Mateusz Gładysz FESSH prep

FESSH prep Imaging Carpal alignment — Gilula's arcs, scapholunate angle and gap, DISI/VISI, MRI and arthroscopic grading

Radiographic assessment of carpal alignment

Last reviewed v1.0

FESSH-030Imaging●●○ intermediate

Regarding the radiographic assessment of carpal alignment and instability:

  1. 1.On a neutral posteroanterior radiograph Gilula described three smooth carpal arcs, and a step or break in any arc indicates carpal malalignment until proven otherwise.

  2. 2.In a dorsal intercalated segment instability (DISI) deformity the lunate is palmar-flexed on the lateral radiograph.

  3. 3.A scapholunate interval of 4 mm on a standard posteroanterior radiograph is by itself diagnostic of scapholunate dissociation.

  4. 4.For scapholunate interosseous ligament tears, with arthroscopy as the reference standard, MR arthrography outperforms 3 T MRI, which in turn outperforms 1.5 T MRI.

  5. 5.In a Geissler grade IV scapholunate injury the interosseous ligament is completely torn and a 2.7-mm arthroscope can be passed between the scaphoid and lunate (the drive-through sign).

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Question ID
FESSH-030
First published
Last reviewed
Version
v1.0
Answer key and explanations — open after answering

  1. 1. On a neutral posteroanterior radiograph Gilula described three smooth carpal arcs, and a step or break in any arc indicates carpal malalignment until proven otherwise.

    True

    Gilula's analytic approach to the posteroanterior view combines three normal arcs, the principle of parallelism between adjacent joint surfaces and the absence of abnormal overlap. Arc I follows the proximal surfaces of the scaphoid, lunate and triquetrum, arc II their distal surfaces, and arc III the proximal surfaces of the capitate and hamate. A disrupted arc or loss of parallelism is the earliest radiographic clue to a dissociation, a perilunate injury or a dislocation.

    • Gilula LA. Carpal injuries: analytic approach and case exercises. AJR Am J Roentgenol. 1979;133(3):503-17. PMID 111512

  2. 2. In a dorsal intercalated segment instability (DISI) deformity the lunate is palmar-flexed on the lateral radiograph.

    False

    Gilula and Weeks named the dorsiflexion and palmar-flexion instability patterns for the direction in which the distal articular surface of the lunate faces. In DISI the lunate is extended, so its distal surface faces dorsally, typically with a flexed scaphoid after scapholunate dissociation; the operational thresholds are a scapholunate angle above 60° and a radiolunate angle above 15°. A palmar-flexed lunate defines VISI, the pattern of lunotriquetral dissociation and of most midcarpal non-dissociative instability.

    • Gilula LA, Weeks PM. Post-traumatic ligamentous instabilities of the wrist. Radiology. 1978;129(3):641-51. PMID 725039
    • Rhee PC, Moran SL, Shin AY. Association between lunate morphology and carpal collapse in cases of scapholunate dissociation. J Hand Surg Am. 2009;34(9):1633-9. PMID 19833447

  3. 3. A scapholunate interval of 4 mm on a standard posteroanterior radiograph is by itself diagnostic of scapholunate dissociation.

    False

    In 100 normal wrists Cautilli and Wehbé measured a mean scapholunate distance of 3.7 mm on routine posteroanterior films, with a range of 2.5 to 5.0 mm, and concluded that a distance of up to 5 mm is not necessarily indicative of carpal instability. The apparent gap depends on where in the joint it is measured and on projection; measured at the mid-joint on a properly angled view the normal interval is 2 mm or less. A widened gap must therefore be read at the mid-joint, compared with the contralateral wrist and, where dynamic instability is suspected, on stress views.

    • Cautilli GP, Wehbé MA. Scapho-lunate distance and cortical ring sign. J Hand Surg Am. 1991;16(3):501-3. PMID 1861035
    • Kindynis P, Resnick D, Kang HS, Haller J, Sartoris DJ. Demonstration of the scapholunate space with radiography. Radiology. 1990;175(1):278-80. PMID 2315496

  4. 4. For scapholunate interosseous ligament tears, with arthroscopy as the reference standard, MR arthrography outperforms 3 T MRI, which in turn outperforms 1.5 T MRI.

    True

    A meta-analysis of 24 studies and 1,902 examinations found sensitivities of 45.7% for 1.5 T MRI, 75.7% for 3 T MRI and 82.1% for MR arthrography, with specificities of 80.5%, 97.1% and 92.8% respectively. Non-arthrographic 1.5 T MRI therefore misses roughly half of scapholunate ligament tears. A systematic review of MRI against arthroscopy concluded that a negative MRI cannot exclude a clinically relevant scapholunate, lunotriquetral or triangular fibrocartilage complex injury, and wrist arthroscopy remains the gold standard.

    • Hafezi-Nejad N, Carrino JA, Eng J, Blackmore C, Shores J, Lifchez SD, et al.. Scapholunate Interosseous Ligament Tears: Diagnostic Performance of 1.5 T, 3 T MRI, and MR Arthrography-A Systematic Review and Meta-analysis. Acad Radiol. 2016;23(9):1091-103. PMID 27426979
    • Andersson JK, Andernord D, Karlsson J, Fridén J. Efficacy of Magnetic Resonance Imaging and Clinical Tests in Diagnostics of Wrist Ligament Injuries: A Systematic Review. Arthroscopy. 2015;31(10):2014-20.e2. PMID 26095820

  5. 5. In a Geissler grade IV scapholunate injury the interosseous ligament is completely torn and a 2.7-mm arthroscope can be passed between the scaphoid and lunate (the drive-through sign).

    True

    Geissler's arthroscopic grading, introduced in a 1996 study of intracarpal soft-tissue lesions accompanying intra-articular distal radius fractures, runs from grade I (attenuation or haemorrhage of the ligament seen from the radiocarpal joint, no midcarpal incongruity) through grade II (midcarpal step-off with a gap narrower than a probe) and grade III (step-off in both joints, probe passes through the gap) to grade IV (gross instability with manipulation and a 2.7-mm arthroscope passing between the carpals). Probe passage defines grade III; scope passage defines grade IV, in which the arthroscope can be driven freely between the radiocarpal and midcarpal spaces.

    • Geissler WB. Arthroscopic management of scapholunate instability. J Wrist Surg. 2013;2(2):129-35. PMID 24436805
    • Geissler WB, Freeland AE, Savoie FH, McIntyre LW, Whipple TL. Intracarpal soft-tissue lesions associated with an intra-articular fracture of the distal end of the radius. J Bone Joint Surg Am. 1996;78(3):357-65. PMID 8613442