Introduction: Aim of our work was to evaluate the diagnostic role and potentials of Magnetic Resonance Imaging (MRI) in the study of groin pain in athletes and in the differential diagnosis among the pathological conditions that cause this syndrome.
Material and methods: MRI examinations were performed with a 1.5 T superconductive magnet, and a 0.2 T permanent magnet. Spin-Echo (SE) T1-w, PD, SE T2-w, Gradient-Echo (GE) T2-w and fat saturation sequences were used, on axial, sagittal and coronal scan planes. We performed MRI on twenty-five athletes (22 men and 3 women; age range 17 to 32 years) with chronic groin pain of questionable origin who had been complaining of it for at least 6 months. In 22 cases, radiographs were available; Computed Tomography (CT) had been performed in 3 cases and Ultrasound (US) in 7 cases. Nine patients were submitted to MRI after the symptoms had disappeared.
Results: In all patients, MRI provided an accurate depiction of pubic bone alterations and of adjacent myotendinous structures. In 14 cases, osteitis pubis was diagnosed, which was bilateral in 2 cases only (muscular asymmetry of the rectus abdominis was found in 4 of these patients); 4 patients had myotendinous posttraumatic changes (1 hematoma of the psoas muscle and 3 injuries of the abductor muscles of the thigh); 4 patients presented isolated dysmetria of rectus abdominis muscles, with unilateral involvement of the sacroiliac joint in 1 patient; 3 patients had inguinal hernia, surgically confirmed in all cases.
Discussion: Osteitis pubis, intended as reactive intraspongiuos edema of the pubic bones, is the most frequent cause of groin pain in athletes. In the early diagnostic phases, both plain films and CT may be negative or not specific. On the other hand, MRI has always proved to be a valuable diagnostic technique in detecting the osteitic change as an area of low signal intensity on T1-w images and of high and homogeneous signal intensity on T2-w scans without fat suppression. Dysmetria of the straight muscles of the abdomen, which may be associated, is always well depicted by MRI on axial planes. Both posttraumatic and dysmetric changes of the muscular structures adjacent to the pubis are well documented by US and MRI. The latter, however, thanks to its multiplanar capabilities, allows better spatial assessment of the alteration, especially if located at peri-insertional level. Possible associated diseases such as the involvement of the sacroiliac joints are also well shown by MRI. Inguinal hernias are easily demonstrated by MRI, which allows the direct visualization of the hernial sac within the inguinal canal.
Conclusions: In our experience, only MRI can permit an accurate and early diagnosis of the different sport-related pubic conditions. MRI is also a valuable tool in monitoring the alterations with reference to their response to treatment, which may also help bring the athletes back to their activities.