MANUAL MINORS
A lunate dislocation occurs when the lunate bone shifts out of its normal position in the wrist joint, typically due to severe trauma, such as a fall onto an outstretched hand. The lunate is one of the eight carpal bones, and its dislocation can compress the median nerve, leading to intense pain, swelling, and functional limitation of the wrist.
Diagnosis
The diagnosis is based on a history of trauma, clinical signs such as severe wrist pain, visible deformity or loss of movement, and imaging studies. X-rays are the most common initial method, where the displacement of the lunate can be seen. In some cases, MRI may be necessary to assess ligament or soft tissue damage.
Differential Diagnosis
Condition | Key Characteristics |
|---|---|
Scaphoid Fracture | Pain in the anatomical snuffbox, specific X-rays needed. |
Perilunate Dislocation | The lunate remains in place, but other carpal bones are displaced. |
Carpal Fracture-Dislocation | Fracture and displacement in other carpal bones, in addition to the lunate. |
Median Nerve Injury | Numbness and paraesthesia in the nerve distribution, without visible bone deformity. |
Emergency Management
Initial management of a lunate dislocation includes immediate immobilisation of the wrist to prevent further damage and pain relief with analgesics. If neurovascular compromise is suspected, prompt reduction of the dislocation is necessary. Closed manipulation may be attempted in the emergency department under sedation and radiological control, but surgical reduction is often required.
Definitive Treatment
Definitive treatment is almost always surgical, involving open reduction and internal fixation to restore proper alignment of the lunate. In cases of severe damage, ligament repairs may be necessary. Physiotherapy is then recommended to restore wrist mobility and strength.
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