Imaging Studies
Plain radiography
Obtain neutral forearm rotation posteroanterior (PA) and lateral x-rays of the wrist to allow assessment of ulnar variance and to assess for chondromalacia of the lunate or ulnar head, degenerative joint disease of the distal radioulnar joint (DRUJ), lunotriquetral (LT) or scapholunate (SL) instability, dorsiflexed intercalated segment instability (DISI), or volarflexed intercalated segment instability (VISI).
Wrist arthrography
The accuracy and diagnostic capability of triple-injection wrist arthrograms have been challenged over the past decade. The test is not specific, with a high incidence of findings on the contralateral asymptomatic side. Wrist arthrography has poor diagnostic agreement with chronic wrist pain.
Positive wrist arthrograms are obtained in 27% of asymptomatic adults. Palmer class 1B tears have positive arthrograms with a DRUJ injection but not with a radiocarpal injection. Palmer class 1C tears have variable findings. Palmer class 1D tears usually have positive arthrograms.
Magnetic resonance imaging
Magnetic resonance imaging (MRI) can predict triangular fibrocartilage complex (TFCC) lesions with 0.8 sensitivity and 0.7 specificity using a dedicated wrist coil. [32, 33, 34] Fat-suppression MRI scans best exhibit the complex structure of the TFCC.
A prospective study by Lee et al suggested that the addition of axial traction during wrist magnetic resonance arthrography may significantly improve the ability of this modality to detect and visualize tears of the TFCC. [35]
A study by Thomsen et al found postcontrast 3T indirect magnetic resonance arthrography to have better diagnostic performance than precontrast imaging for the overall detection of class 1B TFCC tears. [36]
A study by Zhan et al suggested that the more detailed injury patterns detectable with high-resolution 3T MRI may indicate the need for refinement of the classic Palmer classification of TFCC injuries. [37]
Ultrasonography
Ultrasonography (US) has not been as widely employed for imaging TFCC lesions as the preceding modalities have. However, high-resolution US may be useful for diagnosing these injuries. [38] A study by Yuine et al found that using force-monitor US to assess DRUJ instability may help identify TFCC-injured wrists. [39]
Procedures
Wrist arthroscopy has been the criterion standard for diagnosis of these injuries; it can be a diagnostic tool or a therapeutic tool. When compared with other imaging studies, wrist arthroscopy has typically been found to be more accurate. It also allows assessment of the size of the tear, determination of whether an unstable flap is present, and detection of associated synovitis and chondral and ligamentous lesions. However, one study suggested, on the basis of relatively low interrater correlation, that the status of arthroscopy as the reference standard should be reconsidered. [40]
With the trampoline test, normally a probe should bounce off of the TFCC. If a probe sinks into the TFCC as if it is on a feather bed, a tear is usually present.
Wrist arthroscopy is used in the diagnosis of TFCC tears associated with distal radius fractures. Richards examined 118 fractures [41] ; these fractures had wrist arthroscopy that required reduction and fixation because of a failure to obtain or maintain a reduction.
Lee Master et al undertook a study to determine the accuracy of the wrist insufflation test on the basis of mean radiocarpal and midcarpal joint space volumes in 29 patients who underwent three- or four-portal radiocarpal and radial midcarpal portal insufflation before wrist arthroscopy. [42] They concluded that the test allowed detection of complete SL interosseous ligament and TFCC tears and complete SL interosseous ligament and LT interosseous ligament tears.
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Triangular fibrocartilage complex suspends distal radius and ulnar carpus from 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)
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Triangular fibrocartilage complex provides continuous gliding surface across entire distal face of radius and ulna to allow for flexion-extension and translational movements.
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Distally, triangular fibrocartilage complex inserts into lunate triquetrum via ulnolunate and ulnotriquetral ligaments. Triangular fibrocartilage complex solidly connects ulnar axis to volar carpus. Unlabeled arrow points to 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)
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Relation of triangular fibrocartilage complex to distal radius and ulnar styloid.
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Ulnocarpal portion of triangular fibrocartilage complex (TFCC) is composed of discus articularis, ulnolunate ligament (ULL), and ulnotriquetral ligament (UTL). Distally, TFCC inserts into lunate via ULL and into triquetrum via UTL.
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Sigmoid notch of distal radius with distinct dorsal, palmar, and distal margins and indistinct proximal margin; triangular fibrocartilage complex arises from ulnar margin of lunate fossa of radius. (Reprinted with permission from Fernandez D and Palmer AK. Fractures of the Distal Radius. In: Green's Operative Hand Surgery. Vol 1. 1999)
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Seat of ulnar head articulates with sigmoid notch of distal radius. Radially, triangular fibrocartilage complex (TFCC) arises from ulnar margin of lunate fossa of radius. Ulnarly, TFCC inserts into base of 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)
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Palmer class 1A tear of triangular fibrocartilage complex that is being probed.
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Palmer class 1A tear of triangular fibrocartilage complex after debridement, being treated with electrothermal wand.
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Palmer class 1A tear of triangular fibrocartilage complex after debridement with shaver and thermal treatment.
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Traumatic ulnar-side Palmer class 1B tear of triangular fibrocartilage complex.
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Palmer class 1B tear of triangular fibrocartilage complex treated with outside-in technique using 2-0 polydioxanone sutures and wire loop.
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Completion of outside-in repair for Palmer class 1B tear of triangular fibrocartilage complex.
