eMedicine Specialties > Orthopedic Surgery > Hand & Upper Extremity

Triangular Fibrocartilage Complex Injuries

Author: James R Verheyden, MD, Consulting Surgeon, Department of Orthopedic Surgery, The Orthopedic and Neurosurgical Center of the Cascades
Coauthor(s): Andrew K Palmer, MD, Chair, Professor, Department of Orthopedics, State University of New York-Upstate Medical University
Contributor Information and Disclosures

Updated: Jun 23, 2009

Introduction

In 1981, Palmer and Werner introduced the term "triangular fibrocartilage complex" (TFCC) to describe the ligamentous and cartilaginous structures that suspend the distal radius and ulnar carpus from the distal ulna (see image below).¹ The TFCC is the major ligamentous stabilizer of the distal radioulnar joint (DRUJ) and the ulnar carpus.

Functions of the TFCC are as follows:

• Provides a continuous gliding surface across the entire distal face of the 2 forearm bones for flexion-extension and translational movements (see image below)
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    The triangular fibrocartilage complex provides a continuous gliding surface across the entire distal face of the radius and ulna to allow for flexion-extension and translational movements.

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    The triangular fibrocartilage complex provides a continuous gliding surface across the entire distal face of the radius and ulna to allow for flexion-extension and translational movements.

• Provides a flexible mechanism for stable rotational movements of the radiocarpal unit around the ulnar axis
• Suspends the ulnar carpus from the dorsal ulnar face of the radius
• Cushions the forces transmitted through the ulnocarpal axis
• Solidly connects the ulnar axis to the volar carpus (see image below)
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    Distally, the triangular fibrocartilage complex inserts into the lunate and triquetrum via the ulnolunate and ulnotriquetral ligaments. The triangular fibrocartilage complex solidly connects the ulnar axis to the volar carpus. The unlabeled arrow points to the prestyloid recess. (Reprinted with permission from Palmer AK and Werner FW: The Triangular Fibrocartilage Complex of the Wrist - Anatomy and Function. J Hand Surg; 1981; 6:153)

    [ CLOSE WINDOW ]

    

    Distally, the triangular fibrocartilage complex inserts into the lunate and triquetrum via the ulnolunate and ulnotriquetral ligaments. The triangular fibrocartilage complex solidly connects the ulnar axis to the volar carpus. The unlabeled arrow points to the prestyloid recess. (Reprinted with permission from Palmer AK and Werner FW: The Triangular Fibrocartilage Complex of the Wrist - Anatomy and Function. J Hand Surg; 1981; 6:153)

Arthroscopic and open technique studies

Yao et al compared an all-arthroscopic TFCC repair technique with an outside-in technique in 10 matched pairs of fresh-frozen cadaveric wrists and found that the all-arthroscopic technique resulted in decreased operative time; reduced postoperative immobilizations; and decreased irritation from suture knots below the skin.^3,4

In a study of 75 patients with TFCC repair by arthroscopic or open technique between 1997 and 2006, Anderson et al found that there was no statistical difference in clinical outcome for arthroscopic and open techniques for TFCC repair. They did note an increased rate of postoperative superficial ulnar pain in patients who underwent open repair (14 of 39 patients with open technique, vs 8 of 36 patients with arthroscopy). Females had a higher rate of reoperation.⁵

Reiter et al performed a retrospective study of 46 patients who underwent arthroscopic repair of Palmer class IB tears to determine patients' functional and subjective outcomes, as well as whether clinical outcomes were related to ulnar length. Good to excellent results were achieved in 63% of the patients, including increased range of motion and grip strength and pain relief. Ulnar neutral or positive variance was not a contraindication for repair and did not necessitate simultaneous ulnar shortening.⁶

History of the Procedure

Since DeSault's original dissertation in 1777 describing distal radioulnar joint (DRUJ) injuries, much has been written about the DRUJ and the triangular fibrocartilage complex (TFCC). As Palmer has pointed out,^1,7,8 humans are differentiated from lower primates by a radiocarpal joint with a TFCC interposed between the ulna and carpus.¹ This TFCC improves wrist functional stability and allows 6° of freedom at the wrist—flexion, extension, supination, pronation, and radial and ulnar deviation. As interest in this structure evolved, open repair techniques for the TFCC were devised. Small joint arthroscopy provides the opportunity for new techniques in the debridement or repair of these structures.

Problem

Injuries to the triangular fibrocartilage complex (TFCC) present as ulnar-sided wrist pain, frequently with clicking.

Torn TFCCs constitute 35% of intra-articular fractures and 53% of extra-articular fractures. There is no correlation between ulnar styloid fractures and TFCC injuries.

Patients with a torn TFCC display ulnar variance (radial shortening) that is on average 4.6 mm, versus 2.5 mm for no tear, and dorsal angulation of 24° versus 12° for no tear.

Frequency

Mikic looked at 180 wrist joints in 100 cadavers, ranging in age from fetuses to 94 years.⁹ He demonstrated that degeneration of the triangular fibrocartilage complex (TFCC) begins in the third decade of life and progressively increases in frequency and severity in subsequent decades. After the fifth decade of life, he noted no normal appearing TFCCs. Viegas and Ballantyne found similar results.¹⁰

Etiology

Causative conditions for triangular fibrocartilage complex (TFCC) injuries include the following:

• Falls onto pronated hyperextended wrist
• Power-drill injuries in which the drill binds and rotates the wrist instead of the bit
• Distraction force applied to the volar forearm or wrist
• Distal radius fractures

Pathophysiology

Palmer and Werner looked at the axial load distribution through the distal radius and ulna¹¹ and demonstrated that with normal axial loading, 20% of the force is transmitted through the ulna and 80% is transmitted through the radius. Their data also illustrated that small changes in relative ulnar length can significantly alter load patterns across the wrist. For example, with a distal radius fracture that settles 2.5 mm, an increase in ulnar axial load of approximately 40% can be expected.

Palmer, Werner, Glisson, and Murphy demonstrated that the percentage of axial force transmitted through the ulna decreases by sequential removal of the horizontal portion of the TFCC.¹² This percentage decrease is accentuated with more positive ulnar variance.

In a cadaver study, Adams demonstrated that no significant kinematic or structural changes resulted from an excision that did not violate the peripheral 2 mm of the disk and that constituted less than two thirds of the disk area.¹³

Triangular fibrocartilage complex (TFCC) tears are associated with a positive ulnar variance. Ulnar variance increases with pronation and grip and decreases with supination.

The floor of the extensor carpi ulnaris (ECU) tendon sheath broadly connects with the TFCC. After release of the TFCC from its distal ulna attachment, Tang demonstrated a 30% increase in ECU tendon excursion during wrist extension.¹⁴ This suggests the following:

• The TFCC is an important pulley for the ECU tendon.
• Disruption of the normal ECU excursion may contribute to abnormal loading and force transmission through the ulnar wrist and TFCC.

Presentation

The history of triangular fibrocartilage complex (TFCC) injuries includes ulnar-sided wrist pain (frequently accompanied by clicking), a fall or trauma, and/or mechanical symptoms that improve with rest and worsen with activity.

In the physical examination, look for the following:

• Painful grinding or clicking with wrist range of motion (ROM)
• Weakness
• Ulnar deviation of the wrist with the forearm in neutral produces ulnar wrist pain and occasional clicking (Perform a TFCC compression test.)
• Instability of the distal radioulnar joint (DRUJ) with shucking the distal radius and ulna between the examiner's fingers (Perform a DRUJ stress test; always compare this with the opposite wrist.)
• Piano key sign, which is a prominent and ballottable distal ulna with full pronation of the forearm
• Ulnar carpal sag
• Lunotriquetral (LT) interval tenderness
• Positive LT ballottement or shuck test
• ECU tendon subluxation

Indications

If a congruent reduction cannot be achieved or if the dorsal instability is unstable in 30° of supination, then arthroscopic evaluation of the triangular fibrocartilage complex (TFCC) is recommended with repair as needed.

Relevant Anatomy

The triangular fibrocartilage complex (TFCC) is triangular in shape. Palmer found an inverse relationship between ulnar variance and the thickness of the TFCC; the TFCC is thicker in individuals who are ulnar minus.¹² Generally, the TFCC is 1-2 mm thick at its center. This may thicken to 5 mm where the TFCC inserts into the eccentric concavity of the ulnar head and projecting styloid.

The TFCC extends ulnarly to insert into the base of the ulnar styloid (see first image below). Distally, it inserts into the lunate via the ulnolunate (UL) ligament and the triquetrum via the ulnotriquetral (UT) ligament (see second image below), hamate, and base of the fifth metacarpal. Radially, the TFCC arises from the ulnar margin of the lunate fossa of the radius (see third image below).

Underneath the TFCC is the ulnar head. The seat, or the convex portion of the ulnar head, articulates with the sigmoid notch of the radius (see image below). The cartilage-covered nonarticular pole of the ulnar head is deep to the articular disk.

The ulnocarpal portion of the TFCC is composed of the discus articularis and the UL and UT ligaments (referred to by some as the disk carpal ligaments).

Embryologic studies have demonstrated that these ligaments arise from the disk and are critical to the carpal suspensory function of the TFCC.

The dorsal and palmar branches of the anterior interosseous artery and dorsal and palmar radiocarpal branches from the ulnar artery supply blood to the periphery of the TFCC. These vessels supply the TFCC in a radial fashion, with histologic sections demonstrating that the vessels penetrate the peripheral 10-40% of the disk. The central portion and radial attachment are avascular.

Mikic demonstrated that the percentage of the peripheral disk that is vascularized is reduced from one third in a young patient to one fourth in patients of advanced age.⁹

Because the periphery of the TFCC has a good blood supply, tears in this region can be repaired. By contrast, tears in the central avascular area must be debrided, as they have no potential for healing.

The richly vascularized dorsal radioulnar ligament (DRUL) and palmar radioulnar ligament (PRUL) are composed of thick, longitudinally oriented collagen fiber bundles that blend in with the central avascular fibrocartilaginous portion.

Viewing the TFCC during wrist arthroscopy, the styloid attachment appears folded. Some of the blood vessels to the TFCC enter between these folds. This fold, combined with the vascular hilum, is termed the ligamentum subcruentum, which actually is the confluence of the TFCC and the V-shaped ligament (disk ligament) as it extends from the hilar area of the styloid to its twin insertions on the lunate and triquetrum.

From a distal perspective, the TFCC has 2 distinct insertions into the ulna—a superficial portion and a deep portion. The superficial components, the DRUL and PRUL, insert into the base of the styloid. The deep portion, or the ligamentum subcruentum, inserts into the fovea near the axis of forearm rotation.

Contraindications

Repairing triangular fibrocartilage complex (TFCC) tears is contraindicated in the presence of infection or degeneration. Palmer class 2 (see the Palmer classification for triangular fibrocartilage complex abnormalities in Treatment, Medical therapy, below) degenerative TFCC tears represent a pathologic progression of disease associated with ulnar impaction syndrome.

Degeneration of the TFCC is found with repetitive pronation and axial grip loading in association with ulnar positive variance and impaction between the ulnar head and the proximal pole of the lunate. Treatment of degenerative TFCC tears associated with ulnar impaction syndrome consists of nonoperative treatment first with immobilization, avoidance of aggravating activities, and nonsteroidal anti-inflammatory drugs (NSAIDs).

Palmer class 2A and 2B lesions that fail to respond to conservative treatment are treated with gentle debridement. If the patient is ulnar positive and symptomatic, a formal ulnar shortening is considered. An arthroscopic wafer is contraindicated, as this would require resection of intact TFCC to perform the procedure or require performing the procedure entirely through the distal radioulnar joint (DRUJ) portals.

The surgical indications for an arthroscopic wafer procedure are a Palmer class 2C or 2D lesion in an ulnar positive variance of not more than 2 mm without evidence of lunate-triquetrum instability. If lunate-triquetrum instability is present, this is addressed with formal ulnar shortening in an attempt to tighten the ulnocarpal ligaments and decrease the motion between the lunate and triquetrum.

For patients with an ulnar positive variance of more than 2 mm, formal ulnar shortening is performed. For patients with ulnar neutral or negative variance and a Palmer class 2C lesion, an arthroscopic debridement is performed. Palmer class 2E lesions respond unpredictably to arthroscopic debridement. They are usually treated with a salvage procedure such as a limited ulnar head resection, Sauve-Kapandji procedure, or Darrach procedure that addresses the DRUJ and lunate-triquetrum joint pathology.

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