Metatarsal Stress Fracture
What is a stress fracture?
A stress fracture is a hairline crack in a bone. They are generally small and often do not extend all the way through the bone. A simple way to understand stress fractures is to think about a small branch or twig. If you bend that branch but don’t break it in half, then you will hear small cracks forming. They are there although you cannot see them. Bone stress fractures are very similar. They can take several weeks before becoming visible on an x-ray.
What causes a metatarsal stress fracture?
Stress fractures are an over-use injury. They develop slowly with repetitive load on a bone as opposed to a typical fracture that is caused by a sudden twisted or bending force on the bone. Metatarsal stress fractures in runners are the result of the repeated load applied to the foot. Typically, stress fractures start out as a “stress reaction” in the bone. This is only visible on an MRI. That stress reaction weakens the bone and continued load on the bone will cause a stress fracture to form. Some running forms are associated with higher loads in the tibia and thus stress fracture risk. This includes non-heal striking (forefoot strike or midfoot strike) and barefoot running. There is some evidence that minimalist shoes encourage a non-heal striking pattern and thus may increase the risk for metatarsal stress fractures. There are several factors affecting your running form, so caution must be exercised when relying on changes in your form or shoe gear in order to prevent stress fractures. Low bone mineral density, osteoporosis, and inadequate nutritional intake are risk factors for a stress fracture. Estrogen helps maintain bone health, so for women who are post-menopausal are at risk for stress fractures in general.
What are the symptoms of a metatarsal stress fracture?
Swelling and pain are the primary symptoms of a stress fracture. Pain is generally noticed with weight bearing, but often resolves with rest. Bruising is rare but can occur.
How is a metatarsal stress fracture diagnosed?
Clinical examination will reveal tenderness at the stress fracture site and swelling around that area. X-rays are generally taken, but as mentioned above, it can to 2 weeks or more before the stress fracture shows up on an x-ray. CT and MRI are often used when there the x-rays are negative.
How is a metatarsal stress fracture treated?
Treatment for a stress fracture must include rest. Without that, the bone will not heal and the fracture may worsen. Rest does not always include non-weight bearing, but rather a stop to running and other impact training. Ice is often helpful for the pain and inflammation. Non-steroidal anti-inflammatory medications (NSAIDs) can reduce pain and inflammation, but there is some evidence they may inhibit the normal bone healing process which includes inflammation. Unweighting the metatarsal head will reduce the bending force that created the stress fracture and help the injured bone to heal. A surgical boot or surgical shoe is often the best manner to unweight this bone.
Can I continue to exercise with a metatarsal stress fracture?
The simple answer is yes, but it must not include loading the bone with the stress fracture. Consequently, cross-training becomes a staple of exercise for runners with a stress fracture. Deep water running is a simple way to keep the running muscles working but without the load of weight bearing. This is easy to accomplish with any type of floatation device to hold you up in a pool while your legs perform a running motion. Anti-gravity treadmills are available in some locations, but they tend to be expensive to use and hard to find. Upper extremity and core work will provide you with an opportunity to enhance the fitness and strength of areas often neglected with traditional running programs. In the end, always remember with every adversity comes opportunity.
When can I return to running?
The goal of rehabilitation is return you to running as soon as is safely possible. If you return to a full training load too soon, the injury may return or worsen. Everyone recovers from injury at a different rate, so don’t compare your rehabilitation to other runners. Returning to running is determined by how well your foot responds to treatment rather than a set number of days or weeks. In general, stress fractures take 3-6 weeks to heal. Here are some general guidelines for a full return to running.
- An x-ray, MRI, or CT should demonstrate a healed fracture
- Your fracture site should not be swollen or painful.
- You should be able to walk without pain.
- You should be able to jog in a straight line without limping.
- You should be able to sprint without limping.
- You should be able to perform 45-degree and 90-degree cuts without difficulty.
- You should be able to jump on the injured leg without pain.
What can be done to reduce the chances of developing a metatarsal stress fracture?
Stress fractures are an overuse injury and as such a proper training program is key to helping your body adapt to the training load. Too much, too fast, too frequent, and too often are the most common risk factors. Monitor and modulate your training to avoid these mistakes and you’re less likely to develop a stress fracture. Optimizing the biomechanics in the leg can reduce forces in the foot and improve your body’s ability to withstand the sudden injuries that lead to a stress fracture. This involves consistent focus on strength and flexibility of the hips, legs, ankles, and feet. Finally, there is evidence that some running form changes and shoe changes can reduce the load in the tibia that causes the stress fracture. However, these changes should be adopted after optimizing your biomechanics (strength, flexibility, anatomy, and alignment).
This information is not intended to diagnose, treat, or prevent any injury or disease. It is intended to serve as an overview of running-related injuries and should not be used as a substitute for sound medical advice from a doctor or therapist.
