15/05/2023
ECU cheat sheet! Patients who have a TFCC tear often develop symptoms in their ECU. When the TFCC is treated, the ECU symptoms resolve. There are also many cases that have been diagnosed as a TFCC injury which are only an ECU issue.
The ECU subsheath is critical for extensor carpi ulnaris tendon stability and part of the triangular fibrocartilage complex which is why an MRI may show tendonitis, a tear, or TFCC tear and is often misdiagnosed.
When the TFCC is involved, the ECU takes a sharper turn because the DRUJ spreads in TFCC injuries. This causes a common secondary complication to the ECU. Normal range for ulnar deviation is 30-40 degrees (3rd photo).
How do I know the difference? Start with the weight bearing test! If your weight bearing tolerance is normal, then the TFCC is fine and you want to look at the ECU.
ECU ONLY
-No pain on weight-bearing
-Healthy and injured wrist test the same on the Weight Bearing Test
-Wrist aches after wearing the WristWidget®
-Clicking or popping and pain at ECU insertion
-The WristWidget® will NOT be helpful in recovery
TFCC ONLY
-Pain on Weight Bearing
-Injured wrist tests lower than healthy wrist on the Weight Bearing Test
-Injured wrist tests higher with WristWidget®/taping than without
-The WristWidget® will be helpful in recovery
TFCC-ECU COMBO INJURY:
-You know you have a TFCC tear when there is a loss of weight-bearing tolerance and an immediate increase with tape or the WristWidget®.
-You know that the ECU is involved if you have pain to touch at the insertion of the ECU at the back of the hand when the wrist deviates towards the ulna (ulnar deviation).
For ECU taping techniques check out episode 11 in our IGTV.
For more on the ECU check out the TFCC & ulnar side pain podcast (link in bio)