STRESS FRACTURES OF THE FOOT
Stress fractures of the foot and ankle are extremely common. The most common fractured bone is a metatarsal (usually the second or third). Stress fractures however can also occur in cuneiforms, navicular, talus, distal tibia and distal fibula.
The comments below relate to metatarsal stress fractures:
- The patient will complain of pain and swelling on the top of their foot.
- The pain can be excruciating and prevent the patient from walking.
Stress fractures generally occur in two situations:
- They were described in military recruits with normal bone who were marching and overloaded their metatarsals. They were known as “March fractures”.
- They also occur in the presence of low bone density such that normal walking can produce a stress fracture.
Often in the history the patient will report trying to get fit, going to the gym and performing high-impact activity though this is not invariably the case.
A dietary history of the patient is important as certain diets low in calcium can predispose patients to stress fracture.
- The patient has swelling on the dorsum of the foot.
- They are usually exquisitely tender to palpation over the affected metatarsal.
- Plain x-rays are always taken but are often normal.
- In the past bone scan was the preferred investigation but these days MRI has superseded bone scan.
- Most often however the diagnosis is clinical.
- An MRI scan is not usually indicated.
- Resting the affected foot is the mainstay of treatment.
- If the patient is in excruciating pain then crutches nonweight bearing for two weeks
- However, if the patient is not in excruciating pain then rest in a short walking boot for 3-4 weeks. The boot ought to be taken off to shower, to go to bed and to move the patients foot up-and-down a hundred times a day to prevent a DVT.
- I will generally follow the patient up with a further x-ray a month to 6 weeks later. This x-ray will often show callus and confirm the diagnosis.
- If I am in doubt about the diagnosis then an MRI scan is indicated.
Return to activity: once the stress fracture has healed any biomechanical anomalies in the foot should be corrected with a change of shoes and orthotics. I also suggest to the patients that they mix up their training regime to include cycling and swimming i.e. low-impact sports.
If there is a question of low bone density then the patient will need a bone density assessment with blood tests and a scan. The blood tests recommended are calcium, phosphate, parathyroid hormone, 25 hydroxy vitamin D, an MBA 20 and a spot urinary DPD/creatinine.