Triangular ligament

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The triangular ligaments grouped with the ulnar collateral ligament and meniscal homologue, comprise the ulnar-sided components of the triangular fibrocartilage complex (TFCC). The triangular ligament attaches triangular fibrocartilage to the ulnar tip and fovea.

The triangular ligament is composed of two bands of collagen fibers and intervening loose connective tissue known as the ligamentum subcruentum:

  • proximal lamina
    • originates from the ulnar fovea, attach to the TFCC disc (i.e. triangular fibrocartilage) proper
  • distal lamina
    • originates from the ulnar styloid, attach to the TFCC disc proper and the meniscal homologue
    • contributes to the ulnar joint capsule

Radiographic features

MRI

The composition corresponds to the ligament's striated appearance (collagen fibers) with central linear bright signal (subcruentum) on coronal plane MR imaging.