Ulnotriquetral ligament
The ulnotriquetral ligament is one of the intracapsular extrinsic palmar ulnocarpal ligaments and a component of the ulnocarpal complex .
Gross anatomy
The ulnotriquetral ligament forms the anterior and ulnar part of the ulnocarpal joint capsule together with the ulnolunate ligament, with which it shares a common origin and connects the volar radioulnar ligament and thus the triangular fibrocartilage complex to the triquetral bone .
Attachments
The ulnotriquetral ligament originates together with the ulnolunate ligament from the volar radioulnar ligament .
Distally the ulnotriquetral ligament fans out and inserts broadly onto the palmar proximal and ulnar cortex of the triquetral bone .
Variant anatomy
The ulnotriquetral ligament features often a pisotriquetral and prestyloid orifice and variable distal attachments to the styloid process .
Radiographic features
Ultrasound
The ulnotriquetral ligament can be visualized on ultrasound with the transducer placed at the volar ulnar aspect of the wrist in the longitudinal plane. The long axis of the ligament is then displayed as an echogenic, fibrillary structure coursing over the ulnocarpal joint and connecting the volar radioulnar ligament to the triquetrum. Proximally it cannot be demarcated from the ulnolunate ligament .
MRI
The ulnotriquetral ligament can be visualized on MRI best on coronal or 3D images . With proper anatomical knowledge, it can be also variably seen on sagittal images. It has a hypointense, striated appearance and is seen anterior to the medial ulnocarpal joint.
Related pathology
The ligament is most likely injured or involved in the following pathologic conditions :
- traumatic triangular fibrocartilage complex injury
- ulnar-sided perilunate instability
See also
