Morphology of the Ulnar Insertion of the Triangular Fibrocartilage Complex and Related Osseous Landmarks

Abstract

Purpose In triangular fibrocartilage complex (TFCC) injuries, a foveal tear of the radioulnar ligament often requires surgery. Previous studies have suggested that surgeons should attach the TFCC to the center of the fovea. The TFCC and its insertion points are small structures, and few studies have reported details of the foveal insertion. This study aimed to clarify the morphology of the ulnar insertion of the TFCC and related osseous landmarks with 3-dimensional imaging. Methods This study used 26 formalin-fixed cadavers. At the ulna, the TFCC was inserted from the fovea to the middle part of the ulnar styloid. After gross observation of the TFCC, the ulnar insertion was outlined using a 1.0-mm drill. We then created 3-dimensional images of the ulna using computed tomography and marked (with software) an outline of the foveal insertion of the TFCC. We measured the area and the long and short diameters of the TFCC insertion. Results The area of the TFCC insertion was 34 mm 2 and positively correlated with the height of the ulnar styloid and the area of the ulnar head. The TFCC's highest point was 58% of the ulnar styloid height. The center of the TFCC insertion was 1.3 mm ulnar and 0.6 mm dorsal from the lowest point of the ulnar surface. Conclusions The center of the TFCC insertion was slightly ulnar of the lowest point of the ulnar surface. This study revealed the center, the area, and the osseous relation of the ulnar insertion of the TFCC. Clinical relevance When surgeons repair a TFCC foveal tear, they can find the anatomical center of the ulnar insertion efficiently and easily based on its osseous relationship.

Effectiveness of suture anchor and transosseous suture technique in arthroscopic foveal repair of the triangular fibrocartilage complex: a systematic review

“…The concept of foveal repair for Atzei class 2 complete tear or Atzei class 3 proximal tears [ 8 ] explained the inconsistent surgical results after capsular repair for Palmar 1B tear lesions with DRUJ instabilities [ 17 ]. Arthroscopic transosseous suture method was first introduced by Iwasaki in 2009 with single suture strand [ 18 ] and further modified with more comprehensive suture configuration [ 19 ] as recent cadaveric studies demonstrated the three-dimensional morphology of the TFCC foveal insertion [ 20 , 21 ]. Arthroscopic suture anchor repair utilizes one to two non-absorbable sutures to reattach the disrupted TFCC proximal limb to the anchoring fovea insertion site.…”

Arthroscopic transosseous foveal footprint repair of the triangular fibrocartilage complex

“…With a small bone tunnel located at the radial border of the fovea, the four sutures pass in different directions to compress the TFCC stump, including both the anterior and dorsal components, to its footprint in a large fan-shaped area, thus obtaining a larger ligament–bone contact surface for healing. The ligament–bone contact surface should cover most of the normal footprint (Figure 6) based on the findings of recent cadaveric studies about the three-dimensional morphology of the TFCC foveal insertion (Okuda et al., 2021; Shin et al., 2017). In addition, the repair tension is shared by the four sutures instead of only the one or two sutures used in other techniques, thus reducing the stress on each suture and theoretically reducing the risk of sutures cutting through the TFCC.…”

Complications after arthroscopic triangular fibrocartilage complex (TFCC) surgery

“…On the technical side, if the repair is eccentric and not at the isometric footprint, or if the repair attaches the TFCC to a wider area than the anatomical footprint, then there would be excessive tension on either the dorsal or volar distal radioulnar ligaments, or both, which would restrict rotational motion. An anatomical study recommends placement of the tunnel at the lowest point of the ulnar fovea, which although is not the centre of the footprint, correlates best with the attachment of the deep component of the TFCC (Okuda et al., 2021). A C-ring targeting drill guide can facilitate accurate placement of bone tunnel.…”