Triangular fibrocartilage

Anatomy of the triangular fibrocartilage complex

Gray's anatomy illustration of the wrist, showing the triangular fibrocartilage complex

Triangular fibrocartilage complex (TFCC) is a structure located in the wrist, specifically on the ulnar side. It is composed of several ligaments and cartilage, namely the triangular fibrocartilage discus, the ulnolunate and ulnotriquetral ligaments, the meniscus homologue, the dorsal and palmar radioulnar ligaments, and the sheath of the extensor carpi ulnaris tendon.

Etymology

The term "triangular fibrocartilage complex" is derived from the structure's triangular shape and its composition of fibrocartilage and other elements. The term "complex" is used because the TFCC is not a single entity, but a complex of structures.

Structure

The TFCC is a complex structure that serves several functions in the wrist. It is composed of the following elements:

• Triangular fibrocartilage discus: This is a thick disc of fibrocartilage that separates the ulnar carpal bones from the ulnar head.
• Ulnolunate and ulnotriquetral ligaments: These are ligaments that connect the ulna to the lunate and triquetral bones, respectively.
• Meniscus homologue: This is a fibrocartilaginous structure that is analogous to the meniscus of the knee.
• Dorsal and palmar radioulnar ligaments: These ligaments stabilize the distal radioulnar joint.
• Sheath of the extensor carpi ulnaris tendon: This is a sheath that surrounds the tendon of the extensor carpi ulnaris muscle.

Function

The TFCC plays several important roles in the function of the wrist. It serves as a major stabilizer of the ulnar side of the wrist and the distal radioulnar joint. It also acts as a shock absorber, cushioning the forces transmitted across the wrist.

Clinical significance

Injury to the TFCC can result in pain, instability, and loss of function in the wrist. This can occur as a result of trauma, degeneration, or overuse. Diagnosis is typically made through physical examination and imaging studies, such as MRI. Treatment may involve conservative measures, such as rest, immobilization, and physical therapy, or surgical intervention in more severe cases.

See also

• Wrist
• Ulna
• Ligament
• Cartilage