MR-IMAGING OF ANATOMY AND TEARS OF WRIST LIGAMENTS

Numerous intrinsic and extrinsic wrist ligaments are visible at magnet ic resonance (MR) imaging. Because the previously published descriptio ns of these ligaments were often conflicting, the authors derived a cl assification system based on a functional perspective and their experi ence with MR imaging, arthroscopy, and surgical dissection. This syste m was used to evaluate MR images of 23 cadaveric wrists for the presen ce and integrity of 16 wrist ligaments. MR images were prospectively a nalyzed by two observers, and all findings were correlated with the re sults of arthroscopy. The best detection rates and diagnostic confiden ce rates were achieved for the triangular fibrocartilage (100% and 100 %, respectively) and the scapholunate ligament (91% and 87%, respectiv ely). Other ligaments were less well seen, partly because of their siz e and course. Eighty-two percent of the triangular fibrocartilage tear s, 50% of the scapholunate tears, and 40% of the lunotriquetral tears seen at arthroscopy were detectable on MR images. Identification of th ese three types of tears on MR images is important because they are fu nctionally significant and because there are accepted methods of treat ing them in orthopedic practice.