Anatomy of the Dorsal ScaphoLunoTriquetral Ligament Complex
Lauren Elisabeth Wessel, MD1, Kyle Morse, MD1, Francois Loisel, MD1, Jinseong Kim, BS1, Ubaldo Gamboa, MD2 and Scott W Wolfe, MD3, (1)Hospital for Special Surgery, Main Campus, New York, NY, (2)ABC Santa Fe Medical Center, Mexico City, DF, Mexico, (3)Hand and Upper Extremity Service, Hospital for Special Surgery, New York, NY
There is little consensus on the precise origin and insertion points of the dorsal radiocarpal (DRC) ligament and the dorsal intercarpal (DIC) ligaments. Additionally, the dorsal scaphotriquetral ligament (DST) has been variably described in the literature. The purpose of our study is to describe the dimensions of the insertion sites of the DRC, DST and DIC, and the anatomic relationship of the DST and DIC ligaments. We hypothesize that the intracapsular DST and DRC ligaments consistently insert on the dorsal lunate, and the DST represents the deep component of the DIC.
Materials & Methods:
Fourteen fresh-frozen cadaveric specimens (6 M, 8F), age 70.6 (range 61 to 86) were imaged under fluoroscopy to confirm alignment of the proximal carpal row. Wrists with arthritis or carpal malalignment were excluded. The DRC and DIC ligaments were inspected, photographed and measured in situ. The conjoined DRC/DIC ligament insertion on the triquetrum was measured and osteotomized to reveal subsequent insertion sites in an ulnar to radial direction. Insertion sites of the DIC-DST to the lunate, dSLIL, scaphoid tubercle and trapezoid-trapezium were measured, as were insertion sites of the DRC to the lunate and distal radius. All measurements were made in radial-ulnar direction and proximal distal-direction at the midpoints of the insertion. Insertion areas were approximated by multiplying the two distances, assuming a rectangular shape. Insertion locations were mapped to anatomic models (Figure 1).
The conjoined triquetral insertion of the DIC-DST and DRC measures 89.6 ± 6.2 mm2. In each specimen, the DST represented an inseparable deep subsection of the DIC, and had attachments to the lunate 65.0 ± 28.3 mm2, and scaphoid ridge 67.4 ± 26.8 mm2. The DRC consistently inserted on the lunate just proximal to the DIC-DST insertion over a smaller surface area, 29.3±27.6 mm2. The DIC-DST was intimately integrated with the dSLIL, and inserted along the dorsal scaphoid ridge 67.4±26.8 mm2, creating a labral-like covering of the dorsal capitate (Figure 2). The DIC consistently inserted on the trapezoid 56.92±27.0 mm2.
These data demonstrate a consistent insertion of both the DIC and DRC on the lunate. We found the DST to be intimately related to the DIC, constituting a stout deep subsection of the DIC that spanned the entire proximal row. These data have implications for carpal stability and may guide surgeons in avoiding injury to critical ligaments during dorsal approach to the wrist.
Back to 2020 Abstracts