Learning objectives
To enlighten readers about the normal sonographic appearance of intrinsic and extrinsic carpal ligaments;
To describe a systematic approach for US assessment of intrinsic and extrinsic carpal ligaments with detailed anatomic landmarks,
dynamic manoeuvres and scanning technique.
Background
Intrinsic and extrinsic ligaments of the wrist stabilize the carpal bones during movement,
acting as a guide with respect to the forearm bones and metacarpals,
and transmitting motion from one carpal bone to another.
They are intracapsular,
extrasynovial structures,
termed for the origin and insertion bones,
proximal to distal and radial to ulnar.
Extrinsic ligaments connect the carpus with the forearm bones or distal radioulnar ligaments; intrinsic ligaments are entirely situated within the carpus and connect adjacent bones within the proximal or distal row (interosseus...
Imaging findings OR Procedure Details
General Principles of US Examination
Intrinsic and extrinsic ligaments of the wrist consist of bundles of parallel-oriented type I collagen fibers and show a fibrillar pattern at US examination.
The US beam must be directed as perpendicular as possible to the evaluated structure in order to avoid anisotropy,
an artifactual decrease in echogenicity that may be misinterpreted as a pathological change.
The assessment of carpal ligaments is achieved with commercially available high-frequency linear-array transducers,
typically 12 MHz or greater.
All images here presented were acquired...
Conclusion
US provides an imaging modality alternative to MR imaging and MR arthrography in the assessment of the intrinsic and extrinsic ligaments of the wrist.
Taking advantage of the high resolution of latest-generation US systems,
a proper understanding of anatomic landmarks,
dynamic manoeuvres and scanning technique allows to comprehensively evaluating the intrinsic and extrinsic carpal ligaments with exquisite detail.
References
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The anatomy of the ligaments of the wrist and distal radioulnar joints.
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Wrist and Hand.
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Gray’s anatomy The anatomical basis of clinical practice.
40th ed: Churchill Livingstone; 2008:857-898.
Taleisnik J.
The ligaments of the wrist.
J Hand Surg Am.
1976; 1(2):110-118.
Taleisnik J.
Current concepts review.
Carpal instability.
J Bone Joint Surg Am.
1988; 70(8):1262-1268.
Taneja AK,
Bredella MA,
Chang CY,
Joseph Simeone F,
Kattapuram SV,
Torriani M.
Extrinsic wrist ligaments:...