De Quervain tenosynovitis and extensor digitorum brevis manus muscle
Presentation
Right wrist radial side pain for the last few days. No trauma.
Patient Data
Hypoechoic retinacular thickening involving the 1st extensor compartment and minor effusion distally. Both tendons are intact with a normal echopattern.
An extra-structure with muscle echopattern is present deep to the 4th extensor compartment. It starts at the carpal level and ends at the 3rd and 4th metacarpal distal shaft levels.
A structure with similar morphology is present in the contralateral dorsal wrist.
Case Discussion
A female presented with radial side wrist pain. The ultrasound findings matched the clinical diagnosis of De Quervain tenosynovitis. There is an accessory muscle deep in the 4th extensor compartment. It is the extensor digitorum brevis manus muscle. It is present on both sides. Normally there is no muscle deep to the extensor compartments distal to the radius.