Diagnostic ultrasound ( PDFDrive )

CHAPTER 23 Overview of Musculoskeletal Ultrasound Techniques and Applications 863
in planes that can be individualized to the structure of interest
in any given patient, overcoming some intrinsic diiculties that
can be encountered with scan plane prescription for MRI. In
addition to static imaging, dynamic assessment may provide
additional diagnostic information. Normal ligaments consist of
interweaved bundles of collagen, extending between bones, usually
restricting joint movements to prevent pathologic motion. 26
Ligament injury leads to pain and instability. Normal ligaments
are linear bandlike structures and appear hyperechoic and ibrillar
27 (Fig. 23.13). Low-grade injuries consist of mild sprains,
which typically have a good prognosis with conservative care.
Mild sprains are characterized on ultrasound by swelling,
hypoechogenicity, and some loss of ibrillar pattern (Fig. 23.14).
Tears can be partial or complete. In the case of complete tears,
there may be retraction of the torn ligament components from
each other, a inding that can be exaggerated by dynamic imaging
with stress maneuvers (Figs. 23.15 and 23.16). he use of stress
maneuvers is somewhat controversial, however, because of
concerns that a partial tear may be exacerbated or even converted
to a complete tear by additional stress. 28,29
FIG. 23.13 Normal Anterior Taloibular Ligament. Note that the
ligament (arrows) demonstrates a ibrillar appearance and that the ibers
are more densely packed than those seen in a normal tendon. F, Fibula,
T, talus.
FIG. 23.14 Ligament Sprain. The anterior taloibular ligament (arrows) is diffusely thickened and hypoechoic, with intact ibers, consistent
with sprain. Note the cortical irregularity at the lateral ibula (*) consistent with prior avulsion. F, Fibula, T, talus.
FIG. 23.15 Chronic Ligament Rupture. In this patient with a history of multiple ankle sprains, the anterior taloibular ligament is absent and
the joint is widened on dynamic stress maneuver. Hypoechoic luid (*) appears in the lateral recess. F, Fibula, T, talus.