Most athletes with groin pain attend an imaging department if symptoms persist. Therefore, most patients referred by the clinician for further imaging evaluation present with chronic groin injury. In daily radiological practice, acute groin injury is rare. Differential diagnosis of groin pain is broad and clinical diagnosis of groin lesions may be confusing, reflecting the fact that the causes of groin pain are protean. Moreover, combined pathology is often present in chronic groin pain and these different groin conditions are often interlinked. Medical imaging may play a crucial role to narrow differential diagnosis and to display better the interlinked nature of different groin conditions. We know, for example, the anatomical and functional relationship of tendon attachments at the level of the pubic bone, the so-called " rectus abdominis and common adductor origin (RA-CAO)", providing a unifying concept for groin injuries in athletes. Chronic (or acute) stresses applied at these tendon attachments, will shear off the RA-CAO from the pubic bone and this will have an effect on proper function of the conjoint tendon and superficial inguinal ring, leading to a so-called"sports-hernia". This is the reason why symptomatic relief of groin pain may occur after hernia repair, rectusplasty or adductor tenotomy. So what are the imaging modalities available and is there an "ideal" imaging strategy? We believe an ideal imaging strategy does not exist. In daily practice, the imaging pathway to be followed is tailored to individual cases and depends mainly on local expertise (of both clinician and radiologist), equipment available and financial costs. Should we perform plain films in every patient with chronic groin injury? Probably not. Plain radiographs are valuable for detection of acute bone lesions, e.g. avulsion fracture in the immature skeleton, but may also detect chronic bone injury, e.g. sclerotic marginated erosions at the pubic bone ("gracilis syndrome"). For chronic groin injury, multidetector CT scan is not routinely used in our institution. It may be useful for acute bone injury or biometric views, e.g. measurement of femoral neck anteversion. If good equipment (high frequency probe) and local expertise is available, ultrasound should be the imaging modality of first choice to evaluate patients with groin pain. The most important advantage of this technique is the possibility for dynamic assessment, e.g. detection of inguinofemoral hernia or "snapping hip". It is an accurate technique for assessment of the posterior wall of the inguinal canal and conjoint tendon to detect "sports hernia". Peritoneography is another accurate technique for these purposes, but its invasiveness is a major disadvantage. When these imaging modalities only reveal normal or equivocal findings, patients may be referred for magnetic resonance imaging (MRI). MRI is mainly used as a "water map". We specifically look for both bone-marrow and soft tissue oedema on fat-suppressed images. We prefer spectral fat saturation because of its better spatial resolution and signal-to-noise ratio compared with inversion recovery techniques. In patients with clinical suspicion of intra-articular disease (cartilage or labral tear), gadolinium may used either to perform direct or indirect MR arthrography. In our opinion, the indirect technique (after intravenous contrast administration) is an accurate technique for detection of labral or chondral pathology, and importantly, it is less invasive. Another advantage of the indirect technique is the enhancement of peri-articular soft tissues, which may be important for obtaining correct diagnosis, e.g. snapping hip due to illiopsoas tendinitis.
© Copyright 2007 Medicine and Science in Tennis. All rights reserved.