Stress fractures are one of the most feared running injuries. Stress fractures are small cracks in a bone that develop from repeated trauma from running without adequate rest. It is not possible to “run through” a stress fracture – a runner must commit himself or herself to taking an extended period of time off in order to heal properly. One of the most difficult aspects of stress fractures is knowing when it is okay to return to running. In order to provide a more accurate answer about when it is okay resume to training program, a recent study attempted to classify stress fractures by severity.
In the study, the authors used two different methods to categorize stress fractures: (1) the risk level of fracture based on the location of the fracture, and (2) the grade of the fracture as determined by medical imaging.
Examples of high risk locations for stress fractures include the femoral neck, the fifth metatarsal, and the second metatarsal. Examples of low risk locations for stress fractures include the pelvis, femoral shaft, and metatarsal bones other than the fifth and second.
Physicians also use imaging to grade the severity of stress fractures by examining the “uptake” of radioactive material in the injured area. In low grade stress fractures, there is increased uptake at the injured site, but the precise location of the fracture is poorly defined. In high grade stress fractures, the area of increased uptake is very clearly defined.
The study’s authors used “location based” risk factors, and “imaging based” grading methods to derive the following four different types of stress fractures: (1) Low Risk, Low Grade, (2) Low Risk, High Grade, (3) High Risk, Low Grade, and (4) High Risk, High Grade. The authors then applied these categories to 52 different athletes that had stress fractures. The authors found that the average time for a runner to return to running depended on the stress fracture category.
| Category | Average Days to Return to Running |
|---|---|
| Low Risk, Low Grade | 61 |
| Low Risk, High Grade | 153 |
| High Risk, Low Grade | 135 |
| High risk, High Grade | 131 |
