A stress fracture is a break in the bone when repetitive forces are applied and overload the bone. They can occur in any bone, but more common on the bones that have weight bearing forces applied, as most bones of the lower extremities do. The most common bone of the foot to have a stress fracture is the metatarsals.
Symptoms of a stress fracture is a localized pain and possible swelling with activity. It usually is improved with non-weightbearing or rest. The pain occurs usually gradually over time and no history of direct injury. They are very common in military personal, and athletes.
Causes of stress fractures maybe due to fatigue of the muscles and a decrease in shock absorption puts increase forces on the bone causing a fracture when overloaded. It may also occur due to repetitive muscular forces acting on the bone. The actual cause is unknown at this time, but these two theories are most common. Some people may be more prone to this type of injury due to the bone density, or osteoporosis. In others the foot type may lead to improper functioning of muscles. Both high arched feet and low arched feet with excessive pronation can lead to stress fractures. Stress fractures have been seen following other types of foot surgeries, if forces are exchanged from other areas of the foot to apply more weight forces under one particular metatarsal. This can be noted after a bunion surgery if the first metatarsal becomes elevated forcing more pressure on the 2nd or 3rd metatarsal.
Prevention is difficult as the it is hard to control external factors dealing with stress fractures. Insuring proper footwear for the activity engaged in is probably the best prevention.
Diagnosisis first by clinical suspicion of symptoms. This can be hard to diagnosis on initial symptoms as the stress fracture, unlike a pathologic fracture may not be detected to the visible eye on x-ray. After the body begins healing this damaged bone, a bone callous is formed which is detected on x-ray. Commonly, physicians do not see this stage of bone healing on x-ray for approximately 2 weeks following the initial injury and symptoms. Bone scans are sometimes ordered to help detect this new bone formation at an earlier stage. A positive bone scan is not always indicative of having a stress fracture however.
Podiatric Care may include simply keeping off your feet more, or stopping the activity that caused the stress on the bone. This depends on each unique clinical situation. If walking is painful, sometimes your podiatrist will apply a below knee cast for immobilization. With initial symptoms ice, elevation, rest, and non-steriodal anti-inflammatory medications may be helpful. Bone takes around 6-10 weeks in a typical individual for healing. Many factors can increase or decrease this time. When the fracture has healed it is easily prone to re-injury in the initial phase, a gradual progression to full weight activities is usually advised. Orthotics maybe advised or helpful to control your foot structure to prevent another injury of this type.