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Article from Medscape
Background
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 the image below).[1] The TFCC is the major ligamentous stabiliser of the distal radioulnar (DRU) joint and the ulnar carpus.
The triangular fibrocartilage complex suspends the distal radius and ulnar carpus from the distal ulna. T=triquetrum; L=lunate; S=scaphoid. (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)
Functions of the TFCC are as follows:
It provides a continuous gliding surface across the entire distal face of the two forearm bones for flexionÂextension and translational movements (see the first image below)
It provides a flexible mechanism for stable rotational movements of the radiocarpal unit around the ulnar axis
It suspends the ulnar carpus from the dorsal ulnar face of the radius
It cushions the forces transmitted through the ulnocarpal axis
It solidly connects the ulnar axis to the volar carpus (see the second image below)
The triangular fibrocartilage complex provides a continuous gliding surface across the entire distal face of the radius and ulna to allow for flexionÂextension and translational movements.
http://emedicine.medscape.com/article/1240789-overview 1/8
10/11/2015 Triangular Fibrocartilage Complex Injuries: Background, History of the Procedure, Problem
Distally, the triangular fibrocartilage complex inserts into the lunate and triquetrum via the ulna lunate and ulna triquetral ligaments. The triangular fibrocartilage complex solidly connects the ulnar axis to the volar carpus. The unlabeled arrow points to the pre-styloid 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)
History of the Procedure
Since 1777, when DeSault’s original dissertation first described DRU joint injuries, much has been written about this joint and the TFCC. As Palmer pointed out,[1, 2, 3] 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 six degrees of freedom at the wrist—flexion, extension, supination, pronation, and radial and ulnar deviation.
As interest in the TFCC evolved, open repair techniques for this structure were devised. Small joint arthroscopy provides the opportunity for new techniques in the debridement or repair of these structures.
Problem
Injuries to the TFCC present as ulnarÂside wrist pain, frequently with clicking. Torn TFCCs constitute 35% of intraÂarticular fractures and 53% of extraÂarticular 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 (vs 2.5 mm for no tear) and dorsal angulation of 24° (vs 12° for no tear).
Epidemiology Frequency
Mikic looked at 180 wrist joints in 100 cadavers, ranging in age from fetuses to 94 years.[4] He demonstrated that degeneration of the 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 normalÂappearing TFCCs. Viegas and Ballantyne found similar results.[5]
Etiology
Causative conditions for TFCC injuries include the following:
Falls onto pronated hyperextended wrist
PowerÂdrill 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 ulna[6] and demonstrated that with normal axial loading, 20% of the force is transmitted through the ulna and 80% 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 the 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.[7] 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.[8]
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 the release of the TFCC from its distal ulna attachment, Tang demonstrated a 30% increase in ECU tendon excursion during wrist extension.[9] This suggests the following:
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10/11/2015 Triangular Fibrocartilage Complex Injuries: Background, History of the Procedure, Problem
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 TFCC injuries includes ulnarÂside 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 DRU joint with shucking the distal radius and ulna between the examiner’s fingers (perform a DRU joint 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 TFCC is recommended with repair as needed.
Relevant Anatomy
As the name suggests, the TFCC is triangular in shape. Palmer found an inverse relation between ulnar variance and TFCC thickness of the TFCC: The TFCC is thicker in individuals who are ulnar minus.[7] Generally, the TFCC is 1Â2 mm thick at its centre. 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 the first image below). Distally, it inserts into the lunate via the ulna lunate (UL) ligament and the triquetrum via the ulna triquetral (UT) ligament (see the 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 the third image below).
Relation of the triangular fibrocartilage complex to the distal radius and ulnar styloid.
The ulnocarpal portion of the triangular fibrocartilage complex is composed of the discus articularis, the ulna lunate (ULL), and the ulna triquetral (UTL) ligaments. Distally, the triangular fibrocartilage complex inserts into the lunate via the ulna lunate ligament and into the triquetrum via the ulna triquetral ligament.
http://emedicine.medscape.com/article/1240789-overview 3/8
10/11/2015 Triangular Fibrocartilage Complex Injuries: Background, History of the Procedure, Problem
Sigmoid notch of the distal radius with distinct dorsal, palmar, and distal margins and an indistinct proximal margin; the triangular fibrocartilage complex arises from the ulnar margin of the lunate fossa of the radius. (Reprinted with permission from Fernandez D and Palmer AK. Fractures of the Distal Radius. In: Green’s Operative Hand Surgery. Vol 1. 1999)
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 the image below). The cartilageÂcovered nonarticular pole of the ulnar head is deep to the articular disk.
The seat of the ulnar head articulates with the sigmoid notch of the distal radius. Radially, the triangular fibrocartilage complex arises from the ulnar margin of the lunate fossa of the radius. Ulnarly, the triangular fibrocartilage complex inserts into the base of the ulnar styloid. (Reprinted with permission from Fernandez D and Palmer AK. Fractures of the Distal Radius. In: Green’s Operative Hand Surgery. Vol 1. 1999)
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 10Â40% 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 by one-third in a young patient to one fourth in patients of advanced age. [4]
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 because they have no potential for healing.
The richly vascularized DRU ligament and palmar radioulnar (PRU) ligament are composed of thick, longitudinally oriented collagen fibre bundles that blend in with the central avascular fibrocartilaginous portion.
When the TFCC is viewed 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 VÂshaped 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 two distinct insertions into the ulna—a superficial portion and a deep portion. The superficial components, the DRU and PRU ligaments, insert into the base of the styloid. The deep portion, the ligamentum subcruentum, inserts into the fovea near the axis of forearm rotation.
Contraindications
Repairing TFCC tears is contraindicated in the presence of infection or
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10/11/2015 Triangular Fibrocartilage Complex Injuries: Background, History of the Procedure, Problem
degeneration. Palmer class 2 degenerative TFCC tears (see the Palmer classification for TFCC abnormalities in Medical therapy) 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 immobilisation, 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 DRU joint 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 lunateÂtriquetrum instability. If lunateÂtriquetrum 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, SauveÂKapandji procedure, or Darrach procedure that addresses the DRU joint and LT joint pathology.
Workup
Contributor Information and Disclosures
Author
James R Verheyden, MD Consulting Surgeon, Department of Orthopedic Surgery, The Orthopedic and Neurosurgical Center of the Cascades
James R Verheyden, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Medical Association, American Society for Surgery of the Hand
Disclosure: Nothing to disclose.
Coauthor(s)
Andrew K Palmer, MD Chair, Professor, Department of Orthopedics, State University of New YorkÂUpstate Medical University
Andrew K Palmer, MD is a member of the following medical societies: American Osteopathic College of Physical Medicine and Rehabilitation
Disclosure: Partner received salary from Del Palma Orthopedics for board membership.
Specialty Editor Board
Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; EditorÂinÂChief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
N Ake Nystrom, MD, PhD Associate Professor of Orthopedic Surgery and Plastic Surgery, University of Nebraska Medical Center
Disclosure: Nothing to disclose.
Chief Editor
Harris Gellman, MD Consulting Surgeon, Broward Hand Center; Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami, Leonard M Miller School of Medicine, Clinical Professor, Surgery, Nova Southeastern School of Medicine
Harris Gellman, MD is a member of the following medical societies: American Academy of Medical Acupuncture, American Academy of Orthopaedic Surgeons, American Orthopaedic Association, American Society for Surgery of the Hand, Arkansas Medical Society
Disclosure: Nothing to disclose.
Additional Contributors
Joseph E Sheppard, MD Professor of Clinical Orthopedic Surgery, Chief of Hand and Upper Extremity Service, Department of Orthopedic Surgery, University of Arizona Health Sciences Center, University Physicians Healthcare
Joseph E Sheppard, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, Orthopaedics Overseas, American Society for Surgery of the Hand
Disclosure: Nothing to disclose.
References
http://emedicine.medscape.com/article/1240789-overview 5/8
10/11/2015 Triangular Fibrocartilage Complex Injuries: Background, History of the Procedure, Problem
http://emedicine.medscape.com/article/1240789-overview 6/8
10/11/2015 Triangular Fibrocartilage Complex Injuries: Background, History of the Procedure, Problem