PurposeTo investigate the prevalence of magnetic resonance imaging (MRI) findings and define prognostic factors of the return‐to‐play time in young athletes with groin pain. MethodsA total of 1091 consecutive athletes were retrospectively screened; 651 athletes, aged 16–40 years, with pain in the groin regions were assessed using MRI. Of these athletes, 356 were included for analysing the time to return‐to‐play. Univariate and multiple linear regression analyses were used to determine the associations between the time to return‐to‐play (primary outcome variable) and the following variables: age, sex, body mass index, type of sports, Hip Sports Activity Scale, clear trauma history, and 12 MRI findings. ResultsFour MRI findings, including cleft sign, pubic bone marrow oedema of both the superior and inferior ramus, and central disc protrusion of the pubic symphysis, appeared together in more than 44% of the cases. The median time to return‐to‐play was 24.7 weeks for athletes with a cleft sign on MRI, which was significantly longer than the 11.9 weeks for athletes without the sign. The median time to return‐to‐play was 20.8 weeks for athletes with BMI > 24, which was significantly longer than the 13.6 weeks for athletes with BMI ≦ 24.In multiple linear regression analysis of 356 athletes, in whom hip‐related groin pain was excluded, and who were followed‐up until the return‐to‐play, the body mass index and cleft sign were the independent factors associated with a delayed return‐to‐play. In contrast, iliopsoas muscle strain and other muscle injuries were associated with a shorter return‐to‐play. ConclusionsMultiple MRI findings were present in almost half of all cases. Body mass index and the cleft sign were independently associated with a delayed return‐to‐play time in young athletes suffering from groin pain. Level of evidenceIII.

Background:Although iliopsoas disorder is one of the most frequent causes of groin pain in athletes, little is known about its prevalence and clinical impact.Methods:We retrospectively reviewed the cases of 638 consecutive athletes who had groin pain. Each athlete was assessed with magnetic resonance imaging (MRI). First, we identified the prevalence of changes in signal intensity in the iliopsoas. Then we classified the changes in signal intensity in the iliopsoas, as visualized on short tau inversion recovery MRI, into 2 types: the muscle-strain type (characterized by a massive high-signal area in the muscle belly, with a clear border) and the peritendinitis type (characterized by a long and thin high-signal area extending proximally along the iliopsoas tendon from the lesser trochanter, without a clear border). Finally, we compared the time to return to play for the athletes who had these signal intensity changes.Results:Changes in signal intensity in the iliopsoas were detected in 134 (21.0%) of the 638 athletes. According to our MRI classification, 66 athletes had peritendinitis changes and 68 had muscle-strain changes. The time from the onset of groin pain to return to play was significantly shorter for the patients with muscle-strain changes on MRI than for those with peritendinitis changes (8.6 ± 8.3 versus 20.1 ± 13.9 weeks, respectively; p < 0.0001).Conclusions:Changes in MRI signal intensity in the iliopsoas were observed in 21.0% of 638 athletes who had groin pain. Distinguishing between muscle-strain changes and peritendinitis changes could help to determine the time to return to play.