Alexandre Norio Massaki MD, Presenter: Nothing to Disclose

Jeffrey Tan, Abstract Co-Author: Nothing to Disclose

Eric Y. Chang MD, Abstract Co-Author: Nothing to Disclose

Brady Kirk Huang MD, Abstract Co-Author: Nothing to Disclose

Donald L. Resnick MD, Abstract Co-Author: Nothing to Disclose

To demonstrate the anatomy of the extensor retinaculum (ER) of the wrist using gross anatomic correlation with magnetic resonance (MR) imaging after ultrasonographic-guided tenography, and its morphological appearance and changes with dorsiflexion of the wrist to define the morphological features of extensor tendons impingement in athletes who perform repetitive wrist dorsiflexion.

This cadaveric study did not require institutional review board approval or informed consent according to the rules of the hospital where the study was performed. Ten upper extremities were harvested from fresh cadavers (seven men and three women, 53 to 91 years of age at death, mean 77.5). MR imaging before and after an ultrasound-guided tenography of the wrist was performed, followed by gross anatomic correlation. Two radiologists interpreted the MR images and sections by consensus for the anatomic landmarks of the ER, and morphological changes occurring during dorsiflexion of the wrist were measured and analyzed.

The ER of the wrist appeared as a band of low signal intensity on T1 and PD-weighted images. Due to its orientation, axial images were best suited to depict the ER anatomy; specifically, localization of the bony landmarks and their septal attachments. A constant pattern of morphologic changes of the ER after dorsiflexion was seen: from a fusiform morphology in the neutral position seen in sagittal images, the ER shortens and thickens at the abutment point where the extensor tendons of the fourth compartment have a curved excursion during dorsiflexion. The width and thickness of the ER in neutral position averaged 13.56 mm and 1.67 mm, respectively. In wrist dorsiflexion, the average of the width and thickness changed to 8.68 mm and 2.15 mm, respectively.

MR imaging is a useful technique to demonstrate the ER of the wrist, septal attachments, and morphological changes during dorsiflexion of the wrist that lead to impingement of the extensor tendons.

The extensor retinaculum of the wrist is an important and complex structure that may have clinical implications to the development of dorsal wrist impingement of the extensor tendons.

Massaki, A, Tan, J, Chang, E, Huang, B, Resnick, D, The Extensor Retinaculum of the Wrist and Tendon Impingement: Gross Anatomic Correlation with MR Imaging after Ultrasonographic-Guided Tenography.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12029097.html