Update on imaging in femoroacetabular impingement syndrome

Background: Properly performed high-quality imaging is critical in the diagnosis of femoroacetabular impingement syndrome (FAIS). Currently, conventional imaging in the form of an anteroposterior view of the pelvis and at least a second view is still the first step in the diagnosis of FAIS. Here, by determining the various parameters, the acetabular configuration should also be accurately assessed with regard to a combination with dysplasia or acetabular retroversion. MRI: MRI should also be demanded as standard before joint-preserving surgery. It allows for more precise detection of morphology, secondary chondrolabral damage, and thus helps identify outcome-relevant risk factors and cases that are too advanced in terms of degenerative aspects. Other imaging methods: Depending on the problem, MRI can be supplemented by intravenous or intra-articular application of contrast agents (indirect or direct MRA), determination of torsion, and, if necessary, even with the performance of a traction MRA. While the importance of invasive MRA has decreased due to the improvements of 3-Tesla scanners in clinical practice, rotational analysis has gained in importance. Computed tomography (CT), although associated with increased radiation exposure, allows high-resolution imaging of bony structures and extremely illustrative 3D planning of complex corrections, and is an alternative to MRI for this purpose or in contraindications. Prospects: 4D simulations appear useful and may make diagnostics and therapy planning safer and easier in the future. Thus, a broad portfolio of imaging techniques is available today, the advances of which have contributed significantly to the development of differentiated joint-preserving surgery of the hip joint.