Radiology #2 Stress Fractures

After a very overdue spin class, I decided to talk about stress fractures today, in the hopes that I do not acquire one. Stress fractures are caused by unusual or repetitive stress. Unusual stress may be someone deciding they are going to start training for a marathon, having never been a runner before in their life. Repetitive stress may be in the long term runner who overuses or pushes too hard in a short period of time. A radiograph is often negative for stress fractures within the first 4 weeks of injury but after those 4 weeks, callous formation and periosteal reactions are apparent. Let me define: callous meaning hard & thickened cortical bone (the thick, bright white lines outlining each bone), and periosteal meaning the membrane the covers the outside of the cortical bone. Case: 47 year old female who is a regular walker has been experiencing foot pain for several weeks now, the initial radiograph is negative for fracture.... as there are no breaks in any of the cortical lines. Four weeks later, the aforementioned patient has a follow up radiograph taken, where you notice the callous formation and periosteal reaction. Now it is important to take note that metastasis and infection can also cause periosteal reactions so patient history taking is VERY important in ruling in/out the more serious diagnoses. The second case is of a 37 year old female that complains of foot pain after a biking trip. The radiograph to the left is the initial, the middle is after 1 month, and the far right radiograph is a 3 month follow up. Treatment of stress fractures include: resting the injury site, usually a break from activities for 3+ weeks, icing and proper footwear evaluation.

Sources:

Berger, et al. Stress Fractures. Radiographical Department from the Academical Medical Centre, Amsterdam. http://www.radiologyassistant.nl/en/4615feaee7e0a 23 May 2007

Fractures without Significant Trauma. Department of Radiology, University of Washington. 2007