lunate dislocation
Pronunciation: LOO-nate
Displacement of the lunate bone from its normal position in the proximal carpal row.
Full Definition
Lunate dislocation involves complete displacement of the lunate bone, typically in a volar direction, from its normal articulation with the radius and adjacent carpal bones. This high-energy injury often occurs with wrist hyperextension and represents stage IV of progressive perilunate instability. The condition frequently compresses the median nerve in the carpal tunnel and may cause acute carpal tunnel syndrome. Urgent reduction and surgical fixation are typically required to prevent permanent complications including median nerve damage, avascular necrosis of the lunate, and post-traumatic arthritis. The injury pattern differs from perilunate dislocation where other carpal bones dislocate around an intact lunate-radius relationship.
Usage
Usage note: Distinguish from perilunate dislocation in documentation.
In Context
- "Emergency reduction of the lunate dislocation was performed to decompress the median nerve." — Emergency department report
- "The lunate dislocation required open reduction and internal fixation with ligament repair." — Operative summary