The Anatomy of the Dorsal Capsulo-Scapholunate Septum: A Cadaveric Study.

Background  Tears of the dorsal radiocarpal capsule at the level of the scapholunate interosseous ligament (SLIL) have recently been described in association with predynamic scapholunate instability. Purpose  The aim of this anatomical study of the dorsal capsulo-scapholunate septum (DCSS) was to examine the connection of the dorsal capsule on the SLIL and dorsal intercarpal ligament (DICL). Methods  Fourteen fresh frozen wrists from seven adult cadavers were dissected through a dorsal approach. Any dorsal attachment of the DICL on the dorsal surface of the SLIL, that is, the DCSS, was identified and measured (height and width). Results  The DCSS was consistently found connecting the DICL, the dorsal radiocarpal capsule, and the dorsal aspect of the SLIL. It was formed by the confluence of three arches like intersecting ribs in gothic architecture. The mean dimensions of the DCSS were 5.8 mm in height and 4.0 mm in maximum width. Conclusion  The DCSS that connects the SLIL with the dorsal capsule and DICL could be a constant structure of dorsal wrist. Further investigation is required to study the histology of the DCSS and its biomechanical properties in isolation to know whether the DCSS can be considered a secondary stabilizer of the scapholunate ligament complex. Clinical Relevance  A better anatomical knowledge of scapholunate ligament complex could help understand and manage instability of the wrist.