Hong BY, Lim SH, Cho YR, Kim HW, Ko YJ, Han SH, Lee JI: Detection of knee effusion by ultrasonography.
The purpose of this study was to assess which scan view was sensitive in detecting knee effusion by ultrasonography while infusing normal saline in cadaveric specimens.
Intraarticular injection of normal saline with contrast dye was done in increments (5, 10, 15, and 20 ml) into the knee joint of eight fresh cadavers. After infusion of each amount, sonographic images were obtained with five different scans: medial, midline, and lateral on longitudinal scans, and medial and lateral on transverse scans. When 20 ml had been injected, the knee was flexed at 30 degrees and serial images were taken.
After infusion of 10 ml, effusion of more than 2 mm depth with ultrasonography was most frequently seen in lateral transverse scans (14/14), and the next most frequent view was a lateral longitudinal scan (11/14). After knee flexion, the amount of effusion was increased on medial and middle longitudinal scans and was decreased on transverse scans.
For detecting knee effusion by ultrasonography, lateral transverse and longitudinal scans were the most sensitive in the knee extension posture. With knee flexion at 30 degrees, effusion was more readily detected on the medial and midline longitudinal scans than with knee extension.
From the Department of Rehabilitation Medicine (BYH, SHL, YRC, HWK, YJK, JIL) and Department of Anatomy, Catholic Institute for Applied Anatomy (SHH), College of Medicine, The Catholic University of Korea, Seoul, Korea.
All correspondence and requests for reprints should be addressed to Jong In Lee, MD, PhD, Department of Rehabilitation Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-ku, Seoul, Korea 137-040.
Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated.