Triangular Fibrocartilage Complex

The triangular fibrocartilage complex (TFCC) is a structure found in the wrist. The TFCC serves as the primary stabilizer of the distal wrist joint, as well as provides for cushioning from certain activities. It works in a similar fashion to the menisci found in the knee and is often called the “wrist meniscus.” It can be injured either acutely during trauma or from repetitive overuse. There is some evidence that, over time, the TFCCs of all patients will begin to break down (usually beginning in the fourth decade of life) to a certain degree.

The TFCC is made up of several different structures. The primary components are the dorsal and palmar volar ligaments. These ligaments run from the radius to the ulna and provide for the structure of the TFCC. There is also a soft tissue disk that lies between these ligaments and provides extra support. Finally, a portion of the tendon sheath of the extensor carpi ulnaris (ECU) makes up a portion of the TFCC.

The TFCC can be injured either traumatically or through repetitive activity. Patients can suffer TFCC tears related to falls on their wrists and arms or from direct trauma to the ulnar side of the wrist. In particular, any trauma that results in the hand being forced downward against the ulna may result in a TFCC injury. TFCC injury from repetitive trauma and overuse is often seen in patients who perform activities that result in repetitive ulnar deviation of the wrist (e.g., lifting heavy weights, working with equipment such as hammers or drills). In addition, sports that result in repetitive compression of the wrist may result in TFCC tears; these sports include racquet sports, gymnastics, and diving. In addition, distal radius and ulnar fractures are often associated with TFCC tears.

The differential diagnosis of a TFCC tear includes, but is not limited to, fractures of the radius and/or ulna, tendinosis and tenosynovitis of the flexor or extensor tendons, displacement/snapping of the ECU tendon, injuries to other ligamentous or cartilaginous structures of the wrist (distal radioulnar joint [DRUJ], scapholunate, etc.), and arthroses of the wrist joint.

Diagnosis of a TFCC tear can be performed both clinically and radiographically. Typically, the patient will experience discomfort of varying degrees with palpation of the structure. Patients with small tears may experience little to no pain or limitations, while patients with larger and/or chronic tears may have constant debilitating pain both at rest and with use. The location of the tear will be important as well. Typically, the more peripheral a tear, the more likely it is to cause the patient discomfort; central tears of the TFCC can often be asymptomatic.

The outermost structure of the TFCC is easily palpated along the lateral wrist between the ulna and the lateral carpal bones (pisiform and hamate). Palpation of the structure can be accentuated with radial deviation of the hand. There may also be associated swelling around the structure, as well as “clicking” of the wrist, which may be heard or felt by the patient. Patients may also experience decreased grip strength and pain with resisted wrist dorsiflexion. The Apley Grind is the most commonly used diagnostic test. This test is usually performed with the physician gripping the hand of the patient and applying downward pressure, causing the hand to deviate toward the ulna. The hand can then have a twisting force applied to it, causing the TFCC to be compressed and exacerbating the pain.

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