Relevant landmarks to navigate the suture locations for the arthroscopic triangular fibrocartilage complex foveal reattachment

Introduction Key step of arthroscopic triangular fibrocartilage complex (TFCC) foveal reattachment is to suture dorsal and palmar deep components of radioulnar ligaments (RULs) to the fovea of ulnar head to ensure distal radioulnar joint stability. However, the deep components are covered and cannot be identified arthroscopically from standard radiocarpal joint view. Suturing sites described in previous studies have not been proved gasping of the deep components. The purpose of this study was to investigate our TFCC suture locations using relevant landmarks on securing the RULs' deep components for arthroscopic TFCC foveal reattachment. Materials and methods Wrist arthroscopy and horizontal mattress suture was performed in 20 fresh-frozen cadaver wrists. Based on close proximity of the ulnocarpal ligaments to the palmar RUL and fovea, palmar suture location was designated at the junction between ulnolunate, ulnotriquetral ligaments and palmar border of TFCC disc, whereas dorsal suture location was at dorsal border of TFCC disc, opposite the palmar location, at same distance between prestyloid recess and palmar location. The radiocarpal and ulnocarpal joint was subsequently opened to evaluate grasping of RULs' deep components and evaluate the relevant landmarks. Results Thirty-nine of 40 (97%) RULs' deep components were successfully grasped by the sutures. With 0.98-0.99 interobserver agreement for the measurements, mean distance between sigmoid notch to suture and suture to ulnar capsule were 5.6 +/- 1.1 and 4.0 +/- 0.9 mm, respectively. Whereas, the dissecting point of deep component from the superficial component of the RULs was detected immediately radial to the midpoint between the sigmoid notch and the ulnar capsule (4.5 +/- 0.9 mm from sigmoid notch). Conclusions We determined the relevant anatomical landmarks to navigate the TFCC suture locations, which reliably secure the deep components of the radioulnar ligaments for the arthroscopic TFCC foveal reattachment.