Emergency: requires immediate attention
Lunate dislocation
Alerts and Notices
Synopsis
Causes / typical injury mechanism: Lunate dislocation arises as a result of trauma, typically axial loading with wrist extension, supination, and ulnar deviation following a fall, motor vehicle collision, or sports injury. It is important to maintain a high index of suspicion for this injury in high-energy trauma and also to ensure that adequate imaging is obtained, as this injury is often missed.Classic history and presentation: Lunate dislocation presents as pain over the palmar or dorsal wrist and may be associated with stiffness and deformity. Delayed diagnosis may occur in up to 25% of cases. Approximately 10% of cases involve open injuries, and 26% occur in the setting of polytrauma.
The typical patient is an individual with a history of trauma from a fall, motor vehicle collision, or sports injury with associated examination findings and x-rays showing perilunate dislocation or lunate dislocation.
Grade / classification system (if any):
The Mayfield classification is used to stage the injury.
- Stage I injury may show a widened scapholunate interval due to either a disrupted scapholunate ligament or transscaphoid fracture.
- Stage II injury presents with dorsal dislocation of the capitate (due to lunocapitate articulation disruption) as well as the findings seen in stage I injury.
- Stage III injury presents with overlap of the triquetrum on the lunate (due to lunotriquetral ligament disruption).
- Stage IV injury presents as lunate dislocation (due to circumferential disruption of the ligamentous attachments of the lunate).
Codes
ICD10CM:S63.096A – Other dislocation of unspecified wrist and hand, initial encounter
SNOMEDCT:
110029007 – Traumatic dislocation of lunate bone
Look For
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Diagnostic Pearls
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Differential Diagnosis & Pitfalls
- Scaphoid or other carpal fracture without dislocation
- Distal radius fracture
- Metacarpal fracture
- Flexor tendon rupture
- Extensor tendon rupture
- Carpal tunnel syndrome
- Radiocarpal dislocation
- Avascular necrosis of the lunate (Kienböck disease)
- Scapholunate advanced collapse (SLAC) wrist
- Scaphoid nonunion advanced collapse (SNAC) wrist
Best Tests
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Management Pearls
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Therapy
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References
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Last Reviewed:08/26/2020
Last Updated:08/26/2020
Last Updated:08/26/2020
Emergency: requires immediate attention
Lunate dislocation