Diagnostic ultrasound ( PDFDrive )

CHAPTER 24 The Shoulder 891
because the natural history of untreated asymptomatic rotator
cuf tears is frequently the development of symptoms in addition
to tear progression. 82
Direct trauma to the shoulder can also cause thickening and
distention of the subacromial-subdeltoid bursa, sometimes with
more echogenic luid representing blood. he bursa may be
chronically irritated by friction related to subacromial impingement,
and may worsen this clinical syndrome. Additional
inlammatory causes of subacromial subdeltoid bursa thickening
and distention include rheumatoid arthritis, polymyalgia rheumatica,
and hydroxyapatite deposition (calciic bursitis). Infection
of the bursa can also occur either through direct inoculation or
via communication with underlying septic arthritis in the setting
of concomitant full-thickness rotator cuf tear.
FIG. 24.20 Postoperative Supraspinatus Tendon. Long-axis image
of supraspinatus shows a heterogeneous (arrows) but intact supraspinatus
tendon, and irregularity of the greater tuberosity (arrowheads). See also
Video 24.4.
Calciic Tendinitis
Hydroxyapatite crystal deposition within rotator cuf tendons
can be a cause of severe atraumatic pain. hese deposits occur
most frequently in the supraspinatus tendon, slightly more
FIG. 24.21 Fatty Atrophy of the Infraspinatus Muscle. Image obtained of the short axis of the infraspinatus tendon shows low-volume,
hyperechoic infraspinatus muscle (arrowheads), compared with the normal echogenicity of the teres minor (*).
FIG. 24.22 Normal Subacromial-Subdeltoid Bursa. Overlying the infraspinatus tendon, in long axis, the subacromial subdeltoid bursa is
visualized as a thin hypoechoic line (arrow), with thin hyperechoic borders supericial and deep to the bursa (arrowheads).