Dorsal deltoid ligament complex of the thumb
The dorsal deltoid ligament complex of the thumb encases the first carpometacarpal joint from the dorsal and radial aspect and is considered as a primary stabilizer of the first carpometacarpal joint.
Gross anatomy
The dorsal deltoid ligament complex of the thumb consists of the following three capsular ligaments:
- dorsoradial ligament
- dorsal central ligament
- posterior oblique ligament
The dorsoradial ligament is located radially partially covered by the abductor pollicis longus tendon insertion, from radial to ulnar followed by the dorsal central and the posterior oblique ligament, the latter is subjacent to the extensor pollicis longus and the dorsal central ligament to the extensor pollicis brevis tendon .
Attachments
The dorsal deltoid ligament complex of the thumb originates from the dorsal tubercle of the trapezium, with the dorsoradial ligament on the radial side and the dorsal central and posterior oblique ligament taking their proximal attachments at the dorsal surface .
They generate a fan-shaped broad attachment at the radial and dorsal aspects of the first metacarpal base .
Radiographic features
MRI
The dorsal deltoid ligament complex of the thumb is best visualized on MRI in sagittal images or with 3D images as a hypointense linear structure, connecting the trapezium to the first metacarpal on the dorsal side .
Related pathology
The ligament is involved in the following pathologic conditions :
- traumatic carpometacarpal joint injury
- sprain
- dislocation
- Bennett fracture, Rolando fracture
- carpometacarpal joint arthritis
See also
