A stress fracture is a crack in a bone that is caused by excessive or abnormal stress or load. If left untreated, this initial crack can progress and eventually fracture all the way through the bone. The bones can also knit together in poor alignment resulting in lumps and bumps or oddly positioned joints as a result.
A stress fracture can occur in any bone. Within the foot, the most common stress fractures occur within the metatarsal bones as shown on the image, and the navicular bone.
What do stress fractures feel like?
Metatarsal stress fractures cause pain on the top or the sole of the foot local to the affected bone. There may also be swelling and tenderness over the fracture site. The pain can be dull or sharp, and may be constant or intermittent. Usually the pain will be worse during or after activity on your feet with activities such as walking, running, jumping or hopping.
What causes a stress fracture?
Often people who have a stress fracture cannot remember any particular injury or event which caused their foot pain. This is because it is due to prolonged load over a period of time.
Some factors that can contribute to the development of a stress fracture include:
Anything that places excessive or abnormal stress on the metatarsal bones. This may be due to underlying foot deformities (eg, bunions), poor foot biomechanics (eg, flat feet) or obesity.
An increase in activity levels, particularly if this occurs suddenly or without proper conditioning.
Running on hard or uneven terrain, especially if running long distances.
Unstable or poorly cushioned shoes.
Conditions that cause decreased bone density (eg, osteoporosis, hormonal changes) can make bones more susceptible to stress fractures.
How is a stress fracture treated?
Stress fractures are diagnosed by x-ray, however not all stress fractures will be visible on x-ray at the start. If a stress fracture is suspected following examination by a podiatrist, treatment will usually involve immobilising the foot to allow the bone fracture to heal with an x-ray in the upcoming weeks.
A moon boot may be recommended to allow your foot to rest while still enabling you to weight bear on the foot. Treatment will also include advice on gentle exercises to avoid developing stiffness in your joints after your foot has been immobilised. Depending on your situation, orthotics may be recommended to improve biomechanics of the foot and reduce pressure on the injured bone. Advice on appropriate footwear is critical for the prevention of stress fractures. At times, crutches will be recommended to take weight off the foot.
If a stress fracture does not respond well to conservative management then surgical intervention may be sought. Your Podiatrist will refer you to an Orthopaedic Specialist for further management.
It is important to take steps to prevent a future recurrence . Activity modification and load management are crucial for recovery and long term prevention of further stress injuries.