Mateusz Gładysz FESSH prep

FESSH prep Wrist trauma Scapholunate interosseous ligament subregions and strength, secondary stabilisers and DISI, the Garcia Elias prognostic questions, SLAC progression, pooled outcomes of reconstruction

Scapholunate instability: ligament anatomy, secondary stabilisers and reconstruction

Last reviewed v1.0

FESSH-046Wrist trauma●●● advanced

Regarding scapholunate instability:

  1. 1.The dorsal subregion of the scapholunate interosseous ligament is its thickest and strongest part, with a yield strength of roughly 260 N against about 120 N for the palmar and about 60 N for the proximal region.

  2. 2.In cadaveric sectioning studies, dividing the scapholunate interosseous ligament alone does not produce a dorsal intercalated segment instability (DISI) deformity; DISI appears only when a secondary stabiliser such as the scaphotrapeziotrapezoid ligaments or the dorsal intercarpal ligament is also sectioned.

  3. 3.One of the prognostic questions in Garcia-Elias's treatment algorithm for scapholunate dissociation asks whether the radiolunate angle exceeds 15°.

  4. 4.In the scapholunate advanced collapse (SLAC) wrist described by Watson and Ballet, degenerative change begins at the radiolunate joint.

  5. 5.Pooled outcome data for reconstruction of chronic scapholunate injuries show that wrist flexion is reduced after surgery although pain, grip strength and patient-rated outcomes improve, with no technique shown to be superior on clinical outcomes.

FESSH marking: +1 per correct statement, 0 for blank, −1 for incorrect. Click the same TRUE/FALSE button twice to clear it.

Question ID
FESSH-046
First published
Last reviewed
Version
v1.0
Answer key and explanations — open after answering

  1. 1. The dorsal subregion of the scapholunate interosseous ligament is its thickest and strongest part, with a yield strength of roughly 260 N against about 120 N for the palmar and about 60 N for the proximal region.

    True

    Berger's serial histology divides the ligament into dorsal, proximal and palmar regions: the dorsal region is thick, with short transversely oriented collagen fibres; the proximal region is largely fibrocartilage; the palmar region is thin, with obliquely oriented fascicles. In bone-ligament-bone testing of 24 cadaver wrists the dorsal region gave the greatest constraint to translation and the highest yield strength (260.3 ± 118.1 N), followed by the palmar (117.9 ± 21.3 N) and proximal (62.7 ± 32.2 N) regions, which is why repair and reconstruction target the dorsal component.

    • Berger RA, Imeada T, Berglund L, An KN. Constraint and material properties of the subregions of the scapholunate interosseous ligament. J Hand Surg Am. 1999;24(5):953-62. PMID 10509273
    • Berger RA. The gross and histologic anatomy of the scapholunate interosseous ligament. J Hand Surg Am. 1996;21(2):170-8. PMID 8683042

  2. 2. In cadaveric sectioning studies, dividing the scapholunate interosseous ligament alone does not produce a dorsal intercalated segment instability (DISI) deformity; DISI appears only when a secondary stabiliser such as the scaphotrapeziotrapezoid ligaments or the dorsal intercarpal ligament is also sectioned.

    True

    In 30 loaded fresh-frozen forearms, division of the ligament did not increase the radiolunate angle; adding the long radiolunate ligament or one insertion of the dorsal intercarpal ligament increased the angle without reaching the DISI threshold (an increase of more than 15° in the radiolunate angle from baseline), and DISI appeared only after the scaphotrapeziotrapezoid ligaments or both insertions of the dorsal intercarpal ligament were also cut. A 2026 systematic review of 33 cadaver studies (406 wrists) confirms the interosseous ligament as the primary stabiliser and the dorsal intercarpal ligament as the key secondary stabiliser, with DISI only when the interosseous ligament and either the dorsal intercarpal ligament or the scaphotrapeziotrapezoid complex are sectioned.

    • Pérez AJ, Jethanandani RG, Vutescu ES, Meyers KN, Lee SK, Wolfe SW. Role of Ligament Stabilizers of the Proximal Carpal Row in Preventing Dorsal Intercalated Segment Instability: A Cadaveric Study. J Bone Joint Surg Am. 2019;101(15):1388-1396. PMID 31393430
    • Andrews J, Bellringer S, Amarasooriya M, Bain G. Primary and secondary stabilizers of the scapholunate joint: a systematic review of cadaveric ligament sectioning studies. J Hand Surg Eur Vol. 2026:17531934261466074. PMID 42487483

  3. 3. One of the prognostic questions in Garcia-Elias's treatment algorithm for scapholunate dissociation asks whether the radiolunate angle exceeds 15°.

    False

    The 2006 algorithm of Garcia-Elias, Lluch and Stanley stages the injury with five questions: is the dorsal scapholunate ligament intact; is the ruptured ligament reparable; is the scaphoid posture (radioscaphoid angle) normal; is any carpal malalignment reducible; and is the cartilage of the radiocarpal and midcarpal joints normal? A radiolunate-angle threshold is not one of them. The stage then determines the operation, from repair through capsulodesis and three-ligament tenodesis to salvage procedures.

    • Garcia-Elias M, Lluch AL, Stanley JK. Three-ligament tenodesis for the treatment of scapholunate dissociation: indications and surgical technique. J Hand Surg Am. 2006;31(1):125-34. PMID 16443117
    • Andersson JK. Treatment of scapholunate ligament injury: Current concepts. EFORT Open Rev. 2017;2(9):382-393. PMID 29071123
    • Garcia-Elias M. Treatment of scapho-lunate instability. Ortop Traumatol Rehabil. 2006;8(2):160-8. PMID 17603438

  4. 4. In the scapholunate advanced collapse (SLAC) wrist described by Watson and Ballet, degenerative change begins at the radiolunate joint.

    False

    Watson and Ballet reviewed 4,000 wrist radiographs and found scapholunate advanced collapse to be the commonest pattern of wrist arthritis (57 % of 210 degenerative wrists), involving the scaphoid, lunate and radius. The degeneration begins at the radial styloid–scaphoid interface, spreads to the whole radioscaphoid joint and then to the capitolunate (midcarpal) joint; the radiolunate joint is characteristically spared, which is the basis of scaphoid excision with four-corner fusion and of proximal row carpectomy.

    • Watson HK, Ballet FL. The SLAC wrist: scapholunate advanced collapse pattern of degenerative arthritis. J Hand Surg Am. 1984;9(3):358-365. PMID 6725894
    • Andersson JK. Treatment of scapholunate ligament injury: Current concepts. EFORT Open Rev. 2017;2(9):382-393. PMID 29071123
    • Ashmead D, Watson HK, Damon C, Herber S, Paly W. Scapholunate advanced collapse wrist salvage. J Hand Surg Am. 1994;19(5):741-50. PMID 7806794

  5. 5. Pooled outcome data for reconstruction of chronic scapholunate injuries show that wrist flexion is reduced after surgery although pain, grip strength and patient-rated outcomes improve, with no technique shown to be superior on clinical outcomes.

    True

    Montgomery's systematic review of 805 procedures from 37 study groups found that postoperative wrist flexion and pain scores decreased while grip strength and patient-rated outcomes improved, with no statistically significant differences between surgical techniques or between static and dynamic instability. Daly's meta-analysis of radiographic outcomes (978 wrists) did find better maintenance of the scapholunate angle and gap after tenodesis than after capsulodesis, so the radiographic superiority of tenodesis remains debated even though clinical outcomes do not separate the techniques.

    • Montgomery SJ, Rollick NJ, Kubik JF, Meldrum AR, White NJ. Surgical outcomes of chronic isolated scapholunate interosseous ligament injuries: a systematic review of 805 wrists. Can J Surg. 2019;62(3):1-12. PMID 30900438
    • Daly LT, Daly MC, Mohamadi A, Chen N. Chronic Scapholunate Interosseous Ligament Disruption: A Systematic Review and Meta-Analysis of Surgical Treatments. Hand (N Y). 2018;15(1):27-34. PMID 30027766