Fact-sheet: Extensor carpi ulnaris instability
  • Extensor carpi ulnaris tendon dislocation


Updated on 01/04/2019 at 9:23 AM

Note : 0/10
Share

View all RADEOS cases associated with this fact-sheet

Definition

The extensor carpi ulnaris (ECU) tendon may be subject to instability within the ulnar groove due to the angulation of its fibers in supination. This medial angulation places tension on the ECU subsheath, which, in cases of repeated pronosupination trauma, can detach from the periosteum at its medial aspect, creating a detachment pouch into which the tendon can subluxate: this is ECU instability

As the condition progresses, the subsheath may rupture and tendinopathy may develop

Clinical features

Mainly seen in patients who practice racquet sports (the hand closest to the racquet head is most commonly affected).

Ultrasound

Dynamic ultrasound with pronosupination maneuver: reveals ECU instability and subluxation

MRI

  • Displacement of the ECU tendon beyond the tangent line of the floor of the ulnar groove.
  • ECU tendinopathy: hypertrophy and T2 hyperintensity
  • Rupture of the ECU subsheath