Sonography of the acetabular labrum: visualization of labral injuries during intra-articular injections.
Academic Article
Overview
abstract
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.
