Which sign is used to detect lunate dislocation?

• A. Finkelstein's test
• B. Phalen's test
• C. Murphy's sign
• D. Watson test

Answer: (C)

Murphy's sign is used to detect lunate dislocation. When the patient makes a tight fist, the third metacarpal head normally sits higher than the others, creating a visible knuckle. If the lunate is dislocated, the carpal bones lose their normal alignment and the third metacarpal head sits level with the others, causing the knuckle to appear dull or absent—producing a positive Murphy’s sign. This sign points to a carpal problem at the lunate and prompts further imaging. The other signs test different conditions: Finkelstein’s for De Quervain’s tenosynovitis, Phalen’s for median nerve compression, and the Watson test for scapholunate instability, not lunate dislocation.