Effects of Training on ACL Volume in Female Intercollegiate Soccer Athletes.

Abstract

Anterior cruciate ligament (ACL) injuries are one of the most common injuries that occur in competitive sports, affecting female athletes two to ten times more than males. While previous studies have correlated ACL volume with injury retrospectively, little information is available on how the ACL volume changes during periods of intense physical activity. PURPOSE: To characterize the volumetric changes that occur in the ACLs of female soccer athletes over the course of a competitive season. METHODS: A sample of 16 Division I female collegiate soccer players were recruited for participation in this study. To be included in the study, subjects must have been members of the Quinnipiac University women’s soccer team without previous history of ACL injury. All subjects underwent MRI scans of both knees, prior to the start and at the completion of the competitive season. Contours of the ACL were manually delineated in sagittal MR images and volumes were calculated. Mean volume comparisons were made using a paired t-test. ACLs were graded for the presence of edema by an orthopedic surgeon. Changes in the occurrence of edema were evaluated using the McNemar test. RESULTS: Twenty-three of the 32 ACLs (72%) showed a greater volume postseason compared to preseason. The mean difference in volume was statistically significant (preseason 1.43 ± 0.29 cc; postseason 1.56 ± 0.27 cc; p = 0.006). The presence of edema was noted in 33% of the ACLs at preseason versus 47% at postseason, however this increase was nonsignificant (p = 0.17). CONCLUSIONS:The intense physical demand of a competitive soccer season in female collegiate athletes appears to cause an increase in volume of the ACL which may be associated with edema of the ligament. The clinical significance of this finding requires further research.