Diagnostic ultrasound ( PDFDrive )

CHAPTER 55 The Pediatric Hip and Other Musculoskeletal Ultrasound Applications 1931
A
B
C
FIG. 55.5 Hip Joint Transient Synovitis. (A) Transducer position parallels femoral neck. Scan plane is shown by dashed line. (B) Normal hip
sonogram shows joint capsule (arrows) following contours of femoral head (H) and neck (N). (C) Hip effusion sonogram shows bulging joint capsule
(arrows) with hypoechoic luid in anterior recess extending along femoral neck (N) and cephalad over femoral head. A, Anterior; S, superior.
Fluid of varying echogenicity is visible within the capsule.
he echoes are created by inlammatory debris or hemorrhage.
54 Zieger and colleagues 48 concluded that if the luid is
anechoic, the diagnosis of septic arthritis can be excluded.
Other investigators have found the character of the luid to
be nonspeciic, 49,53 describing echoes (probably representing
hemorrhage) in the luid in transient synovitis and anechoic
luid in cases of septic arthritis. Color Doppler sonography has
also been used in an attempt to distinguish between infectious
and noninfectious efusions, but the technique has proved to
be unreliable. 56
When luid is detected, arthrocentesis can be performed using
sonographic guidance; a saline lavage can be used if luid cannot
be withdrawn. Although the procedure requires patient cooperation,
it is relatively easy to perform and avoids the ionizing
radiation required in luoroscopic arthrocentesis. Some clinicians
use arthrocentesis therapeutically in Perthes disease, which can
be recognized by fragmentation of the femoral head and thickened
articular cartilage. 57 Sonograms to check for efusion may show
other pathology, such as slippage of the head in slipped capital
femoral epiphysis and cortical disruption in fracture or osteomyelitis,
but these indings are better evaluated radiographically.