Triangular fibrocartilage complex (TFCC) tear is the most common cause of ulnar-sided wrist pain and instability. TFCC provides distal radioulnar joint (DRUJ) stability and transmits axial loads, consisting of: articular disc (triangular fibrocartilage), dorsal and palmar radioulnar ligaments, ulnar collateral ligament, meniscus homologue, and subcapsular recess. Palmer classification separates traumatic (Class I) and degenerative (Class II) tears. Coronal MRI showing TFCC signal abnormality is diagnostic. MR arthrography is superior to conventional MRI (sensitivity 90%+ vs 75-85%). 3T MRI is significantly superior to 1.5T.
Age Range
20-55
Peak Age
35
Gender
Equal
Prevalence
Common
TFCC is a complex structure filling the space between the radial sigmoid notch and ulnar head on the ulnar side of the wrist. The main component, the articular disc, extends from the distal radius to the ulnar styloid and transmits 20% of axial loads through the ulnocarpal joint (this ratio increases with positive ulnar variance). Traumatic tears (Palmer Class I) result from falls, forceful rotation, or axial loading. Central tears are in the avascular zone with poor healing potential; peripheral tears are in the vascular zone and are repairable. Degenerative tears (Palmer Class II) are age-related, more common with positive ulnar variance — the longer ulna creates friction (impaction) on the disc. MRI disc signal increase reflects increased water content in fibrocartilage: degeneration and tear → collagen disorganization → free water seepage → hyperintense signal on T2.
Linear hyperintense signal extending to the surface of the TFCC articular disc on coronal T2-weighted images is the most reliable conventional MRI finding of tear.
On coronal T2-weighted (especially gradient-echo or 3D sequences) images, linear or focal T2 signal increase is seen in the TFCC articular disc. Normal TFCC shows homogeneous low signal (fibrocartilage). Tear appears as linear high signal extending to the inferior (articular) or superior surface of the disc. In full-thickness tear, signal increase reaches both surfaces.
Report Sentence
Linear T2 signal increase is noted in the TFCC articular disc on coronal images, consistent with TFCC tear.
On MR arthrography, after gadolinium injection into the radiocarpal joint, contrast leaking from the TFCC disc into the DRUJ on T1 fat-sat images is direct evidence of full-thickness tear. MRA sensitivity is 90-95%, specificity 88-93%, superior to conventional MRI.
Report Sentence
Contrast material injected into the radiocarpal joint is seen leaking into the DRUJ on MR arthrography, consistent with full-thickness TFCC tear.
On coronal MRI, positive ulnar variance (ulnar distal articular surface longer than radius) can be measured. Positive ulnar variance is a predisposing factor for degenerative TFCC tear — the longer ulna applies chronic impaction force to the TFCC disc. Normal ulnar variance is 0 ± 2mm; >2mm positive variance is considered pathological.
Report Sentence
Positive ulnar variance is noted, creating susceptibility to chronic impaction force on the TFCC.
On T2/STIR, bone marrow edema may be seen in the proximal surface of the lunate and/or triquetrum — indicating ulnocarpal impaction syndrome, frequently associated with degenerative TFCC tear. Bone marrow edema in the ulnar head may also accompany.
Report Sentence
Bone marrow edema is noted in the proximal lunate, consistent with ulnocarpal impaction syndrome.
With high-frequency US (≥12 MHz), the dorsal TFCC component and articular disc can be evaluated. Tear appears as a hypoechoic defect. Dynamic US can demonstrate DRUJ instability during pronation/supination. US sensitivity is lower than MRI but offers advantages of speed, cost, and dynamic assessment.
Report Sentence
A focal hypoechoic defect is noted in the TFCC region on US; further evaluation (MR arthrography) is recommended for TFCC tear.
Criteria
Traumatic, tear in central avascular zone of disc.
Distinct Features
Low healing potential (avascular). Debridement treatment. MRI: central disc defect.
Criteria
Traumatic, detachment from ulnar styloid insertion. Most common type requiring surgical repair.
Distinct Features
High healing potential (vascular zone). Repairable. DRUJ instability common.
Criteria
Age and use-related degenerative tear. Stage A-E (wear → perforation → lunate chondromalacia → LT ligament tear → ulnocarpal arthritis).
Distinct Features
Positive ulnar variance commonly accompanies. Lunate/triquetral chondromalacia may accompany. Ulnar shortening osteotomy may be considered.
Distinguishing Feature
De Quervain shows first compartment tendon sheath pathology at radial styloid level, while TFCC tear shows ulnar-sided disc signal abnormality
Distinguishing Feature
Ganglion cyst is a T2-bright cystic lesion that may be secondary to TFCC tear; structural disc disruption is the primary finding in TFCC tear
Distinguishing Feature
Epicondylitis shows pathology at tendon origins at elbow level, while TFCC tear is at wrist level
Urgency
routineManagement
surgicalBiopsy
Not NeededFollow-up
specialist-referralTFCC tear treatment is planned based on Palmer classification, type, and location, and referral to wrist arthroscopy specialist is recommended. Conservative treatment (first step — 4-6 weeks): wrist splint (dorsal block or muenster splint — stabilizes DRUJ), NSAIDs, activity modification, corticosteroid injection (ulnocarpal joint or DRUJ — short-term pain relief). Surgical treatment (non-responsive to conservative or specific indications): Palmer Class IA (central perforation): arthroscopic debridement — low healing potential in central avascular zone, unstable edges are shaved. Success rate 80-85%. Palmer Class IB (peripheral ulnar tear): arthroscopic repair — high healing potential in peripheral vascular zone, fixed to ulnar styloid with suture anchor technique. Most common type requiring surgery and strongest association with DRUJ instability. Success rate 85-90%. Palmer Class IC (distal detachment): with carpal ligament repair. Palmer Class ID (radial side tear): avulsion from radial insertion, surgical refixation. Palmer Class II (degenerative): debridement (Stage A-C) ± ulnar shortening osteotomy (corrects positive ulnar variance — reduces impaction force on TFCC). Stage D-E may require lunotriquetral ligament repair and additional procedures. 3T MRI or MR arthrography is the gold standard for preoperative evaluation — assessing tear type, location, and accompanying pathologies (ulnocarpal impaction, lunotriquetral ligament, carpal instability).
Treatment of TFCC tears depends on tear type and patient symptoms. Degenerative tears are generally treated conservatively. Traumatic peripheral tears (Class 1B-1D) are in the vascularized zone and are treated with arthroscopic repair. Central perforations (Class 1A) are in the avascular zone and are debrided.