Triangular Fibrocartilage Tear Syndrome
Triangular fibrocartilage tear syndrome, also known as triangular fibrocartilage complex (TFCC) lesion, is caused by trauma or degenerative changes to the wrist. The TFCC is a group or complex of ligament and cartilage structures that together serve four major functions related to the function of the human wrist, as follows: (1) The TFCC helps suspend the distal radius and ulnar carpus from the distal ulna; (2) the TFCC is the major ligamentous stabilizer of the distal radioulnar joint; (3) the TFCC provides a continuous gliding surface across the entire distal face of the radius and ulna to allow smooth flexion/extension and translational movements of the wrist; and (4) the TFCC acts as a shock absorber for forces transmitted over the ulnocarpal axis.
Function of the Triangular Fibrocartilage Complex
|Helps suspend distal radius and ulnar carpus from distal ulna|
Acts as major ligamentous stabilizer of distal radioulnar joint
Provides continuous gliding surface across entire distal face of radius and ulna
Allows for smooth flexion/extension and translational movements of wrist
Acts as shock absorber for forces transmitted over ulnocarpal axis
Degeneration of the TFCC begins to occur as part of the natural aging process in the third decade. This degenerative process predisposes the TFCC to traumatic injury. Common injuries that lead to TFCC tear syndrome are listed in the below table. These injuries include falls onto a fully pronated and hyperextended wrist; waterskiing and horseback riding injuries, in which the patient is dragged by the wrist by a tangled ski rope or reins, causing critical distraction forces to be applied to the volar forearm and wrist; power drill injuries, in which the drill bit binds and the drill handle forcibly rotates the wrist rather than the drill bit; and distal radius fractures. Fractures of the distal radius usually affect the radial side of the TFCC, and the clinical symptoms, as described subsequently, may be less clear-cut.
Common Causes of Triangular Fibrocartilage Tear Syndrome
|Falls onto fully pronated and hyperextended wrist|
Waterskiing and horseback riding dragging injuries causing critical distraction forces to be applied to volar forearm and wrist
Power drill injuries in which the drill bit binds and the drill handle forcibly rotates the wrist rather than the drill bit
Distal radius fractures
Patients with triangular fibrocartilage tear syndrome usually give a history of trauma to the affected wrist, although older patients may report ulnar-side wrist pain in the absence of trauma, often attributing their symptoms to arthritis. Reports of increased pain when stirring coffee or other activities that require rotation of the distal radioulnar joint are common with triangular fibrocartilage tear syndrome. Some patients also may report a catching or clicking sensation with movement of the wrist and a feeling of weakness. Occasionally, patients note that the bones beneath their little finger have sunken in. This finding is due to the loss of support of the carpal bones on the ulnar side of the wrist resulting from disruption of the TFCC.
What are the Symptoms of Triangular Fibrocartilage Tear Syndrome
Physical examination of patients with triangular fibrocartilage tear syndrome reveals pain on rotation of the wrist with a marked exacerbation of this pain with stress loading of the distal radioulnar joint with the wrist in pronation and supination. Hyperpronation may also reproduce the pain. A clicking sensation may be appreciated by the examiner on range of motion and depression or sag of the carpals on the ulnar side of the unsupported wrist.
Instability of the distal radioulnar joint often can be shown by shucking or pressing one’s fingers between the distal radius and ulna. Similar instability may be shown between the lunotriquetral interval. A positive piano key sign is often present and can be elicited by pressing down on the ulnar styloid as if it were a piano key. If the ulnar styloid readily depresses, the test is considered positive
How is Triangular Fibrocartilage Tear Syndrome diagnosed?
Plain radiographs are indicated in all patients who present with triangular fibrocartilage tear syndrome to rule out underlying occult bony pathological processes.
Based on the patient’s clinical presentation, additional tests, including complete blood cell count, uric acid level, erythrocyte sedimentation rate, and antinuclear antibody testing, may be indicated. Magnetic resonance imaging (MRI) of the wrist is indicated in all patients suspected to have triangular fibrocartilage tear syndrome or if other causes of joint instability, infection, or tumor are suspected.
Magnetic resonance arthrography also will help confirm the diagnosis of fibrocartilage tear syndrome in questionable cases, as will arthroscopy of the wrist. Ultrasound imaging will also help confirm the diagnosis and identify other causes of ulnar-sided pain. Electromyography is indicated if coexistent ulnar or carpal tunnel syndrome is suspected. A very gentle injection of the radioulnar joint with small volumes of local anesthetic and steroid provides immediate improvement of the pain, but ultimately surgical repair is required.
Coexistent arthritis, gout of the radioulnar joint, carpometacarpal and interphalangeal joints, and tendinitis also may coexist with triangular fibrocartilage tear syndrome and exacerbate the patient’s pain and disability.
Ulnocarpal abutment syndrome, Kienböck disease, and extensor carpi ulnaris tendinitis also may mimic the pain of triangular fibrocartilage tear syndrome.
Initial treatment of the pain and functional disability associated with triangular fibrocartilage tear syndrome should include a combination of nonsteroidal antiinflammatory drugs (NSAIDs) or cyclooxygenase-2 (COX-2) inhibitors and short-term immobilization of the wrist. Local application of heat and cold also may be beneficial.
For patients who do not respond to these treatment modalities, an injection of a local anesthetic and steroid into the radioulnar joint may be a reasonable next step. Vigorous exercises should be avoided because they would exacerbate the patient’s symptoms. Ultimately, surgical repair is the treatment of choice.
Failure to treat significant triangular fibrocartilage tear syndrome surgically usually results in continued pain and disability and in some patients leads to ongoing damage to the wrist.
Injection of the radioulnar joint with local anesthetic and steroid is a safe technique if the clinician is attentive to detail, specifically using small amounts of local anesthetic and steroid and avoiding high injection pressures, which may disrupt the complex further. Another complication of this injection technique is infection. This complication should be exceedingly rare if strict aseptic technique is followed. Approximately 25% of patients report a transient increase in pain after this injection technique, and patients should be warned of this possibility.
Triangular fibrocartilage tear syndrome is a straightforward diagnosis in the presence of obvious antecedent trauma. The diagnosis is less obvious in the absence of trauma, however, unless the clinician includes it in the differential diagnosis with all patients with ulnar-sided wrist pain.
Coexistent arthritis, tendinitis, and gout also may contribute to the pain and may require additional treatment with more localized injection of a local anesthetic and depot steroid.
The use of physical modalities, including local heat and cold and immobilization of the wrist, may provide symptomatic relief. Vigorous exercises should be avoided because they would exacerbate the patient’s symptoms and may cause further damage to the wrist. Simple analgesics and NSAIDs may be used concurrently with this injection technique.