Arcuate ligament of the wrist: normal MR appearance and its relationship to palmar midcarpal instability: a cadaveric study.
OBJECTIVE
To describe the magnetic resonance (MR) imaging and gross anatomic appearance of the scaphocapitate (SC) ligament and triquetrohamocapitate (THC) ligament, which are the radial and ulnar limbs of the composite arcuate ligament, a critical volar midcarpal stabilizing ligament.


METHODS
T1 spin-echo and 3D gradient-echo MR imaging in the standard, coronal oblique, and axial oblique planes were performed both before and following midcarpal arthrography in seven cadaveric wrists. The seven specimens were then sectioned in selected planes to optimally visualize the SC and THC ligaments. These specimens were analyzed and correlated with their corresponding MR images.


RESULTS
The SC and THC ligaments can be visualized in MR images as structures of low signal intensity that form an inverted "V" joining the proximal and distal carpal rows. The entire ligamentous complex is best visualized with coronal and axial oblique MR imaging but can also be seen in standard imaging planes.


CONCLUSIONS
SC and THC ligaments together form the arcuate ligament of the wrist. Their function is crucial to the normal functioning of the wrist. Palmar midcarpal instability (PMCI) is a resulting condition when abnormalities of these ligaments occur. Dedicated MR imaging in the coronal and axial imaging planes can be performed in patients suspected of having PCMI.
Chang
Weiling
W
Department of Radiology, Veterans Administration Medical Center, San Diego, CA 91942, USA. weilingchang@gmail.com
Peduto
Anthony J
AJ
Aguiar
Rodrigo O C
RO
Trudell
Debra J
DJ
Resnick
Donald L
DL
D000368:Aged; D000369:Aged, 80 and over; D001175:Arthrography / Q000379:methods; D002102:Cadaver; D050824:Carpal Joints / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007472:Iohexol; D007593:Joint Instability / Q000175:diagnosis*; D008023:Ligaments, Articular / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D014955:Wrist Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging
D003287:Contrast Media; D007472:Iohexol; D019786:Gadolinium DTPA