Watson Test is used to assess instability of which carpal region?

• A. TFCC instability
• B. Scapholunate instability
• C. Lunotriquetral instability
• D. DRUJ instability

Answer: (B)

Watson test checks the stability between the scaphoid and lunate, so it evaluates scapholunate instability. The scapholunate interosseous ligament keeps these two bones moving in harmony; when it’s torn or stretched, the scaphoid tends to shift out of place during wrist movement. In this test, the examiner applies pressure to the scaphoid tubercle while moving the wrist from its position toward radial deviation and slight extension, producing a palpable clunk as the scaphoid relocates back into place. A painful or felt clunk indicates scapholunate instability due to injury of that ligament.

This isn’t used to assess TFCC instability (ulnar-sided wrist pain and other signs), DRUJ instability (forearm joint stability), or lunotriquetral instability (between lunate and triquetrum, tested by other maneuvers). The distinctive clunk or relocation during wrist motion points to scapholunate disruption.