Stress fracture of the foot is a relatively common injury amongst runners, especially long distance runners.
One of my patients, Ms R, who is about 30 years old, has been a regular runner for some years, usually running about 2 to 3km once a week. Recently, she signed up and completed a 21km marathon, bearing with the pain and pushing on till the finish line. Thereafter, she started having a severe pain in her Right thigh, and it worsened in the days after the marathon. Eventually, she came to my clinic. Suspecting a stress fracture, an MRI was performed which confirmed that she had a stress fracture of the lower half of her thigh bone. She was put on limited weight-bearing with crutches and her stress fracture healed after about 6 weeks.
What is a stress fracture? Does it occur only in people with poor bone quality?
A stress fracture is defined as a fracture that occurs due to repetitive impact on an otherwise normal bone. In most cases, there is nothing wrong with the bone quality. It often occurs in patients who suddenly increase the frequency, duration or intensity of their exercises without sufficient rest in between or incremental training.
A stress-related injury can vary from a simple stress reaction, where the patient only has pain without any crack in the bone, to a stress fracture where an actual fracture line actually develops in the bone. In the foot, it frequently occurs in the metatarsal bone, usually the second or third metatarsal bone. Patients will experience pain when walking, and there is often swelling over the top of the foot. At times, bruising may be seen at the top or the bottom of the foot. For long-distance runners, it is also common to develop stress injuries and stress fractures in the shin bone.
Diagnosis of a stress fracture can be made via an MRI of the foot or a bone scan. In most cases, a stress fracture cannot be detected in X-rays in the early phase, but radiological signs of healing may show up in X-rays about 1 to 2 months after the injury, with callus or new bone forming over the stress fracture area.
The treatment for a stress fracture of the foot is conservative. Rest, icing and analgesia is important. The use of a walker boot is useful in patients who have significant pain when walking.
The stress fracture heals in 1 to 2 months. Factors such as repeated trauma or smoking can hinder or prolong the healing time. It is advisable that the patient work with a physiotherapist for rehabilitation and progressive strengthening to prevent recurrent injuries.