Severe carpal injury resulting from wrist hyperextension.
Space of Poirier: Inherently weak area palmarly between the lunate and capitate that lacks substantial ligamentous connections.
There are many variations of injury that include combinations of fractures and dislocations. When describing an injury the prefix, "trans", is used when describing a fracture. For instance when a fracture passes through the scaphoid and there is a perilunate dislocation one would say, "transscaphoid perilunate dislocation".
- Lesser arc injuries: refers to a purely ligamentous injury about the lunate.
- Greater arc injuries: involve fractures of some of the bones surrounding the lunate.
The injury typically propagates from radial to ulnar through the carpus. The injury force typically enters the carpus through the scaphoid (transscaphoid fracture) or through the scapholunate interval followed by the space of Poirier and finally the lunatotriquetral articulation. Variations of this pattern include fractures through the carpal bones surrounding the lunate, as well as trans-radial styloid fractures.
Four stages of progressive instability:
- Disruption of scapholunate articulation or scaphoid fracture
- Force continues through the space of Poirier (lunatocapitate articulation)
- Disruption of lunotriquetral articulation and separation of the carpus from the lunate (typically dorsally)
- The lunate dislocates from the lunate fossa and rotates into the carpal tunnel, hinged on the palmar ligaments ("spilled teacup sign"). The images below demonstrate a trans-radial styloid, trans-scaphoid, Stage IV perilunate dislocation
Describe the natural history,epidemiology and prognosis
Patient History and Physical Findings
Imaging and Diagnostic Studies
Include a list with links to relevant conditions
- Closed vs. open reduction
- Open reduction preferred if swelling is not excessive
- Consider carpal tunnel release with some injuries
- Closed reduction and percutaneous pinning may be employed when an acceptable closed reduction can be achieved
- Perilunate dislocations: Open reduction is the preferred technique
- Dorsal approach:
- scapholunate joint pin fixation and ligament repair
- scaphocaptiate pin fixation
- lunotriquetral reduction and pinning
- ligament typically nonrepairable
- Volar approach:
- carpal tunnel release
- capsular repair
- Transscaphoid perilunate dislocation
- ORIF of the scaphoid
- CRPP of lunotriquetral joint
- Consider repairing the volar ligaments
Pearls and Pitfalls
Tips and problems to avoid
Include immediate postoperative care and rehabilitation
Include functional and prosthetic survivorship data as applicable