What's the Diagnosis? By Dr. Jacob Martin

A 40 yo M presents to the ED with R wrist pain. Onset was just before arrival when he was lifting at work, "felt a pop" and had sudden onset of pain. Exam reveals swelling and tenderness of the R wrist. Neurovascular exam is normal. A R wrist xray is done and shown below.  What's the diagnosis? (scroll down for answer)



Answer: Scapholunate Dissociation

  • Background
    • scapholunate ligament is most commonly injured ligament in the wrist
    • SLD is part of a spectrum of traumatic carpal bone instabilities
  • Etiology
    • most commonly occurs w/ FOOSH- causes forceful wrist extension, rupturing the scapholunate interosseous ligament
    • also associated with spastic paresis, RA, and congential ligament laxity
  • Presentation
    • wrist swelling and point tenderness over dorsal aspect of wrist
    • pain w/ wrist extension, radial deviation, and "clicking" sensation with movement
  • Diagnosis
    • obtain AP and lateral views (+/- grip compression view/wrist in ulnar deviation)
    • radiographic signs:
      • widening of the scapholunate joint space > 3mm ("Terry Thomas sign")
      • cortical ring sign-- loss of ligamentous support results in rotary subluxation and palmar tilt of the scaphoid on AP radiograph 
    • MRI provides definitive diagnosis, rarely done in ED 
  • ED Management
    • pain management
    • radial gutter splint
    • urgent referral to ortho/hand specialist 
  • Pearls and Pitfalls
    • prompt recognition crucial
    • delayed diagnosis is associated with chronic pain, joint instability, inflammatory arthritis, long-term degenerative changes



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Long B, Koyfman A. Wrist Injuries. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, StapczynskiJ, Cline DM, ThomasSH. eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill; Accessed September 29,2020.https://accessmedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=222324635

Ramponi D, McSwigan T. ScapholunateDissociation.Adv Emerg Nurs J. 2016;38(1):10-14.doi:10.1097/TME.0000000000000094

Stevenson M, Levis JT. Image Diagnosis: Scapholunate Dissociation.Perm J. 2019;23:18-237. doi:10.7812/TPP/18-237