Triangular Fibrocartilage Complex (TFCC) - Anatomy, Imaging, and Classifications with Special Focus on the CUP Classification.

The TFCC consists of several components whose functional significance has been recognized in detail in recent years. Existing classifications are partly incomplete. In addition, the TFCC requires specific and dedicated imaging techniques.This review describes the anatomy and pathoanatomy of the TFCC. The different types of TFCC lesions on MRI as well as MR and CT arthrography are explained and compared with the current literature. In addition, the novel CUP classification is presented and illustrated with image examples.Anatomically and functionally, the articular disc and radioulnar ligaments with their ulnar insertions and the inhomogeneously structured TFCC periphery must be differentiated. For accurate imaging, thin slices with high in-plane resolution and techniques to optimize contrast are required. Plain MRI is exclusively dependent on T2 contrast, while gadolinium-enhanced MRI offers the additional benefit of focal contrast enhancement, e.g., of fibrovascular repair tissue at the lesion site. However, the reference standard continues to be MR and CT arthrography, which should be used for focused indications. The CUP classification, which allows a comprehensive description and categorization of TFCC lesions, is presented and illustrated. · Anatomically, the TFCC consists of the central ulnocarpal disc, the dorsal and palmar radioulnar ligaments, and the ulnocarpal joint capsule including intracapsular ligaments and the meniscus homologue.. · The most important restraining structure of the TFCC is the lamina fovealis, which stabilizes the DRUJ. This structure constitutes the proximal (deep) continuation of the radioulnar ligaments at the ulnar insertion.. · Imaging of the TFCC requires high spatial and contrast resolution due to its minute structures. MR and CT arthrography are the reference standard in imaging.. · The CUP classification clearly describes all structures of the TFCC with the categorization of individual or combined lesion patterns.. · Schmitt R, Kunz AS, Reidler P et al. Triangular Fibrocartilage Complex (TFCC) - Anatomy, Imaging, and Classifications with Special Focus on the CUP Classification. Fortschr Röntgenstr 2024; DOI 10.1055/a-2411-8444.