Scaphotrapeziotrapezoid ligament
The scaphotrapeziotrapezoid (STT) ligament is one of the intracapsular, intrinsic midcarpal ligaments .
Gross anatomy
The scaphotrapeziotrapezoid ligament connects the distal pole of the scaphoid with the trapezium and trapezoid bones in a V-shaped fashion. .
Attachments
The scaphotrapeziotrapezoid ligament originates at the radial and ulnar surfaces of the distal pole of the scaphoid .
It inserts distally at the volar and radial surfaces of the trapezium and the volar surface of the trapezoid bone .
Radiographic features
MRI
The scaphotrapeziotrapezoid ligament can be difficult to visualize on MRI. It can be best appreciated on coronal, sagittal and 3D images or MR arthrograms and usually has a hypointense appearance . Likewise, any injury to the scaphotrapeziotrapezoid ligament is difficult to detect in particular if the scaphocapitate ligament is intact.
Related pathology
The ligament serves as a secondary scaphoid stabilizer. If it is injured in addition to the scapholunate ligament and scaphocapitate ligaments this can result in dorsal intercalated segment instability .
See also
