The palmar radiocarpal ligaments are the primary stabilisers of the wrist, running from the distal radius and ulna to the carpal bones. The main ligaments are the radioscaphocapitate (RSC), the long radiolunate (LRL, radiolunotriquetral), the short radiolunate (SRL), and the ulnocarpal ligaments (ulnolunate and ulnotriquetral). The space between the RSC and LRL is the space of Poirier, a relative weak zone in the volar capsule.
Prevent volar carpal instability and radial-to-ulnar ligament disruption, maintaining alignment of the carpus with the distal radius during wrist loading and rotation.
The palmar radiocarpal ligaments are the primary constraint to carpal translocation (radial-to-ulnar carpal shift). Their disruption in high-energy dorsiflexion injuries produces perilunate dislocations (lunate dislocates relative to capitate) or transscaphoid perilunate fracture-dislocations. The space of Poirier (between RSC and LRL) is the anatomical weak spot through which the lunate escapes anteriorly in lunate dislocations. Repair of the palmar ligaments is essential in perilunate injury surgery to prevent recurrent instability.
High-energy wrist hyperextension disrupts the palmar radiocarpal ligaments sequentially through the space of Poirier, producing perilunate or lunate dislocation; emergency ORIF requires repair of all disrupted ligament layers along with fracture stabilisation to prevent carpal arthrosis from the high-energy injury.
