The palmar extrinsic wrist ligaments — radioscaphocapitate, long radiolunate (radio-triquetral), and short radiolunate — are the strongest wrist ligaments and the primary restraints against carpal dorsal translation and ulnar drift. The space of Poirier is a weak area between the radioscaphocapitate and the long radiolunate ligament through which the lunate escapes volarward in perilunate dislocation.
| Origin | Palmar distal radius |
|---|---|
| Insertion | Proximal carpal row (radioscaphocapitate, long radiolunate, short radiolunate) and distal carpal row (radioscaphocapitate extends to capitate) |
| Actions | Primary palmar wrist stability; resist carpal dorsiflexion and ulnar translation |
|---|
Perilunate and lunate dislocations occur when the wrist experiences extreme dorsiflexion loading, with the carpal bones progressively dislocating around the lunate through the space of Poirier. Lunate dislocation (the most advanced stage) results in the lunate rotating volarward into the carpal tunnel, compressing the median nerve. Emergency open reduction and ligament repair are required.
Carpal dislocation through the space of Poirier producing lunate rotation into the carpal tunnel with median nerve compression, managed with emergency open reduction and ligament repair.
