Updated: 8/23/2017

Snapping ECU

Topic
Review Topic
0
0
Evidence
3
0
0
https://upload.orthobullets.com/topic/6030/images/ecu.jpg
https://upload.orthobullets.com/topic/6030/images/attenuate.jpg
https://upload.orthobullets.com/topic/6030/images/rotation.jpg
https://upload.orthobullets.com/topic/6030/images/torn.jpg
https://upload.orthobullets.com/topic/6030/images/subsheath.jpg
Introduction
  • Overuse of wrist can lead to spectrum of ECU tendonitis and instability
  • Pathoanatomy
    • ECU subluxation is secondary to attenuation or rupture of the ECU subsheath (6th dorsal compartment)
    • attenuation  
      • remains intact but is stripped at ulnar/palmar attachment to produce a false pouch that the ECU tendon can subluxate/dislocate into
    • rupture  
      • ulnar sided ECU subsheath tears
        • ECU subluxates on supination, and reduces on pronation
      • radial sided ECU subsheath tears
        • ECU subluxates on supination, and lies on top of the torn subsheath on pronation
    • subluxation and snapping can lead to ECU tendonitis
  • Risks
    • tennis 
    • golf
Anatomy
  • Extensor tendon compartments  
    • Compartment 1 (De Quervain's Tenosynovitis )
      •  APL
      •  EBP 
    • Compartment 2 (Intersection syndrome )
      •  ECRL 
      •  ECRB 
    • Compartment 3
      •  EPL 
    • Compartment 4
      •  EIP 
      •  EDC 
    • Compartment 5 (Vaughn-Jackson Syndrome )
      •  EDM
    • Compartment 6 (Snapping ECU )
      •  ECU
  • ECU tendon
    • ECU subsheath is part of the TFCC that is most critical to ECU stability   
    • ECU subluxates during ulnar deviation, supination, wrist flexion  
      • this position has the greatest angulation of the ECU tendon with respect to the ulna
Presentation
  • Symptoms
    • pain and snapping over dorsal ulnar wrist
  • Physical exam
    • extension and supination of the wrist elicit a painful snap   
    • ECU tendon reduces with pronation 
Imaging
  •  Radiographs
    • unremarkable
  • Ultrasound
    • can dynamically assess ECU stability
  • MRI
    • can show tendonitis, TFCC pathology, or degenerative tears of ECU 
Treatment
  • Nonoperative
    • wrist splint or long arm cast 
      • indications
        • first line of treatment
      • technique
        • arm immobilized in pronation and slight radial deviation
  • Operative
    • ECU subsheath reconstruction +- wrist arthroscopy
      • indications
        • if nonoperative management fails
      • technique
        • direct repair in acute cases
        • chronic cases may require a extensor retinaculum flap for ECU subsheath reconstruction
        • wrist arthroscopy shows concurrent TFCC tears in 50% of cases
 

Please rate topic.

Average 4.0 of 15 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
ARTICLES (3)
Topic COMMENTS (6)
Private Note