|
Year |
2002 |
|---|---|
|
Question Number |
111 |
|
Category |
Hand |
Question
A 32 year-old professional baseball player notes an episode of sharp dorsal ulnar wrist pain after swinging at a bad pitch. Examination reveals that extension and ulnar deviation of the wrist elicit a painful snap. What is the most likely diagnosis?
1. Triangular fibrocartilage complex tear
2. Distal radioulnar joint capsule tear
3. Extensor carpi ulnaris subluxation
4. Lunotriquetral instability
5. Pisotriquetral instability
Figures
Answer (click for answer)
Preferred Answer: 3
Recurrent subluxation of ECU tendon is characterized by painful "snap" over ulnodorsal aspect of wrist particularly on forearm rotation. Extension/ ulnar deviation of supinated wrist, displaces tendon, often audible snap. On pronation, it relocates into its normal sulcus. The sixth dorsal compartment is unique because it has a subsheath that is critical to the stability of the ECU. When these fibers are attenuated, due to either chronic or acute conditions, the ECU can subluxate in an ulnar and volar direction. The common risk factors include distal radius fracture (Colles fx), RA, entrapment from ulnar styloid frx.
Reference: Miler MD, Brinker MR Review of Orthopeadics, 3rd edition. pp305,333