Stress Fractures

Everyone is anxiously anticipating the milder weather this week – maybe some of the snow will melt! As people think about resuming their exercise regimens, they should be mindful of an under-recognized risk: stress fractures. Stress fractures are the result of excessive stress on the bone, resulting in microfractures with insufficient time for repair, leading to bone stress reaction and eventually fracture. Persons who participate in repetitive, high-intensity training are at risk for stress fractures, such as runners who average more than 25 miles per week. Women are at higher risk (especially if there is an eating disorder or osteoporosis). Other risk factors include consuming more than ten alcoholic beverages per week, smoking, sudden increase in physical activity and low levels of vitamin D.

It can be difficult to make a diagnosis of stress fracture. Most patients (81%) will have pain with walking, many will have swelling at the site of injury (18-44%) and almost all will have tenderness at the site of the fracture. It may take more than one imaging study to clinch the diagnosis.

Initial treatment is reducing activity to pain-free functioning. Healing time varies from four to twelve weeks (or longer) from the time that activity is restricted. Acetaminophen (Tylenol) may be used for pain relief; there is some animal data that indicates NSAID’s such as ibuprofen (Motrin) and naproxen (Aleve) may inhibit healing. Physical therapy and cross-training will help maintain flexibility, strength and cardiovascular fitness.

Prevention of stress fractures has been studied in military personnel. Shock-absorbing shoes inserts have been shown to be effective and calcium and vitamin D supplementation may play a role in prevention of stress fractures. Adequate rest is important, but there are currently no definitive recommendations as how much rest is needed. Once again, it appears that moderation is the key: a healthy diet with a gradual increase in exercise while cutting back on alcohol and smoking.

Am Fam Physician. 2011;83(1):39-46.