Deep transverse metacarpal ligament
Joints and ligaments · Latin: Ligamentum metacarpeum transversum profundum
The deep transverse metacarpal ligament (also called the deep transverse palmar ligament) is a narrow fibrous band which runs across the palmar surfaces of the heads of the second, third, fourth and fifth metacarpal bones, connecting them together.
Definition from Wikipedia, CC BY-SA 4.0.