LIGAMENTS OF WRIST
The ligaments of the wrist are divided into three separate groups: the
dorsal intercapsular, the volar radiocarpal, and the interrosseous ligaments.
Confusion regarding these structures often centers on the numerous different
names utilized to identify these structures.
The volar radiocarpal ligaments
are the most critical of these structures and provide the majority of
ligamentous stability to the carpus. The volar ligaments consist of the
radioscaphocapitate ligament, the long/short radiolunate ligaments, the
radioscapholunate ligaments (more of a vascular conduit), and the
ulnotriquetral and ulnolunate ligaments. The radioscaphocapitate ligament is a
critical restraint to ulnar translocation of the carpus and must be preserved
during proximal row carpectomy and/or during radial styloidectomy. The space of
Poirier is a weak point between the radioscaphocapitate and long radiolunate
ligaments, where the lunate can dislocate during a lunate dislocation. During a
volar approach to lunate/perilunate dislocations this space can be sutured to
provide increased stability to the injured carpus. The dorsal intercapsular
ligaments consist of the dorsal radiocarpal and dorsal intercarpal ligaments.
These provide additional structural support to the carpus, and numerous
“ligament-sparing approaches” to the wrist have been described to preserve
these structures. These dorsal ligaments can also be utilized to correct carpal
instability by being transferred to function as a capsulodesis. There are
numerous intercarpal ligaments, the most critical being the scapholunate and
lunotriquetral ligaments. Disruption of these intercarpal ligaments can lead to
dorsiflexed or volar-flexed intercalated segment instability (DISI or VISI)
deformities, respectively. Repair of these ligaments can be performed in the
acute setting, whereas numerous reconstructive procedures have been described
for use in the chronic setting when symptomatic.
The triangular fibrocartilage
complex (TFCC) describes a confluence of soft tissue
structures that stabilize the distal radioulnar joint (DRUJ) and transmit
forces across the ulnocarpal joint. The individual components include dorsal
and palmar radioulnar ligaments, meniscus homologue, ulnotriquetral and
ulnolunate ligaments, articular disc, and the extensor carpi ulnaris subsheath.
The dorsal and palmar radioulnar ligaments are most critical for DRUJ
stability. TFCC pathology can often be diagnosed and treated with
arthroscopic techniques.
