorb shock. The overload of stress is then transferred to the underlying bone, which can partially or completely crack.

Two types of stress fractures may occur:

bulletFatigue fractures. A normal bone is subjected to overuse or repetitive stress beyond its fracture point, which causes it to crack.
bulletInsufficiency fractures. An abnormal bone — such as one deficient in minerals or weakened by osteoporosis — is subjected to relatively normal stresses, and then cracks.

The bones most often affected are the shinbone (tibia), the metatarsal bones (which run from the midfoot to the toes) and the tarsal bones (located at the top of the arch, heel and ankle). Fractures often occur during high-impact physical activity such as running and jumping, but they also can occur as a result of prolonged activities such as hiking or walking.

Risk factors

You may be at increased risk of stress fracture if you're:

bulletAn athlete who participates in high-impact sports such as track and field, basketball, tennis and gymnastics
bulletAn adolescent whose bones haven't yet fully hardened
bulletAn individual who has osteoporosis or other conditions that have weakened the bone or decreased bone density
bulletA person who suddenly shifts from a sedentary lifestyle to an active training regimen, such as a military recruit subjected to intense marching exercises
bulletA person with an underlying condition such as Paget's disease, diabetes and rheumatoid arthritis

When to seek medical advice

See your doctor promptly if you perceive any signs or symptoms of a stress fracture. The sooner the problem is diagnosed and treated, the quicker you can heal and eventually resume normal physical activity.

Screening and diagnosis

Your doctor may use a number of methods to diagnose a stress fracture. Initially, he or she will ask about your symptoms and any physical activity you have participated in, and check for swelling or tenderness.

Your doctor also may take an X-ray of the bone to identify the fracture, although in some cases a crack won't be visible in an X-ray until two to 12 weeks after the injury occurs. More commonly, advanced imaging techniques such as a bone scan or magnetic resonance imaging (MRI) are used to assess stress fractures. These methods can provide the image resolution needed to spot miniscule cracks in the bone.

Treatment

Self-care methods such as rest may be enough to heal a stress fracture. But in more severe cases a stress fracture may require treatment. Treatment may include:

bulletCrutches. You may have to reduce the weight-bearing load the bone experiences for a time to enable it to fully heal.
bulletIcing. Applying ice packs to the injured area as needed may help reduce swelling and relieve pain. Limit to 10 minutes each application for three to four times daily.
bulletPhysical therapy. Working with a physical therapist during later stages of healing may be beneficial. The therapist can help you balance a slow increase in activity from non-weight-bearing activities — such as water exercise — to partial-weight-bearing exercises to a gradual return to impact activities. They also may instruct you in lower leg strength and stability exercises and can assess the need for arch supports (foot orthotics), which fit into your shoes.
bulletAnti-inflammatory drugs. A low dose of nonsteroidal anti-inflammatory drugs can be used for pain relief as needed.
bulletSplinting. Immobilizing the affected bone with a splint or cast may reduce pain and healing time.
bulletInternal fixation. For more severe stress fractures, your doctor may surgically insert a pin into the bone to hold it together and promote proper healing.

Prevention

You can help avoid the onset of a stress fracture by:

bulletWarming up and stretching before physical activity.
bulletStarting any new exercise program slowly, and progressing gradually.
bulletAvoiding sudden changes in intensity or type of exercise. Stay away from the "terrible toos" — too much, too fast, too hard and too long.
bulletWearing cushioned insoles and footwear appropriate to your physical activity.
bulletCross-training, or alternating exercises to prevent overloading any one area with the same repetitive stress.
bulletConsidering medical evaluation for arch supports if you have flat or rigid feet or you're prone to overuse injuries in your feet, ankles or legs.