Objective: We have found in our practice that the normal extensor retinaculum of the wrist may appear hypoechoic on sonography and, because it is closely applied to the extensor tendons, may simulate tenosynovitis. This study prospectively evaluates the extensor retinaculum in 50 healthy adult volunteers, characterizing its sonographic appearance.
Conclusion: The extensor retinaculum has a characteristic appearance on sonography. A hypoechoic appearance from anisotropy should not be confused with tenosynovitis.