Arthroscopic Anatomy of the TFCC with Relevance to Function and Pathology

Abstract

Introduction The authors present a new comprehensive arthroscopic anatomical description of the fibrocartilage complex “TFCC” which is related to the current TFCC functional and pathological knowledge. Methods Our description of the TFCC is based on an arthroscopic view from the 3-4 portal as observed in more than 100 wrist arthroscopies in fresh cadavers and more than 1000 diagnostic and/or therapeutic wrist arthroscopies. Results TFCC is considered as a 3-D-3-part box-like structure (Reins, Wall and Disc). The first TFCC component (“R”) corresponds to 2 strong radio-ulnar ligamentous Reins, one dorsal (DRUL) and one palmar (PRUL). This “V-shaped” RUL reins diverge from the fovea and ulnar styloid to the volar and dorsal edges of the sigmoid notch. It is a main stabilizer of the DRUJ. The second TFCC component (“W”) is a continuous, radially concave Peripheral Capsular Wall attached and perpendicular to the RUL reins. It surrounds the ulnar aspect of the ulno-carpal interval while attaching to the RUL reins proximally and to the medial carpus distally. Along with the radiocarpal ligaments, the TFCC peripheral capsular wall contributes to the stability of the carpus with respect to the radius-ulna entity. This is especially true for the thick volar TFCC capsular wall. The third TFCC component (“D”) is the disc proper which is a static and dynamic shock absorber intercalated between the ulnar head and the medial proximal row in the coronal/sagittal planes and between the two strands of the RUL in the axial plane. Its pathology is influenced and related to the ulnar variance. Discussion This new arthroscopic description of the TFCC provides a comprehensive anatomical, functional ant pathological background for TFCC disorders analysis and treatment. Currently known disorders are included as “R 1,2,3,4”, “W 1, 2, 3, 4”, and “D 1, 2”. Combined TFCC disorders and further new pathology descriptions may be included in this open classification.

A New Arthroscopic Classification of Triangular Fibrocartilage Complex Disorders

“…There is increasing evidence 3 19 that the deep (proximal) and superficial (distal) dorsal and palmar radioulnar ligaments are intimately merged so that they act simultaneously during forearm rotation to stabilize the DRUJ. The well-vascularized 20 deep and superficial dorsal radioulnar ligaments are taut in pronation.…”

“…During wrist arthroscopy from the 3–4 portal, what we have described as the TFCC wall “W” 3 is the radially concave vertical well-vascularized 20 fibrous layer raising from the reins at the periphery of the disc and inserting on the medial aspect of the proximal carpal row (i.e., on the ulnar part of the lunate and triquetrum).…”

“…The use of wrist arthroscopy has become a prerequisite for the diagnosis and treatment of any triangular fibrocartilage complex (TFCC) disorders. 1 2 3 4 Palmer's landmark paper was the first attempt at producing a comprehensive three-dimensional (3-D) classification of TFCC lesions including wrist arthroscopy as one of its criteria. 5…”

Structurally intact and functionally incompetent foveal triangular fibrocartilage complex injuries

“…6 The more superficial, distal radioulnar ligament (dRUL) converges onto the ulnar styloid at a more acute angle and is thought to provide supplementary stability by a checkrein effect (Figure 1). 7,8 Injury to the TFCC, specifically the palmar or dorsal pRUL, may be significant enough to produce obvious DRUJ instability, manifested as painful clicking and/or subluxation with loaded pronosupination. Ulnar wrist pain in this context represents a more straightforward diagnosis with a clear treatment strategy.…”

“…6 The more superficial, distal radioulnar ligament (dRUL) converges onto the ulnar styloid at a more acute angle and is thought to provide supplementary stability by a checkrein effect (Figure 1). 7,8…”