We examined the relationship between the Kaeding-Miller (K-M) stress fracture classification system with time to return to running or practice in female track and field athletes diagnosed with tibial stress fracture.
All female athletes with tibial stress injuries who competed for a Division I university from 2011-2014 were identified. Their charts were reviewed retrospectively to collect demographic variables, medical history, training variables, injury history, and nutritional or dietary risk factors. The K-M classification system was used to grade all injuries and to compare the time to return to practice. Body mass index (BMI) was evaluated independently with time to recovery.
Twenty-four tibial stress injuries were identified in 18 female track and field athletes on the same Division I collegiate team over a 3-year period. The average time to return to running was 13.7 wk (SD 5.02). Athletes with a K-M grade of V had an average time to return to running of 17 wk compared with 11.7 and 13.7 in Grade II and III, respectively. This difference did not reach significance (P=0.534), but there was a positive relationship between K-M grade and time to recovery (coefficient=0.785). There was no statistically significant relationship between BMI and time to return to sport (P=0.767), but there was an inverse relationship between BMI and time to clinical healing (coefficient=−0.191).
Data suggest that higher K-M grade injuries correlate with longer time to recovery, but larger studies are needed to determine if this relationship is significant.