Sonography of the acetabular labrum: visualization of labral injuries during intra-articular injections.
OBJECTIVE
The purpose of this series was to describe the improved conspicuity in the sonographic appearance of acetabular labral injuries during routine sonographically guided intra-articular injections.


METHODS
Sonographic examinations of patients undergoing routine sonographically guided intra-articular hip injections were reviewed for evidence of labral injuries (n=21). Sonographic examinations were then correlated with magnetic resonance images of the ipsilateral hip when available (n=14).


RESULTS
Before injection, 13 acetabular labra had linear or irregular hypoechoic clefts or fissures through the normally hyperechoic fibrocartilaginous labrum, thought to represent tears. Eight of the labra showed a more globular alteration in morphologic characteristics, with diffuse thickening and irregularity. During intra-articular injection, the visualized injected fluid outlined the labrum, yielding a "sonoarthrographic effect," providing a fluid interface along the labral boundaries, and confirming the presence of a tear by imbibition of injected material into the defect with a resultant subjective improvement in the labral injury.


CONCLUSIONS
Evaluating the labrum after injection may improve visualization of labral injuries, as a result of greater labral conspicuity.
Sofka
Carolyn M
CM
Department of Radiology and Imaging, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021, USA. sofkac@hss.edu
Adler
Ronald S
RS
Danon
Martha A
MA
D000077:Acetabulum / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000368:Aged; D018771:Arthralgia; D005260:Female; D025981:Hip Injuries / Q000000981:diagnostic imaging*; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods*; D008023:Ligaments, Articular / Q000000981:diagnostic imaging* / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography