[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.