Iliopsoas Disorder in Athletes with Groin Pain: Prevalence in 638 Consecutive Patients Assessed with MRI and Clinical Results in 134 Patients with Signal Intensity Changes in the Iliopsoas

Abstract

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.

Fig. 1

Figs. 1-A and 1-B A 20-year-old man was diagnosed with iliopsoas-related groin pain on the basis of physical examination. We obtained axial and coronal T1-weighted sequences and axial, coronal, and oblique sagittal STIR sequences. To assess the iliopsoas, the oblique sagittal plane was imaged parallel to the iliopsoas. Fig. 1-A Coronal view. The solid white line indicates a slice cut for the oblique sagittal view, and the 2 white dotted lines indicate the edge of the field of view for oblique sagittal slices. Note that this athlete had degenerative changes at the symphysis pubis with edema in addition to the iliopsoas disorder. Fig. 1-B Oblique sagittal view. The arrows indicate the anterior margin of the iliopsoas. The high-signal area around the iliopsoas tendon is indicative of peritendinitis.

Fig. 2

Figs. 2-A and 2-B Classification of changes in signal intensity in the iliopsoas on STIR oblique sagittal MRI scans. Fig 2-A The muscle-strain type is characterized by a massive high-signal area in the belly of the iliopsoas muscle with a distinct border (green arrowheads). Fig. 2-B The peritendinitis type is characterized by a long and thin high-signal area (green arrowheads) extending proximally along the iliopsoas tendon from the lesser trochanter (white arrowhead). The contrast is lower than that seen with muscle-strain changes.

Fig. 3

Patient flow diagram. The time from onset of groin pain to return to play was compared between patients who had the muscle-strain type of changes in MRI signal intensity and those who had peritendinitis changes.

Fig. 4

Figs. 4-A and 4-B Follow-up STIR oblique sagittal MRI scans showing the peritendinitis type of changes in an 18-year-old male soccer player. Fig. 4-A Scan obtained 4 days after the onset of groin pain. A long, thin high-signal area was observed along the iliopsoas tendon. Fig. 4-B Scan obtained 4 weeks after the onset of groin pain. The high-signal area remained.

Fig. 5

Figs. 5-A and 5-B Follow-up STIR oblique sagittal MRI scans showing the muscle-strain type of changes in a 22-year-old male soccer player. Fig. 5-A Scan obtained 2 days after the onset of groin pain, showing a massive high-signal area in the iliopsoas muscle belly. Fig. 5-B Scan obtained 6 weeks after the onset of groin pain. The size of the high-signal area had decreased.